■■Hi Httjltjljlj ANATOMY IN A NUTSHELL LAUGHLIN (Second Edition.) Poor Humanty. The following | try was found in the pocketbook of the lute G. H. Laughlin. More than half a century since the following lines were found in the Royal College of Surgeons, London, beside a skeleton, remarkable for its symmetry of form. They were sub- sequently published in the London Morning Chronicle, and a vain effort made to ascertain tuthor, even offering a reward of fifty guineas. I. Behold this ruin! 'Twas a skull < Mice of ethereal spirit full. This narrow cell was Life's retreat, This space was Thought's mysterious seat. \\ hat beauteous visions filled this spot With dreams of pleasures long forgot ! Nor hope, nor joy, nor love, nor fear. Have left one trace of record here. II. Beneath this moulding canopy ( dice shone the bright and busy eye. But start not at the dismal void! If social love that eye emplox >'d; If with no lawless fire it gleamed, Hut through the dews of kindness beamed, That eye shall be forever bright When sun and stars are sunk in night. 111. Within this hollow cavern hung The ready, swift and tuneful tongue. If Falsehood's honey it disdained. And when it could not praise was chain* If bold in Yin lie's cause it spoke, ^ et gentle concord never broke Thai silent tongue shall plead lor thee, \\ hen time unveils eternitv! [V. Say, did these lingers delve the mine, ( )r with the envied ruby shine? To hew the rock or wear t he gem, ( 'an little now avail to them. Hut if the page of truth they sought, ( >r comfort to the mourner brought — These hands a richer meed shall claim Than all who wait on Weal or fame. Avails it whether bare 01 shod, These feet the path of duty trod'.' If from the bowers of ease they lied. To seek Affliction's humble shed; If Grandeur's guilty bribe they Spurned, And home to Virtue's cot returned These feet with angel's wings shall vie. And tread the palace of the skies. Anonymi m - ANATOMY IN A NUTSHELL A TREATISE ON HUMAN ANATOMY IN ITS RELATION TO OSTEOPATHY WILLIAM ROSS LAUGHLIN, M. S., D. 0. PROFESSOR OF DESCRIPTIVE ANATOMY, NEUROLOGY AXD OSTEOPATHIC TECHNIQUE IN THE AMERICAN SCHOOL OF OSTEOPATHY, KIRKSVILLE. MO. IX OXE VOLUME. ILLUSTRATED BY TWO HUNDRED AND NINETY PLATES. KIRKSVILI.I WILLIAM ROSS LAUGHLIN, M.S.. D. 0. 611 East Harrison Street 1905. QS *f 3' Copyright, L905, by William Rosa Laughlin. \lii\. n ^ pb l < » M l • IS1 i ION PRESS OF in' RN \l. PR] \ I im. CO KIRKSVILLE, MISSOURI TO fll>£ present ano former Stuoents of Enatomp THIS WORK IS AFFECTIONATELY DEDICATED BY THEIR FELLOW WORKER, THE AUTHOR. (Qui ram prafirit, deficit. List of Illustrations. Plate I. II. III. IV. V. VI. VII. VIII. IX. X. XI. XII. XIII. XIV. XV. XVI. XVII. XVIII. XIX. XX. XXI. XXII. XXIII. XXIV. XXV. XXVI. XXVII. XXVIII. XXIX. XXX. X XXI. XXXII. XXXIII. XXXIV. XXXV. XXXVI. XXXVII. XX XVIII. XXXIX. XL. XI. I. XLII. XLIII. Page The Bony Man is The Muscular Man 21 Showing the Origin and Insertion of Biceps 2 1 A Transverse Section of Spinal Cord 25 Posterior Mew of the Spinal Cord 29 Brachial Plexus 81 Nutrient Arteries of Bones of the Hand 33 Relative Position of Vessels Above and Below Diaphragm 30 The Fetal Circulation and the Adult Circulation 39 The Left Clavicle, Inferior Surface 41 The Left Clavicle, Superior Surface 41 The Sterno-Clavicular Articulation 43 Acroinio-( "lavicular Articulation and Shoulder-Joint 44 Muscles of Face and Triangles of Xeck 47 External ( >blique Muscle of Abdomen and Numerous * >ther Structures 4!) Internal ( >blique Muscle of Abdomen,, Numerous ( >ther St ructures 51 Transversalis Muscle of Abdomen, Numerous Other Structures 53 Muscles of the Back. Superficial Layers 57 The Hyoid Bone 59 The Left Scapula, Posterior Surface or Dorsum 63 The Left Scapula. Anterior Surface or Venter 6 I The Left Humerus, Posterior View The Left Humerus, Anterior View The Left Radius and Ulna, Posterior View The Left Radius and Tina, Anterior View Bones of Left Hand, Posterior View Bones of Left Maud. Anterior View Showing Quadrilateral Space, Struct ures Passing Through it Muscles of Left Forearm First Layer — Anterior View Muscles of Left Forearm — Second Layer Anterior View Muscles of Left Forearm Third and Fourth Layers Anterior View Muscles of the Left Forearm— Superficial Layer Posterior View. ... Muscles of t he Left Forearm Peep Layer Posterior Vie\* The Four Dorsal Interossei The Three Palmar Interossi Showing t he Cutaneous Nerve Supply of Upper Extremity Lymphatics and Veins of I he Upper Extremity Superficial 1 ... 1 1 The Elbow Joint , External View The Elbow-Joint, Internal View The Wrist-Joint , Posterior View 1 The Wrist-Joint, Anterior View 1 Showing the Synovial Membranes of the Wrisl 1 Externa] Mew of the Left [nnominate Bone 1 i\ 1 17 lis 70 71 7:; 74 SO 83 86 89 90 93 '.il 07 00 03 in 07 us 1 1 2 I IS [.1ST OF ILLUSTRATIONS. Plate Page XLIV. Internal View <>f Lefl Innominate Bone 127 X l.\ . Posterior View of Sacrum and Coccyx 130 XL VI. Anterior View <>l Sacrum and Coccyx 133 X I. VI I Anterior and Superior View of Pelvis 136 XLVIII. Posterior View of Lefl Femur 139 XLIX. Anterior View of Left Femur 142 I. Posterior View of Lefl Tibia and Fibula 145 LI. Anterior View of Lett Tibia and Fibula 148 Id I. Dorsum of Left Fool 151 I III. Plantar Surface of Left loot 155 LIV. Showing the I >i red ion of Nutrient Arteries of Bones of Fool 159 LV. Plant 'ii' Fascia and First Layer of Muscles of Foot 161 LVI. First Layer of Muscles of the Foot, Also Internal and External Plan- tar Arteries 163 LVII. I.umliricale.-.. Internal and External Plantar Vessels and Nerves 165 I.YI 1 1. Accessorius Mi ode and Plantar Vessels 167 I. IX. Flexor Longus Digitorum Tendon and Four Lumbricales 169 I.X. Third Layer of Muscle- of Foot 171 I. XL The Four Dorsal Interossei 173 LXII. The Three Plantar Interossei 175 I.X 1 1 1. Lumbar, Sacral and ( 'occvyeal Plexuses 177 I.X IV. ( 'otninon. Superficial and Profunda Femoral Arteries 179 LXV. Muscle- in ( (luteal Region and Hack of Thigh 181 LXVI. Superficial Lymphatic Vessels and Veins of Leg 183 LXV] I. External or Short Saphenous Vein 185 LXVIII. Anterior View of Entire Lower Limb 187 I.X IX. Showing Arteries and Nerves of Hack of Leg 189 LX X. Showing Muscles of Hack of Ley; 191 LXX I. Showing Muscles of I unci and Anterior Part of the Thigh 193 LXXII. The Arteries of Entire Lower Extremity 195 I.XXIII. The Diaphragm, Psoas Magnus and Parvus 197 LXXIV. The Muscles in Front oftheThigh 199 LXXV. Musclesin Front of Ley 201 LXXVI. Arteries and Nerves in Front of Leg 203 LXXVII. Muscles in Hack of Ley (Superficial Layer) 205 LXX VIII. Posterior View of Entire Leg 207 LX NIX. Musclesol Back of Leg l I >eep Layer) 209 L.N N.N. Cutaneous Nerve Supply of the Lower Extremity 211 I. XXX I. Cutaneous Nerve Supply of the Plantar Surface of the Foot 213 I.NNXII. Ligaments of Hip-Joinl 215 LXXXIII. Ligamentum Patella 217 LXXXIV. Posterior Ligamenl of Knee. loin t 219 LXXXV. Showing ( !ondyles and Ligaments of Knee-Join1 . Anterior View 221 LXXXVI. Semilunar Fibro-< 'art i la ye of Knee-Joint 222 LXXXVII. Ligaments oi Ankle-External View 223 LXXXVIII. Ligaments of Ankle [nternalView 224 I..N.N.NI.N Forms of Club Fool 226 XC. Showing Great Vessels Belowthe Diaphragm 228 XCI. Showing Abdominal Arota and its Terminal Branches 229 XCII. Anterior View of Sternum 231 XCIII. Posterior View of Sternum 233 N< TV. Bones of the Thorax 235 XCV. The Atlas 237 X('\ I. Posterior View of Axis 239 XCVII. Anterior View of Axis 241 LIST OF ) ILLUSTRATIONS. XI Plate Page XCVIII. The Fifth Cervical Vertebra 243 XCIX. A Dorsal Vertebra with Long Spine 245 C. A Lumbar Vertebra 247 CI. Veins of Spinal Cord and Column (Transverse View) 249 CII. Veins of Spinal ( '<>nl and Column (Sagittal View) 251 CIII. The Spinal Column 253 CIV. Ligaments of Spinal Column . . 255 (A'. Anterior Mew of Cervical Vertebrae 257 < VI. Posterior View of Cervical Vertebrae 259 CVII. The Peculiar 1 tarsal Vertebras 261 CVTLT. The Second and Seventh Ribs 263 CIX. Ligaments of Upper Cervical Vertebrae 265 CX. Muscles of Anterior Cervical Region 267 CXI. Muscles of Back (Dee]) Layer) 269 CXLT. The Posterior Cervical Plexus -'71 CXIII. The Cervical Plexus 27:1 CXIY. Thyroid axis and Cords of Brachial Plexus 27."> ( 'XV. Lymphatics of Neck and Face 277 CXVL The External Carotid Artery 279 CXVH. The Internal Carotid Artery 281 ( Will. The Arteries from Arch of Aorta to Circle of Willis 283 CXIX. The Cervical Fascia 285 CXX. The Trachea 287 (XXL The Heart, Thyroid Claud, and Lungs (Turned Downward) 289 CXXII. Anterior Mew of Lungs 290 CXXIII. Posterior View of Lungs 291 ( XXIV. Showing the Capacity of the Lungs 292 ( 'XXV. Showing Pleura- and Roof of the Lungs 293 CXXVL Air Cells of the Lungs 294 CXXVII. A Transverse Section of the Pleurae Through Root of Lungs 295 ( XX VIII. Arch of Aorta and Heart 296 ('XXIX. Showing Circulation of the Blood Through Heart 297 CX XX. Semilunar Valve (Aortic) 298 < WXXI. The Thoracic Duct and Azygos Veins 299 CXXXII. Thyroid Gland of Fetus 300 CXXXIII. Thyroid Cartilage (Anterior View) 301 (XXXIV. Eyoid Bone/Thyroid and Cricoid Cartilages (Anterior View) 302 CXXXV. Thyroid ( 'artilage (Posterior View) 303 CXXXVI. Arytenoid Cartilage and Epiglottis 304 CXXXVII. True and False Vocal Cords 305 CXXXVIII. Showing the Entire Alimentary Canal and Portal Circulation 308 ( XXX IX. Anterior and Posterior Pi Hal's of Fauces and ( 'artilages of Nose 310 ('XI.. The Salivary Glands 312 ( XLI. Showing Muscles of the Pharynx 314 CXLII. A Sagittal Section of Head and Neck showing Pharynx 316 CXLIII. The Dorsum of the Tongue 31«» CXLIV. Circumvallate Papilla- 321 CXLV. The Extrinsic Muscles of the Tongue ; -'.: CXLVI The (Esophagus and Stomach 325 CXLVII. Showing Viscera Below Diaphragm 321 CXLVIII. Showing Blood Supply of Stomach 328 CXLIX. Showing Muscular < 'oats and Relations of Stomach 329 ('!.. Showing Peritoneum Closed Sac 330 CLE Sagittal Section of Trunk Showing Peritoneum. . . •"• :;| CLII. Relationsof Liver Xll Plate CLIII. ci l\ CLV. CLVI. CIA II. CLVIII. CLIX. CLX. CI. XI. CLXII. CI. XIII. CI. XIV. CI. XV. CI. XVI. CI. XVII. CI. XVIII. CLX IX. CI.XX. CLXXI. CLXXII. CLXXIII. CI.WIN CLXXV. CLXXVI. CLXXVII. CLXXVIII. CI. XXIX. CI. XXX. CI. XXXI. CLXXXII. (I. XXXIII. CI. XXX IV. CI. XXXV CLXXXVI. CLXXXVII. CI.XX.W III. CI. XXXIX. CXC. CXCI. CXCII. CXCIII. CXCIV. cxcv. CXCVI. CXCVII. CXCVIII. CXCIX. cr. CCI. ecu. OCIII. CCIV. cc\. CCVI. CCVII. LIST OF ILLUSTRATION'S. Page The Superior Surface of Liver 333 The [nferior Surface of Liver 334 The Vessels of a Lobule of Liver 335 Showing Blood Supply to Small Intestine 336 Showing Blood Supply to Large Intestine 337 Showing the Vermiform Appendix and Four Forms of Caecum 33S [leo-Caecal Valve 339 A Transverse Section of the Large Intestine 34o The Pancreas, I Juodenum, and Kidney 341 Lobes and Fissures of Liver 342 Showing the Four Coats of Stomach and Pyloric ( >ririee 343 Showing ( terminal Area 344 Showing 1 >evelopmen1 of t lie Sympathetic Nerve 345 A Horizontal Section of Vertebrate Brain 346 A Sagittal Section of Vertebrate Brain 347 A Sagittal Section of the Brain 348 A Coronal Section Through Anterior Horn of Lateral Ventricle 340 A Coronal Section Through Middle Commissure of Brain 350 A ( 'oronal Section Through Posterior Horn of Laterial Ventricles 351 A ( 'ast of Ventricles of the Brain 352 The Circle of Willis 353 Showing Blood Supply on External Surface of Brain 354 Showing Distribution of Middle cerebral Artery 355 Showing Blood Supply on Mesial (Sagittal Surface) of Brain 356 Showing Blood Supply at Base of Brain 357 Showing Falx Cerebri, etc 358 Sinuses at the Base of Brain 359 Sagittal Section of Brain Showing Third and Fourth Ventricles 360 Sagittal Section of BrainShowing Fibers 361 Sagittal Section of Brain Showing Centers of Smell and Taste 362 Location of Centers in Brain 363 A Sagittal Section of the Brain 364 Showing Long and Short Association Fibers of the Brain 365 A Horizontal Section of the Brain 366 Showing Superficial I origin of Cranial Nerves 367 Superior View of t he ( lerebellum 368 Inferior View of t he Cerebellum 369 Showing t lie Writing Center in the Brain 370 Anterior View of < 'auda Equina 371 Showing Dura Mater, Arachnoid and Piamater 372 Transverse Section of the Con 1 at Different Levels 373 Transverse Sect ions of t he ( !ord Shewing Tracts, 1 hseases, etc 374 Vena Azygos Major, Abdominal Aorta and Sympathetic Nerve 375 Anterior View of Sympathetic Nerve and Spinal Cord 377 Side View of S\ mpat hetic System 379 Showing Kami ( !ommunicantes 380 The ( Ufactory or First Cranial Nerve 381 The Layers of Retina 382 Blood Supply to Eye-Ball 383 Showing Venae Vorticosae 384 I distribution of < (phthalmic Artery 386 ( Iptical Axis and Visual Line 388 Nasal 1 >UC1 . < lonjunctiva and Lachrymal ( iland 390 The Muscles of the I Irbital Region 391 Showing Directions that Muscles of Eve-Ball move Eve 392 Plate CCVIII. CCIX. ccx. ('('XI. ('('XII. ('('XIII. CCXIV. ccxv. CCXVI. CCXVII. CCXVIII. CCX IX. ccxx. CCXXI. CCXX 1 1. CCXXIII. ( (XXIV. ( (XXV. CCXXVI. CCXX VI I. (( XXVIII. CCXXIX. CCX XX. CCXXXI. CCXXXII. CCXXXIII. CCXXXIV. ( (XXXV. CCXXXVI. ('( XXXVII. C( XXXVIII. CCXXXIX. CCX I.. CCXLI. CCXLII. CCXLIII. CCX I. IV. CCXLV. CCXLVI. CCXLVII. CCXLVIII. CCXLIX. CCL. CCLI. CCLII. CCLIII. CCLIV. CCLV. CCLVI. CCLVII, CCLVIII. CCLIX. CCLX. CCLXI. CCLXII. LIST OF ILLUSTRATION--, xill Page Showing Refraction of Light Through Crystalline Lens 393 Superior Fornix and Inferior Fornix of Conjunctiva 304 Crystalline Lens 395 A Horizontal Section of the Eye-Ball 396 The Third Cranial or Motor ( )culi Nerve 397 The Fourth Cranial or Trochlear Nerve 398 Showing Brandies of Fifth Xerve 399 Show Distribution of Filth Nerve in Reference to » >t her Structures. . . 400 Cutaneous Xerve Supply of Head and Neck 401 Meckel's Ganglion and ( >tic Ganglion |(i:; The Sixth Cranial or Abducens Xerve 405 Branches of Facial Xerve 407 Showing Facial Xerve and Superficial Cervical Plexus 109 Origin and Distribution of Auditory Xerve 411 Showing Distribution of Xinth, Tenth, Eleventh Cranial Nerves 413 Showing Pneumogastric Xerve and Sympathetic Ganglia 415 Showing Si ructures Passing Through the Sphenoidal Fissure 117 Showing the Abdominal Areas 419 The Permanent Teeth 421 A Vertical Section of Canine Tooth 424 The Hard Palate 426 The Bones of Orbit 128 Showing the Sensory Pathways to Brain 430 Showing the Motor Pathways from Brain 432 The Cavernous Sinus (Modified from Cunningham) 434 Showing Both Sensory and Motor Pathways 430 The Sutures of Skull 438 Showing Foramina at Base of Skull 440 The Inferior Surface of Base of Skull 442 Internal Surface of Frontal Bone 444 External Surface of Frontal Bone 446 Internal Surface of Parietal Bone 448 External Surface of Parietal Bone 450 External Surface of Occipital Bone 452 Internal Surface of < >ccipital Bone 15 1 Posterior View of the Sphenoid Bone 455 Anterior View of Sphenoid Bone 450 The Pterygoid Processes 457 The External Surface of Temporal Pone 1"> S The Petrous Portion of the Temporal Hone 159 400 461 162 163 10 1 107 170 17:; 176 170 182 is.". 188 491 10 1 The Temporal Pone Laid ( >pen The Inferior Surface of Petrous Portion of Temporal Pone The Nasal Bone The Lachrymal Pone The Internal Surface of Superior Maxillary Hone External Surface of Superior Maxillary Bone Internal Surface of Malar Bone External Surface of Malar Bone External Surface of Inferior Maxillary Bone. Interna] Surface of Inferior Maxillary Hone. Lateral View of the Ft hmoid Superior View of I he Ft hmoid Inferior Turbinated Hone The Vomer The Palate Bone i Posterior Views) XIV Plate CCLXIII. (CI. XIV. CCLXV. CCLXVI. CCLXVII. (CI. XVIII. (CI. XIX. (CI. XX. CCLXXI. CCLXXII. (CI. XXIII. CCLXXIV. (CI. XXV. CCLXXVI. (CI. XXVII. CCLXXVII1. (CI. XXIX. (CI. XXX. (CI. XXXI. (CI. XXXII. (CI. XXXIII. ('('I. XXXIV. CCLXXXV. CCLXXXVI. (CI. XXX VII. (CI. XXXVIII. CCLXXXIX. ccxc. LIST OF ILLUSTRATIOXS. Page The Lateral Mew of the Palate Bone 497 The Meatuses 500 The Uriniferous Tubules 503 Sagittal Section of Kidney 506 The Female External Organs of Generation 509 Colles' Fascia and the Triangular Ligaments of Perineum 512 The White Line and Ischio Rectal Fossa 515 Showing the Muscles of Perineum 518 The Uterus, Horizontal Section 521 A Sagittal Section of the Female ( >rgans of ( feneration 524 The Uterus with Vagina Laid Open 527 A Transverse Section of Penis 530 A Horizontal Section of Penis 533 Testicle and Spermatic Cord 53(i The Testicle 539 A Sagittal Section of the Male ( )rgans of Generation 542 The Mammary Gland 545 The ( 'uter Surface of the Left Pinna 548 Diagrammatic View of the Organs of Hearing 551 Posterior View of the Far with Auricular Muscles 554 The Bony Cochlea 557 The Bony Cochlea Cut Through 560 The Interior of the Labyrinth with Distribution of Auditory Xerve. . . 563 Interior of Bony Labyrinth 566 Malleus, Incus and Stapes 569 Forms of Congenital Hernia? 572 The Lamphatic Man 575 A Lymphatic Xode 576 Preface. Preface to Second Edition. Six years ago the author compiled a little book of one hundred and fifty pages called Anatomy in a Nut Shell, which was the outgrowth of his studying and teaching anatomy in the American School of Osteopathy. It filled its place as it was intended only as an aid to the student in preparing his work. There seemed to be no work upon anatomy taken up in a teachable and sys- tematic manner and the student complained that it took more time to find his lesson in the books at hand than to learn it when found. In presenting the subject of anatomy to the student, we first teach a few rules and fundamental principles to give him a working knowledge of the sub- ject, and then we take up the work complete as it comes in the human body. For instance in teaching the anatomy of the arm we take the clavicle, giving its ossification, articulations, attachment of muscles and blood supply. Then the origin and insertion with action, blood supply and nerve supply of these muscles. So it is with every bone of the upper extremity and the entire body. What is gained by saying that the greater tuberosity of the humerus has three muscles attached to it, namely the Supraspinatus, Infraspinatus and Teres minor, unless we learn the functions of these muscles? By this method of teach- ing anatomy we find it to be one of the most interesting of all subjects both to teacher and pupil. The original book of one hundred and fifty pages has been revised ami enlarged to over six hundred pages, but the name Anatomy in a Nut Shell is retained, because any book of six hundred pages covering such an inexhaustible subject as human anatomy would be a Nut Shell indeed. In preparing this work the following authors, through their writings, have been my constant companions: Gray, Gerrish, Morris, Denver. Potter, Holden, Heath, Cunningham, McClellan, Eckley, Rockwell, Butler, Hale, ami last but not least, Dr. A. T. Still has been my inspiration and best teacher. The entire work is given in lessons so that each day the student has some thing definite to do. "He who every morning plans the transactions of the day, and follows out that plan, carries on a thread which will guide him through the Labyrinth of the most busy life." — Blair. "The chief art of learning is to attempt but little at a time." Locke. What was omitted in the first edition, such as the origin ami insertion of muscles, is here given, so that the work is complete in itself. Ami any one who masters this work can justly feel proud of his anatomical knowledge. \v Xvi PREFACE. The author was most fortunate in securing Dr. Win. Most, a senior student of tin' American School of Osteopathy, in make the drawings, and he is espec- ially grateful to his wife. Dr. Isabel Cash Laughlin for writingthe entire manu- scripl the lasl time over and assisting in proof-reading. Dr. A. E. Daugherty, editor of the A. S. (). Student, deserves special mention for making the index. Preface to First Edition. This book is noi intended to lake the place of any standard text-book in anatomy, hut is to he used as an aid for the student. The origin and insertion of the muscles have noi been given, as that is ou1 of the province of this book. In preparing this hook, several authorities have keen consulted, as A. T. Still, Gray's Anatomy, Morris' Anatomy, Gerrish's Anatomy, Century Dictionary, etc. ANATOMY IN A NUTSHELL. LESSON I. Anatomy is concerned with the form, structure and connections of the parts of the body. It has the following divisions: 1. Osteology (os-te-ol-o-je) is the anatomy of the bones. 2. Syndesmology (sin-dez-mol-o-je) is the anatomy of the joints. 3. Myology (mi-ol-o-je) is the anatomy of the muscles. 4. Angiology (an-je-ol-o-je) is the anatomy of the vessels. 5. Neurology (nu-rol-o-je) is the anatomy of the nerves. 6. Splanchnology (splangk-nol-o-je) is the anatomy of the viscera. 7. Adenology (ad-en-ol-o-je) is the anatomy of the glands. 8. Dermatology (der-mat-ol-o-je) is the anatomy of the skin. 9. Genesiology (jen-e-ze-ol-o-je) is the anatomy of the generative organs. Aponeurosis (ap-on-u-ro-sis) is the end of a muscle where it becomes a tendon. (a) It is any fascia or fascial structure, especially the tendons of a muscle when broad, thin, flat and of a glistening white color. (b) It is the expansion of a tendon covering more or less of a muscle. (c) It is a thin, whitish ligament. The name was given to these structures when they were supposed to be expansions of nerves — any hard, whitish tissue being then considered nervous. In present tisage aponeurosis is nearly synonymous with fascia, but it is oftener applied to the fascia like tendons of muscles; as the aponeurosis of the external oblique of the abdomen. (Plate XV.) Fascia is a sheet or layer of dense connective tissue. The general contour of the body is invested, just beneath the skin, with a thin, light fascia, as dis- tinguished from the thicker, tougher and more densely fibrous deep fascia which invests and forms sheaths for muscles and dips down among the mus- cles and bundles of muscular fibers forming intermuscular septa. A tendon is a hand or layer of dense fibrous tissue at the end of a muscle for attachment to a hard part. A very hard flat tendon is called fascia and aponeurosis. Tendons are directly continuous at one end with the periosteum and at the other end with the' fascial tissue which invests the muscle. A sinus means a cavity in hone or other tissue. The sinus of the superior maxillary hone is called the antrum of Highmore. The veins of the dura mater are called sinuses. 17 PLATE I. ' THERE ARE 200 BONES IN THE BODY EXCLUDING THE BONES OF THE MIDDLE EAR -MALLEUS. INCUS. STAPES, ALSO THE SESAMOID AND THE WORMIAN BONES STAPES, ALSO THE SESAMOID AND THE WORMIAN BONES. V^_j L . ^-^^fc THE SESAMOID BONES ARE FOUNO IN TENDONS OF ^^t^"^ fr MUSCLES. THE WORMIAN BONES ARE IN THE SUTURES : J" / OF THE SKULL. MANUBRIUM GLADIOLUS ENSIFORM APPENDIX OLECRANON The Bony Max. 18 ANATOMY IN A NUTSHELL. 19 All processes of bone are either apophyses or epiphyses. An apophysis is a process that has grown from the bone and has no separate ossific center. An epiphysis has a separate ossific center and is joined to another bone by car- tilage. This cartilage becomes ossified but this change does not make the epiphysis an apophysis. Once an epiphysis always an epiphysis. The head of the femur is an epiphysis ami the neck of the femur is an apophysis. The nutrient arteries of the bones of the arm and forearm run towards the elbow: in bones of the lower extremity they run from the knee. Rule 1. — The epiphysis towards which the nutrient artery runs joins the bone first always, but ossifies last in all bones except the fibula. Rule 2. — When there is but one epiphysis then the nutrient artery runs towards the end of the bone which has no epiphysis; e. g., the clavicle and met- acarpals and metatarsals. (Plate VII.) Rule 3. — When there are two or more nucleii in an epiphysis they con- solidate before the epiphysis joins the diaphysis. Rule 4. — The epiphysis which ossifies first is the larger, and the cartilage between it and the diaphysis grows longer and faster than the cartilage at the other extremity of the bone. An epiphysis may become separated from the diaphysis and such an in- jury may be mistaken for a fracture or dislocation. A knowledge of this prin- ciple is of great importance in medical jurisprudence; e. g.. the epiphysis at the distal end of the femur ossifies at the ninth month of fetal life. The covering of bone is called periosteum. It covers all the bone except the articular cartilage and uives attachment to tendons. Periosteum besides giving attachment to the tendons of muscles; 1. Gives nutrition to the bone. 2. Forms all capsular ligaments. .'!. Tends to hold the end of broken bones. 4. From it the bone grows in thickness. 5. It hinders the progress of contiguous inflammation. A long bone grows in length by the development of the epiphyseal cartil- age and interstitial deposits; in thickness from the osteogenetic layer of the periosteum and interstitial deposits. There are 300 bones in the body (Platel.) They are divided into long, short . flat and irregular ones. 90 of the bones are Long ones and are found in the extremities. In reality a long bone may not be :is long as a Hat or irreg- ular one o]- even a short bone. e. g., the last phlanx is shorter than the os calcis. The long bones act as lexers and have a medullary canal in the center of each ; and a shaft called diaphysis. and two extremities. They are developed by osseous deposits in cartilage. In each upper extremity there is a clavicle, humerus, ulna, radius, five metacarpal and fourteen phalanges, making 23 long bones in each upper extremity, then in both extremities there are 2x23 or 16 long bono. In each lower extremity there is a femur, tibia, fibula, five met- atarsals ami fourteen phalanges, making 22 long bones in each lower extremity, then in both extremities there are 2x22, or II long bono. The 46 long bone- in the upper extremity and the 44 long ones in the lower extremities make _>() ANATOMY IN A NUTSHELL. 90 Long bones. There are 30 short bones. They also are developed by osseous it in cartilage and arc found in the extremities. They are found where strength but no1 much motion is required. In each carpus (Plate XXVI.) there ones, viz., scaphoid, semi-lunar, cuneiform, pisiform, trapezium, trapezoid, 08 magnum and unciform, making 8 hones: 2x8 are 16, the number of short bonesinthe two upper extremities. In each ankle. (Plate LIV.)there are 7 bones, viz.. os calcis, astragalus, navicular or scaphoid, cuboid, external cuneiform, middle cuneiform, and internal cuneiform, making 7 short bones in each tarsus; then in the two tarsi there are 2x7 or 14 short bones; the 14 short bones in the lower extremity and the 16 short ones in the upper extremity make the 30 short bones. LESSON II. There are 40 flat bones, all of which are found in the trunk, and head ex- cept four and these are in the extremities. They are the two patellae and two scapulae. The flat bones in the trunk protect the viscera. They are develop- ed by osseous deposits in membranes and consist of two dense layers separated by cellular or cancellated osseous tissue, the diploe. There are the two parie- tal, frontal and occipital in the cranium. In the face there are two nasal, two lachrymal and the vomer. In the thorax 24 ribs and the sternum; then there ate the tun innominata, two patellae, two scapulae, making 40 Hat bones in the body. There are io Irregular bones. They are found in the trunk and head. They are the 24 vertebrae, the sacrum, coccyx, two temporal, ethmoid. sphenoid and the hones of the face except the two nasal, two lachrymal and the Vomer. Then the hvoid holie. There are s hones in the cranium. The 4 flat ones are the frontal, two parietal and occipital: the 4 irregular ones are two temporal, sphenoid and ethmoid. There are 1 I hones in the face; the 5 tlat ones are the two nasal, two lachry- mal ami vomer. The 9 irregular ones are the two superior maxillary, two malar, two palate, two inferior turbinated and the inferior maxillary. Then in the cranium and the face together there are 8 plus 14. making 22 hone.-. In the trunk there are 75 hon< s. if the 22 of the head are included. In the trunk without the head there are 53 hones, which are 24 vertebrae, 24 ribs, sternum, sacrum, coccyx and 1 wo innominata. In the extremities there are 12 1 1 is, 64 in the upper and 60 in thelower. In the pelvis there are 4 bones, two innominata. sacrum and coccyx. \oi counting the vertebra' in the cranium there an- :::; vertebra?; 7 cervical, 12 dorsal, 5 lumbar. 5 sacral and 4 in the coccyx. There are 12 pairs of iil>-. 7 of which are true and 5 false. 2 of which are float Lng. Besides the 200 hones mentioned there are sesamoid bone- which are de- veloped in tendons such as the patellae, but these on account of their size ami shape are called flat ones; and the wormian bones, which are found in the sutures of the skull; and the malleus, incus and stapes found in the middle ear. PLATE II. The Muscul \i; .Max. 21 WAToUY IN \ NUTSHELL. There are 32 teeth: in each jaw there is one pair <>!' canine, two pairs of incisors two pairs of bicuspids, ami three pairs of molars. The eminences of bones are: 1. Apophyses an example, neck of the femur. 2. Condyles, which mean irregular heads example, lower part of the femur. :;. Epiphyses example, head of femur. \. Heads, smooth ami convex, found in joints — mi femur and humerus. 0. Spines, sharp and slender on vertebrae. ti. Trochanters, for turning joints on the femur. 7. Tubercles, -mall tuberosities deltoid tubercle on clavicle. 8, Tuberosities, broad prominences— on the humerus. Besides these s . there are 11 other prominences on hones. 1. Azygos, without a fellow— odontoid on axis. •_'. Clinoid, like a bed on the sphenoid hone. :;. Coracoid, like a crow's beak- on the scapula. -1. Coronoid, like a crown on the ulna. 5. llaninlar, hook-like on sphenoid. ii. Malleolar, mallet-like lower part of fibula. 7. Mastoid, nipple-like on temporal hone. 8. Odontoid, tooth-lik< — on axis. 9. Pterygoid, wing-like on sphenoid. 10. 1 1 c » — t mm, a beak on sphenoid. 11. Spinous, thorn-like on sphenoid. 12. Squamous, scaly on temporal. ]'.'>. Styloid, pen-like — on temporal. 14 Vaginal, ensheathing on temporal. There arc •"> articular cavities in bones. 1. Alveolar, socket-like- tooth in the jaw. '_'. Cotyloid, cup-lik( — hip-joint. :;. I'acet . face on the »reat tuberosity. I. Glenoid, shallow- shoulder-joint. 5. Trochlear, pulley-like in the orbit. There arc 10 mm -articular cavities. 1. Aqueducts Aqueduct of Fallopii in temporal hone. 2. Canal- Vidian canal in sphenoid hone. :'.. (ell- Mastoid cells in mastoid process of temporal bone. 1. Depressions Meckel's cave on petrous portion of temporal bone. 5. Fissures Sphenoidal fissure in sphenoid hone. • '>. Foramina Base of skull. 7. Fossae; also at base of skull. v Grooves On inner surface of Parietal bone for middle meningeal artery. !•. Notches Ethmoid notch on frontal hone. 10. Sinusi - Frontal -inn-, superior maxillary sinus which is called Antrum of Highmore. ANATOMY IX A NUTSHELL. 23 1. Radius means spoke 27. 2. Carpus — wrist 28. 3. Scaphoid— boat 29. 4. Semilunar — half moon 30. ."). Cuneiform — wedge-like 31. 6. Pisiform — pea-like 32. 7. Trapezium — table 33. 5. Trapezoid — table shape o4. 9. Os Magnum — large bone . 35. 10. Unciform — hook 36. 11. Metacarpus — beyond the wrist 37. 12. Phalanges — fingers and toes 3S. 13. Pelvis— basin 39. 14. Femur — thigh 40. 15. Patella — small pan 41. 16. Tibia— flute 42. 17. Fibula — clasp. 43. 18. Obturator — closed . 44. 19. Glenoid — shallow 45. 20. Cotyloid— cup-like 46. 21. Tarus— ankle 47. 22. Os calcis— heel 48. 23. Astragalus— die 49. 24. Navicular or scaphoid — boat 50. 26. Cuneiform — wedge-like 51. 25. Thyroid— shield. 52. Cuboid — cube Cranium — helmel Frontal— forehead Occipital — against the head Parietal — wall Ethmoid — sieve Sphenoid — wedge Temporal — time Nasal — nose Superior Maxillary — jaw bone Inferior Maxillary — mandible . Lachrymal — tear Malar — cheek Palate — palate Turbinated — whirl Vomer — ploughshare Vertebra — to turn Thorax — chest Sacrum — sacred ( loccyx — cuckoo Innominata — without a name Clavicle — key Scapula — spade Humerus — arm Ulna — elbow Sternum — breast plate LESSON III. Muscles. — We have said there are 200 bones in the body, but the num- ber of muscles cannot be given exactly, for there are some which at times are absent and again double. There are, ordinarily, thirteen muscles from the knee to the ankle, but there may be only twelve or there may be fourteen, as the Plantaris may be absent or double. The [nfracostals vary in number, however, there are generally ten pairs. Ordinarily there are twenty muscles in the forearm, sometimes nineteen, other times twenty-one as the Palmaris longus may be absent or double. So it is im- possible to give the exact number. However, there are more than 550 muscles in the human body. ( Plate II.) The muscles give form to the body and move it from place to place. They take their names in various ways. 1. From the attachment, as Sterno-cleido mastoid, which mean- this muscle is attached to the sternum, and the clavicle (key) and the mastoid pro- cess of the temporal bone. 24 ANATnMV IN A NUTSHELL. 2. From the number of parts, as Biceps, which means Two heads, and Triceps, which means three head-. From the shape, as Deltoid, like the Greek letter delta, inverted. 1 From the function, as Levator anguli scapulae, which means to lift the angle of the scapula. From the position, as Subclavius and Subscapularis which means under the clavicle and under the scapula. 6. From the function, attachment and shape, as Pronator radii teres, which means this muscle first pronates, second it is attached to the radius, and third it is round teres I. .Muscle*, have tv\<> or more points of attachments; the part which is most stationary is called the "origin" and is generally the larger; the most movable PLATE III. Showing the Origin and Ensertion op the Biceps. part is called the "insertion" and is generally the smaller pan of the attach- ment of the muscle. (Plate ill.) Muscle- must have a blood and nerve supply in order to be in a healthly condition. Principle: Function makes struc- ture and the cessation of function leads to the disappearance of structure. For instance, in the primative man the Pectorialis minormuscle was continued from the coraciod process of the scapula to the humerus; now this part of the muscle is a Ligament. Again, the internal lateral ligament of the knee was at one time a part of the Adductor magnus muscle. Thelong external lateral Ligament of the knee was at one time a pari of the Peroneus Longus, and the ligamentum teres belonged to the Pectineus muscle. Joints \m> Ligaments. A joint is made up of two or more hones, a syn- ovial membrane, articular cartilage, white fibrous cartilage, and ligaments, and is for the purpose of motion. The bones are larger where they enter into A.NATOMY IN A NUTSHELL. 25 the joint and are covered with articular cartilage. This cartilage has no blood vessels, is a hylaine variety, and is nourished by the lymph. These bones are held together by ligaments (to bind) which are flexible but not extensible. Joints, like muscles must have blood and nerve supply. Hilton's Law — A nerve trunk which snpplies a joint supplies the muscle which moves the joint and the integument over the fullest insertion of the mus- cle . The Circumflex nerve to the shoulder joint is a good example of this law. There are three great classes of joints in the body: A. Immovable or Synarthrosis. B. Partly movable or Amphiarthrosis. ('. Freely movable or Diarthrosis. PLATE IV. ANT. PRIMARY BRANCH SPINAL NtHvb POSTERIOR PRIMARY BRANCH ANT OR VENTRAL R00T-M0TUR EXT. DIVISION INT DIVISION 1 - GALL 6 - VENTRO LATERAL ASSOCIATION 2 - BURDACK 7 - DEEP LATERAL ASSOCIATION 3 - MARGINAL 9 - DIRECT PYRAMIDAL 4 - DIRECT CEREBELLAR 9 - CROSSED PYRA MIOAL 5 -ASCENDING LATERAL TRACT (GOWERSt 10 COMMA A Transverse Section of the Spinal Cord. Under (A) Synarthrosis we have the following: 1. True sutures or sutura vera. a. Dentata ;is interparietal. b. Serrata as interfrontal. c. Limbosa as fronto-parietal. 2. Sutura notha. a. Squamosa as squamo-parietal. b. Harmonia as intermaxillary. 3. Schindylesis as the sphenoid with the vomer. 4. Gomphosis, as the teeth. 5. Synchondrosis, which means the union of bones by mean- of fibrous or elastic cartilage, e. g. ; epiphyseal line.-. WATiiMV IN A NUTSHELL. I'.. Amphiarthrosis. I. Symphysis, as between bodies of vertebrae ; and the anterior part of the innominata : symphysis pubes. This kind of joint has no synovial membrane. •_'. Syndesmosis, as the inferior tibio-fibular articulation. c. Dlarthrosis. All the diarthrosis or movable joints are represented in the shoulder girdle and the upper extremity. 1. A.rthrodia (gliding) in the acromio-clavicular-joint. 2. Enarthrodia, (ball-and-socket) in the shoulder-joint. :;. ( iinglymus (hinge) in the elbow. \. Trochoides or Pivet-joint, in the superior radio-ulnar joint. 5. Condyloid, as the wrist-joint, having all movements except axial rotation. 6. Reciprocal Reception (saddle shaped-joint) in the carpo-metacarpal joint of the thumb. Ligaments take their names from the bones they join, as sterno-clavicu- lar ligamenl which joins the sternum and the clavicle. When it goes across a notch or groove it is called a transverse ligament and when it goes around a joint it is culled a capsular ligament. Ligaments are composed mostly of white fibrous tissue; the ligaments subflava,and the ligamentum nucha' of the lower animals arc yellow elastic tissue. Nerves. If a nerve goes to integument it is called ■•cutaneous;"' if it goes to muscles, i1 is called "muscular;" if it goes to muscles and integument, it is called " musculocutaneous. n There are twelve pairs of cranial nerves and thirty-one pair- of spinal nerves. All spinal nerves are compound nerves be- came they have an anterior root which is motor and a posterior root which is sensory. These two roots unite to form the nerve which contain- both motor and sensory fibers. Bach nerve as it leaves the spinal foramen divides into an anterior and posterior branch. Principle l. (Plate IV.) Posterior nerve roots are larger than anterior nerve roots, with the single exception of the first cervical. They are from one and one-half to three times as large. Principle II. The anterior branches are larger than the posterior branches in all cases except the firsl and second cervical nerves. Principle III. The posterior branches divide into an internal and external division in all cases except the firsl cervical, fourth and fifth sacral, and coc- ■ ! nerve-. Principle IV. The anterior branches make the plexuses. Principle V. (Plate V) The posterior nerve root has a ganglion upon it which lies in the intervertebral foramen, outside the sac of the dura mater, ex- cept the first one which is not always present, and when present is situated within the dura mater. This one. and the second, are placed on the arches of the vertebra over which the nerves pass. The ganglia of the last four sacral nerves are situated outside the dura mater bu1 in the spinal canal; the coccy- geal ganglion when presenl is within the dura muter. The nervi nervorum are nerve filament^ going to the nerves and the nerve sheaths. ANATOMY IN A NUTSHELL. 27 LESSON [V. The roots of the first and second spinal nerves pass outward at right angles- All the rest pass obliquely downward and outward, and as the cord ends at the second lumbar, the lower roots have a long course before they leave the canal, and are situated around the filnni terminale of the spinal cord forming the cauda equina. A motor nerve is any nerve whose function is to excite muscular conn-ac- tion, anil thus effect movement in an animal body. Most nerves are mixed in character or sensorimotor, effecting both motion and sensation. A sensory nerve is a nerve conveying sensory impulses, or more strictly, one composed exclusively of sensory fibers; nearly equivalent to afferent nerve. Vasomotor nerves are those which supply the muscular coats of the blood- vessels. A nerve center is a group of ganglion-cells closely connected with one an- other and acting together in the performance of some function, as the cerebral centers, Of the cranial nerves, some are compound, some are motor and others are nerves of special sense. They take their names, olfactory, optic, etc., from their function, but the names, first, second, etc., from the order of piercing the dura mater from before backward. TABLE OF CRANIAL NERVES. Name. Distribution. Fitncton. Mktiiod of Ex it 1st. Olfactory. Upper third of nasal cavity. Special sense Smell. Cribiform Plate of Eth- moid. 2nd. Optic. Retina. Special sense Sight. Optic Foramen. .lid, oculo- motor. Muscles of eyeball except In- ternal rectus and Superior oblique. Motor. Sphenoidal fissure. 4th. Trochlear. Superior oblique of eyeball. Motor. ( Ordinary Sense and motor. sphenoidal Fissure. 5th. Trificial. Sensory part to lace, fore part of scalp, external car. eye, teeth, gum, cheek, lore part of tongue. Motor part to muscles of nias- cation. < tphthalmic division thro Sphenoidal Fissure. Superior Maxillary thro Rotundum, [n f eri <> r Maxillary thro Ovale. 6th. Abducent. Externa] rectus muscle of eve ball. Motor. Sphenoidal fissure. 28 ANAIOMV IX A NUTSHELL. TABLE OF CRAN1 M- NERVES— Continued Name. 7th. Facial. 8th. Auditorx . 9th. Ulosso- Pharyngeal I >l-l KIBUTION. Function. Method of Exit. Superficial muscles <>f lace, Frontalis, Platysma, Stylo- boid and posterior belly or Motor, Digastric. Internal Auditory Meatus a n (1 leaves l>y Stylo- mastoid Foramen. Special sense, Membranous labyrinth oi ear. (hearing) and Equilibrium. Internal Auditory Meatus; remains in ear. Pharynx and hind partof ton gue; some motor fibers. Special sense jugular Foramen. (taste). Ord'y Sense, Motor. S< M-' 'iy in external ear, motor loth - Pneumo- and 8en sory to pharynx . ,,.,s.iri,. or \'-i ii <>rdinar\ sense _asun oi \ a- larynx, trachea, lungs, oeso- • , Jugular Foramen, mis , ' ,i.i and motor. -" • phagus, stomach, heart, and pm sometimes to li\ er l l tli. Spinal Accessory. Motor to Trapezius and Sterno- mastoid muscles. Rest is ac- Motor, cessory t<> the pneumogastric. .1 ugular Foramen. lJth. Hypo- glossal Muscles of tongue. Motor. Anterior Condyloid Fora- men. LESSON V. ART I. K II.-. The arterial system consists of two separate divisions of circulations. The pulmonary arterywith its branches forms the lesser or pulmonary circulation, and the aorta with its branches forms the greater or systemic circulation. Blood vessels. Vasa vasorum are blood vessels which supply the larger arteries. The blood circulates through the body to nourish the various parts. The circulation of the blood was demonstrated by Harvey in 1628. All ves sels which carry 1>I 1 from the heart are arteries, and those which carry blood to the heaii are veins. The connecting link between the arteries and the veins is the capillaries. Harvey was not able to sec these connecting links for they are microscopic and the microscope was no1 invented until some years later. Harvey said the l>l I filtered through the tissues from the arteries to the veins, which is not very far wrong. Malpighi discovered the capillaries in 1661. As a rule the arteries carry pure or oxygenized blood, and the veins carry impure or non-oxygenized blood, but there are exceptions to this rule forthe pulmonary artery carries impure blood and the pulmonary veins carry pure blood. Perhaps the puresl Mood in the body is in the right renal vein. When the blood enters the kidney it is as pure as when it left the left ventricle of the heart and in the kidney it throws off more impurities than it takes from the kidney. The left renal vein receives the spermatic vein in the male and the ovarian vein in the female, SO it contains blood less pure than the PLATE V GLOSSOPHARYNGEAL PNEUMOGASTRIC SPINAL ACCESSOR CERVICAL — ~_~" — CKvV < V- in — 1st _j~V ' SUPERIOR CEREBELLAR PEDUNCLt IDDLE CEREBELLAR PEDUNCLE NFERIOR CEREBELLAR PCQUNCLE TERMINAL CONE VENTRAL ROOTS FILUH TERMINAll Posterior View of the Spin w. < '< 29 30 \N V.TOM1 1\ A NUTSHELL. righl renal vein. These veins of the righl side enter into the inferior vena cava :iinl have valves. The heart is a voluntary muscle (straited) in structure bill is presided over by the sympathetic nerve which makes it involuntary in action. The average weighl of the heart is about 11 ounces. Its covering is called pericardium, its lining endocardium, and the muscle itself is called myocardium. It has four chambers, the two upper ones arc the auricles (ears) and the two lowerones ventricles (bellies). The two auricles contract at the same time that the ven- tricle- expand, and vice versa. The contraction is called the systole and the expansion the diastole. The systole is the work, and the diastole is the rest. Capillaries arc not found in cartilage- epithelium — epidermis. The net work of capillaries is very close in the lungs mucous membrane — muscle and adipose tissue and in the gray matter of the brain and cord. The capillary meshes an' wider and the vessels fewer in the fascia — aponeurose — tendons and ligaments. In their simplest form the capillaries consisl only of endo- thelial lining of the arteries and veins with which they are connected, being both elastic ami contractile, their lumen varies under pressure. They are microscopic and in order to get a drop of blood many musl be ruptured. Arter- ies and veins have nerves called vaso-motor which forms a net-work around the muscular coat, especially of the arteries. \ EINS. Veins are found in almosl all the tissues and carry the blood from the cap- illaries to the heart. A.s they are generally larger and more numerous than the arteries, their total capacity greatly exceed- that of the arterial system. Not only the smaller branches, but even the larger trunks communicate with each other very freely. The venous system has two distind subdivisions, the pulmonary ami the systemic. The pulmonarj veins aid in the pulmonary circulation and convey arterial bl 1 to the left auricle; they are but slightly larger than their arteries, and have no valvt s. The systemic veins aid in the general circulation and convey venous blood to the righl auricle. They are divided (systemically) into three sets; super- ficial, deep, and sinuses. The superficial or cutaneous veins lie just under the skin between the layers of the superficial fascia; they pierce the deep fascia to empty into the deep veins. The deep veins usually accompany the arteries and are enclosed in the same -heath. There i- generally only one vein with each of the larger arteries as the subclavian but two (venae comites) ac- company each of the -mailer arteries as the radial, and all the arteries of the lower extremities excepl the femoral artery, one lying on each side of them ; in certain regions they do nol accompanythe arteries. The sinuses are venous channels which are found only in the skull ami are formed by a separation of the layer- of the dura mater: they are lined by endothelium. The arteries and veins have threecoats; fir-t the tunica intima, second the tunica media and third the tunica externa (adventitia). This third coat is the "tily one not ruptured in ligation of an arterv. The tunica media has muscular PLATE VI. The Brachial Plexi s. 31 32 ANATOMY IN A NUTSHELL. fillers in it and supplied with vasomotor nerve- (vaso-constrictor and vaso- dilator). These nerves run in the same -heath and are part of the sympathet- ic nervous system. The vaso-constrictor acts to a greater or lesser degree at all times; the vaso-dilator acts upon the constrictor and inhibits its action. The artery which passes over a joint gives off branches above and below the joint and these branches run towards the joint and join one another. This joining is called anatsomosis. Its purpose is for the blood to run in these small arteries as a mean- of passing the joint when the main one is closed. This cir- culation i- called collateral. Arteries and veins hear a certain relation to one another. Rule.— (Plate VIII.) Above the diaphragm veins are are on the same level, or in front of their companion arteries. Below the diaphragm the arter- ies are on the same level, or in front of their companion veins, excepting the renal and the profunda. The tYtiis gets it- food and oxygen from the placenta, while after birth the food come- through the alimentary canal and the oxygen through the lungs. In tracing the circulation after birth we start with the blood in the right auricle: a systole of the heart -ends it through the tricuspid valve into the right ven- tricle; here a systole sends it through the semilunar valves into the pulmonary artery ami the lungs, where it gives n{] carbon dioxid and receives oxygen; it i< continued from the lungs through the pulmonary veins (three to five) to the left auricle of the heart, then a systole sends it through the bicuspid valve into the left ventricle; from here a systole sends it through the aorta to all parts of the body, to pas- through the capillaries and to be collected into the superior and inferior vena- cava- which empty into the right auricle of the heart. Veins have valves which keep the blood from running back in its course. All veins do not have valves; some of those which do not have valves are the veins of the dura mater, or sinuses, the pulmonary veins, veins of the portal system and those of the spinal cord. The others will be mentioned when described. Arteries a- a rule do not have valves, but there is an exception to this also; the pulmonary artery has valves. Veins receive tributaries, or radicles; arter- ies break into branches. The portal vein breaks into branches like an artery and the vertebral arteries join like a vein to make the basilar artery. The veins are in two -el-; the superficial and the deep; the superficial ones are in the superficial fascia, but send communicating branches to the deep veins. The deep veins accompany the arteries in the extremities and there are two for each artery: they are called vena' comites. They are presenl in the arm and forearm and from the knee to the ankle, but not from the hip to the knee. The veins are larger than the arteries. If they were all put into one vessel it would be the shape of ;1 cone with the apex at the heart ami its base at the surface of tli.' body because the combined area of the tributaries is greater than that of the main veins. AXATOMY IN A NUTSHELL. 33 LESSON VI. In the fetal heart the Eusatchian valve is large. The foramen ovale which joins the two auricles gives a free communication between them until the middle of fetal life, at which time a valve grows from the posterior wall of the right auricle to the left of the foramen ovale, and prevents the blood from passing through except from right to left. In twenty per cenl of the cases the foramen ovale remains open throughout life. (Plate IX.) PLATE VII. PHALANGES. TWO CENTERS FOR EACH BONE. ONE FOR SHAFT. ONE FOR ( £ METACARPAL EXTREMITY. APPEAR BETWEEN THE THIRD AND FIFTH YEAR CONSOLIDATE IN THE EIGHTEENTH YEAR. APPEAR IN THE THIRD CONSOLIDATE IN THE TWENTIETH YEAR METACARPUS TWO CENTERS FOR EACH BC ONE FOR SHAFT. ONE FOR DIGITAL EXTREMITY EXCEPT FIRST CARPUS. ONE CENTER FOR EACH BONE ALL CARTILAGINOUS AT BIRTH APPEARS IN THE THIRD YEAR. CONSOLIDATES IN THE ' TWENTIETH YEAR. Nutrient Arteries of Hoxk.s ok 1Iwi>. The ductus arteriosus which is aboul half an inch long joins the de- scending aorta just below the origin of the lefl subclavian artery. It arises from the left pulmonary artery at first from the common pul- monary. The hypogastric or umbilical arteries arise from the internal iliac, and after passing beside the bladder go through the umbilicus to the placenta a 34 ANATOMY IN A NUTSHELL. The umbilical win passes from the placenta to the under surface of the liver going through the umbilicus and the free margin of the suspensory liga- ment. At the transverse fissure this vein divides into two branches. A large <»ne which is joined by the portal vein and enters the right lobe of the liver. A smaller one the ductus venosus — joins the left hepatic vein at its junction with the interim' vena cava. Before it divides the umbilical vein gives branches to the left, quadrate, and Spigelian lobes. The pure blood coming from the placenta in the umbilical vein reaches the interim- vena cava in three ways; 1. A small quantity via ductus venosus into the hepatic veins and in- ferior vena cava. 2. Smne enters the liver directly and then passes through the hepatic veins. :!. Most of it passes through the liver with the portal venous blood and then through the hepatic veins. In the inferior vena cava all this blood mixes with venous blood from the lower extremities and abdominal wall. It now enters the right auricle from which it passes to the lefl auricle through the foramen ovale being guided by the Eustachian valve. In the lefl auricle it mixes with the blood which comes from the pulmonary veins, which is venous and a small amount. It now passes through the auriculo-ventricular opening into the left ventricle, from here through the aorta to the head and upper extremity, some passing into the de- scending aorta. The venous blood from the upper extremities and head de- scends in the superior vena cava into the right auricle of the heart and here it mixes with a small pari of the blood from the inferior vena cava. From here it passes through the auriculo-ventricular opening to the right ventricle. A systole sends the blood from the right ventricle into the pulmonary artery, a small pari of the blood passing into the lungs and the remainder goes through the ductus arteriosus to the descending aorta, where it mixes with blood from the left ventricle after it has passed through the arch of the aorta. Most of the lil 1 in the descending aoria passes through the umbilicus to the placenta, and the rest to the lower limbs and viscera. The adult gets nourishment from the alimentary canal and oxygen from the lungs. The placenta acts both as a nutritive and a respiratory organ. The liver, the head, and the upper extremities are large in the fetus because the purely arterial blood passes to these organs. The other viscera and the lower extremities are small because the blood which passes to them is practically venous. At birth the placental circulation stops, while the pulmonary circulation is increased and the lungs expand. The foramen ovale closes about the tenth day and the valvular folds adhers to its margin. As said before, the foramen ovale remains open throughoul life in one case ou1 of five. The umbilical arteries become obliterated beyond the bladder in from two to five days. The umbilical vein and ductus venosus dose about thesame time as the umbili- cal arteries. The ductus arteriosus closes in from four to ten days. \ plexus i- a net-work. (Plate VI.) The Brachial Plexus is a net work of nerves situated in the axilla. It is called brachial because its branches supply A.NATOMY IN A NUTSHELL. 35 the arm or brachium. On each side of the spinal cord are five plexuses, making five pairs in all. We learn the anatomy of the lateral half of the body and the other half is similar, with a few exceptions in the viscera. The first plexus is made of the anterior divisions of the first four cervical nerves and is called the Cervical Plexus. The next plexus in order is called the Brachial, and is com- posed of the anterior branches of the fifth, sixth, seventh and eighth cervical nerves and part of the first dorsal nerve. In the dorsal or thoracic region there are no plexuses, except sympathetic. There are plexuses of nerves where there is much work to be done by the nerves. The next plexus is the Lumbar which is composed of the anterior branches of the first, second, third and part of the fourth lumbar nerves. The part of the fourth lumbar nerve which does not enter into the formation of this plexus joins the fifth lumbar nerve and these two nerves make the lumbo-sacral cord which, although it has lumbar nerves in it, belongs to the sacral plexus. This cord with the anterior divisions of the first, second, third and part of the fourth sacral nerves make the Sacral Plexus. The remaining part of the fourth nerve with the fifth and coccygeal nerve, make the Coccygeal Plexus. As the spinal cord is so much shorter than the spinal canal, the nerves leave the cord above the foramina where they leave the spinal canal. There are eight cervical nerves although only seven cervical vertebra?, as the first cervical, or suboccipital nerve, is above the atlas and the eighth cervi- cal nerve below the seventh cervical vertebra, or vertebra prominens. The eight cervical nerves leave the cord above the spinous process of the sixth cer- vical vertebra. There are twelve pairs of dorsal or thoracic nerves; the first six of these lea 1 ,!' the cord between the spinous processes of the sixth cervical and the fourth dorsal vertebra; the lower six dorsal or thoracic nerves leave the cord between the spinous processes of the fourth and eleventh dorsal. The five Lumbar nerves leave the cord between the spinous processes of the eleventh and twelfth dorsal. The five sacral nerves leave the cord between the spinous processes of the twelfth dorsal and the first lumbar. The lower nerve roots have such a long course between the cord and the foramina that they are called cauda equina (horse tail.) LESSON VII. Clavicle (Key.)— This is a long bone but it has no medullary canal as (he other long bones have. It is quite elastic, and with the scapula acts ;is a cush- ion to lessen the force of blows upon the shoulder. In sonic animals it does not articulate with any other bone, but is held in position by the muscles. This bone and the scapula make the shoulder girdle. It is present in those animals which have claws and use the upper or front extremity for other purposes than that of progression. It acts as a fulcrum for t he various movements of t he upper extremity. It is situated at the upper anterior part of the chest, between the manubrium of the sternum and the acromion process of the scapula. It has a double curve with the convexity anterior at the sternal extremity and the con- PLATE VII. COMMON CAROTID INNOMINATE A. 4 ' : ■ SUB- CLAVIAN VEIN AND ARTERY ANTERIOR JUGOLCR- 4NTERN6L JUGULAR, EXTERNAL JUGULAR. VENA-AZYGOS MAJOR VENA AZYGOS TERTIUS. INTERCOSTAL VEIN INTERCOSTAL AJITEHT VENA-AZTGOS MINOR. Relative Position of Vwssles Above wi> Below the Diaphragm. ANATOMY IN A NUTSHELL. 37 cavity anterior at the acromial extremity. It is more often broken than any other bone in the body and when broken will press upon the Brachial Plexus producing temporary paralysis. It has but one epiphysis, which is at the sternal extremity, hence the nutrient artery runs towards the acromial extrem- ity (Rule 2, Lesson 1.) The bone is divided into an inner two-thirds which is somewhat triangular on cross-section, and an outer one-third which is more flattened from above downward; the coracoid process of the scapula is under this division of the clavicle. (Plates X-XI.) Outer one-third. — The upper extremity of this portion has the attachment of the Deltoid muscle in front and the Trapezius behind, with a small interval between them. The under surface has first a conoid tubercle near the poster- ior border and internal boundary of this part of the bone. The conoid liga- ment passes from this tubercle to the coracoid process of the scapula, which is immediately under it. Second, the trapezoid, or oblique line, sometimes a furrow, passes from the conoid process forward and outward and gives attach- ment to the trapezoid ligament. The conoid and trapezoid ligaments make the coraco-clavicular ligament. The anterior border is concave and gives at- tachment to the Deltoid; this border has a deltoid tubercle. The posterior border is broader than the anterior one; it is convex and gives attachment to the Trapezius. Inner two-thirds. — This part may be described as having three borders and three surfaces. The anterior border extends from the anterior border of the outer one-third to the inner extremity of the bone, separating the anterior and inferior surfaces. The superior border extends from the upper part of the pos- terior border of the outer one- third to the inner extremity of the bone, separat- um the anterior and posterior surfaces of the clavicle. The posterior border extends from the conoid tubercle to the rhomboid impression, separating the posterior and inferior surfaces. The anterior surface gives attachment to the Pectoralis major and the Sterno-cleido-mastoid muscles. The posterior sur- face gives attachment to the Sterno-hyoid and occasionally the Sterno-thyroid. It has a nutrient foramen which is directed outward according to Rule 2, Lesson ]. Sometimes there are two foramina, one of which may be mi the inferior surface. The inferior or subclavian surface has near its inner part the rhomboid impression which gives attachment to the costo-clavicular or rho- boid ligament; this impression is about as inch long. The subclavian groove occupies about the middle' one-third of the under surface of the clavicle and gives attachment to the Subclavius muscle. The sternal extremity is triangu- lar, with one angle above and two below; it looks inward, downward and a little forward. It is convex from above down and concave antero-posterior- ily. It articulates with the manubrium and its circumference is rough for the attachment of the ligaments of this joint. The acromial extremity has an oval articular facet somewhat convex, which is directed downward and forward to articulate with the acromion; its circumference is rough for the attachment of the ligaments of this joint. The righl clavicle is longer, thicker, and rougher than the left. Those of the male are longer, thicker, rougher ami more curved than those of the female. 38 ANATOMY IN A NUTSHELL. Ossification.— Its ossification is from two centers, one for the diaphysis, the sixth week, or may be as early as the thirtieth day. which is the first in the body, and the other a1 the sternal extremity, about the eighteenth or twen- tieth year, complete ossification taking place about the twenty-fifth year. It begins as a membranous bone, but the ossification later extends into the under lying cartilage. Articulation. (Plate XII.) It articulates with the sternum, the cartilage of the first rib and the acromion process of the scapula. The sterno-olavicu- lar articulation is a reciprocal reception (saddle shaped-joint,) which belongs to the diarthrodial class and has all the movements except rotation. The blood supply of this joint i: — (1) the internal mammary from the subclavian. (2) suprascapular from the thyroid axis. (3) superior thoracic from the first portion of the axillary, and occasionally twigs from a muscular branch from the sub- clavian which crosses the intersternal notch. The nerve supply to this joint i~ , l the subclavian from the Brachial plexus and (2) the suprasternal from the Cervical plexus. The ligaments are the anterior sterno-clavicular ligament which is attached to the upper and anterior part of the manubrium; from here it passes to be attached to the upper and anterior part of the sternal extremity of the clavicle. The posterior sterno-clavicular ligament ha- a similar attach- ment from the posterior surfaces of the same hones. These two make the cap- sular ligament. The interarticular fibro-cartilage is thinner in the center than at the circumference and gives attachment to the sternal end of the clavicle above and the firsl costal cartilage at its junction with the manubrium below; thus it divides the synovial membrane, having one on each side. The costo-clavicular or rhomboid ligament passes upward, backward and outward from the sternal end of the cartilage of the first rib to the rhomboid impression of the clavicle. The inter-clavicular ligament is a flat cross-band attached to the upper margin of the manubrium, connecting the upper parts of the inner end- of the clavicle. The acromlo-clavicular articulation is anarthrodial joint. (Plate XIII.) The blood supply is (1) the suprascapular from the thyroid axis. (2)theacromio- thoracic and (3) posterior circumflex. The nerve supply is (1) circum- flex from the posterior cord of the Brachial plexus, (2) suprascapular, from Brachial plexus and (3) supra-acromial from the Cervical plexns. The lig- aments are the superior acromio-clavicular ligament, a quadrilateral band which passes between ihe otiier end of the upper surface of the clavicle and the upper surface of the acromion process. The inferior acromio-clavicular liga- ment covers the joint below, but is thinner than the superior one. These two make the capsular ligament. The interarticular fibro-cartilage is not always present; it may fill the articulation, then there are two synovial membrane-; more often it only occupies the upper part of the joint, then there i> only one synovial membrane. The trapezoid ligament is the anterior and externa] part of the coraco-clavicular ligament and is attached above to the oblique line of the under surface of ihe clavicle and below to the posterior half of the upper surface of the coracoid process. The conoid ligament is the pos- terior and internal pari of ihe coraco-clavicular ligament and is attached above PLATE IX. 39 40 ANATOMY IX A NUTSHELL. by its base to the conoid tubercle of the clavicle and a line running internally for half an inch: below by its apex to the rough impression at the base of the coracoid process. Blood Supply.- The nutrient artery of the clavicle is from the supra- scapular. The acromial end receives a branch from the acromial thoracic artery and twigs from the arteries in the muscles attached to it. LESSON VIII. Muscles. 'The muscles of the clavicle are six. viz., Sterno-cleido-mastoid. Sterno- hyoid, Subclavius, Pectoralis major. Deltoid, Trapezius, and occasionally the Sterno-thyroid. Sterno-cleido-mastoid; Description. — (Plate (XIV.) This muscle passes obliquely across the side of die neck and is enclosed between the two layers of the deep cervical fascia. It is broad and thin at each extremity, hut is thicker mm. I narrower at the central portion. The portion which is attached to the sternum is directed upward, backward and outward. This attachment is ten- dinous in front and fleshy behind. The portion which is attached to the clav- icle is directed almosl vertically upward and is composed of fleshy and aponeu- rotic fibers. These two portions are separated at their origin, but become gradually Mended below the middle of the neck into a thick, round muscle. The attachment of this muscle to the clavicle may he as small as the sternal attachment or it may extend to the attachment of the trapezius muscle at the outer portion of the clavicle. This muscle divides the quadrilateral space at the side of the neck into two triangles, an anterior and posterior. Origin. By two heads; first from the anterior surface of the upper part of the manubrium of the sternum; the second from the inner one-third of the superior border ami anterior surface of the clavicle. (Plate XI.) Insertion. Mastoid process of temporial bone and the outer two-thirds or one half of the superior curved line of the occipital bone. Action. To depress and rotate head and elevate the thorax. Nerve Supply. Spinal accessory (eleventh cranial) and deep branches of the cervical plexus (second and (third'.') nerves.) Blood Supply. The superior sterno-mastoid artery from the occipital artery, the middle sterno-mastoid artery from the superior thyroid artery, the inferior sterno-mastoid artery from the suprascapular artery, also branches from the posterior auricular artery. Sterno-hyoid. Description. The sterno-hyoid covers the thyroid gland and upper pari of the trachea, and is a thin narrow muscle, its lower portion being immediately beneath the Sterno-mastoid. This muscle comes in contact with its fellow in the middle of their course, and from there on lie side by side, but they are separated below from each other by a considerable interval. Origin, i 1 i Posterior surface of the manubrium of the sternum. (2) ster- nal end of the clavicle and posterior sterno-clavicular ligament. ANATOMY IX A XUTSUhLL. 41 Insertion. — Body of the hyoid bone. (Plate XIX.) Action. — To depress the hyoid bone. Nerve Supply. — Branches from Loop of communication between the cervical plexus and the twelfth cranial nerve. TUBEROSITY FOR CONOID LI GMT OBLIQUE VINE FOR TRAPEZOID LICKT. PLATE X. — POSTERIOR SUBCLAVIU5 STERNO-THYROiD. STERNO HYOID. ARTIC. WITH THE SCAPULA. capsular lkvm-t pectoral1s major. anterior. Left Clavicle. Ixferioh Surface. Blood Supply. — Lingual, inferior and superior thyroid arteries. Sterno-thyroid. — Origin. — (1) Posterior surface of the manubrium of the sternum and the cartilage of the first rib, occasionally from the second rib and _' -ometimes from the clavicle. Insertion. — Oblique line of ala of thyroid cartilage. Action. — Depressor of larynx. Nerve Supply. — Branches from the loop of communication between the cervical plexus and the twelfth cranial nerve. Blood Supply. — Lin qual, inferior and superior thyroid arteries. PLATE XL -ANTERIOR. PECTORALIS MAJOF acromial end trapezius — posterior.- — Left Clavicle. Superior Surface. Pectoralis major. — Description. — (Plate XV.)- This muscle is situated in front of the axilla, also on the upper and foreparl of the chest. P is trian- gular, being both broad and thick. From it s origin the fibers nil pa-- towards its insertion, giving it the shape of a fan. tts tendon, which i- flat, is aboul two inches in breadth. The tendon i> made of two layers placed one in front of the other and usually blended together below. The anterior layer which is thicker receives the clavicular and upper half of the sternal portion of the mus- cle and its fibers are inserted in the same order a- that in which they arise. The 42 ANATOMY JX A NUTSHELL. rior layer of the tendon receives the attachment of the lower half of the sternum and the deeper pari of the muscle from the costal cartilages. These deep fibers, and particularly those of the lower costal cartilages ascend, the higher turning backward successively behind the superficial and upper ones, so thai the tendon appears to be twisted. The posterior layer reaches higher on the humerus than the anterior one and from it an expansion is given off that covers the bicipital groove and blends with the capsule of the shoulder- joint. An expansion is given off, which lines the bicipital groove, from the inseriton of the deeper fibers. An expansion passes downward to the fascia of the arm from the lower part of tendon. This muscle is separated from the Deltoid by slight interspaces in which lie the cephalic vein and the humeral branch of the acromio-thoracic artery. Its border forms the anterior margin of the axilla. ORIGIN. — (1) The anterior surface of the sternal half of the clavicle. (2) Half the breadth of the anterior surface of the sternum as far down as the attachment of the cartilages of the sixth and seventh ribs. (3) Cartilages of all the true ribs, excepting the first and seventh, or both, and aponeurosis of the External oblique of the abdomen. (Plate XI.) Insertion. The fibers which arise from the the clavicle pass obliquely outward and downward: those from the lower part of the sternum and cartil- ages of the lower true ribs upward and outward, whilst the middle fibers pass horizontally. The tendon of termination is inserted into the outer bicipital ridge of the humerus. (Plate XXIII.) Action. Draws the arm forward and downward, also elevated the ribs in forced inspiration. \'i.i;\ e Si ri ia . --- External and internal anterior thoracic. The nerves receive filaments from all spinal nerves entering into the format ion of the brachial plexus. The costo-coracoid membrane is a strong fascia situated in the interval between the Pectoralis minor and Subclavius muscles and protects the axillary els and nerves. It divides above to enclose the Subclavius muscle and its two layers are attached to the clavicle, one in front of and the other behind the muscle. The latter layer fuses with the deep clavicular fascia and with fascia of the axilla r\ vessels. Internally, it blends with the fascia covering the firsl two intercostal spaces and is also attached to the first rib, internal to the < » r i - i 1 1 of the Subclavius muscle. Externally it is very thick and dense and is attached to the coracoid process. This membrane is pierced by two arteries, two nerves, and two veins. The superior and acromial thoracic arteries, the external and internal anterior thoracic nerves, and the acromial ihoracic and cephalic veins. Blood Supply. Internal mammary, intercostals, superior thoracic, acromial thoracic, am! long thoracic. LESSON VIII. Subclavius. (Plate XV). Des< ription.- This is a small triangular mus- •le placed in the interval between the clavicle ami the firsl rib. It is separated from the firsl rib by the subclavian vessels and brachial plexus of nerves. Its interior surface i- separated from the Pectoralis major by the costo-coracoid membrane, which with the clavicle, forms an osseo-fibrous sheath in which the ANATOMY IN A NUTSHELL. 43 muscle is enclosed. The insertion of this muscle is larger than the origin. Origin. — By strong tendon from the first rib and its cartilage at their junction in front of the rhomboid ligament. Insertion. — Under surface of the clavicle in a deep groove about its middle third. (Plate XL) Action. — Depresses shoulder by drawing the clavicle downward and for- ward. Nerve Supply. — Filaments from the fifth and sixth cervical. Blood Supply. — First intercostal and short thoracic arteries. Deltoid.— Description.— (Plates XYIII-XIY-XY-XYI. i— The Deltoid is a triangular muscle which gives the rounded outline to the shoulder. It i- PLATE XII. ANTERIOR STERNO-CLAUCULAR LIGAMENT THE INTERARTICULAR FIBRO-CARTILAGE THE JOINT BETWEEN THE STERNUM A\D SECOND COSTAL CARTILAGE Sterno-Claviculak Articulation. large and thick. It surrounds the shoulder-joint in the greater part of its of its extent, covering it on it- outer >ide and in front and behind. It- •: surface is separated from the head of the humerus by a large sacculated syn- ovial bursa. It- anterior border i- separated at its upper part from the Pec- toralLs major by a cellular interspace which lodges the cephalic vein and the humeral branch of the acromial thoracic artery. This muscle i- remarkably coarse in its texture. Origin.— (Plate.- XI-XX.> — (1) Outer thiol of anterior border and upper surface of clavicle. (2) Outer margin and upper surface of acromion proc< (3) Lower lip of posterior border of -pine of scapula as far back as the trian- gular surface at the inner end. The part arising from the acromion process 44 ANATOMY IX A NUTSHELL. consists of oblique fibers which arise in a bipenniform manner from the sides of tendinous intersections, generally four in number, which are attached above id the acromion process and pass downward parallel t<> one another in the sub- stance of the muscle. The portion of the muscle which arises from the clavicle and the -pine of the scapula are no1 arranged in this manner, bu1 pass directly from i heir origin to their insertion. Insertion. (Plate XXIII.) The fibers of this muscle converge to- wards their insertion, the middle passing vertically, the anterior obliquely backward, and the posterior obliquely forward; they unite to form a thick ten- PLATE XIII TRANSVERSE LIGAMENT Acromio-Clavicular Articulation and Shoulder-Joint. don which is inserted into a rough triangular prominence on the middle of the outer side of the shafl of the humerus. At its insertion is given oft' an expan- sion t<> the deep fascia of the arm. The oblique filters arising from the tendi- nous intersections, generally three in number, pass upward from the intersec- tion of the muscle ami alternate with the descending septa. Action. To raise the arm ami helps to draw it forward ami backward. Xi.i;\ i. Si ppli ( Jircumfiex. Blood Supply. rPosterior circumflex ami acromial thoracic arteries. ANATOMY IX a NUTSHELL. 45 Trapeszius. — Description. — (Plate XVIII.) This is a broad, Hat. trian- gular muscle, placed immediately beneath the skin and fascia, and covering the upper and back part of the neck and shoulders. It is fleshy in the •:• part of its extent, but tendinous at its origin and insertion. At its origin, from the spines of the vertebrae, it is connected to the bones by means of broad semi- elliptical aponeurosis, which occupies the space between the sixth cervical and the third dorsal vertebra, and tonus, with the aponeurosis of the opposite side, a tendinous ellipse. Origin. — (1) by thin fibrous lamina' from the external occipital protuber- ance and the inner one-third or one-half of the superior curved line of the occipi- tal bone. (2)from the ligamentum nuchas. (3)from spinous processes of the seventh cervical and all the dorsal vertebra 11 (4) and from the corresponding portion of the supraspinous ligament. Insertion — (PlateXI-XX) — Thesuperior fibers pass downward and out- ward and are inserted into the outer one- third of the posterior border of the clavicle varing greatly in the extent of its attachment, sometimes advancing as far as the middle of the clavicle, and may even become blended with the posterior edge of the Sterno-mastoid oroverlapingit. The middle fibers pass horizontally outward and are inserted into the inner margin of the acromion process and superior lip of the posterior border or crest of the spine of the scapula. The inferior fibers pass upward and outward, converging near the scapula, and ter- minate in a triangular aponeurosis which glides over a smooth surface at the inner extremity ofthe spine, to be inserted into a tubercle at the outer part of this smooth surface. Action". — When this muscle acts as a whole it lifts the shoulder ami ro- tates the lower angle of the scapula outward. The upper part raises the shoulder, the middle part draws it toward the spine, and the lower pan in pulling the scapula down and inward tilts the acromion process upward. If the shoulder girdle i> fixed, this muscle will draw the head backward. Nerve Supply. — Spina! accessory and third and fourth cervical. Blood Supply. — Princeps cervicis from occipital, superficial cervical ami posterior scapular from transversalis colli. LESSON IX. Scapula (Spade.)— (Plates XX-XXI.) — The scapula makes the posterior pari of the shoulder-girdle, h is situated on the upper posterior part of the thorax, between the second lib above and the seventh or eighth ribs below, articulating with the clavicle by its acromion process laterally. 'This bone is made up of several triangles; first, the main pari of the bone i> triangular with two angles above and one below; the one n< \t to the vertebral column is called the superior angle; the one n< ar< s1 the clavicle is called the anterior or external angle and articulates with the humerus; the one near the seventh or eighth rib is the inferior angle. Being a triangle it will have two surfaces and three bor- ders, as well as three angles. The anterior surface or venter is concave, deepest where the upper one-fourth joins the lower three-fourths; this is to give more room. {li WATOMY JX A NUTSHELL. for the Subscapulars muscle; this surface is also called the subscapular fossa- On this surface there arc several oblique lines running from the vertebral bor- der upward and outward, for the attachment of the fascia of the Subscapulars. The vertebral asped of this surface gives attachment to the Serratus magnus, which attachment is triangular above and below with a long narrow attach- ment between. The posterior surface, or dorsum, as a whole is convex. It is separated into two parts by a second triangle, which is called the spine of the scapula. The part above the spine is called the supraspinous fossa and is for the Supraspinatus muscle, and the part below is the infraspinous fossa and is I'm- the Infraspinatus muscle. 'This spine separates the upper one-fourth from the lower three-fourth- opposite the deepest part of the subscapular fossa. The superior border is the shortest and has a notch called the suprascapular notch, which i- about at the junction of the external one-third with the in- ternal two-thirds. This notch transmits the suprascapular nerve and is crossed by the transverse ligament of the scapula. The outer extremity of this border i- continued as the coracoid process which may be called a third triangle or rather pyramid; it gives attachment to three muscles, the short head of the Bi- ceps, Coraco-brachialis, and Pectoralis minor. The vertebral or posterior bor- der is the longest and i.- called, the base; it has three muscles attached to it, the Levator anguli scapulae, and the Rhomboideus minor and major. The axillary border is the thickest of the three and would be the longest of the borders if it were continued to meet the superior bonier. It has three muscles attached, i he Teres major and minor and the long head of the Triceps. Then with the axillary border continued to meet the superior border we have a triangle whose base is the vertebral border, whose altitude is the superior border and whose hypotenuse is the axillary border continued, and in this case would be the longest. There is a groove on the axillary border at the junction of the upper one-third with the lower two-thirds, for the dorsalis scapulae artery, and an oblique line separating the attachments of the Teres minor and major. The spine represented a- a triangle will have its base, the anterior border, attached io the dorsum of the scapula from a point about one-fourth the distance from the vertebral border to the glenoid fossa to within half an inch of the glenoid fossa; the portion between the spine and the glenoid fossa is the great scapular notch. The glenoid fossa is the deficiency between the superior and axillary borders, with which the head of the humerus articulates. The altitude is the external border, called by some author.- the base; the posterior border or crest repre- ■ the hypontenuse of the triangle. The crest, posterior border, or hypo- tenuse is continued outward a- t he acromion process of the scapula and is some- what triangular. Its upper lip gives attachment for the Trapezius and the lower lip to the Deltoid muscle. This process articulates with the clavicle and gives attachment for theligaments of that articulation, beside- to the coraco- acromial ligament, between the spine of the scapula and the vertebral border is a smooth surface for the Trapezius to glide over. Ossification. The scapula ha- seven centers of ossification, occasionally it has nine center-. One for the body of the scapula makes its appearance about the eighth week of intrauterine life; the one for the posterior border and also PLATE XIV | - OCCIPITO FRONTALIS. 2 - ORBICULARIS PALPEBRARUM. 3 - CORRUGATOR SUPERCIlll. 4- PYRAVUOALIS. 5 - COMPRESSOR NAR1S. 6 - COMPRESSOR NARIUM MINOR. 7 - DILATOR NARIS ANT. 8 -DILATOR NARIS POST 9 - DEPRESSOR ALA NAS 10- LEVATOR LABIISUP. ALfcQUE NASI. 31-STERNO CLEIOO MASTOID. 32-STERNO HYOID 33-OMO HYOIO. 34-THYRO HYOID. 35- STERNO THYROID 36- INF. CONSTRICTOR. 37- SCALENUS MEDIUS. SCALENUS POSTICUS LEVATOR ANGULI SCAPUL/t. SPLENIUS CAPITIS ET-COLLI. 41-TRAPEZIUS. 42-APONEUROSIS 43 -EXT. LATERAL LI G 44- HYOID BONE 4S-ZYG0MA. 46 INF.MAXILARV. 47 CLAVICLE. 48 PECTORALIS MAJOR. 49 DELTOID. II - LEVATOR LABII-SUP.PROP. 12-LEVATOP ANGUL I3-2YGOMAT1CUS MINOR. I4-2YG0MATICUS MAJOR. 15 -ORBICULARIS ORIS. 16- RISORIUS. 17 -BUCCINATOR. 18-MASSETER. 19- LEVATOR LABII INF. 20- DEPRESSOR LABII INF. 2I-0EPRESSOR ANCULI ORIS. 22- PLATYSMA-MYOIDES. 23-ATTRAHENS AUREM. 24- ATTOLENS AUREM. 25-RETRAHENS AUREM 26- DIGASTRIC. 27- STYLO HYOIO. 2S-MYL0-HY0ID. 29-HYO-GLOSSUS. 30- MID. CONSTRICTOR W* Muscles ok Face \ \i> 'I'.m vngli 17 i !■' N I I K is ANATOMY IX A NUTSHELL. the one for the inferior angle appear aboul the 15th year and join the body of the scapula the 25th year. There are two for the acromion process which ap- pear the l">tli year and join the body of the scapula the 20th year. The cor- acoid process has two centers, the one a1 the base of the process appearsatthe linh year and the other during the 1st year; they both join the body of the scap- ula the 25th year. Articulation. It articulates with the clavicle, (a description of which is given in Lesson Vll.) and with the humerus, making the shoulder-joint. This joint is a diarthro dial joint and belongs to the sub-class enarthrodial (ball-and- socket.) Plate XIII.) Blood supply of the shoulder-joint is ( 1 ) suprascapular from the thyroid axis, ('_) anterior circumflex, (3) posterior circumflex, and (4) subscapular. The last three are from the third part of the axillary artery. Nerve supply. (1) Suprascapular and (2) circumflex, both are branches formthe Brachial plexus. Ligaments. The true ligaments of the scapula are the transverse or supra- scapular which passes o\cr the suprascapular notch separating the suprascap- ular nerve from the suprascapular vessels above. The coraco-acromial lig- ament, which is triangular, is attached by its base to the entire outer border of the coracoid process, and by its apex to the tip of the acromion process. The ligaments of the shoulder- joint are (1) The capsular which is very loose and permits free movements of the joint. It is attached to the circum- ference of the glenoid cavity and to the anatomical neck of the humerus. This is thickesl above. It may have three openings in it. one for the long head of i he Biceps between the two tuberosities, another below the coracoid process, partially filled by the tendon of the Subscapulars and a third (which is not always present) for the tendon of the Infraspinatus muscle. These openings are for the communication between the synovial membranes of the joint and the bursa' beneath the tendons. A bursa is a sac or pouch. The long head of the Biceps is a ligament. On the inner and anterior as- pect of the capsular ligament are three gleno-humeral ligaments, thickened portions of the capsular ligament, (a) The upper one of these is called Flood's ligament, (b) the middle one is the interna] brachial of Schlemm and (e) the inferior is called the broad ligament of Schlemm. (2) The coraco-humeral or accessory ligament, is also a part of the capsular ligament; it is attached to the outer border of the base of the coracoid process above and to the ureal tuberosity of the humerus below. (3) The transverse ligament passes over the bicipital groove, holding down the long head of the Biceps. (4) The glenoid I i 'j a men i i- a continuation of the long head of the Biceps which makes the glenoid fossa deeper ;i 1 1 • 1 it join.- the long head of the Triceps below. It is narrow at tin' circumference, but broad at its base. It is a fibro-cartilaginous rim. A synovia! membrane lines these joints ami is reflected through the opening in the capsule and oxer the long head of the Biceps in the groove. PLATE XV MEDIAN NERVE. RACHIAL ARTERY Mk BSSIL.C .; BRACHIAUS AMICUS. SUPINATOR LONGUS External Oblique Muscle of Abdomen and Numerous other Structures. 19 50 ANATOMY IN A NUTSHELL LESSON X. Mus< i.i.-. There are seventeen muscles attached to the scapula. Three to the vertebral border- Three to the fossae — Levator anguli scapulae; Supraspinatus — in the supraspinous Rhomboideus minor; fossa-; Ethomboideus major. Infraspinatus — in the infraspinous TWO L'O A( ROMION PRO< ESS — fossa; Trapezius;. Subscapularis— in the subscapular Deltoid. fossa. Three to the axillary bori>eh Three to the coracoid process — Long head of the Triceps; Short head of Biceps; Teres minor: Coraco-brachialis ; Teres major. Pectoralis minor. Three irregularly arranged — Omo-hyoid, near transverse ligament; Serratus magnus, on the vertebral aspect of the venter; Latissimus dorsi, on the interim' angle, dorsal aspect. When all the muscles of the clavicle ami scapula are uiven. we have all the muscles in the upper extremity as far as the elbow, except the Brachialis an- ticus. (Plate XVI.) Pectoralis minor. — Description. — (Plate XVI.) — This is a thin. flat, tri- angular muscle situated at the upper part of the thorax beneath the Pectoralis major. Its upper border is separated from the clavicle by a triangular inter- val, broad internally, narrow externally, which is occupied by the costo-cor- acoid membrane. In this space is the first part of the axillary vessels ami nerves. Running parallel to the lower border of the muscle is the long thoracic artery. Origin. —Upper margin ami outer surface of the third, fourth and fifth ribs near cartilages, and aponeurosis covering the Intercostal muscles. Insertion. The fillers converge and form a flat tendon which is inserted into the inner horde!' and upper surface of the coracoid process of the scapula. (Plate XXI.) Action.- To depress the point of the shoulder and aids in forced inspira- tion. Nerve Si pply. -Internal anterior thoracic, the filaments being derived from the eighth cervical and first dorsal nerves. Blood Supply is from the internal mammary, intercostals, superior thor- acic, acromial thoracic, and long thoracic. Triceps. Description. (Plate XVIII.)— The Triceps is situated at the hack of the arm. extending the entire length of the posterior surface of the humerus. It is of large size and divided above into three parts, hence its name. The-.- portions have been named (1) the middle, scapular, or long head; (2) PLATE XVI OF BICEPS ANO COMCO BRtCMIA CUTANEOUS NERV. ^PRONATOR RAOM TERES Internal Oblique Muscle of Abdome 51 OMEN AND Numerous Other Structures 52 ANATOMY IN A NUTSHELL. the external, or long humeral; and (3) the internal, or short humeral head. The common tendon of the Triceps commences about the middle of the back part of the muscle; it consists of two aponeurotic lamina', one of which is sub- cutaneous and covers the posterior surface of the muscle for the lower half of it- extenl : the other is more deeply seated in the substance of the muscle. After receiving the attachment of the muscular fibers they join together above the elbow, forming the tendon of Insertion. A small bursa is situated beneath the tendon. Origin.- The middle or long head arises from a rough triangular depres- sion on the scapula, just below the glenoid cavity, being blended at its upper part with the capsular ligament. (Plate XXI.) The external head arises from the posterior surface of the shaft of humerus, between the insertion of the Teres minor and the upper pari of the musculo- spiral groove; also from the external border of the humerus and external in- termuscular septum. (Plate XXII.) The internal head arises from the posterior surface of shaft of humerus, below the groove for the musculo-spiral nerve, extending from the insertionof the Teres major to within an inch of the trochlear surface; also from the internal borderof the humerus andfrom the back of the whole length ofthe internal and lower part of the external intermuscular septum. (Plate XXII.) Insertion.- Upper end of olecranon process of ulna, a band of fibers being continued downward to blend with the deep fascia of forearm. (Plate XXIV.) Action- Extensor of forearm. Nerve Supply- Seventh and eighth cervical through musculo-spiral. Blood Si pply — Brachial and superior profunda. Latissimus dorsi. — Description. — (Plate XYIII.) — This is a broad, flat muscle which rovers the lumbar and lower half of the dorsal regions and is gradually contracted into a narrow fasciculus which passes upward across the interior angle of the scapula, and occasionally receives a few fibers from it. It belongs to the first layer of muscles in the back. The muscle then curves around the lower border of the Teres major, and is twisted upon itself. It terminates in a short, quadrilateral tendon, about three inches in length, which, as it passes in front of the tendon of the Teres major becomes united with it. the surfaces of the two being separated by a bursa; another bursa is sometimes interposed between the muscle and the inferior angle of the scapula. At the insertion of this muscle an expansion is given off to the deep fascia of the arm. There IS usually a fibrous slip which passes from the lower border of the tendon of the Latissimus dorsi. near its insertion, to the long head of die Triceps. This is occasionally muscular and is the representa- tive of the Dorso-epitrochlearis muscle of apes. Origin. From the spinous processes of die six inferior dorsal vertebra?, and from the posterior layer of the lumbar fascia, by which it is attached to the spines of die lumbar ami sacral vertebrae, and to the supraspinous ligament, also from the external lip of the cresl of the ilium behind theorigin of the ex- ternal oblique, and bv fleshy digitations from the three or four lower ribs, which PLATE XVI] 5TH CElWlCAL N 6TH CERVICAL N. 7TH CERVICAL N ACROM'AL THORACIC. L R CORO. ANT. CIRCUMFLEX. -POST. CIRCUMFLEX. SUPERIOR PROFUNDA. DIGITAL BRANCHES. B DCPSALIS Transversalis Muscle op Abdomen \\i> Numerous Otheb Structures 53 54 ANATOMY IN A NUTSHELL. are interposed between similar processes of the External oblique muscle. The upper fibers pass longitudinally outward, the middle fibers obliquely upward, and ihc lower fibers vertically upward, converging at the inferior angle of the scapula. ( Plate XX.) Insertion.- Into the bottom of the bicipital groove of the humerus, its insertion extending higherthan that of the Pectoralis major. (Plate XXIII.) A' riON.- Draws the arm down and hack, raises the lower ribs, and draws the trunk forward. Nerve Supply.- Middle or long subscapular. Blood Supply. Subscapular artery. Serratus magnus. — Description. — (Plates XV-XVI1I.) — This is a thin irreg- ularly quadrilateral muscle situated between the ribs and scapula at the upper and lateral part of the chest. It is partly covered in front by the Pectoral muscles, behind by the Subscapulars. The axillary vessels and nerves lie upon its upper part, while its deep surface rests upon the ribs and intercostal muscles. Origin.- By nine digitations or slips from the outer surface and upper border of the eight upper ribs (the second rib giving origin to two slips,) and from the aponeurosis covering the corresponding intercostal muscles. The fiber- pass backward closely applying the chest wall and the vertebral border of the scapula. The lower four slips interdigitate at their origin with the upper five slips of the External oblique muscle of the abdomen. Insertion. — The slips from the first and the higher of the two from the second rib. converge to be inserted into the triangular area on the ventral aspect of the superior angle of the scapula. The next two slips spread out to form a thin triangular -heath, the base of which is directed backward and is in- serted into nearly the whole length of the ventral aspect of the vertebral border of the scapula. The lower slips converge as they pass backward from the ribs and form a fan-shaped structure, the apex of which is inserted, partly by mus- cular and partly by tendinous fibers, into the triangular impression on the ven- tral aspect of the inferior angle. (Plate XXI.) \< tion. — A pushing muscle. It also raises the point of the shoulder. Xi:i;\ i. SUPPLY. Posterior thoracic which is derived from the fifth, sixth, and seventh cervical nerves. Blood Supply, [ntercostals, long and short thoracic LESSON XI. Levator angull scapulae. — Description.— (1'late XVIII.) — This muscle lies jusl beneath the Trapezius at the back part and side of the neck. Origin. By tendinous -lips from the transverse process of the atlas, and from the posterior tubercle- of the transverse processes of the second, third, and fourth cervical vertebras. These slips become fleshy and unite so as to form a flat muscle which passes downward and backward to its insertion. Insertion. Into the posterior border of the scapula between the superior ANATOMY IN A NUTSHELL. 55 angle and the triangular smooth surface at the root of the spine. (Plate XX.) Action. — To raise the superior angle of the scapula. XeryeSupply. — Third and fourth cervical, and frequently by a branch from the nerve to the Rhomboidei. Blood Supply. — Vertebral, ascending cervical, superficial cervical, and posterior scapular. Rhomboideus minor. — (Plate XVIII.) — Origin. — Ligamentum nucha 1 and spinous processes of the seventh cervical and first dorsal vertebrae. Insertion. — Smooth surface at root of spine of scapula. (Plate XX.) Action. — To draw the scapula backward and upward. Nerve Supply. — Fifth cervical. Blood Supply. — Posterior scapular. Rhomboideus major. — (Plate XVIII.) — Description. — This muscle is situated immediately below the minor, the adjacent margins of the two being occasionally united. Origin. — Spinous processes of the four or five upper dorsal vertebrae and the supra-spinous ligament. Insertion. — Into a narrow tendinous arch attached above to the lower part of the triangular surface at the root of the spine, and below to the inferior angle, the arch being connected to the border of the scapula by a thin mem- brane. When the arch extends but a short distance, as it occasionally does, the muscular fibers are inserted into the scapula itself. (Plate XX.) Action. — To draw scapula backward and upward. Nerve Supply. — The fifth cervical. Blood Supply. — Posterior scapular. Supraspinatus. — Description. — (Plates XXYIII-XY111.) — The supra- spinatus muscle occupies the whole of the supraspinous fossa. The fibers converge to a tendon which pas>e> across the upper part of the capsular liga- ment of the shoulder joint.. to which it is intimately adherent. Origin. — (1) Internal two-thirds of supraspinous fossa. (2) Strong fascia covering surface of fossa. (Plate XX.) Insertion. — Upper facet of greater tuberosity of humerus. (Plate XXIII.) A< tion. — Raises arm and supports tuberosity of humerus. Xf.rve Supply. — Fifth and sixth cervical through the suprascapular nerve. Blood Supply. — Suprascapular artery. Infraspinatus. — Description. — (Plates XXVII1-XVIII.) This is a thick, triangular muscle which occupies the chief part of the infraspinous fossa. The fibers converge to a tendon which glides over the external border of the spine of the scapula and passes over the posterior part of t he capsular ligamenl of the shoulder-joint. This tendon is occasionally separated from the -pine of the scapula by a synovial bursa which communicates with the synovial cavity of the shoulder-joint. Origin. — (1) Internal two-thirds of infraspinous fossa; (2) tendinous fibers from ridges on its surface; (3) strong fascia covering it externally ami separating it from the Teres major and minor. (Plate \ \ Insertion.— Middle facet of greater tuberosity of humerus. (Plate XXII.) 56 ANAloMY IX A NUTSHELL. A.ction.- -Rotates head of humerus outward. Nerve Slpply. — Fifth and Sixth cervical through the suprascapular nerve. Blood Supply. Suprascapular artery. Subscapulars. Description. — The subscapular fascia is a thin mem- brane attached to the entire circu inference of the subscapular fossa, and afford- in-- attachment by its inner surface to some of the fibers of the Subscapularis muscle. The Subscapularis is a large triangular muscle which fills up the sub- scapular fossa. The muscle terminates in a tendon which is in close contact with the anterior part of the capsular Ligament of the shoulder- joint and glides over a large bursa, which separates it from the base of the coracoid process. This bursa communicates with the cavity of the joint by an aperature in the capsular ligament. It- anterior surface forms a considerable part of the pos- terior wall of the axilla, and its lower border is contiguous with the Teres major and Latissimus dorsi muscles. Origin. — (Plate XXI.) — From the inner two-thirds of the subscapular fossa, with the exception of a narrow margin along the posterior border, and the surface- at the superior and inferior angles; also from the lower two-thirds of the groove on the axillary border of the bone. Some fibers arise from tendinous lamina', which intersect the muscle, and are attached to ridges on the bone, and others form an aponeurosis which separates the muscle from the Teres major and the long head of the Triceps. Insertion. — Lesser tuberosity of the humerus. (Plate XXIII.) A.CTION. — Rotates head of humerus inward. Nerve Supply. — Upper and lower subscapular (first and third.) Blood Supply. Subscapular artery. Teres minor.— (Plates XXVIII-XVIII.) — Description. — This is a narrow, elongated muscle lying between the Infraspinatus and Teres major, being sep- arated from the latter anteriority by the long head of the Triceps. Origin.— Upper two-thirds of dorsal surface of axillary border of the scapula and from the two aponeurotic laminae, one of which separates it from the Infraspinatus, the other from the Teres major. (Plate XX.) Insertion.- bower facet on greater tuberosity of humerus and bone be- low. (Plate XXII.) A.CTION. Rotates head of humerus outward. Xi:i;\i.Si pply.— Fifth cervical through the circumflex. Blood Supply. -Infrascapular from dorsalis scapulae, circumflex arteries. LESSON XII. Teres major. Description.— (Plates XXVIII-XVIII.)— This is a thick, but somewhat flattened muscle, lying immediately below the Teres minor. Its fibers are directed upward and outward and terminate in a tendon about two inches in length. This tendon, at its insertion, lies behind that of the Latissi- mus dorsi, from which it is separated by a synovial bursa, the two tendons, however, being united along their borders for a short distance. The axillary vessels and the brachial plexus of nerves lie upon its anterior surface. Its PLATE XVIII ;Tsf SERRATUS MAGNUS NTERNAL OBLIQUE GREAT SACRO- SCIATIC LIG Muscles of Back -Superficial Layers 57 5S ANATOMY IN A NUTSHELL. lower border tonus, in conjunction with the Latissimus dorsi, part of the pos- terior boundary of the axilla. Origin. From the oval surface on the dorsal aspect of the inferior angle of the scapula, and from the fibrous septa interposed between it and the Teres minor and Infraspinatus. (Plate XX.) Insertion, [nner bicipital ridge of humerus. (Plate XXIII.) A.CTION. Assists Lattissimus dorsi in drawing humerus downward and backward. Nerve Supply. — Fifth and sixth cervical through the lower subscapular. Blood Si pply. Subscapular artery. Coraco-brachialis. Description. — This is the smallest of the three mus- cle- in the ant. hum< ral region, and is situated at the upper and inner part of the arm. Its fibers pass downward, backward, and a little outward, and ter- minate in a Hat tendon. This muscle is perforated l>y the musculo-cutaneous nerve and its inner border forms a guide to the position of the brachial artery in tying this vessel in the upper part of its course. The brachial vessels and median nerve lie upon its anterior surface at its insertion. (Plate XVI.) Origin. Apex of coracoid process in common with short head of Biceps. (Plate XX 1.) INSERTION.— Ridge on inner side of shaft of humerus about its middle, between the origins of the Triceps and Brachialis anticus. (Plate XXIII.) Action. — Draws the humerus forward and inward and assits in elevating the same. Nerve Supply.— Seventh cervical through the Musculo-cutaneous. Blood Supply. — Brachial, muscular branches. Biceps. — Description. — (Plates III-XY-XYI.) — The Biceps is a long fusiform muscle, occupying the whole of the anterior surface of the arm, and divided above into two portions or heads, from which circumstance it has re- ceived its name. Each head is tendinous but is succeeded by an elongated muscular belly, and the two bellies, although closely applied to each other, may readily be separated until within about three inches of the elbow-joint. Here they end in a flattened tendon, a synovial bursa being interposed between it and the front of the tuberosity of the radius. As this tendon approaches the radius it become.- twisted U] itself so that its anterior surface becomes ex- ternal. ( >pposite the bend of the elbow it gives off. from its inner side, a broad aponeurosis, the bicipital fascia (semilunar fascia,) which passes obliquely downward and is continuous with the deep fascia of the forearm. The Biceps muscle occasionally has a third head which may consist of two slips passing down, one in front of the other behind the brachial artery, concealing this ves- sel in the lower half of the arm. The inner border of the Biceps froms a guide to the position of the artery in tying that vessel in the middle of the arm. ORIGIN.— (Plates XX-XXI.) The long head arises from the upper mar- gin of the glenoid cavity and is continuous with the glenoid ligament. The tendon arches over the head of the humerus, being enclosed in a special sheath of synovial membrane, passes through an opening in the capsular ligament and ANATOMY IX A NUTSHELL. 59 descends in the bicipital groove, in which it is retained by a fibrous prolonga- tion from the tendon of the Pectoralis major. The short head arises from the apex of the coracoid process in common with the Coraco-brachialis. Insertion. — Back of tuberosity of radius; fascia of forearm. (Plate XXV.) Action. — Flexes and supinates forearm, and tenses fascia. Nerve Supply. — Fifth and sixth cervical through the musculo-cutaneous. Blood Supply. — Brachial artery, muscular branches. Omo-hyoid — Description. — This muscle passes from near the suprascapular notch of the scapula to the hyoid bone, thus dividing the anterior and posterior triangles of the neck into two triangles each. (Plate XIV.) Origin. — From the superior border of the scapula, internal to the supra- scapular notch. (Plate XX.) PLATE XIX. MIDDLE CONSTRICTOR OF PHARYNX. LESSER CORNU. GREATER CORNU \ f/ 1/1 'If HYO-GLOSSUS. STYLO- HYOID. THYRO-HYOID. GENIO-HYOID MYLO-HYOID STERNO-HYOID. The Hyoid Bone Insertion. — Into the lower borderof the bgdy of hyoid bone. (Plate XIX.) Blood Supply. — Lingual and superior thyroid from the external carotid, and the inferior thyroid from the thyroid axis. Action. — Depresses hyoid bone. Nerve Supply. — Branches from the loop betweenthe cervical plexus and the 12th cranial nerve. Blood Supply of Scapula. — The glenoid fossa, supraspinous fossa, infra- Bpinous fossa and the spine all get the suprascapular artery from the thyroid axis. The infraspinous fossa, in addition, receives the dorsails scapula? which is a branch of the subscapular, from the third portion of the axillary. 1 he acromion process is supplied by branches from the arcomial thoracic artery. The venter receives the subscapular, and a subscapular branch from the suprascapular; andthe vertebral border receives the posterior scapularfrom the suprascapular. 60 ANATOMY IN A NUTSHELL. LESSON XIII. Humerus.- (Plates XXII-XXIII.) — The humerus is the longest bone in the upper extremity, and is the only one in the arm. hs upper extremity con- i n head, neck ami two tuberosities, a greater ami lesser. The head is directed inward, upward and backward: on this account one can lift his arm higher when broughl a little forward than when at right angles to the body; the head i- about a hemisphere. The contracted pari below the head is called the anatomical neck; it is rarely broken, while the part below the tuberosity is called the surgical neck on accounl of it being the seat of fracture. Between the two neck- are the tuberosities, the greater on the outer aspect of the bone, separated from the lesser by the bicipital groove which is for the long head of the Biceps. The greater tuberosity has three facets, the upper one for the Supraspin- atus muscle, the middle one tor the Infraspinatus muscle, and the lowerone for the Teres minor. The lesser tuberosity is in the form of a cone and has at- tached to it the Subscapulars. The bicipital groove extends about one-fourth the way down the bone; its outer ridge is also anterior and is for the attach- menl of the Pectoralis major: the inner ridge is posterior and is for the attach- ment of tin' Too- major; the groove has the Latissimus dorsi attached. The diaphysis is somewhat triangular on cross section and has three surfaces and three borders. The anterior border extends from the front of the great tuberosity to the coronoid depression below, separating the external from the internal surface.-; it- upper part is the external bicipital ridge for the insertion of the Pectoralis major muscle; the lower part is covered by the Brachialis anticus. The ex- ternal border extends from the posterior part of the great tuberosity to the ex- l condyle, and separate- the external and posterior surfaces; its lower part i- the supracondylar ridge. From above downward it has attached the lower pari of the Teres minor on the posterior aspect, the middle or long humeral head of the Tricep.- separated from the short head of the same by the musculo- spiral groove which transmits the musculo-spiral nerve and the superior pro- funda artery. The external supracondylar ridge has attached the external intermuscular septum which gives attachment to five muscles, viz., Deltoid, Brachialis anticus, Triceps, Supinator longus, and Extensor carpi radialis longior. The internal border extends from the inner part of the lesser tuber- osity to the internal condyle, separating the internal and posterior surfaces. From above downward it has the Teres major, and Coraco-brachialis. |{el<>\\ the Insertion of the Coraco-brachialis is the canal for the nutrient artery, which run- toward- the distal extremity of the bone (Page 19, Lesson 3econd canal i- often presenl on the posterior surface; its artery comes from the superior profunda. The internal intermuscular septum is attached to the internal supracondylar ridge and has attached to it three muscles, viz., Tricep-. Brachialis anticus, Coraco-brachialis, and occasionally a fourth mus- cle. Pronator radii teres. The external surface gives attachment to the Del- toid about two-fifth- or one-half the way down the hone, andbelow this to the ANATOMY IN A NUTSHELL. 61 external part of the Brachialis anticus. The internal surface gives attachment to the Coraco-brachialis opposite the Deltoid, and below this to the internal part of the Brachialis anticus. The posterior surface has the two lower heads of the Triceps and the mus- culo-spiral groove separating them. The lower part of the hone articulates with the radius and ulna: the part which articulates with the radius is called the radial head or capitellum and is on a higher level than the part which artic- ulates with the ulna which is called the trochlear surface. These two articula- ing surfaces are separated by a ridge. Above the radial head on the external surface is the radial depression for the head of the radius to fit into when the forearm is flexed; above the trochlear surface on the internal surface is the coronoid depression for the coronoid process of the ulna; above the trochlear surface on the posterior surface is the olecranon depression for the olecranon process of the ulna. The internal condyle is more prominent than the external one. and is on a lower level. It gives attachment to the Pronator radii teres, the common tendon for some of the flexors of the forearm, and the internal lateral ligament. The external condyle is less prominent than the internal one and gives attach- ment to the common tendon for the attachment of some of the extensors of the forearm as well as the Supinator longus and external lateral ligament. Ossification. — The ossification is from seven centers, occasionally eight. One for the shaft appears about the eighth week of intrauterine life. The one for the head the first year, one for the great tuberosity the third year; occasion- al]}' one for the lesser tuberosity. These three coalesce at the 17th year and join the shaft about the 20th year. At the distal extremity there are four centers of ossification; one for the capitellum appears at the 3rd year; one for the in- ternal condyle at the 5th year; one for the trochlear at the 10th year; one for the external condyle at the 14th year. The nucleus of the internal condyle joins the shaft in the 18th year, while i lie other three nuclei coalesce and join the shaft the 17th year. Articulation. — It articulates with the scapula, radius, and ulna. Its artic- ulation with the scapula makes the shoulder-joint, a description of which is given in Lesson IX; and its articulation with the radius and ulna makes the elbow-joint. Elbow-joint.— (Plates XXXVIII-XXXIX.)— This is a movable joint (dia- throsis) and belongs to the sub-class ginglymus (hinge-joint.) The part be- tween the trochlear surface of the humerus and ihe greal sigmoid cavity of the ulna is a ginglymus joint, but the part between the capitellum of the humerus and the head of ihe radius is an arthrodial join! (gliding.) The pari between the lesser cavity of the ulna ami the head of ihe radius is a trochoides. The anterior ligament is continuous with the internal and external lateral ligaments covering the joint in froni and being itself covered by the Brachialis amicus; above, it is attached to the humerus above the coronoid and radial fossae and in front of the internal condyle; below, it is attached to the anterior surface of the coronoid process of the ulna and the orbicular ligamenl and the neck of the radius. 62 ANATOMY IX A NUTSHELL. The internal lateral ligament is continuous with the anterior and posterior ligaments; it is triangular in shape, with the apex above, attached to the in- ternal condyle of the humerus; the anterior angle below is attached to the inner edge <>t' the coronoid process. Its posterior angle below is attached to the inner edge of the olecranon process. There are filters running from the apex to eaeh inferior angle, also fibers connecting the inferior angles. The Flexor sublimits digitorum is attached to this ligament. The posterior ligament is continuous with the two lateral ligaments; it is attached above to the margin of the olecranon fossa and below to the ole- cranon process ami orbicular ligament. The external lateral ligament is attached above to the depression below the external condyle of the humerus; below, it is attached to the orbicular liga- ment, head of the radius and the outer side of the ulna: there are two muscles attached to this ligament, the Extensor carpi radialis brevior and Supinator brevis. These four ligaments make a capsular ligament. Synovial mem- brane lines that portion of the ligaments and bones which make the joint and sends a part into the superior radio-ulnar articulation. The ligamentous muscles of the elbow-joint are the Biceps, Triceps. Bra- chials anticus and all the muscles in the forearm except, the Flexor profundus digitorum, Flexor longus pollicis. Pronator quadratus and Extensor ossis met- acarpi pollicis. Extensor brevis pollicis. Extensor longus pollicis and Extensor indicis. Nerve supply.— Musculo-spiral, musculo-cutaneous, median and ulnar nerve-. Blood supply. — Anterior and posterior ulnar recurrent, radial recurrent. interosseous recurrent, anastomatica magna, superior profunda and inferior profunda. LESSON XIV. ARTERIES. Axillary artery. The subclavian artery passes under the clavicle and over the firsl rib, from the lower surface of which it is called the Axillary artery until it leaves the axillary space at the lower border of the tendon of the Teres major, then it take.- the name Brachial artery. This artery is crossed by the Pector- alis minor muscle which divides the artery into three (tarts; the pari above it is called the firsl pari, the part behind it is called the second part ami the part below it is called the third part (Plate XVI.) Branches. This artery has seven branches, (Plate XVII) two from the first portion, the superior thoracic and the acromial thoracic; two from the sec- ond portion, the alar thoracic ami the long thoracic or external mammary, and three from the third portion, the subscapular, anterior circumflex, and poster- ior circumflex. The superior thoracic arises so close to the upper border of the axillary artery that it is sometimes given as a branch of the subclavian. It may come from the acromial thoracic axis. It i> between the Pectoralis major and minor. ANATOMY IN A NUTSHELL. 63 along the upper border of the latter, supplying both these muscles, the Ser- ratus magnus and the chest wall. It anastomoses with the internal mammary, intercostal arteries and the long thoracic. It helps to supply the sterno-clav- icnlar joint. The acromial thoracic arises just above the Pectoralis minor from the front CORACO-ACROMIAl LIG'T. PLATE XX 0M0-HY0 D AND TRANSVERSE LIGAMENT.(O) SUP. ANGLE. LEVATOR ANGUU SCAPULAE. (I) SUPRASPINATUS(O). Q NECK NOTCH GLENOID FOSSA AND HEAD CAPSULAR LIGAMENT. GROOVE FOR DORSAL ARTERY OF THE SCAPULA. TERES MINOR.(O) RHOMBOIDEUS MAJOR.(I). TERES MAJOR.(O) lattissimus dorsi.(o) — ^^t^j^' inf. angle. The Left Scapula — Posterior Surface, or Dorsum pari of the artery. It has an axis and gives off three branches. (1) humeral or descending branch which passes down bet ween the Pectoralis major and Deltoid with the cephalic vein, supplying both these muscles; it anastomoses with the anterior and posterior circumflex arteries. (2) the acromial branch which supplies the Deltoid muscle and the acromio-clavicular joint, anastom- osing with the anterior and posterior circumflex and suprascapular arteries 1.1 ANATOMY IX A NUTSHELL. making the acromial rete. [f we substitute in this rete or net-work of arter- ies, thisbranch for the subscapular artery we will have the blood supply to the shoulder-joint. (3) The thoracic branches supply the Pectoral muscles and the Serratus magnus, and anastomoses with the intercostal arteries both from the aorta and the internal mammary. There are two or three of these branches. I \ clavicular branch may pass to the Subclavius muscle. PLATE XX] CONOID LIG'T. TRAPEZOID LIGT BICEPS AND CORACOBRACHIALIS RIOCES SERRATUS MAGNUS. Tin I.i l i Si \n i.\ Anterior Surface, or Venter The alar thoracic is no1 a constanl branch; ii supplies the glands and half of the axillary space. V> hen ii is absenl its place is filled by a branch from on.' of the other thoracic arteries. The anterior or ion- thoracic, oi external mammary passes along the lower border of the Pectoralis minor muscle to about the sixth intercostal space, sup- plying the Pectoral and Serratus magnus muscles, and the mammary gland. h anastomoses with the intercostal, internal mammary, and superior thoracic ANATOMY IN A NUTSHELL. 65 arteries. There is often an accessory external mammary which is behind the main branch. The anterior circumflex arises from the outer side of the axillary artery, passing between the Coraco-brachialis and the short head of the Biceps around the anatomical neck of the humerus to the under surf ace of the Deltoid, which it supplies. A branch from this artery passes up the bicipital groove, with the longhead of the Biceps, to supply the shoulder-joint;, [ts anastomoses with the posterior circumflex and acromial thoracic. An occasional cut mucous branch is often given to the floor of the axilla. The posterior circumflex comes from the posterior part of the artery, below the subscapular. It passes through the quadrilateral space which is bounded above by the Teres minor, below by the Teres major, on the inner side by the long head of the Triceps and on the other side by the humerus; its veins and the circumflex nerve go with it. It anastomoses with the anterior circumflex, subscapular, suprascapular, acromial thoracic, and a branch from the superior profunda. This artery maybe a branch from the brachial, superior profunda, or may come from a common trunk with the subscapular. It goes to the Del- toid, long head of the Triceps, Teres minor, shoulder-joint and head of the humerus. The subscapular artery runs along the lower border of the Subscapularis muscle with the subscapular nerve to the inferior angle of the scapula, where it anastomoses with the posterior scapular and a terminal branch of the trans- versalis colli; it also anatomoses with the intercostal and long thoracic arter- ies. It gives branches to the glands and areolar tissue of the axilla, to the Teres major, Latissimus dorsi. Subscapular which passes through the triangu- lar space bounded above and internally by the Subscapularis, below by the Teres major, and externally by the long head of the Triceps. It anastomoses with the suprascapular and posterior scapular arteries. It gives branches to the Subscapularis and Infraspinatus muscles. Relations. — First Portion of Axillary Artery. In Front. — (1) Pectoralis major, (2) Costo-coracoid membrane, (3) Ex- ternal anterior thoracic nerve, (4) Acromio-thoracic vein, (5) Cephalic vein. Behind. — (1) First intercostal space, (2) First intercostal muscle, (3) Second and third serrations of Serratus magnus. (4) Posterior thoracic nerve, and (5) Internal anterior thoracic nerve. Outer Side. — Brachial plexus. [nnee Side. — Axillary vein. Second Portion of Axillary Artery. Ix Front. — (1) Pectoralis major. (2) Pectoralis minor. BEHIND. — (1) Subscapularis, (2) Posterior cord of plexus. Outer Side. Outer cord of plexus. Ixwkk Side.— (1) Axillary vein, (2) Inner cord of plexus, and (3) Inter- nal anterior thoracic nerve. Third Portion of Axillary Artery. Ix Front. — (1) Integument and fascia. (2) Pectoralis major, (•">") Inner head of median nerve, and (4) Internal cutaneous nerve. 66 ANATOMY IN A NUTSHELL Behind. — (1) Subscapular^, (2) Tendon of Latissimus dorsi, (3) Tendon of Teres major, (4; Musculo-spiral nerve, and (5) Circumflex nerve. Outer Side.— (1) Coraco-brachialis, (2) Median nerve. (3) Musculo- cutaneous nerve. Inner Side.— (1) Tina nerve. (2) Lesser internal cutaneous nerve, and (3) Axillary veins. LESSON XV. Brachial artery. — Plato XYI-XYII.) — The brachial artery extend- from the lower border of the Teres major, above which it is called Axillary, to about one and a half inches below the elbow where it divides into the Radial and Ulnar. It passes along the inner and fore part of the arm. being accompanied by venae comites and is comparatively superficial. It has the following rela- tions: 1\ Front. — (1) Integument and fascia. (2) Bicipital fascia. (3) Median basilic vein, (4) Median nerve, and (5) Overlapped by Coraco-brachialis and Biceps. Behind. — (1) Triceps, (2) Musculo-spiral nerve. (3) Superior profunda artery, (4) Coraco-brachialis (insertion), and (5) Brachialis anticus. Outer Side. — (1) Vena comes. (2) Median nerve (above), (3) Coraco- brachial'^, and (4) Biceps. [nner Side. — (1) Vena come-. (2) Internal cutaneous nerve. (3) Ulnar nerve, I b Median nerve (below), and (5) Basilic vein (upper half). [ts branches are the superior profunda, inferior profunda, nutrient, mus- cular, anastomotica magna, and occasionally the vasa aberrantia. The superior profunda, the largest branch, arises from the inner and back pari of the artery opposite the lower border of the Teres major. It winds back- ward and outward with the musculo-spiral nerve in the musculo-spiral groove. It gives off an anterior branch which pierces the external intermuscular septum to anastomose with the radial recurrent. It continues behind the external intermuscular septum with a branch of the musculo-spiral nerve to the An- coneus, where it anastomoses with the anastomotica magna and interosseous re- current. It supplies the Triceps and Anconeus. The anterior branch which it gives off passes to the front of the elbow in the groove between the Supinator longus ami the Brachialis amicus to the front of the external condyle. It gives branches to the Deltoid, Brachialis anticus, and Triceps, and a branch to anas- tomose with the circumflex artery. The artery continues as the posterior branch. The inferior profunda may come from the superior profunda, but generally comes from the brachial opposite the insertion of the Coraco-brachialis. It accompanies the ulnar nerve to the back of the internal condyle, having pierced the internal intermuscular septum from before backward. It anastomoses with tin- anastomotica magna ami posterior ulnar recurrent. lt> anterior branch extends to the front of the internal condyle to anastomose with the anastomo- tica magna and anterior ulnar recurrent. PLATE XXII. CAPSULAR LIGAMENT INFRASPINATUS (I). TERES MINOR (I) (RICEPS (EXT. HEAO) (0) MUSCULO-SPIRAL GROOVE ANCONEUS (0). EXTERNAL CONDYLE. EXT. LATERAL LIGAMENT TRICEPS (INT. HEAD).(OJ. .HEAO. CAPSULAR LIGAMENT. OLECRANON FOSSA. -FLEXOR CARPI ULNARIS (0) INT. CONDYLE. GROOVE FOR ULNAR NERVE. The Left Bumerus — Posterior \ uw 67 PLATE XXIII. HEAD. SUBSCAPULAR (I) CAPSULAR LIGAMENT LESSER TUBEROSITY.*!.) LATISSIMUSDORSI TERES MAJOR (I) CORACOBRACHIAL^ (I) IBRACHIALIS ANTICUS (I) NUTRIENT FORAMEN fSUPRACONDYLOID PROC PRONATOR RADII TERES (0). FLEXOR CARPI RADIALIS (0) PALMARIS LONGUS (0) FLEXOR SUBLIMIS DIGITORUM (0) r LEXOR CARPI UNARIS (01 INT. CONDYLE. INT. LATERAL LIGAMENT CAPSULAR LIGAMENT SUPRASPINOUS (I). GREATER TUBEROSITY. TRANSVERSE HUMERAL LIGAMENT. BICIPITAL UI.OOVE. PECTORALIS MAJOR (I). ROUGH SURFACE FOR DELTOID. SUPINATOR LONGUS. (0). EXT. CONDYLAR RIOGE EXTENSOR CARPI RADIALIS LONGIOR (0) CORONOiD rossA RADIAL DEPRFSSION EXTtNSOR CARPI RADIALIS BREVIOR (0). EXTENSOR COMMUNIS DIGITORUM (U) EXTENSOR MINIMI OlGlTI (0). EXTENSOR CARPI ULNARIS (0). SUPINATOR 8REVIS (0) EXTERNAL CONDYLE. EXT. LAItHAL LIGAMENT. The Left Hi merus Anterior View 68 ANATOMY IN A NUTSHELL. 69 The nutrient artery comes from the brachial about the middle of the fore- arm; it pierces the tendon of the Coraco-brachialis to enter the nutrient canal which is below the insertion of the Coraco-brachialis; It is directed towards the elbow (page 19. Lesson 1.) A branch from the musculo-cutaneous nerve enters the bone with this artery. The artery may be a branch of the superior profunda. The muscular branches are three or four in number and arise from the outer >ide of the artery and supply the Bicep-. Coraco-brachialis, and Brachialis amicus. The same muscles are supplied by the musculo-cutaneous nerve. The anastomotica magna arises two inches above the elbow-joint, passing inward over the Brachialis anticus to pierce the internal intermuscular septum to pass to the back of the internal and external condyles. It anastomoses in front of the internal condyle with a branch from the inferior profunda and an- terior ulnar recurrent. It anastomoses behind the internal condyle with the sterior branch of the inferior profunda and the posterior ulnar recurrent. It anastomoses behind the external condyle with the posterior branch of the superior profunda and the interosseous recurrent. The vasa aberrantia are collateral branches which connect the brachial or axillary artery with the arteries of the forearm, generally with the radial. Forearm. — There are twenty muscles in the forearm, eight in the anterior (radio-ulnar) region arranged in four layers: in the first layer there are four — I Plate XXIX) — The Pronator radii teres. Flexor carpi radialis, Palmaris longus, and Flexor carpi ulnaris. The first three of these are supplied by the median nerve, which conies from the outer and inner cords of the brachial plexus. The Flexor carpi ulnaris is supplied by the ulnar nerve, which comes from the inner cord. (Plate VI.) In the second layer there is one muscle, the Flexor sublimis digitorum. (Plate XXX.) It is supplied by the median nerve. In the third layer there are two muscles. (Plate XXXI.) Flexor longus pollicis and the Flexor profundus digitorum. The first is supplied by the anterior interosseous,, which is a branch of the median; the second one by the anterior interosseous and the ulnar. In the fourth layer there is one muscle, the Pronator quadratus, which is supplied by the anterior interosseous nerve. In the radial region there are threemuscles (Plate XXXII) Brachio-radialis (Supinator longus,) Extensor carpi radialis longior, and the Extensor carpi radialis brevior. The first two are supplied by the musculo-spiral nerve: the last one by theposterior interosseous aervewhich Lsa branch of the musculo- spiral nerve. In the posterior radio-ulnar region there are nine muscles, Plate XXXII,) four in the superficial layer andfive in the deep layer. Thefour in the superficial layer are the Extensor communis digitorum, Extensor minimi digiti, Extensor carpi ulnaris, and Anconeus. The fust three are supplied by the posterior in- terosseous nerve; theAnconeus by the musculo-spiral nerve. (Plate XXXIII). The five muscles in the deep layer are the Supinator brevis, Extensor ossis meta- carpi pollicis. Extensor brevis pollicis. Extensor longus pollicis, and the Exten- sor indicis; they are all supplied by the posterior interosseous nerve. The bones of the forearm are the radius and ulna: the radius has nine mus- PLATE XXIV GROOVES FOR - 1ST.- EXTENSOR OSSIS METACARPI POLLICIS AND EXTENSOR PRIMI INTERNODII POLLICIS. 2ND. -EXTENSOR CARPI RADIALIS LONGIOR AND BREVIOR. 3RD. - EXTENSOR SECUNDI INTERNODII POLLICIS 4TH.-EXTENS0R COMMUNIS DIGITORUM AND EXTENSOR INDICIS. 5TH.-EXTENS0R MINIMI DIGITI. 6 TH.- EXTENSOR CARPI ULNARIS. POSTERIOR RADIO-ULNAR LIGAMENT IAL LATERAL LIGAMENT — POSTERIOR RADIO-CARPAL LIGAMENT. TRICEPS (I) SUPINATOR BREVIS (I). BICEPS (I). LOWER LIMIT OF ORBICULAR LIGAMENT; CAPSULAR LIGAMENT. I.i ii Radius and Ulna— Posterior View. 70 PLATE XXV. INTER- ARTieULAft-FIBHO-CARTIUCE. ANTERIOR RADIO-CARPAL LIGAMENT. IlXT. LATERAL LIGAMENT SUPINATOR LONGUS.lll PRONATOR QUAORATUS (I). FLEXOR LONGUS POLLICIS.(O), — RADIUS PRONAIOR RADII TERES/1) FLEXOR SUBLIMISDIGITORUM. (0 OBLIQUE LINE. SUPINATOR BICIPITAL TUBERCLE BICEPS. (I)"" LOWER LIMIT OF ORBICULAR LIGAMENT NECK OF RADIUS HEAD OF RADIUS GREATER SIGMOID FOSSA. INT LATERAL LIGAMENT ANT. RADIO-ULNAR LIGAMEN PRONATOR QUADRATUS. 'O INTEROSSEOUS MEMBRANl. FLEXOR PROFUNDUS DIGITORUM.iO ■ NUTRIENT FORAMEN. OBLIQUE LIGAMENT FLEXOR LONGUS POLLlClS(O) ~ (ACCESSORY HEAD). BRACHIALIS ANTICUS. PRONATOR RADII TERESILESSER HEAD)(0) TUBERCLE FOR FLEXOR SUBLIMIS DIGITORUM. INT. LATERAL LIGAMENT CAPSULAR LIGAMENT Left Radius and Ulna— Anterior View. 71 72 ANATOMY IN" A NUTSHELL. cles attached to it and the ulna fourteen. Although there are twenty-three muscles attached to these two bones, yet there are but twenty muscles in the forearm, the Triceps, Biceps, and Brachialis anticus are in the arm (between the shoulder and elbow.) The elbow-joint isdescribed in Lesson XIII. LESSON XVI. The Radius (Plates XX IV-XXV) is theshorterof thetwo bones of the fore- arm. Its distal extremity is larger than that of the ulna, while its proximal extrem- ity is smaller than that of the ulna. Thesetwo boneslie parallel. The proximal extremity has a head, neck, and tuberosity; the circumference of the head is concave, tts inner portion which articulates with the lesser sigmoid cavity of the ulna is broader than the remaining portion which articulates in the orbicu- lar Ligament. The upper surface of the head is also concave for the articula- tion of the capatellum or radial head of the humerus; it is covered with cartil- age in the recent state. The neck is the constricted part below the head; the proximal part of the neck is surrounded by the distal part of the orbicular lig- ament and distally it gives attachment to the Supinator brevis externally. The bicipital tuberosity is distally from the neck at the antero-internal aspect of the bone. It has a rough posterior portion for the insertion of the tendon of the Biceps, and a smooth anterior portion for a bursa which is between the tendon and the bone. The shaft is triangular on cross section and has three borders and three surfaces. The anterior border extends from the bicipital tuberosity distally to the outer aspect of the bone, then to the anterior border of the sty- loid process. The proximal one-third of this border is the oblique line of the radius; it separates the Supinator brevis from the Flexor longus pollicis, and gives a1 tachmenl to the third head of the Flexor sublimis digitorum ; it separates the anterior surface from theexternal surface. The inner or interosseous bor- der, extends from the posterior pail of the bicipital tuberosity proximally to the sigmoid cavity of the radius; its distal part divides into an anterior and posterior portion and has the interosseous membrane attached to most of its extent; it separates the anterior from the posterior surface. The posterior border which is well marked in the middle one-third, extends from the back pari of the neck of the radius to the middle tubercle on the posterior aspect of the distal extremity; it separates the posterior from the external surface. The anterior surface is concave at the proximal extremity and smooth at the distal extremity. The proximal three-fourth gives attachment to the Flexor longus pollicis, and the distal one-fourth to the Pronator quadratus. Where the proximal one- third joins the middle one-third, is the nutrient foramen which is directed to- wards the elbow. The nutrient artery is a branch of the anterior interosseous. 'I'h. posterior surface is convex from the proximal to the distal extremity; it is covered by the Supinator brevis. Extensor ossis metacarpi pollicis, Extensor brevis pollicis. and the distal one-third is covered by tendons. The oblique line marks the proximal limit of the Extensor ossis metacarpi pollicis. The exter- ANATOMY IN A NUTSHELL. 73 nal surface is convex from the proximal to the distal extremity; it has attached to it the Supinator brevis, and about the center the Pronator radii teres, and distally it is covered by the Extensor carpi radialis longior and Extensor carpi radialis brevior which are crossed by the Extensor ossis metacarpi pollicis and Extensor brevis pollicis. The lower extremity is quadilateral. The lower surface which is concave, articulates with the scaphoid and semilunar. The part which articulates with PLATE XXVI EXTENSOR COMMUNIS DIGITORUM (I) EXTENSOR MINIMI DIGITI (I), (I) EXTENSOR INOICIS. EXTENSOR SECUNDI INTFRNODII POLLICIS. EXTENSOR CARPI UL:.ARIS. (I) — r\ PISIFROM il) EXTENSOR PRIMI INTERNOOII POLLICIS. 1ST METACARPUS. EXTENSOR CARPI RADIALIS LONGIOR AND BREVIOR. Bones of Left Hand— Posterior View the scaphoid is triangular, while that which articulates with the semilunar is quadrilateral. These part- are separated by a ridge. The inner surface is concave and articulates with the head of the ulna. The interarticular fibro-cartilage is attached to the border between the sigmoid cavity and the semilunar sur- faces. The perimeter is triangular, having an anterior, external, and posterior 74 ANATOMY IN A NUTSHELL. surfaces. The anterior surface gives attachment to the anterior ligament of the wrist, the external is prolonged downward making the styloid process to the base of which is attached the Supinator longus and to the apex externally the lateral ligament. This process has a groove passing distally and forward for the Extensor ossis metacarpi pollicis and Extensor brevis pollicis. The poste- rior surface gives attachment to the posterior ligament and has three grooves* which are lir>t. for the Extensor carpi radialis lorigior and brevior, the second for the Extensor longus pollicis. and the third for the Extensor communis digitorum ami Extensor indicis. PLATE XXVII (I) FLEXOR PROFUNDUS DIGITORUM. (I) FLEXOR SUBLIMUS DIGITORUM I 1 ' FLEXOR LONGUS POLLICIS (I) FLEXOR BREVIS ANO ADDUCTOR POLLICIS. A30UCTOR POLLICIS. ANt (I) FLEXOR BREVIS OPPONENS POLLICIS Ml FLEXOR CARPI RADIALIS. HI EXTENSOR OSSIS METACARPI POLLICIS (0) OPPONENS POLLICIS ABDUCTOR POLLICIS. (0) (I) ABDUCTOR AND FLEXOR BREVIS MINIMI DIGIT! (I) OPPONENS MINIMI DIGITI. (0) ABDUCTOR TRANSVERSUS POLUCIS. (I) FLEXOR CARPI ULNARIS. OPPONENS MINIMI DIGITI (0.) FLEXOR BREVIS MINIMI DIGITI (0)." (0) ABDUCTOR MINIMI DIGTI (I) FLEXOR CARPI ULNARIS. FLEXOR BREVIS POLLICIS. (0) (0) ADDUCTOR 0BLIQUUS POLLICIS. Bones oi Left Hand- Anterior View Ossification. From three centers, one for the diaphysis about the eighth week of intrauterine life, one for the distal epiphysis about the second year which join- the bone aboul the twentieth year, and one for the proximal extremity, the fifth year, which joins the bone about the seventeenth year. grooves correspond to the second, third, and fourth of the posterior annular ligament oi tin- wrist-joint ANATOMY IN A NUTSHELL. 75 Articulation. — It articulates with four bones, the humerus, ulna, scap- hoid and semilunar. Muscles. — It has nine muscles attached, the Biceps, third head of the Flexor sublimis digitorum. Supinator brevis, Flexor longus pollicis, Pronator quadratus, Pronator radii teres. Supinator longus, Extensor ossis metacarpi pollicis and Extensor brevis pollicis. Blood Supply. — The nutrient artery is derived from the anterior inter- osseous trunk: it enters the shaft near the middle of the anterior surface, and runs towards the proximal end of the bone. The head of the hone is supplied by the radial recurrent and interosseous recurrent arteries. The lower end is supplied by the anterior and posterior interosseous arteries and numerous twigs from carpal arches. LESSON XVII The Ulna (Plates XXIY-XXY.) is the longer of the two bones of the fore- arm; its proximal extremity islarger than that of the radius, while its distal ex- tremity is smaller than that of the radius. On cross section it is triangular, but its distal part is more circular. It has a proximal and distal extremity and a dia- physis. The proximal extremity has the olecranon process and the greater and lesser sigmoid cavities. The olecranon (meaning head of elbow) is con- cave from above down, and convex transversely on its articular surface 1 which is covered with cartilage in the recent state. Its margins give attachment to the capsular ligament of the elbow. This surface makes the greater part of the greater sigmoid cavity. On its inner surface is a tubercle for the ulnar origin of the Flexor carpi ulnaris. The internal lateral ligament has an attach- ment in front of the tubercle. The other surface gives attachment to part of the Anconeus. The extremity of the process fits into the olecranon fossa of the ulna when the arm is extended. Its upper surface has a concave impression for the ten- don of the Triceps and the anterior margin for the posterior ligament. The posterior surface is covered by a bursa. The coronoid (like a crown) makes the lower part of the greater sigmoid cavity and the upper pari of the bone. Its upper surface is covered with cartilage in the recent state. When the arm is flexed it fits in the coronoid impression of the humerus. <>n its outer surface is the lesser sigmoid cavity for the head of the radius. The orbicular ligament is attached to the margin of the lesser sigmoid cavity. On it> inferior surface is an impression for the insertion of the Brachialis anticus. Where it joins the shaft of the ulna is the tubercle for the attach- ment of the oblique ligament. On the inner surface is the attachment of the internal ligament, one attachment for tin- Flexor sublimis digitorum; Behind this is a depression for the attachment of the flexor profundus digitorum, anddis- lally from this one for the Pronator radii teres, and occasionally one attach- ment for the Flexor longus pollicis. The greater and lesser sigmoid cavities have been described with these two processes. The diaphysis has three borders and three surfaces. The anterior border extends from the inner angle of the coronoid process to the from of the styloid process; for most of the extent it is smooth and rounded. It separates the anterior and internal surfaces andgives attachment to the Flexor profundus 76 ANATOMY IN A NUTSHELL. digitorum proximally, and the Pronator quadratus distally. The posterior border commences at the apex of a triangular subcutaneous surface at the back of the olecranon and continues to the back part of the styloid process. It is well marked in the proximal three-fourths and gives attachment to the common aponeurosis which has three muscles attached to it. viz.. the Extensor carpi ulnaris, Flexor carpi ulnaris and Flexor profundus digitorum. This border separates the internal and posterior surfaces. The outer or interosseous bor- der, is divided above, extending to the anterior and posterior extremities of the sigmoid cavity; embracing the triangular depression (the bicipital hollow). In the trout part of this impression lodges the tubercle and tendon of the Bi- ceps, when the arm is pronated, and the back part gives attachment to the Supinator brevis. It separates the anterior and posterior surfaces. To its distal four-fifths is attached the interosseous membrane. The anterior sur- face is grooved in the proximal three-fourths of its extent, which is broader than the distal portion, and gives attachment to the Flexor profundus digi- torum. Its distal one-fourth gives attachment to the Pronator quadratus. The pronator ridge, or oblique line, is directed distally and inward at the prox- imal limit of the Pronator quadratus. The nutrient foramen is on this surface at the junction of the proximal one- third with the middle one-third, and is directed towards the elbow. The nutri- ent artery is a branch of the anterior interosseous. The internal surface is broad and concave proximally. narrow and convex distally. The proximal three-fourths gives attachment to the Flexor profun- dus digitorum, whereas the distal one-fourth is subcutaneous. The posterior surface is broad and concave proximally, narrow and convex in the middle. narrow, smooth, and round distally. It> oblique line runs from the posterior extremity of the lesser cavity distally to the posterior border. The first part of this line gives attachment to the Supinator brevis. The triangular surface between this line and the elbow receives the insertion of the Anconeus. The "Uter portion of this surface gives attachment to the Supinator brevis. Ex- tensor ossis metacarpi pollicis, Extensor Longus pollicis, and Extensor indicis. The inner portion is smooth, being covered with the Extensor carpi ulnaris. A perpendicular ridge separates these two portions of this surface. The lower extremity is small ami consists of two parts, a head and styloid process. ' m the articular surface they are separated by a groove which re- ceive- the apex of the interarticular fibro-cartilage, thus separating the ulna from the wrist-joint. The margin of the head is received in the sigmoid cavity of the radius and the styloid process is a continuation of the posterior border projecting from the inner and back part of the bone. Its apex gives attach- ment to the internal lateral ligament; it> posterior surface is grooved for the Extensor minimi digiti. Ossifk ITION. From three center-, one for the shaft about the eighth week, one tor the distal extremity about the fourth year which joins the shaft the eighteenth or twentieth year, and one tor the proximal extremity the tenth year which join- the shaft the sixteenth or seventeenth year. Ai:t)< i lation.- It articulates with the humerus and radius. ANATOMY IN A NUTSHELL. 77 Muscles. — It has fourteen muscles attached, Triceps, Anconeus, Flexor carpi ulnaris, Brachialis anticus, Supinator brevis. Flexor sublimis digitorum, Flexor profundus digitorum, Pronator quadratus, Extensor carpi ulnaris Pronator radii teres, Extensor ossis metacarpi pollicis, Extensor longus pollicis, Extensor indicis, and Flexor longus pollicis. PLATE XXV III DORSALIS SCAPULAE ARTERY GREAT TUBEROSITY POST. CIRCUMFLEX ARTERY CIRCUMFLEX N MUSCULO-SPIRAL N — THE QUADRILATERAL SPACE IS BOUNOED ABOVE BY THE TERES MINOR; BELOW BY THE TERES MAJOR; EXTERNALLY BY THE HUMERUS; INTER- NALLY BY THE LONG HEAD OF THE TRICEPS. IT HAS THE CIRCUMFLEX N. AND THE POST. CIRCUMFLEX ARTERY PASSING THROUGH IT. THERE ARE TWO TRIANGUAL SPACES FORMED BY THESE SAME BOUNDARIES. ONE TRIANGLE HAS THE MUSCULO-SPIRAL N. PASSING THROUGH IT. AND IS BOUNDED ABOVE BY THE TERES MAJOR, EXTERNALLY BY THE HUMERUS. INTERNALLY BY THE LONG HEAD OF TRICEPS. THE OTHER TRIANGLE HAS THE DORSALIS SCAPULAE ARTERY PASSING PARTLY THROUGH IT AND THEN PASSING BETWEEN THE SCAPULA AND THE TERES MAJOR INTO THE INFRASPINOUS FOSSA. Showing the Quadrilateral Space and Structures Passing Through it Blood Supply. — The nutrienl vessel enters the shaft near the middle of the anterior surface; it is derived from the anterior interosseous trunk, and is directed towards the proximal end. The upper extremity receives branches from the anterior and posterior ulnar recurrent and from the interosseous re- current. The lower end receives twigs from the anterior and posterior inter- osseous arteries. 7S ANATOMY IN A NUTSHELL. LESSON XVIII. The wrist-joint is a condyloid joint (Plate XL) having all movements ex- cept axial rotation. It is formed by the lower head of the radius and the inter- articular fibro-cartilage proximally and the scaphoid, semilunar, and cuneiform bones distally. The ulna docs not go into the joint, being separated by the interarticular fibro-cartilage from the done- of the wrist. The ligaments of this joint arc the anterior, posterior, internal lateral, and external lateral which make a capsular ligament. The anterior ligament ex- tend- from the anterior surface of the lower border of the ulna to the front of the interarticular fibro-cartilage, also from the anterior surface of the lower border of the radius and its styloid process, to the palmar surface of the scap- hoid, semilunar, and cuneiform bones distally, some fibers continuing to the c* magnum and the unciform hones. There are some superficial fibers passing from the styloid process ^i the ulna to the semilunar and cuneiform. This ligamenl is pierced by small vessels. The posterior ligament is weaker than the anterior one: it extend- from the posterior surface of the lower part of the radius and the triangular interarticular fibro-cartilage to the posterior surface of the scaphoid, semilunar and cuneiform bones. The internal lateral ligament ex- tends from the tip of the styloid process of the ulna to the inner surface of the cuneiform, by one of its divisions, and to the pisiform and annular ligament by the other. The external lateral ligament extends from the styloid process of the radius to the outer side of the scaphoid, some fibers continuing to the trape- zium and annular ligament. A synovial membrane which is very lax and does not communicate with the joint above and below, lines the ligaments of this joint. (Plate XLII.) The nerve supply is the ulnar, anterior and posterior interosseous. The blood supply is the anterior and posterior interosseous, anterior and erior carpal arches, and recurrent branches from the dee]) palmar arch. The superior radio-ulnar articulation is a trochoides, and is formed by the head of the radius and the lesser sigmoid cavity of the ulna. Its only liga- menl i- the orbicular, which surrounds the head of the raidus. It is connected io the anterior and posterior borders of the lesser sigmoid cavity, and with it make- a complete ring. It- lower circumference is less than that of the upper, thus holding the head <<\ the radius in position. It blends with all the liga- ments of the elbow, except the internal: the synovial membrane continues with that of the elbow. The middle radio-ulnar articulation has two ligaments: first, the oblique ..i- round ligament which passes distally and outward from the base of the coronoid process to the bicipital tuberosity of the radius. This ligament is often absent. Second, the interosseous membrane, passing between the two adjacent border- of the radius and ulna: its liber- pass distally and inward. It commences beyond the bicipital tuberosity of the radius and extends almost to the di-tal extremity of the two bones. It affords attachment to the muscles. The anterior interosseous artery passes to the back of the forearm, between the radius and ulna beyondthis membrane. The posterior interosseous vessels pass ANATOMY IN A NUTSHELL. 79 to the back of the forearm between the radius and ulna above this membrane. The inferior radio-ulnar articulation is a trochoides, and is formed by the head of the ulna and the sigmoid cavity of the raidus and fibro-cartilage. Its ligaments are the anterior and posterior radio-ulnar which make the capsular ligament. The anterior radio-ulnar ligament passes from the front border of the sigmoid cavity of the radius to the anterior surface of the head of the ulna. The posterior one is a similar ligament on the posterior surface. The triangular interartieular fibro-cartilage is at the lower end of the ulna, between the styloid process and the radius. Its perimeter is attached to the ligaments of the wrist; it is attached by its apex to the depression between the head and styloid pro- cess of the ulna, by its base to the lower end of the radius. Sometimes it is perforated, in such a case the synovial membrane communicates with that of the wrist. The blood supply is the anterior interosseous and anterior carpal arch. The nerve supply is the anterior and posterior interosseous. Synovial membrane, the membrana sacciformis, lines the adjacent surfaces of the ulna and the interartieular fibro-cartilage. and the ulna and the radius. As stated before, it sometimes communicates with the wrist-joint. j Brachialis amicus. — Description. — (Plate XVI.) — This is a broad muscle which covers the elbow-joint and the lower half of the front of the humerus. It is somewhat compressed from before backward and is broader in the middle than at either extremity. Its fibers converge to a thick tendon. The outer border of the muscle is in relation with the musculo-spiral nerve and radial re- current artery. Origin. — (1) Lower half of outer and inner surfaces of shaft of humerus; (2) intermuscular septa; (3) commences above at insertion of Deltoid and ex- tends below to within one inch of margin of articular surface. (Plate XXIII.) Insertion. — Into a rough depression on the anterior surface of the coron- noid process of the ulna, being received into an interval between two fleshy slips of the Flexor profundus digitorum, (Plate XXV.) Action. — Flexor of forearm. Nerve Supply. — Fifth and sixth cervical through the musculo-cutaneous and musculo-spiral. Blood Si pply.- Brachial artery. Subanconeus. Description.- The Subanconeus is a name given to a few fibers from the under surface of the lower pai I of the Triceps muscle. By some authors it is regarded as the analogue of the Stfbcrureus in the lower limb, but it is not a separate muscle. Origin. — Humerus above olecranon fossa. Insertion. Posterior ligament of elbow-joint. A< tion. 1 >raws up posterior ligamenl during extension of forearm. Nerve Supply. —Musculo-spiral. Blood Supply. Brachial artery. Pronator radii teres. Description. (Plate KXIX.) This muscle arises by two heads, beiween which the median nerve enters the forearm. It passes obliquely across the forearm from the inner to the outer side, and ter- PLATE XXIX LUMBRICALES ABDUCTOR INDICIS FLEXOR LONG US POLLICIS i ADDUCTOR IRANS VETSE POLLICIS FLEXOR BREYIS POLLICIS ABDUCTOR POLLICIS OPPONENS POLLICIS POST. ANNULAR LIGT EXTENSOR BREVIS POLLICtS EXTENSOR OSSIS METACARPI POLLICIS FLEXOR LONGUS POLLICIS •SUPINATOR LONGUS LEXOR PROFUNDUS DIGITORUM. FLEXOR SUBLIMIS DIGITORUM DIGITAL ARTERIES^DIGITALtJEKVE SUPERFICIAL TRANSVERSE LIGT. — FLEXOR BREVIS MINIMI DI&ITI. ABDUCTOR MINIMI DIGIT!. PALMARIS BREVIS PISIFORM BONE ANT. ANNULAR LIG-'T- FLEXOR SUBLIMIS DIGITORUM: -FLEXOR CARPI ULNARIS PALMARIS LONGUS. FLEXOR CARPI RADIALIS. PRONATOR RADII TERES. BRACHIALIS ANTICUS. BICEPS TRICEPS. Muscles of the Left Forearm First Layer— Anterior View 80 ANATOMY IN A NUTSHELL. 81 minates in a flat tendon which turns over the outer margin of the radius. Origin. — One head. (1) immediately above internal condyle of humerus: (2) common tendon: (3) fascia; i4i intermuscular septum. The other head, thin fasciculus from inner side of coronoid process of ulna, joining first head at an acute angle. (Plate XXIII.) Insertion. — Rough impression on middle of outer surface of shaft of radius. (Plate XXV.) A' tii»n. — To pronate hand. Nerve Supply. — Median. Blood Supply. — Radial artery. Flexor carpi radialis. — Description. — (Plate XXIX.) — This muscle lies on the inner side of the preceding muscle. It is slender and aponeurotic in structure at its commencement above, but increases in size and terminates in a tendon which forms rather more than the lower half of its length. This tendon 3£ s through a canal on the outer side of the annular ligament and runs through a groove in the os trapezium. The radial artery lies between the ten- don and the Supinator longus muscle, and may easily be tied in this situation. Origin. — (1) Internal condyle by common tendon: (2) fascia; (3) inter- muscular septum. (Plate XXIII. Insertion. — (Plate XXYII.) — Bases of metacarpals of index and middle finger.-. Action. — Flexor of wrist. Nerve Supply. — Median. Blood Supply. — Radial arterv. LESSON XIX. Palmaris longus. — Description. — (Plate XXIX.)— Thi- is a slender, fusiform muscle lying on the inner side of the preceding. It is often absent and is subject to much variation: it may be tedinous above and muscular below: or it may be muscular in the center with a tendon above and below; or it may present two muscular bundles with a central tendon: or finally, it may consist simply of a mere tendinous band. Origin. — (1) Inner condyle of humerus by the common tendon: (2) deep fascia: (3) intermuscular septa. (Plate XXIII.) Insertion. — Palmar fascia and occasionally a Tendinous ligamenl to shorl muscles of thumb. (Plate XXIX \< tion. — Tenses palmar fascia. \i:i;\ i: Supply. — Median. Blood Supply. — Radial and ulnar arteries. Flexor carpi ulnarls. — Description.- Tins muscle lie- along the ulnar Bide ^i the forearm. It arises by two head- connected by a tendinous arch, beneath which pass the ulnar nerve and posterior ulnar recurrent artery. The fibers terminate in a tendon which occupies the anterior part of the lower half of the muscle. The ulnar artery lies on the outer side of this tendon, in the lower two-thirds of the forearm. (Plate- XXIX-.W 82 ANATOMY IN A NUTSHELL. Origin.— One head from internal condyle of humerus by common tendon; the other from inner margin of olecranon, upper two-thirds of posterior border of ulna by an aponeurosis common to it, the Extensor carpi ulnaris, and Flexor profundus digitorum, and also from the intermuscular septum. (Plate XXIII.) Insertion. Pisiform bone, annular ligament, and base of fifth meta- carpal and unciform bones. (Plate XXVII.) Ai in i\. Flexes wrisi . \'u;\ i: Si imma . Ulnar. Blood Supply. Ulnar artery. Flexor sublimis digitorum (perforatus). Description.— (Plates XXX.) This muscle lies just beneath the preceding and is the largest of the muscles of the superficial layer. It arises by three heads. The fibers pass vertically downward, forming a broad and thick muscle which speedily ■ livides into two planes of muscular fibers, superficial and deep. The super- ficial plane divides into two parts which end in tendonsfor the middle and ring fingers; the deep plane also divides into two parts which end in tendons for the index and little fingers, hut previous to having done so it gives off a muscular slip which joins that part of the superficial plane which is intended for the ring finger. As the four tendons thus formed pass beneath the annular ligament into the palm of the hand they are arranged in pairs, the superficial pair cor- responding to the middle and ring fingers, the deep pair to the index and little fingers. The tendons diverge as they pass onward. Opposite the bases of the first phalanges each tendon divides into two slips to allow the passage of the corresponding tendon of the Flexor profundus digitorum: the two portions then unite and form a grooved channel for the reception of the deep flexor tendon. Finally they subdivide a second time prior to their insertion. Origin. (By three heads) first head, (1) internal condyle of humerus by common tendon; (2) internal lateral ligament of elbow-joint; ami (3) inter- muscular septum. Second head, inner side of coronoid process of ulna. Third head, oblique line of radius, from the tubercle to the insertion of the Pronator radii ten-. (Plates XXV-XXIII.) 1 nsertion. t Plate XXVII.)- Lateral margins of second phalanges about their middle. Action. Flexes second phalanges. \'u;\ i. Si ppl"5 . Median. Hi.< Supply. Radial and ulnar arteries. Flexor profundus digitorum. Description.— (Plate XXXI.) This muscle is situated on the ulnar side of the forearm, immediately beneath the su- per fiicial flexors. Its fibers form a fleshy belly of considerable size which divides into four tendons; these pass under the annular ligament beneath the tendons of the Flexor sublimis digitorum. Opposite the first phalanges the tendons pass through the openings in the two slips of the tendons of the Flexor sublimis digitorum. The portion of the muscle for the index finger is usually distinct throughout, bu1 the tendons for the three inner fingers are connected together by cellular tissue and tendinous slips as far as the palm of the hand. Four Bmall muscles, the Lumbricales, are connected with the tendons of the Flexor profundus in the palm. PLATE XXX SUPERFICIAL TRANSVERSE LIGAMENT LUMBRICALIS. RADIAL PORTION OF PALMAR BURSA, INNER H FLEXOR BREVIS P0LLIC1S. OUTER HEAD tBDUCTOR POLLICIS. EXTENSOR BRE'.IS POLLICIS EXTENSOR OSSIS WETACARPI POLLICIS FLEXUS LONGUS POLLICIS EXTENSOR CARPI RAO.ALIS LONGIOR SUPINATOR BREVIS DEEP TRANSVERSE LIGAMENT. ~ ULNAR PORTION OF PALMAR BURSA. PALMARIS BREVIS. CPPONENS MINIMI OIGITI ADDUCTOR MINIMI DIGIT! ANTERiOR ANNULAR LIGAMENT. DEEP FASCIA OF FOREARM. FLEXOR V.BLIMlSDIWTORUM. ) RSDIAU Wi ',J. - \ I. ' FLEXOR CARPI ULNARls Vim u FLEXOR CARPI RADlAllS PRONATOR RAlu BRALhIALIS AMICUS w [bicep: _ l Muscles op the Left Forearm Second Layer Anterior \ n\\ 83 ANATOMY IN A NUTSHELL. Origin. (1) Upper three-fourths of shaft of ulna, anterior and inner sur- faces; (2) depression ob inner side of coronoid process; (3) by aponeurosis from upper three-fourths of posterior border of ulna; and (4) ulnar half of in- terosseous membrane. (Plate XXV.) Insertion. Bases of last phalanges. (Plate XXVII.) \. noN. Flexes phalanges. \ii;\i Supply. Eighth cervical and first dorsal through ulnar, and the anterior interosseous branch of median. Blood Si ppli . Ulnar artery. Flexor Longus pollicis. — Description. — (Plate XXXI.) — This muscle is situated od the radial side of the forearm, lying on the same plane as the preceding . The fibers pass downward and terminate in a flattened tendon which passes beneath the annular ligament and is then lodged in the interspace between the outer head of the Flexor brevis pollicis and the Adductor obliqus pollicis. The anterior interosseous vessels and nerve lie between this muscle and the Flexor profudus digitorum. Origin.- Front the grooved anterior surface of the shaft of the radius, from the tuberosity and oblique line to within a short distance of the Pronator quadratus; also from the adjacent part of the interosseous membrane, and gen- erally by a fleshy slip from the inner border of the coronoid process of ulna, or from the internal condyle of the humerus. (Plate XXV.) Insertion.- Base of last phalanx of thumb. (Plate XXVII.) \« tion. Flexes thumb. Nerve Supply.- Eighth cervical and first dorsal through the anterior interosseous branch of the median. Blood Supply.- Radial artery. Pronator quadratus.— Description. — (Plate XXXI.) — This is a small, flat, quadrilateral muscle extending transversely across the front of the radius and ulna, above their carpal extremities. Origin. (1) Oblique ridge on lower part of anterior surface of ulna; (2) l"\\er fourth of anterior surface and anterior border of ulna; and (3) strong aponeurosis covering inner third of muscle. (Plate XXV.) Insertion. (Plate XXV.)- Lower fourth of anterior surf ace and anterior border of shaft of radius. \< I [ON. Pronates the hand. Nerve Supply. Eighth cervical and first dorsal through anterior interosseous branch <<\' median. Blood Supply. Radial and ulnar arteries. LESSON XX. Supinator longus. Description. (Plate XXXII.)— The Supinator longus (Brachio-radialis) is the mosl superficial muscle on the radial side of the forearm; it is fleshy for the upper two-thirds of its extent, tendinous below, the tendon commencing above the middle of the forearm. Its inner border, above the elbow, is in relation with the musculo-spiral nerve and radial recurrent artery, and in the forearm with the radial vessels and nerve. ANATOMY IN A NUTSHELL. 85 Origin. — Upper two-thirds of external supracondylar ridge of humerus and external intermuscular septum. (Plate XXIII.) Insertion. — Outer side of base of styloid process of raidus. (Plate XXV. Action. — Supinates hand. Nerve Supply. — Sixth cervical through the musculo-spiral nerve. Blood Supply. — Brachial and radial arteries. Extensor carpi radialis longior. — Description. — (Plate XXXII.) — This muscle lies partly beneath the Supinator longus, its fibers terminating at the upper third of the forearm in a flat tendon which runs along the outer border of the radius beneath the extensor tendons of the thumb. It then passes through a groove common to it and the Ex'.ensor carpi radialis brevior. immediately behind the styloid process of the radius. Origin. — From the lower third of the external supracondylar ridge of the hu- merus and from the external intermuscular septum by a few fibers from the common tendon of origin of the extensor muscles of the forearm. (Plate XXIII.) Insertion. — Base of metacarpal of index finger, radial side. (Plate XXVI.) Action. — Extends the wrist. Xerve Supply. — Sixth and seventh cervical through the musculo-spiral. Blood Supply. — Radial artery. Extensor carpi radialis brevior. — Description. — (Plates XXXII.) — This muscle is shorter and thicker than the preceding, beneath which it is placed. Its fibers terminate about the middle of the forearm in a flat ten- don which is closely connected with that of the Longior, and accompanies it to the wrist, lying in the same groove on the posterior surface of the radius; it passes beneath the extensor tendons of the thumb, then beneath the annular ligament. The tendons of the two preceding muscles pass through the same com- partment of the annular ligament and are lubricated by a single synovial mem- brane, but are separated from each other by a small vertical ridge of bone as they lie in the groove at the back of the radius. Origin. — From the external condyle of the humerus by a tendon common to it and the three following muscles: from the external lateral ligament of the elbow-joint, from a strong aponeurosis which covers its surfaces, and from the intermuscular septa. (Plate XXIII.) Insertion. — (Plate XXVT.) — Base of metacarpal bone of middle finger on its radial side. Action. — It assists the Extensor carpi radialis longior in extending the wrist and may also act slightly as an abductor of the hand. Nerve Supply. — Sixth and seventh cervical through the posterior inter- osseous. Blood Supply. — Radial artery. Extensor communis dijritoruni. — Description. (Plates XXXII.) — This muscle is situated at the back part of the forearm and divides just below the middle into three fleshy masses, from which tendons proceed; these pass to- gether with the Extensor indicis through a separate compartment of the annu- lar ligament. The tendons then diverge, the innermost one dividing into two. PLATE XXXI FLEXOR SUBLIMIS WGITOHtM •U6A*ENTUm VA6INALE, FIRST LUMBRICALIS FIRST DORSAL INTEROSSEOUS TRANSVERSE ADDUCTOR POLLICIS. OBLIQUE (OUTER HEAD) (0) FLEXOR BRE\ IS POLLICIS (INNER MtADI (I,. /.BDUCTOR POLUCIS FLEXOR PRORINOUS DtGITORUM FLEXOR BREVIS MINIMI DIGJTI PALMARIS BREVIS FLEXOR SUBLIHtUS WGITOROW ABDUCTOR MINIMI DIGITI DEEP FASCIA OF FORLARM EKTINSCR CARPI RADVALIS LONGIOR. J.JPINATOS BREVIS M , fl/j, \\m :\\ V ■ FUXOR PROFUNDUS DI&ITORUM Mtt'< .it 1 ? (ill :.»!'> : FLEXOR SUBLIMIS DIGITORIUM BRACHlO-RI.DIALlS FLEXOR CARPI ULNARIS PALMARIS LONGUS. FLEXOR CARPI RADIALIS PRONATOR RADII TERES 'X v.- m m m I jfl , BRACHIALIS ANTIC!';, ',1 Ml, K I Li I / T'4 M "' -^TRICEPS m MuscLES f OF theJLept F( m i, uim— Third and Fourth Layers— Anterior View 86 ANATOMY IN A NUTSHELL. 87 Each tendon opposite the metacarpophalangeal articulation becomes nar- row and thickened and gives off a thin fasciculus upon each side of the joint, which blends with the lateral ligament and serves as a posterior lig- ament; after having passed the joint it spreads out into a broad aponeurosis which covers the whole of the dorsal surface of the first phalanx, being rein- forced in this situation by the tendons of the Interossei and Lnmbricales. Opposite the first phalangeal joint this aponeurosis divides into three slips, a middle and two lateral. Origin. — (1) External condyle of humerus by common tendon; (2) deep fascia; (3) intermuscular septum. (Plate XXIII.) Insertion. — Into the second and third phalanges of the fingers in the fol- lowing manner; the outermost tendon accompanied by the Extensor indicis, goes to the index finger; the second tendon is sometimes attached to the first by a thin transverse band and receives a slip from the third tendon ; it goes to the middle finger; the third tendon gives off a slip to the second and receives a very considerable part of the fourth tendon ; the fourth or innermost tendon, after dividing, sends one slip to join the third tendon; the other, rein- forced by the Extensor minimi digiti, goes to the little finger. After the di- vision of the aponeurosis opposite the phalangeal joint, the middle slip is in- serted into the base of the second phalanx, while the two lateral are continued onward along the sides of the second phalanx and are inserted into the dorsal surface of the last phalanx. (Plate XXVI.) Action. — To extend the fingers. Nerve Suplpy. — Seventh cervical through the posterior interosseous. Blood Supply. — Posterior interosseous. Extensor minimi digiti. — Description. — (Plate XXXII.) — This is a slender muscle placed on the inner side of the Extensor communis digitorum with which it is generally connected. Its tendon runs through a separate compartment in the annular ligament behind the inferior radio-ulnar joint, then divides into two as it crosses the hand, the outermost division being joined by the slip from the innermost tendon of the common extensor. The two slips thus formed spread into a broad aponeurosis and receive a slip from the Ab- ductor minimi digiti. Origin. — Common tendon by a thin tendinous slip and intermuscular septa. (Plate XXIII.) Insertion. — Second ami third phalanges of the little finger. ( Plate XXVI.) Action. — Extends the little finger. Nerve Supply. — Seventh cervical through the posterior interosseous. Blood Supply. — Posterior interosseous and radial. Anconeus. — Description. — This is a small triangular muscle placed be- hind and below the elbow-joint, and appears to be a continuation of the external portion of the Triceps. Its filters diverge from their origin, the upper ones being directed transversely, the lower obliquely inward. (Plate XXXII.) Origin. — External condyle of humerus posteriorly. (Plate XXII.) Insertion. —Side of olecranon process and upper fourth of posterior sur- face of shaft of ulna. (Plate XXIV.) 8S ANATOMY IN A NUTSHELL. A.< riON. Extends forearm. \i.i,\ i. Supply. Seventh and eighth cervical through the musculo-spiral, Blood Supply. Radial and superior profunda. LESSON XXI. Supinator brevis. — Description. — (Plate XXXIII.) — This is a broad mus- cle of hollow cylindrical form, curved round the upper third of the radius. It consists of two distinct planes of muscular fibers, between which lies the posterior interosseous nerve. The two planes arise in common. The fibers of the deeper plane form a sling-like fasciculus, which encircles the neck of the radius above the tuberosity. Between the insertion of the two planes the posterior interosseous nerve lies on the shaft of the bone. Origin— The superficial plane by tendinous and the deep by muscular fibers from tl) the external condyle of the humerus; (2) external lateral lig- ament of elbow-joint; (3) orbicular ligament of radius; (4) oblique ridge of ulna; (5) triangular depression in front of the ridge; (6) tendinous expansion covering the surface of the muscle. (Plates XXIII-XXIV.) Insertion. The superficial fibers into the outer edge of the bicipital tuberosity and oblique line of the radius; the deeper fibers into the posterior and external surface of the shaft, midway between the oblique line and head of the bone, except the sling-like fasciculous which is attached to the back part of the inner surface of the radius. (Plate XXIV.) A.CTION.— Stipulates hand. Nerve Supply. Posterior interosseous. Blood Supply Interosseous and radial arteries. Extensor ossis metacarpi pollicis. — Description. — (Plate XXXIII). — This is the mosl external and the largest of the deep extensor muscles. It lies im- mediately below the supinator brevis, with which it is sometimes united. From its origin it passes obliquely downward and outward and terminates in a tendon which runs through a groove on the outer side of the styloid processof the radius. The tendon of the Extensor brevis pollicislies in the samegroove. The Extensor pollicis occasionally gives off two slips near its insertion, one to the trape/.ium. and the other to blend with the origin of the Abductor pollicis. Origin. From outer part of posterior surface of shaft of ulna below in- sertion of Anconeus, from the interosseous membrane, and from the middle third of the posterior surface of shafl of radius. (Plate XXIV.) Insertion. Base of metacarpal bone of thumb. (Plate XXVII.) Action. Extends thumb. Nerve Si pply. Posterior interosseous. Bl< Si pply. Posterior interosseous. Extensor brevis pollicis. Description. (Plate XXXIII.) — The Exten- sor brevis pollicis (Extensor primi internodii pollicis,) the smallest muscle of this group, lies on the inner side of the preceding, having a similar direction and passing through the same groove on tin 1 outer side of the styloid process. PLATE XXXII tffc !&) EXTENSOR INCMCIS EXTENSOR MINIM: DIGIT! EXTENSOR COMMUNIS CIGlTORUM POSTERIOR ANNULAR LIGAMENT. ATTACHMENT OF EXTENSOR COMMUNIS DIGITORUM TO THIRI ATTACH «J£I EXTENSOR CO» TO SEC s /- V J. ! fl adductoh i-ul EXTENSOR MINIMI DIGITI EXTENSOR CARPI ULNARIS. FLEXOR CARPI ULNARIS. EXTENSOR BREVIS POUICIS. - EXTENSOR CSSiS METJCARP1 POLLiClS. EXTENSOR CARPI RSDIALIS BREvlOR. EXTENSOR COMMUNIS QiGITORuM. EXTENSOR CARPI RAOIALIS LONGIOR, SUPINATOR LONGUS BRACHIALIS ANIICUS. . , ' it] \ __ biceps. Muscles of the Left Forearm — Superficial Layer— Posterior \ iew 89 PLATE XXXI 11 -.'!•, DR MINIM L'iG'T ABDUCTOR MINIMI DIGITI EXTENSOR CARPI ULNARIS. EXTENSOR IND4CIS. RAOIAUS.EXTENSORS. FLEXOR PROFUNDUS OIGITOBUM FLEXOR CARPI ULNARIS ETtTENSOR OSSIS METACARPI POLLICIS. SUPINATOR BREVIS. EXTENSOR CARPI RAOIALIS LONGIOR. -SUPINATOR I ONGUS BRACHIAUS ANTICUS. Muscles op the Left Forearm — Deep Layer — Postesior View 90 ANATOMY IX A NUTSHELL. '.'1 Origin. — Posterior surface of shaft of radius, below Extensor ossis meta- carpi pollicis and from the int< -- - membrane. (Plate XXH . Insertion. — Base of first phalanx of thumb. (Plate XW 1. Ai tion. — Extends the proximal phalanx of thumb. Xerye Supply. — Seventh cervical through the posterior inter ss Blood Supply. — Posterior interosseous artery. Extensor longus pollicis. — Description. — (Plate XXXIII.) — The Ex- tensor longus pollicis (Extensor secundi internodii pollicis) is much larger than the preceding muscle, the origin of which it parti}' covers in. It termi- nates in a tendon which passes through a separate compartment in the annu- lar ligament, lying in a narrow, oblique groove at the back part of the lower end of the radius. It then crosses obliquely the tendons of the Extensor carpi radialis longior and brevior. being separated from the other extensor tendons of the thumb by a triangular interval in which the radial artery is found. Origin. — Outer part of posterior surface of shaft of ulna distally from origin of Extensor ossi< metacarpi pollicis and from interosseous membrane. (Plate XXIV.) Insertion. — Base of last phalanx of thumb. (Plate XX\ I. Action. — Extends thumb. Nerve Supply. — Seventh cervical through posterior interosseous. Blood Supply. — Posterior interosseous artery. Extensor indicis. — Description. — Plate XXXIII.) — This is a narrow, elongated muscle placed on the inner side of. and parallel with the preceding. Its tendon passes with the Exten.-or communis digitorum through the same canal in the posterior annular ligament and subsequently joins the tendon the Extensor communis digitorum which belongs to the index finger, opposite the lower end of the corresponding metacarpal bone, lying to the ulnar side of the tendon from the common extensor. Origin. — Shaft of ulna posteriorly, and distally from Extensor longus pollicis and from interosseous membrane. (Plate XXIV. Insertion. — Second and third phalanges of index finger with tendon common extensor. (Plate XXVI.) A' tion. — Extends index ring Nerve Supply. — Seventh cervical through posterior inter ss Blood Supply. — Posterior inter — 3 artery. LESSON XXII. Radial artery. — The radial artery extends from the bifurcation of thebrach- ial and ends in the deep palmar arch. It- course i- shown by a line from a point about half an inch below the middle of the bend of the elbow to the inner side of the base of the styloid process of the radius. Tin- artery is more a con- tinuation of the brachial than the ulnar, which is more of a branch. It is ac- companied by venae comites. It- branches in the forearm an- radial recurrent, muscular, superficialis volae, and anterior carpal. ANATOMY IX A NUTSHELL. The radial recurrent arises from the radial just below the elbow, passes outward between the Supinator brevis and Supinator longus, also separating the radial and posterior interosseous uerves; it then runs towards the elbow between the Supinator longus and the Brachialis anticus to supply these mus- cles and to anastomose with the anterior terminal branch of the superior pro- funda. The muscular branches supply the muscles on the radial side of the fore- arm. The anterior carpal arises near the lower border of the Pronator quadratus; ii passes to the ulnar side ^\ the forearm under the tendons to anastomose with anterior carpal of ulnar, thus forming the loop which gives branches to the wrist-joint. The superficialis volae arises from the artery near the wrist where it is about to wind around the carpus. It passes between the muscles of the ball of the thumb, sometime- over them. It anastomoses with the ulnar, completing the superficial palmar arch. The pulse may often be felt in this artery, as well a.- in the radial, when it arises higher than usual. The branches in the wrist are the posterior carpal, metacarpal or first dor- sal interosseous, dorsales pollicis, and dorsalis indicis. After the radial gives off the anterior carpal it crosses the external lateral ligament to the base ofthe metarcapal of the thumb, lying upon the scaphoid and trapezium. In this situation it is crossed by the three extensors of the thumb, viz., Extensorossis metacarpi pollicis which is a broad muscle and comes from both bones, the Extensor longus pollicis which comes from the long bone or ulna, and the Ex- tensor brevis pollicis which comes from the short bone or radius. It then passes between the two heads of the first dorsal interosseous or Abductor indicis, into tin' palm. It passes to the back of the hand for two reasons, first to supply tin' hack of the hand on the radial side, and second for protection. The posterior carpal arises beneath the extensors of the thumb, passing beneath the extensor tendon- of the forearm to join the posterior carpal of the ulnar, making the posterior carpal arch. It uives off the second and third dor- sal interossei which pass on the back of the Third and Fourth interossei mus- cles to the metacarpophalangeal joint where it divides into digital branches to supply the contiguous sides of the middle, ring, and little fingers. At their proximal extremity they receive perforating branches from the deep palmar arch. At the distal extremity they give perforating branches to the digital branches to join the palmar digital arteries. The metacarpal or first dorsal interosseous may conn' from the posterior carpal, bu1 it generally arises from the radial. It passes over the Second dorsal interosseous muscle to the metacarpophalangeal joint where it is divided to supply thr contiguous side- of the index and middle finders. At its proximal extremity it receives perforating branches from the deep palmar arch; at its distal extremity it gives branches to join the corresponding digital arteries. The digital arteries end at the firsl interphalangeal joint where they join the posterior branch of the collateral digital branches. The dorsales pollicis are two in number; they arise from the radial near the base of the first metacarpal bone and pass along the sides of the dorsum of the thumb. ANATOMY IN A NUTSHELL. 93 The dorsalis indicis arises from the radial just before it passes between the two heads of the Abductor indicis; it then passes over the dorsum of this mus- cle, which it supplies, to the radial side of the index finger. At the first inter- phalangeal joint it anastomoses with the posterior branch of the radialis in- dicis. PLATK XXXIV THIRD DORSAL INTEROSSEOUS lill-fij SECOND DORSAL INTEROSSEOUS FIRST DORSAL INTEROSSEOUS FOURTH DORSAL INTEROSSEOUS The Four Dorsal Enterossej The deep palmar arch is formed by the radial, after it pusses between the two heads of the Abductor indicis, and a terminal branch of the ulnar. This arch has its convexity distally; it lies upon the bases of the metacarpal bones. It has five branches, four from the convexity and one from the concavity. The princeps polllcis first passes between the Abductor indicis and the 94 ANATOMY IX A NUTSHELL. n- • , thP distal extremity of the metacarpal of the thumb ffh ti« i. -I from the convexity; H passes along the raM'i an- mihv m m. ....... „, , Th J an rTourth palmar Inter i just before they divide m to collateral ,,■;:;,', branches. They join ,1 1 ling digital branches of the super- ^tSX^'i— ■ - """" ' '■■ They pass """""" ANATOMY IN A NUTSHELL. 95 two heads of the Three inner dorsal interossei to join the dorsal interosseous arteries. The palmar recurrent, two or three, pass towards the wrist and join the anterior carpal and anterior interosseous t<> supply the wrist-joint. Relations of the Radial Artery in the Forearm. In Front. — (1) Skin. (2) Superficial and deep fasciae, 3 Supinator Longus. Behind. — (1) Tendon of Biceps, (2) Supinator brevis, (3) Pronator radii teres, (4) Flexor sublimis digitorum, (5) Flexor longus pollicis, (6) Pronator quadratus, (7) radius. Outp:r Side. — (1) Supinator longus, (2) Radial nerve (middle thir Inner Side. — (1) Pronator radii teres. (2) rdexor carpi radialis. LESSON XXIII. Ulnar artery. — The ulnar artery is a branch of the brachial about one-half an inch below the bend of the elbow. It is larger than the raidal. which seems to be a continuation of the brachial . It passes over the anterior annular lig- ament on the radial or outer side of the pisiform bone. The anterior ulnar recurrent arises from the ulnar just below its origin. 11 passes towards the elbow upon the Brachialis anticus and under the Pro- nator radii teres to the front of the internal condyle to anastomose with the an- terior branch of the inferior profunda and the anastomotica magna. The posterior ulnar recurrent is the larger of the vessels and has its origin below the anterior. It passes backward and inward upon the Flexor sublimis digitorum. It passes between the two heads of Flexor carpi ulnaris, with the ulnar nerve, to the back of the internal condyle to anastomose with the posterior branch of the inferior profunda and the anastomotica magna. The common interosseous is the next in order, having its origin opposite the bicipital tuberosity. It passes upward and distally to the beginning of the interosseous membrane where it divides into anterior interosseous and pos- terior interosseous. The lumen of this branch is the largest of the branches. The anterior interosseous passes to the distal extremity of the interosseous membrane in company with the anterior int< - nerve, where il pass the back of the forearm. It has venae comites. It sends a branch with the median nerve called the median artery or conn.- nervi mediani. At the wrist it anastomoses with the anterior carpal artery and recurrent branches from the deep palmar arch. It may help to form the superficial palmar arch. It gives nutrient branches to both the radius and ulna. The posterior nterosseous artery passesto the back of the forearm between the oblique ligamenl and inl - membrane. It passes between the Supinator brevis and the Extensor ossis metacarpi pollicis, then lies between the two layers of muscles on posterior part of forearm as far as the wrist. It lies internal to posterior interosseous nerve. It anastomoses with the carpal of radial and ulnar, and anterior interosseous arteries. It gives off the posterior interosseous recurrent which passes under the Anconeus to the interval be- tween olecranon and external condyle, where it anastomoses with the superior profunda, the anastomotica magna and posterior ulnar recurrent. The muscular branches vary in number and supply the adjacent muscles. 96 ANATOMY IN A NUTSHELL. The anterior carpal is a small branch which has itsorigin at the distal part of the ulnar artery near the anterior annular ligament. It passes outward to anastomose with the anterior carpal of the radial. These two arteries make the anterior carpal arch. It anastomoses with the anterior interosseous, and recurrent branches from the deep palmar arch. It lies beneath the tendons of the Flexor profundus digitorum. 'The posterior carpal arise- a little proximally of the pisiform hone. It passes beneath the Extensor carpi ulnaris to the hack of the wrist to join the posterior carpal of the radial under the extensor tendons. 'The superficial palmar arch is made by the continuation of the ulnar in the hand, joining the superficialis volae, or the radialis indicis, or the princeps pollicis, rarely joining a large median artery. The deep ulnar branch passes between the Abductor minimi digiti and the Flexor brevis minimi digiti to make the deep palmar arch. The convexity of the superficial palmar arch gives four digital branches, one to the ulnar side and palmar aspect of the little finger, and the other three to the adjacent sides of the little, ring, middle and index fingers. On the fingers these arteries are pos- terior to the nerves. Relations of the Ulnar Artery in the Forearm. 1\ Front. Upper half. — (1) Superficial layer of flexor muscles. (2) Me- dian nerve. Lower half — (3) Superficial fascia. (4) Deep fascia. Behind. — (1) Brachialis anticus, (2) Flexor profundus digitorum. Outer Side.— Flexor sublimis digitorum. Inner Side. -(1) Flexor carpi ulnaris. (2) Ulnar nerve (lower two-thirds.) Relations of the Superficial Palmar Arch. 1\ Front. — (1) Skin. (2) Palmaris brevis, (3) Palmar fascia. Behind. — (1) Annular ligament, (2) Flexor brevis minimi digiti, (3) Superficial flexor tendons. (4) Divisions of median and ulnar nerves. BRACHIAL PLEXUS. LESSON XXIV. A plexus is a net-work. The Brachial Plexus is a net-work of nerves sit- uated in the axilla. Its branches supply the upper extremity. It is called "brachial" because it supplies the arm or brachium. It is composed of the anterior primary branches (Principle IV Lesson III) of the fifth, sixth, seventh, eighth cervical and first dorsal nerves. The anterior branches of the fifth and sixth cervical nerves make the first trunk. The anterior branch of the seventh cervical nerve makes the second trunk. The anterior branches of the eighth cervical nerve and part of the first dorsal nerve make the third trunk. These trunks divide into anterior and posterior branches (secondary). The anterior branches of the firsl and second trunk make the outer cord; the anterior branch of the third trunk make- the inner cord; and the posterior branches of all three trunks make the posterior cord. They are called outer, inner, and posterior cords of the brachial plexus beneath the Trapezius and Omo-hyoid to pass through the suprascapular notch into the supraspinous fossa where ii gives two branches to the Supraspinatus muscle and a branch to the shoulder-joint, then passes around the greal scapular notch into the infraspinous fossa, giving two branches to the Infraspinatus muscle and one to the scapula itself. All the other branches are below the clavicle. The external or superficial anterior thoracic nerve comes from the outer cord jusl below the clavicle and it- fibers may he traced to the fifth, sixth, and ANATOMY IN A NUTSHELL. 99 seventh cervical nerves. It passes inward across the axillary vessels, pierces the costo-coracoid membrane and supplies the Pectoralis major. It commu- nicates with the internal or deep anterior thoracic. This loop is around the front and inner side of the axillary artery and branches are often given from it to the Pectoralis major. The Internal or deep anterior thoracic nerve comes from the inner cord and its fibers may be traced to the eighth cervical and first dorsal nerves. It passes between the axillary artery and vein, sometimes piercing the sheath of the vein. It gives a filament to a branch from the external or superficial anterior thoracic then pierces the costo-coracoid membrane to supply the Pectoralis minor; after passing through the substance of this muscle it supplies the Pectoralis major. The subscapular nerves are three in number, the upper, the middle, and the lower. All are from the posterior cord, as a rule, although the upper one may come from the posterior branch of the first trunk before it enters into tin- posterior cord. The upper one may be traced to the fifth and sixth cervical: it supplies the Subscapulars muscle. The middle or long subscapular may be traced to the seventh, occasionally to the fifth and sixth; it supplies the Latissimus dorsi. The lower one may be traced to the fifth and sixth cervical and supplies the axillary border of the Sub- scapularis and the 'Feres major. The Teres major may be supplied by a separate branch. The circumflex comes from the posterior cord in common with the musculo- spiral. It is traced to the fifth, sixth, and seventh cervical nerves. It lies behind the third portion of the axillary artery where it passes downward and outward to the lower border of the Subscapularis muscle; it then passes through the quadrilateral space with the posterior circumflex artery. This space is hounded above by the Teres minor, below by the Teres major, on the outside by the Humerus, and on the inside by the long head of the Triceps. It gives an articular branch to the shoulder-joint which pierces the capsular ligament : it then divides into a superior and inferior branch. The -ulterior branch winds around the surgical neck of the humerus with the posterior circumflex vessels., along the Deltoid to its anterior border, supplying the muscle and the integu- ment over its lower part. The inferior branch supplies the Deltoid and Teres minor. The part supplying the Teres minor has a ganglion upon it. It then pierces the deep fascia to supply the integument on the lower two-thirds of the posterior surface of the Deltoid and the integument over the long head of the Triceps. A branch from the circumflex nerve supplies the long head ol the ♦Biceps, the head of the humerus and the shoulder joint. The median nerve is formed by a branch from the outer cord and one from the inner cord. Its fillers may be traced to the fifth, sixth, seventh and eighth cervical and first dorsal nerves. This junction takes place a1 the lower border of the Teres minor as a rule, although it may be almost to the elbow-joint. The branch from the inner cord crosses the third pari of the axillary artery; the nerve lies then to the outer side of axillary artery, passing to the distal extremity of the arm to pass between the two heads of the Pronator radii teres. In the axilla it lies first to the outer side of the third part of the axillary artery, in the ►When the long head ol the Biceps slips from Its normal position 11 presses on this nerve and produces pain — "Glass .inn." This can be cured osteopathlcally. PLATE WWII DEEP CERVICAL NODE AXILLARY NODES EPICONDYLAR NODE OR GLAND MEDIAN CEPHALIC Lymphatics \m> Veins oi the Qppee Extremity Superficiai 100 ANATOMY IN A NUTSHELL. 101 arm it lies to the side of the brachial artery and after crossing it t<> the inner side of the artery. It lias no branches in the arm: at the elbow it gives off two articular branches to the joint. After passing between the two heads of the Pronator radii teres it passes to the distal extremity of the forearm where it passes under the anterior annular ligament. In its course, in the forearm.it first lies between the Flexor sublimis digitorum ami Flexor profundus digitorum, then between the tendon.- of the Flexor sublimis digitorum and Flexor longus pollicis. It supplies all the mus- cles in the first layer of the forearm except the Flexor carpi ulnaris. which are the Pronator radii teres. Flexor carpi radialis. and Palmaris longus: it also sup- plies the one muscle in the second layer which is the Flexor sublimis digitorum. LESSON XXV. The anterior interosseous nerve is given off just below and is accompanied by the anterior interosseous artery to the distal extremity of the forearm lying on the interosseous membrane. The nerve is external to the artery being be- tween the Flexor profundus digitorum and Flexor longus pollicis. This branch supplies the Flexor longus pollicis, Pronator quadratus, and the outer side of the Flexor profundus digitorum. It send- a branch to the wrist-joint, also one to the anterior interosseous artery and to the interosseous membrane, to the medullar}- arteries and to the periosteum of the radius and ulna. It i> worth while to note that the anterior interosseous nerve is a branch from the median. and the posterior Interosseous nerve is a branch of the musculo-spiral nerve, while the anterior ami posterior interosseous arteries are both branches of the same artery, viz.. the common interosseous. The palmar cutaneous branch of the median nerve arises in the distal third of the forearm, passes between the Flexor carpi radialis and Palmaris longus, pierces the deep fascia proximally to the anterior annular ligament and passes over that ligament to the integument and fascia on the palmar surface of the hand. It divides into two divisions, external and internal. The external one supplies the skin over the ball of the thumb ami anastomoses with the anterior cutaneous branches of the musculo-spiral and radial nerves. The internal division supplies the integumenl on the palm, except that on the ulnar side and anastomoses with the palmar cutaneous branches of the ulnar nerve. The median nerve then enters the hand beneath the anterior annular lig- ament. It spreads out and is of a reddish color. It divides into external and internal divisions. It lies upon the flexor tendons and is covered by integu- ment, palmar fascia, and the superficial palmar arch. The external division supplies the Abductor pollicis. Opponens pollicis. ami superficial head ^\ the Flexor brevis pollicis. and occasionally the deep head of that muscle. The other muscles of the thumb are supplied by the ulnar. It then divides into first, second, and third digital branches for the thumb and index finger. The internal division gives off the fourth and fifth digital branches which supply the contiguous sides of the index and middle fingers and the middle ami ring fi] then there are five digital branches from the median nerve. L02 ANATOMY IN A NUTSHELL. The ulnar nerve arises a little below the lower border of the Pectoralis minor, from the inner cord of the brachial plexus. Its fibers may be traced to the eighth cervical and firsl dorsal. It lies on the inner side of the axillary artery, also of brachial artery, until it passes below the insertion of the Coraco- brachialis where it forms an acute angle, and, in company with the posterior branch of the inferior profunda artery, pierces the internal intermuscular septum, then passing down to the groove between the internal condyle and the ole- cranon process it gives off two or three branches to the elbow-joint, then passes between the two heads of the Flexor carpi ulnaris in company with the pos- terior ulnar recurrent artery. In the forearm it lies between the Flexor pro- fundus digitorum ami Flexor carpi ulnaris; in the middle third of the forearm between the same two muscles with the Flexor sublimis digitorum on the other side. It is situated on the inner side of the ulnar artery and crosses the anterior annular ligament on the radial side of the pisiform. In the forearm it gives off branches near the elbow-joint which supply the Flexor carpi ulnaris and the inner part of the Flexor profundus digitorum. The cutaneous branches arise about the middle of the forearm; there are two of these branches. The one most superficial pierces the deep fascia near the wrist to supply the integument and anastomose with the internal cutane- ous. The other branch, which is the deeper one, is called the palmar cutane- ous. It accompanies the ulnar artery, being upon its anterior surface, to the hand. 1 he dorsal cutaneous arises about two or three inches from the wrist; it passes to the dorsal aspect of the wrist under the Flexor carpi ulnaris, super- ficial to the Extensor carpi ulnaris to supply the integument on the ulnar as- pect of the dorsum of the hand and that of the little and half of the ring fingers. The superficial terminal or palmar branch supplies the Palmaris brevis, the hypothenar eminence, the inner side of the little finger on its volar aspect, and the contiguous sides of the little and ring fingers. The deep palmar arch or branch passes between the Abductor minimi digiti and Flexor brevis minimi digiti. then through the Opponens minimi digiti to the deep surf ace of the flexor tendons and their synovial sheaths. It supplies the Abductor minimi digiti, Flexor brevis minimi digiti. opponens minimi digiti, two inner Lumbricales, all the [nterossei, Adductor transversus pollicis, Adductor obliqus pollicis, and inner head of the Flexor brevis pollicis and occasionally the outer head. The ulnar nerve SUppileS eighteen muscles. The musculO-CUtaneOUS or external cutaneous (perforans Casserii) comes from the outer cord and its fibers may be traced to the fifth, sixth, and seventh cervical nerves. It supplies muscles in the arm but no integument, whereas it supplies integument in the forearm but no muscles. It begins opposite the lower border of the I Vctoralis minor, passing outward and downward to pirece the Coraco-brachialis which it supplies. It divides in the substance of this muscle and passes to the outer side of the arm between the Biceps and the Brachialis amicus, supplying these muscles. It sends a branch with the nutri- ent artery into the bone. The branch to the Coraco-brachialis is given off from the nerve close to its origin. Occasionally this muscle is supplied by a separate branch from the outer cord. The branch to the Brachialis amicus ANATOMY IN A NUTSHELL. 103 sends filaments to the elbow-joint. Near the outer border of the arm and a little above the tendon of the Biceps the nerve pierces the deep fascia, anas- tomosing with the proximal external cutaneous branch of the musculo-spiral, passing below the median cephalic vein where it divides into anterior and pos- terior. It then becomes cutaneous. The anterior branch passes along the radial side of the forearm to supply the integument on the outer half of the anterior surface, ending in the thenar eminence. It anastomoses with the radial and the palmar cutaneous branch of PLAT i OBLIQUE. LIGAMENT POST. LIGAMENT The Elbow-Joint — External View the median. It gives off an articular branch to the carpal bones which pierces the deep fascia to pass with the radial artery to the back of the wrist. The posterior branch is smaller than the anterior one. It passes along the posterior aspect on the radial side of the forearm to the wrist. It anastomoses with the radial and the distal external cutaneous of the musculo-spiral. LESSON XXVI. The musculo-spiral is the largest branch of the brachial plexus. It mid the circumflex are the terminal branches of the posterior cord. It supplies mus- cles and integument both above and below the elbow . Its libers may be traced 104 ANATOMY IX A NUTSHELL. to the fifth, sixth, seventh, and eighth cervica] nerves and the first dorsal nerve. It commences a1 the lower border of the Pectoralis major. It first lies behind the third part of the axillary artery in front of the Subscapulars. Teres major, and Latissimus dorsi. After leaving the axilla it lies on the inner side of the upper one-third of the humerus behind the brachial artery and in front of the long head of the 'Triceps, li passes between the two humeral heads of the Triceps in the musculo-spiraJ groove in company with the superior profunda artery. This nerve and the anterior branch of the superior profunda artery perforate the externa! intermuscular septum and pass in the groove between the Supinator longus and Extensor carpi radialis longior on the outer side, and PLATE XXXIX 8'ceps T £ND0N ,'0BLlQ Ut UGAM El u r 0AB/ CUUfi L 'GAMEH T J" The Elbow-Joint — Internal View the Brachialis anticus on the inner side. In the lower part of this gr00V< it divides into the posterior interosseous and radial nerves. The musculo-spiral nerve supplies five muscles vi/... Supinator longus, Extensor carpi radialis longior, Triceps, Brachialis anticus and Anconeus. If we substitute Anconeus for heboid we will have the live muscles attached to the external intermus- cular septum. This nerve has muscular branches (just given), an articular branch, cutaneous branches and two terminal branches, viz., posterior interos- seous and radial. ANATOMY IN A NUTSHELL. 105 Its articular branch is given off from one of the branches to the Supinator longus, Extensor carpi radians longior, or Brachialis anticus to the elbow-joint. Its cutaneous branches supply the integumenl of the arm over the musculo- spiral groove; in the forearm over the radial aspect of the dorsum of the forearm as far as the wrist. The internal cutaneous branch given off in the axilla crosses the tendon of the Latissimus dorsi, then passes behind the intercosto-humeral nerve, pierces the dee]) fascia to supply the integument on the middle of the back of the arm nearly to the olecranon. Ii gives off its upper and lower ex- ternal cutaneous before it pierces the external intermuscular septum; the upper one perforates the outer head of the Triceps, accompanies the cephalic vein to the elbow and supplies the integument over the lower half of the outer and inner aspect of the arm. The lower one is the larger. It arises behind the external condyle to simply the integument on the lower part of the arm and radial as- pect of posterior surface of forearm as far as the wrist. It anastomoses with the musculo-spiral and internal cutaneous. The radial nerve is the smaller of the two terminal branches of the musculo- spiral and is purely cutaneous. It runs towards the wrist under the Supinator longus. It passes in front of the elbow. radial recurrent a., and Supinator bre vis. In the middle third of the forearm it lies parallel to. and on the outer side of. the radial artery, superficial to the Pronator radii teres muscle. The nerve turns backward beneath the tendon of the Supinator longus and becomes cu- taneous by piercing the deep fascia of the outer side of the forearm about three inches from its distal extremity: here it divides into two branches, external and internal. The externa! one supplies the integument on ball and outer border of thumb, anastomosing with the musculo-cutaneous. The inner one anastomoses with the musculo-cutaneous and dorsal branch of the ulnar, sup- plying integument on the dorsum of the hand and fingers in a manner somewhat similar to that of the median nerve on the palmar surface, the first branch to the inner side of the thumb, the second to the radial side of the index finger, the third to the adjacent sides of the index and middle fingers, and the fourth to the adjacent sides of the middle and ring fingers. The posterior-interovseous nerve passes around the outer side of the prox- imal end of the radius, through the substance of the Supinator brevis to the back of the forearm, then passe> between the superficial and deep layers to about the middle of the forearm where it passes beneath the Extensor longus pollicis to lie on the interosseous membrane on which it passes almosl to the wrisl in company with the posterior interosseous artery. At the the distal ex- tremity it accompanies the terminal branch of the anterior interosseous artery. It then passes through the rourth opening of the posterior annular ligament to the back of the wrist where it has a ganglion upon it. from which are given oft its branches of distribution to the wrist-joint and carpal joint.-. It supplies all the muscles on the back of the forearm excepl the Anconeus. It supplies nine muscles in all. viz., Extensor communis digitorum, Extensor minimi digiti, Extensor carpi ulnaris, Supinator brevis, Extensor ossis metacarpi pollicis, Extensor longus pollicis, Extensor brevis pollicis, Extensor indicis, all ol which 106 ANATOMY IN A NUTSHELL. are on the back of the forearm, and Extensor carpi radialis brevior in the radial region. The internal cutaneous nerve comes from the inner cord and its fibers may be traced to the eighth cervical and first dorsal nerves. The cutaneous branch perforates the deep fascia in the axilla to supply integument over the back of the arm nearly to the elbow. About half way along the inner side of the arm it pierces the deep fascia with the basilic vein, dividing into anterior and pos- terior branches. The anterior branch passes to the forearm either in front of, or behind the median basilic vein, supplies integument of the ulnar aspect of the anterior surface of the forearm as far as the wrist and communicates with the ulnar. The posterior branch passes in front of the internal condyle to the forearm where it supplies integument on the ulnar aspect of the dorsum of the forearm as far as the wrist. Above the elbow it anastomoses with the lesser internal cutaneous and at the wrist with the dorsal cutaneous of the ulnar. The lesser internal cutaneous (nerve of Wrisberg) is the smallest branch of the brachial plexus. It comes from the inner cord and its fibers are traced to the first dorsal and sometimes the eight cervical in addition. In the axilla it communicates with the intercosto-humeral forming one or two loops. It is sit- uated on the inner side of the axillary often being separated from the vein by the ulnar nerve. About the middle of the arm it pierces the dee]> fascia supply- ing integument over the olecranon. LESSON XXVII. The hand.— (Plates XXVI-XXVII.) — There are twenty-seven bones in the hand while there are but twenty-six in the foot, there being one more bone in the carpus (wrist ) than in the tarsus (ankle.) The number of muscles in the hand is twenty, the same as in the foot. There are also twenty muscles in the forearm. In the thumb (thenar eminence) there are five muscles, viz., Ab- ductor pollicis, < >pponens pollicis ( Flexorossis metacarpi pollicis.) Flexor brevis pollicis, Adductor obliquus pollicis, and Adductor transversus pollicis. The first two gel the median nerve, the third one gets both the median and the ulnar nerves, while the last two get the ulnar. On the ulnar side of the hand there is the Palmaris brevis and the three muscles of the little finger (hypothenar emi- nence!, viz.. A lull ict or minimi digit i. Flexor brevis minimi digiti, and theOpponens minimi digiti (Flexor ossis metacarpi minimi digiti). All these are supplied by the ulnar nerve. In the middle palmar legion there are four Lumbricales, f our Dorsal interossei, and three Palmar interossei. The two outer Lumbricales are supplied by the median nerve, and the two inner ones and the seven Interossei by the ulnar nerve. The bones in the carpus are in two rows, those of the first row. beginning on the radial side are the scaphoid, semilunar, cuneiform, and pisiform, and those in the second row beginning on the radial side are the trape- zium, trapezoid, os magnum, and unciform. The five beyond the carpus are called the metacarpals, and the fourteen in the fingers and thumb are the phal- langes. Then the eighl carpal, plus the five metacarpal, plus the fourteen phalanges, make the twenty-seven bones of the hand. ANATOMY IN A NUTSHELL. 107 The scaphoid ossifies the sixth year. It articulates with five bones, viz.. radius proximally. trapezium and trapezoid distallv. and os magnum and semi- lunar internally. It has one muscle attached, the Abductor pollicis. The blood supply of the carpal bones is the anterior and posterior carpal arch, and a large branch from the anterior interosseous, and small branches from the pos- terior interosseous. The semilunar ossifies the fourth year. It articulates with five bones, viz.. radius proximally. os magnum and unciform distallv. scaphoid and cuneiform CAPSULAR LIGAMENT INT. LATERAL LISA! -1ENT \\\ X .-X P0 \]^2i^ A *l 1 '^\ It',' POST. RADIO-ULNAR LIGAMENT EXT. LATERAL LIGAMENT. Tin: Wrist-Joint — Posterior View on either side. It has no muscle attached. The blood supply i- the same as the carpus. The cuneiform ossifies the third year. It articulates with three bone-. viz., semilunar externally, pisiform in front, and unciform distally, and with the triangular interarticular fibro-cartilage which separates it from the distal end of the ulna. There are no muscles attached to this bone. The pisiform ossifies the twelfth year. It articulates with one bone, the cuneiform. It has two muscles attached. Flexor carpi ulnaris and Abductor minimi diuiti. 108 ANATOMY IN A NUTSHELL. The trapezium ossifies the fifth year, and articulates with four bones, viz., scaphoid proximally, trapezoid and second metacarpal internally, and the first metacarpal distally. It has three muscles attached, Abductor pollicis, Flexor brevis pollicis, Flexor ossis metacarpi pollicis. and occasionally the Extensor ossis metacarpi pollicis. 'The trapezoid ossifies the eighth year. It articulates with four hones, the scaphoid proximally, second metacarpal distally, trapezium externally, and the os magnum internally. It may have a few fibers of the Adductor obliquus pollicis attached. PLATE XLI CAPSULAR LIGAMENT EXTERNAL LATERAL LIGAMEN1 Tiii: Wrist-Joint — Anterior View The OS magnum ossifies the first year. It articulates with seven bones, scaphoid and semilunar proximally, second, third, and fourth metacarpal dis- tally, trapezoid on the radial side, and the unciform on the ulnar side. It has one muscle attached, the Adductor obliquus pollicis. The unciform ossifies the second year. It articulates with five bones, semi- lunar proximally, the fourth and fifth metacarpal distally, the cuneiform inter- nally and the os magnum externally. It has three muscles attached, Flexor ANATOMY IN A NUTSHELL. 109 carpi ulnaris, Flexor ossis metacarpi minimi digiti, and Flexor brevis minimi digiti. Metacarpal bones. — (Plate VII.) — Each one has two centers, one for the shaft and one for the distal extremity, except the metacarpal of the thumb and it has one for the proximal extremity. The nucleus for the shaft appears about the eighth or tenth week of intrauterine life, and that for the diaphysis the third year, uniting with the shaft about the twentieth year. Each phalanx has two centers, one for the shaft "which appears the eighth or tenth week, and one for the epiphysis between the third and fifth year, and joins the shaft the eighteenth year. The epiphysis for each phalanx is proximal, so the nutrient artery runs towards the distal end (Principle III, Lesson I). The center for the distal phalanx is at the distal extremity of the shaft, while that for the other phalanges is at the center of the shaft. The metacarpal of the thumb articulates with two bones, viz.. trapezium proximally. and the first phalanx of the thumb distally. It has four muscles attached, Extensor ossis metacarpi pollicis, Flexor ossis metacarpi pollicis, Flexor brevis pollicis, and the First dorsal interosseous. The second metacarpal articulates with five bones, the trapezium, trapezoid, and os magnum proximally, the third metacarpal internally, and the first phalanx of the index finger distally. It has six muscles attached, the First and Second dorsal interossei. Extensor carpi radialis longior on the dorsal aspect of the bone and the Extensor carpi radialis, First palmar interosseous, and the Adductor obliquus pollicis on the palmar aspect of the bone. The third metacarpal artic- ticulates with four bones, os magnum proximally, the second metacarpal ex- ternally, the fourth metacarpal internally, and the first phalanx of the middle finger distally. It has six muscles attached; on the dorsal aspect the Second and Third dorsal interossei, and the Extensor carpi radialis brevior and on the palmar aspect the Adductor transversus pollicis. Adductor obliquus pollicis, and Flexor carpi radialis. The fourth metacarpal articulates with five bones. os magnum and unciform proximally, os magnum and third metacarpal exter- nally, the fifth metacarpal internally and the first phalanx of the ring finger distally. It has three muscles attached; on the dorsal aspect the Third and Fourth dorsal interossei, and on the palmar aspect the Second palmar inter- osseous. The fifth metacarpal articulates with three hones, the unciform prox- imally, the unciform and fourth metacarpal externally, and the lirst phalanx of the little finger distally. It has five muscles attached; the Extensor carpi ulnaris, Plexor carpi ulnaris, Third palmar Interosseous, Fourth dorsal inter- osseous, and Plexor ossis metacarpi minimi digiti. Flood supply of the first metacarpal bone is derived from the princeps pollicis artery; it enters on the ulnar side, and is directed towards the head of the hone. For the second metacarpal bone, the nutrient artery P derived from lirsl palmar interosseous. It enters on the ulnar side, and is directed towards the proximal end or base of the bone. For the third metacarpal hone ih< nutrient artery is derived from the interosseous; il enters as a rule, on the radial side and is directed towards the base. 110 ANATOMY IX A NUTSHELL. For the fourth metacarpal bone the nutrient artery is furnished by the second interosseous; it enters on radial side of shaft, and is directed towards the proximal end. For the fifth metacarpal bone the nutrient artery is derived from the third interosseous; it enters the shaft on the radial side, and is directed to- wards the proximal end. (Plate VI 1 . page 33.) LESSON XXVIII. The first phalanx of the thumb articulates with two bones, the metacarpal of the thumb proximally, and the second phalanx distally. It has five muscles attached, the Al idiictor pollicis, Adductor obliquus, Adductor transversus pollicis. Extensor brevis pollicis. and the Flexor brevis pollicis. The second, or Last phalanx of the thumb articulates with one bone, the first phalanx of the thumb. It has two muscles attached, the Extensor longus pollicis and the flexor longus pollicis. The first phalanx of the index finger articulates with two bones the second metacarpal proximally. and the second phalanx of the index finger distally. It has two muscles attached, the First dorsal interosseous, and the First palmar in- terosseous. The second phalanx of the index finger articulates with two bones, the first phalanx proximally, and the third phalanx distally. It has three muscles attached, the Extensor communis digitorum Extensor indicis. and the flexor sublimis digitorum. The last phalanx of the index finger articulates with one bone, the second phalanx proximally. It has three muscles attached, the Extensor communis digitorum, Extensor indicis. and Flexor profundus digitorum. The first phalanx of the middle finger articulates with two hones, the metacarpal of the middle finger proximally. and the second phalanx of the middle finger distally. It has two muscles attached, the Second and Third dorsal interossei. The second phalanx of the middle finger articulates with two bones, the first phalanx proximally. and the third phalanx distally. In has two muscles attached, the Extensor communis digitorum and Flexor sublimis digitorum. The third phalanx articulates with one hone, the second phalanx proximally. It has two muscles attached, the Extensor communis digitorum and flexor profundus digitorum. The lir>t phalanx of the ring finger articulates with two bones, the fourth metacarpal proximally. and the second phalanx of the ring finger distally. It ha- two muscles attached, the Fourthdorsal interosseous and the Third palmar interosseous. The second phalanx of the ring finger articulates with two bones. the first phalanx of the ring finger proximally, and the third phalanx distally. It has two muscles attached, the Extensor communis digitorum and Flexor sublimis digitorum. The third phalanx of the ring finger articulates with one hone, the second phalanx proximally. and has two muscles attached, the Ex- tensor communis digitorum ami flexor profundus digitorum. The first phalanx of the little finger articulates with two bones, the fifth metacarpal proximally. and the second phalanx of the little finger distally. It ha- three muscles attached, the Extensorbrevis minimi dieiti, Abductor minimi ANATOMY IN A NUTSHELL. Ill digiti, and the Third palmar interosseous. Thesecond phalanx of the little finger articulates with two hones, the first phalanx proximally and the third phalanx distally. It has three muscles attached, the Extensor communis digitorum. Extensor minimi digiti, and Flexor sublimis digitorum. The third phalanx of the little finger articulates with one hone, the second phalanx prox- imally, and has three muscles attached, the Extensor communis digitorum Extensor minimi digiti. and Flexor profundus digitorum. Abductor pollicis. — Description. — (Plate XXXI.)- This is a thin flat muscle placed immediately beneath the integument. It passes outward and PLATE XLII Showing the Synovial Membranes of the Wrist downward and terminates in a flat tendon, sending a slip to join the tendon of the Extensor longus pollicis. ORIGIN. — Ridge of trapezium and annular ligament. (Plate XXVII.) Insertion.- Radial side at base of first phalanx of thumb. (Plate XXVII.) Action.— Abducts the thumb. Nerve Supply. Sixth cervical through the median. 112 ANATOMY IN A NUTSHELL. Blood Supply. From superficialis volae artery. Opponent pollicis. ■■-( Flexor ossis metacarpi pollieis.) — Description. — (Plate XXXI.) This is a small triangular muscle placed beneath the preceding. Origin.— (Plate XXVI.)— Palmar surface of trapezium and annular ligament. I nsertii in. Whole length of metacarpal of thumb on radial side. (Plate XXVI. Action. Flexes metacarpal of thumb. Nerve Supply. Sixth cervical through the median. Blood Supply. From radial and superficialis volse arteries. Flexor brevis pollicis. Description. — (Plate XXXI.) — This muscle con- sists of two portions outer and inner, having separate origins and insertions. The outer portion is the more superficial and has a sesamoid hone developed in its tendon. The inner and deeper portion is very small. Origin.- (Outer portion) Trapezium and outer two-thirds of annular lig- ament. ( Inner portion) Ulnar side of first metacarpal bone. (Plate XXVIII.) Insertion. — Both sides of base of first phalanx of thumb by two tendons. (Plate XXVII.) Action.- Flexes thumb. Nerve Supply. — Outer portion, sixth cervical through median; inner portion, eighth cervical through ulnar. Blood Supply. — From radial artery. Adductor obliquus pollicis. — Description. — (Plate XXXI.) — This muscle arises by several slips. The greater number of fillers pass obliquely downward and converge to a tendon which mutes with the tendons of the deeper portion of the flexor brevis and Adductor transversus pollicis, a sesamoid bone being developed in the tendon of insertion. A considerable fasciculus passes ob- liquely outward beneath the tendon of the long flexors to join the superficial portion of the short flexor and the Abductor pollicis. This muscle was formerly described as the deep portion of the Flexor brevis pollicis. Origin.— (1) Os magnum; (2) bases of second and third metacarpal bones; (3) anterior carpal ligaments; (4) sheath of tendon of Flexor carpi radialis. (Plate XXVII.) Insertion.- Inner side of base of first phalanx of thumb. (Plate XXVII.) Action. Moves thumb inward toward index finger. Nerve Supply. Eighth cervical through ulnar. Blood Supply.- From the palmar arches. Adductor transversus pollicis. Description. — (Plate XXXI.) — This is the mosl deeply seated of tins group of muscles; it is triangular in form, arising by its broad base. The libers converge toward their insertion which is in com- mon with the inner part of the Flexor brevis pollicis and the Adductor obliquus pollicis. From this common tendon a slip is prolonged to the Extensor longus pollicis. Origin. bower tw< -thirds of metacarpal of middle finger on palmar sur- face. (Plate XXVII.) Insertion. Ulnar side of base of firsl phalanx of thumb by common ten- don. (Plate XXVU i ANATOMY IN A NUTSHELL. 113 Action. — Draws thumb towards median line. Xerye Supply. — Eighth cervical through ulnar. Blood Supply. — From the palmar arches. LESSOX XXIX. Palmaris brevis. — Description. — (Plate XXXI.) — This is a thin, quad- rilateral muscle placed beneath the integument on the ulnar side of the hand. The palmar fascia is in relation with its deep surface and separates it from the ulnar vessels and nerve. Origin. — Annular ligament by tendinous fasciculi and palmar fascia. Insertion. — Skin on inner border of palm. (Plate XXXI.) Action. — Corrugates skin of hand. Xera'e Supply. — Eighth cervical through the ulnar. Blood Supply. — The ulnar artery. Abductor minimi digiti. — Description. — (Plate XXXI.) — This muscle is situa ted on the ulnar border of the palm of the hand. Origin. — Pisiform bone and from the tendon of the Flexor carpi ulnaris. Insertion. — By two slips, the one into ulnar side of base of first phalanx of little finger: the other into ulnar border of the aponeurosis of the Extensor minimi digiti. (Plate XXVII.) Action. — Abducts little finger from middle line of hand. Xerye Supply. — Eighth cervical through the ulnar. Blood Supply. — The ulnar artery. Flexor brevis minimi digiti. — Description. — (Plate XXXI-XXVII.) — The Flexor brevis minimi digiti lies on the same plane as the preceding muscle, on its radial side. It is separated from the Abductor at its origin by the deep branches of the ulnar artery and nerve. This muscle is sometimes wanting; the Abductor is then usually of large size. Origin. — From the convex aspect of the hook of the unciform bone and anterior surface of annular ligament. Insertion. — Inner side of base of first phalanx of little finger. Action. — Flexes little finger. Nerve Supply. — Eighth cervical through the ulnar. Blood Supply. — The ulnar artery. Opponens minimi digiti (Flexor ossis metacarpi minimi digiti). — Descrip- tion. — (Plate XXXI.) — This is a triangular muscle placed immediately beneath the preceding . Origin. — From convexity of hook of unciform bone and contiguous por- tion of annular ligament. (Plate XXVII.) Insertion. — Whole length of metacarpal of Little finger along ulnar mar- gin. (Plate XXVII.) Action. — Draws fifth metacarpal forward so as to deepen hollow of palm. Nerve Supply. — Eighth cervical through ulnar. Blood Supply. — Ulnar artery. Lumbrieales. — Description. — (Plate XXXI) — The Lumbricales are four small fleshy fasciculi, accessories to the deep Flexor muscle. 1 14 ANATOMY IN A NUTSHELL. Origin. Tendons of deep flexor. (Plate XXXI.) [nsertion.- Tendinous expansion from Extensor communis digitorum on hack of each finger. \i i ion. To flex firsl phalanges. Nerve Si pply. The two outer Lumbricales by the sixth cervical through the third and fourth digital branches of the median; the two inner by the eighth cervical through deep palmar branch of ulnar. The third lnm- brical receives the median in almost half the cases. Blood Si pply.— From digital branches of the superficial palmar arch and the interosseous branches of the deep palmar arch. Dorsal Interossei. — Description. — ( 1 dates | XXXI Y-XXX [II.) —These small muscles, four in number, occupy the intervals between the metacarpal bones. They are bipenniform. Between the double origin of each is a narrow triangular interval, through the firsl of which passes the radial artery; through each of the miter three passes a perforating branch from the deep palmar arch. The Abductor indicis or the Firsl dorsal interosseous is the largest of these muscles. Origin. — by two heads; (1) Outer head from upper half of ulnar border of first metacarpal hone. ('_') Inner head from almost the whole length of the radial border of the second metacarpal bone. (Plate XXVI.) Insertion. Into the radial side of base of first phalanx of index finger. 'The Second dorsal interosseous. Origin. By two heads from the adjacent sides of the second and third metacarpal. ( Plate XXVI. J Insertion into the radial side of the first phalanx of middle finger. The Third dorsal interosseous. ORIGIN. By two heads from the adjacent sides of the third and fourth meta- carpal bones. (Plate XXVI.) Insertion. -Into the ulnar side of the firsl phalanx of middle finger. The Fourth dorsal interosseous. Origin. By two heads from the adjacent sides of the fourth and fifth meta- carpal bones. (Plate XXVI.) Insertion. Into the ulnar side of the first phalanx of ring finger. Action. (1) Extend the last two phalanges. (2) Flex the metacarpo- phalangeal joints, (3) Ahdnct the fingers. Blood Supply. From deep palmar and posterior carpal arches. Nerve Supply. Deep branches of the ulnar nerve. The Palmar interossei which are placed on the palmar surface of the sec- ond. Fourth and fifth metacarpal bones are three in number. Their insertion besides being into the bone is into the aponeurotic expansion ^( the common tendon of the same finger, the same as the dorsal interossei. (Plate XXXV.) Firsl palmar interosseous. Origin. By one head from the ulnar side of the second metacarpal hone. Insertion. Into the ulnar side of the firsl phalanx of index finger. Second palmar interosseous. < >RIGIN. By one head from the radial side of the fourth metacarpal hone ANATOMY IN A NUTSHELL. 115 Insertion. — Into the radial side of the first phalanx of ring finger. Third palmar interosseous. Origin. — By one head from the radial side of the fifth metacarpal bone. Insertion. — Into the radial side of the first phalanx of little finger. Each finger has two [nterossei muscles except the little finger. The Ab- ductor minimi digiti takes the place of one of the pair. Nerve Supply. — Ulnar. Blood Supply. — Deep palmar arch. Action. — Same as the Dorsal interossei,bu1 these adduct instead of abduct. LKSSOX XXX. Fascia of the arm. — Just beneath the skin is the superficial fascia which has two layers, a superficial one consisting mainly of adipose tissue, and a deep one which is fibrous in structure and is in contact with the deep fascia. The superficial nerves; vessels and lymphatics lie between these two layers. The deep fascia of the arm forms a sleeve which encloses the muscles and most of the vessels and nerves. It is continuous with the fascia of the chest. back, shoulder above by being attached to the clavicle, the scapula ami the spine, and to that of the forearm by being attached to the condyles of the hu- merus and olecranon of the ulna. It is thin over the Biceps, thick over the Triceps; strengthened on the inner side by fibers from the tendon of the Pec- toralis major and Latissimus dorsi, on the outer side by fiber- from the tendon of the Deltoid; the axillary fascia is also continuous with it. The external in- termuscular septum extending from the insertion of the Deltoid to the External condyle and attached to the superior condylar ridge joins the inner surface of the deep fascia, thus dividing the sleeve or cylinder of fascia into an anterior and posterior compartment, the anterior one having flexor muscles in it and the the posterior one extensor muscle.-. This septum is pierced by the musculo- spiral nerve and superior profunda artery from behind forward. It has five muscles attached to it, viz.. Deltoid, Brachialis anticus, Triceps. Supinator longus, and Extensor carpi radialis longior. In these five muscles if we sub- stitute the Deltoid for Anconeus we will have the five muscles supplied by the musculo-spiral nerve. The internal intermuscular septum i- thicker than the external one: it extends from the insertion of the Coraco-brachialis to the internal condyle ^\ the humerus, being attached to the supracondylar ridge to the inner surface of the sleeve of fascia of the forearm. It also divides the muscles into an anterior and posterior division. Il has three muscles attached to ii. vi/... the Triceps, Brachialis anticus, and Coraco-brachialis, and occasionally the Pronator radii teres. If we stubsitute the Triceps for Biceps in this group of muscles we will have the muscles supplied by the niusculo-cutaneotis nerve. The basilic vein pierces the deep fascia at the junction n\' the lower third with the middle third of the humerus. The deep fascia of the forearm is continuous with thai of the arm at the elbow and with that of the hand ;it the wrist. It passes over the anterior an- lit) ANATOMY IN A NUTSHELL. nular ligament which is in reality the aponeurosis which separates the first and second layers of the muscles of the forearm. It passes from the pisiform bone and unciform process to the scaphoid and trapezium; it is a strong fibrous band. At the posterior aspect it is thickest where it is attached to the sides of the triangluar posterior surface of the olecranon and to all of the posterior ridge of the ulna. It receives a band from the bicipital fascia below the internal con- dyle in front, and an aponeurosis from the insertion of the Triceps behind. It is pierced by a communicating vein at the cubital fossa. The posterior annular ligament is strengthened by transverse fibers and passes from the outer border of the lower end of the radius across to the inner side of the pisiform and cuneiform bones, its inner surface being attached to the ridge on the posterior surface of the radius. It makes six canals for the passage (if the extensor tendons; the first canal has the Extensor ossis metacarpi pol- licis and Extensor brevis pollicis; the second the Extensor carpi radialis longior and Extensor carpi radialis brevior; the third the Extensor longus pollicis; the fourth the Extensor communis digitorum, which is in the superficial layer, and the Extensor indicis, which is in the deep layer; the fifth, the Extensor minimi digiti which is in the superficial layer; the sixth, the Extensor carpi ulnaris which, is in the superficial layer. The anterior annular ligament has nine muscles attached to it, all those of the thumb except the Adductor transv< rsus pollicis, and all those of the little finger except the Abductor minimi digiti; then there are four of the thumb and two of the little finger, making six ; besides these six it has the Flexor carpi ulnaris, Palmaris longus, and Palmaris brevis, making the nine. The tendon of i he Flexor carpi radialis pierces the anterior annular ligament and the Palmaris Longus passes over it. but is also attached to it. The median nerve and the tendon- of three muscles pass under it; the muscles are the Flexor sublimis digitorum, flexor profundus digitorum, and Flexor longus pollicis. Fascia of the hand. — The fascia on the back of thehand isthinand is com- posed mostly of transverse fibers. This fascia is a continuation of the posterior annular ligament. It connects the extensor tendons together on the back of the hand. Between the fingers it dips down to join the web which connects the bases of the fingers. The deep layer is attached to the back of the meta- carpal.- and covers the Dorsal intemssei. Palmar Fascia. The deep palmar fascia consists of strong fibrous tissue covering the palmar surface of the hand. It is for the most part formed by the expansion of the tendons of the Palmaris longus. It is also continuous with the anterior annular ligamenl proximally. It has a central and two lateral portions. The central portion is triangular with the apex towards the wrist and base towards the fingers. The superficial part is formed by longitudinal filier- and the deep part bytransverse fibers. Its base is divided into four pro- cesses wh'n h j< in the ligamenta vaginalis of the finger tendons. (Plates XXIX- XX XI o Ligamenta vaginalis are fibrous -heaths or theca over the flexor tendons. They are so attached to the phalanges as to form osseo-aponeurotic canals These -heaths are strong opposite the middle of the first and second phalanges, ANATOMY IN A NUTSHELL. 117 but much thinner opposite the joints. Each sheath is lined by a synovial mem- brane, which is reflected upon the tendons. The synovial sheaths for the ten- dons of the thumb and little finger are continuous with the two synovial bursa' beneath the anterior annular ligament, but those for the intervening digits terminate in a sac near the metacarpophalangeal articulation. The outer por- tion (thenar fascia) covers the ball of the thumb. Proximally it is attached to the anterior annular ligament, the tendons of the Palmaris brevis and apo- neurosis from the tendons of the Extensor ossis metacarpi pollicis. It contin- ues distally with the ligamenta vaginalia of the Flexor longus pollicis. The inner portion or hypothenar fascia, is triangular with the apex proximally and at- tached to the anterior annular ligament and deep fascia of the forearm at the inner side of the wrist : distally it is covered above by the Palmaris brevis. (Plate XXX.) LESSON XXXI. Besides the arterial, venous and capillary circulation there is a lymphatic circulation extending over the body by beginning in microscopical spaces and extending until they form lymphatic vessels. These vessels are enlarged by receiving radicles or tributaries in a like manner to the veins. Along the course of the lymphatic vessels are lymphatic nodes, sometimes called glands. There are in the neighborhood of seven hundred of these nodes. They are situated principally in the abdominal and thoracic cavities. In the upper extremity they are found no farther than the elbow. In the lower extremity they are found no farther than the popliteal space, as a rule: however, a few may be found on the anterior tibial artery. These nodes manufacture the white blood corpuscles. There are four other places in the body where they are manu- factured. viz.. spleen, thymus gland, thyroid gland and the red marrow of b The lymph of all the body, except the right side of the head, the right side of the thorax, the right arm, and the upper surface of the liver collects into a large duct, the left lymphatic or thoracic duct. It is called thoracic duct be- cause it passes through the thorax. It is about fifteen or eighteen inches long. It begins in front of the second lumbar vertebra where it is enlarged (recep- taculum chyli) and extends through the thorax, through the superior opening of the thorax, and empties into the left subclavian or innominate vein. The heart is the main factor in the circulation of the lymph. The other factors will be learned in physiology. The lymphatic vessels and nodes, like the veins of the arm, are in two sets, a superficial and deep set. After the blood has passed through the arteries and capillaries, nourishing the various parts, it comes back by means of the vein.-. The superficial veins of the distal extremity receive the name radial, an- terior and posterior ulnar, and median. They lie between the two layers of the superficial fascia. (Plate XXXVII.) The anterior ulnar is formed by a network of veins at the anterior and ulnar side of the hand and wrist. It extends on this aspect of the forearm t<> the bend of the elbow where it joins the posterior ulnar to form the common ulnar. lis ANATOMY IN A NUTSHELL. The posterior ulnar begins a1 the ulnar aspecl of the wrist, from which it passes to the bend of the elbow to join the anterior ulnar. The common ulnar runs upward and outward to join the median basilic to form the basilic, which pierces the deep fascia in the inner side and below the middle of the forearm to ascend with the brachial artery and continues as the axillary vein. At times the common ulnar is absent, the anterior and posterior ulnar joining the median basilic separately. The median vein is formed on the palmar surface of the hand and passes to the bend of the elbow where it divides into two branches, median basilic and median cephalic. It communicates with the venae comites of the ulnar be- fore it reaches the elbow. This communicating link is called the deep median vein. The radial begins on the dorsum of the thumb and radial aspect of the hand; ii passes to the elbow-joint where it joins the median cephalic forming the cephalic. The cephalic vein passes on the outer side of the Biceps to the groove be- tween the Heboid and the Pectoralis major; it perforates the deep fascia and the costo-coracoid membrane to end in the axillary vein below the clavicle. It occasionally connects with the external jugular or subclavian by a branch in front of the clavicle called the jugular cephalic. The deep veins of the upper extremity accompany the arteries; they are called venae comites and are connected along their course by transverse branches. The digital arteries have venae comites which unite at the base of the fingers to end in venae comites of the superficial palmar arch. Those of the radial side accompany the superficialis volae,while those of the ulnar side end in the deep ulnar veins. The veme comites of the ulnar and radial unite to form the brachial venae comites. The venae comites of the anterior and posterior inter- osseous unite at the proximal extremity of the forearm, ending in the ulnar venae comites. The deep palmar veme comites empty into the radial externally and the ulnar internally. The brachial veme comites are formed by those of the forearm; they accompany the artery and empty into the axillary just above the lower border of the tendon of the Latissimus dorsi. The axillary vein is a continuation of the basilic. It accompanies the axil- lary artery and becomes the subclavian vein at the upper extremity of the axilla. It has a pair of valves opposite the lower border of the Subscapularis. It receives radicles corresponding to the branches of the axillary artery. It also receives the cephalic vein. ANATOMY IN A NUTSHELL. 119 The axilla is the anatomical space through which passes the brachial plexus and the axillary vessels. It is filled with lymphatic vessels and nodes and areo- lar tissue. It is pyramidal in shape,having four sides, a base. and an apex. The apex corresponds to a point between the clavicle, the upper part of the scapula and the first rib. The base is the arm-pit which is made by fascia passing from the lower borders of the Latissimus dorsi behind and the Pectoraiis major in front. The anterior margin of the base is higher than the posterior margin. This space is narrow externally, but broad internally. Its boundaries are as follows: Plate XVI. In Front: — (1) Pectoraiis major. (2) Pectoraiis minor. Behind: — (1) Subscapulars (above,) (2) Teres major and (3) Latissimus dorsi (below.) Outer Side: — (1) Humerus, 2) Biceps, (3) Coraco-brachialis. Ennek Side: — (1) First four ribs and their intercostal spaces. (2) a part of the Serratus magnus. The axillary vessels, brachial plexus, branches of the intercostal nerves, lymphatic nodes, all connected by areolar tissue and fat lie in this space. In finishing the arm it is well to review the cutaneous nerve supply of the hand which is as follows: Plate XXXVI. All the integument on the ulnar side of the middle line of the ring finger on both palmar and dorsal surfaces of the hand is supplied by the ulnar nerve. This line on the dorsum of the hand may be drawn through the middle OF THE MIDDLE FINGER INSTEAD OF THE RING FINGER. All (ill the radial side of this line on palmar surface is supplied by the median, on the dorsal surface by the radial. The radial nerve extends to the base of the thumb nail, to the distal interphalangeal joint of index finger and not quite to the proximal interphal- angeal joint of middle finger, and sends a few twigs to the skin of the metapha- langeal articulation of ring finger. The parts of the dorsal of the thumb, index. middle and ring fingers not supplied by the radial get the median. The synovial membrane of the wrist (Plate XLII.) This membrane con- sists of five portions. First portion is called membrana sacciformis and is between the interarticular fibro-cartilage and the ulna, also extending between the radius and ulna. The second portiox is between the radius and inter- articular fibro-cartilage proximally and the scaphoid, semilunar and cuneiform distally. The third portion is between the trapezium and metacarpal nl the thumb. The fourth portion is large and extends between the scaphoid, semilunar and cuneiform proximally and after sending septa between the bones of the second row of the wrist ends by separating this second row from the sec- ond, third, fourth and fifth metacarpal bones distally. It also sends projec- tions between the metacarpal bones just mentioned. Tim: fifth PORTION is between the cuneiform and pisiform bones. 120 ANATOMY IN A NUTSHELL. REVIEW QUESTIONS. 1. I trim.- Anatomy. 2. Define each of its nine divisions. :;. ( rive three definitions for Aponeurosis. I. What IS a tendon? .",. Give two definitions for Sinus, ft. Define Apophysis 7. Define Epiphysis. 8. Which way do the nutrient arteries run in the bones of the arm? !t. Which way do the nutrient arteries run in the bones of the leg? 10. ( rive four rules tor Epiphysis. ll.i rive functions of Periosteum. 12. How does a long hone grow in length, also in thickness? L3. Name the ninety long hones. 11. Name the forty flat horn-. 1."). Name the forty irregular bones, lfi. Name the thirty short bones. 1 7. Name eight eminences on bones. 18. Name fourteen prominences on bones. 19. Name five articular cavities in bones. l'ii. Name ten non-articular cavities in bones. 21. Name the bones of the body and tell what each means. 22. Now many muscles in the body? 23. Name six ways in which muscles take their names. 2 1. What is the origin of a muscle? 25. Whal is the insertion of a muscle? 26. Give parts thai make a joint. 27. < rive Hilton's law. 28. ' uve all subdivisions of synarthrosis and an example of each. 29. Same of A.MPHIARTHROSIS. 30. Same of DIARTHROSIS. 31. How do ligaments take their names? 32. What is a muscular nerve? .",:;. What is a cutaneous nerve? 34. What is a musculo-cutaneous nerve? :;.". Give live principles concerning nerve roots and their branches. 36. Give definition for nerve center. :;7. Give name, distribution, function ami method of exit of the 1st cranial nerve. 38. Same of 2nd cranial nerve. .'!'.). Same of 3rd cranial nerve. Hi. Same of 1th cranial nerve. II. Same of 6th cranial nerve. •12. Same of tith cranial nerve. ANATOMY IN A NUTSHELL. 121 43. Same of 7th cranial nerve. 44. Same of 8th cranial nerve. 4o. Same of 9th cranial nerve. 46. Same of 10th cranial nerve. 47. Same of 11th cranial nerve. 48. Same of 12th cranial nerve. 49. What is the lesser circulation of the blood? 50. What is the greater circulation of the blood? 51. Who demonstrated the circulation of the blood? 52. Where is the purest blood in the body found? 53. What kind of muscle is the heart? 54. Capillaries are not found in what structures'.' 55. Which are the larger, arteries or veins? 56. What do you understand by anastomosis? 57. Give rule for arteries and veins above and below the diaphragm. 58. Name >ome of the veins that do not have valves. 59. Trace the fetal circulation. 60. Name the things obliterated at birth in the fetal circulation. 61. The eight cervical nerves leave the spinal cord above the spinous process of what cervical vertebra? 62. The first six dorsal nerves leave the spinal cord between the spinous processes of what vertebrae? 63. The lower six dorsal nerves leave the spinal cord between the spinous processes of what vertebrae? 64. The five lumbar nerves leave the spinal cord between the spinous processes of what vertebrae? 65. The five sacral nerves leave the spinal cord between the spinous pro- cesses of what vertebrae? 66. Bound the Axilla. Ii7. Bound the Quadrilateral Space. 68. What pierces the Costo-coracoid .Membrane? 69. Describe the Costo-coracoid .Membrane. 70. What structures lie in the Axilla'.' 71. What structure- pass through the Quadrilateral Space? 72. What nerves branch from each cord of the Brachial Plexus? 73. What and how many muscles are supplied by the musculocutane- ous? 74. What and how many muscles are supplied by the median? 75. What and how many muscle- are supplied by the circumflex? 70. What and how many muscles are supplied by the musculo-spiral? 77. What and how many muscles are supplied by the ulnar? 78. What and how many muscles are supplied by the Subscapular nerves? 7'.i. The Rhomboid nerves come from which one'.' 80. The Posterior Thoracic comes from which one-'.' 81. What is another mime tor this nerve? 82. The Supra-scapular come- from which ones? 1 22 ANATOMY IN A NUTSHELL. 83. < rive the nerve supply of integument of hand. 84. Give the nerve supply of Lumbricales. 85. < live the nerve supply of [nterossei. 86. Group the musch son forearm; give nerve supply. 87. Wha1 muscles are attached to the External Lateral Ligament? ss. \\ lint muscl< s are attached to the Internal Intermuscular Septum? 89. Wha1 muscles arc attached to the Externa] Int< rmuscular Septum? 90. What thr< e muscL s are attached to the Common Aponeurosis? 91. What passes under the Anterior Annular Ligament? 92. What passes through the Anterior Annular Ligament? 94. W Mat musclt s are attached to Ann i Lor Annular Ligament? 95. What muscles pass through the six openings in Posterior Annular Ligament ? 96. Give the three divisions of Axillary Artery. ( .i7. Give the relations of the first part of Axillary Artery. 98. I rive the relations of the second part of Axillary Artery. 99. < rive the relations of the third part of Axillary Artery. LOO. < rive the branches of each part of Axillary artery. 101. Give relations of Brachial Artery. 102. Name the branches of Brachial Artery. L03. Give the relations of Radial Artery. lo I. Name the branches of the Radial Artery. in."). Give relations of Ulnar Artery. L06. Give the branches of Ulnar Artery. 107. Give relations of Superficial Palmar Arch. ins. What pierces the Coraco-brachialis? 109. What passes between the two heads of the Pronator radii teres? 110. What passes between the two heads of Flexor carpi ulnaris? 111. Whai pierces the Internal intermuscular septum? 112. What pierces the External intermuscular septum? 1 13. Desci Lbe i he ( lubital fossa? 1 1 I. \\ "hat passes through the Cubital fossa? 1 15. Name I be bon< sof 1 be Carpus. I 16. I rive articulation of each hone. 1 17. Which ones have muscles attached to them? lis. What muscles are attached to the Trapezium? 1 19. W hat muscles are attached to the 0s magnum? 120. What musclt - are attached to the Unciform? 121. What muscles arc attached to the Pisiform? 122. W hat musclt - are attached to the .Metacarpal (each hone)? 1 23. What muscles are attached to the Phalanges of the thumb? P_' 1. What muscles are attached to the Phalanges of the fingers? 125. How many bones in the hand? I 'jt\. ( live ligamenl - of clavicle. 127. < rive Ligaments of scapula. 128. Give ligaments of shoulder. ANATOMY IN A NUTSHELL. 123 129. Give ligaments of elbow. 130. Give ligaments of forearm. 131. Give ligaments of wrist. 132. What kind of joint is Sterno-clavicular? 133. What kind of joint is Acromio-clavicular? 134. What kind of joint is the shoulder? 135. What kind of joint is the elbow? 136. What kind of joint is the wrist? 137. From what do cords of Brachial plexus take their names? 138. What (-(inverts the Supra-scapular notch into a foramen? 139. What vessels pass above the Transverse Ligament? 140. What structure passes below the Transverse ligament? 141. What structures go through the Musculo-spiral groove? 142. What holds the arm in position? 143. What forms the Superficial palmar arch? 144. What forms the deep palmar arch? 145. Give the Anastomosis of elbow-joint. 146. How many muscles are attached to the clavicle? 147. How many muscles are attached to the scapula? 148. How many muscles are attached to the humerus? 149. How many muscles are attached to the ulna? 150. How many muscles are attached to the radius? 151. Name the muscles lacking origin or insertion into bone. 152. Describe the deep fascia of arm. 153. Describe the deep fascia of forearm. 154. Describe the Anterior and Posterior Annular ligaments. 155. Describe synovial membranes of wrist. 156. Name principal Flexor and Extensor muscles of hand. 157. What muscles are attached to the greater tuberosity? 158. What muscle is attached to the lesser tuberosity? 159. The pulse is felt between what two tendons? 160. How does the radial artery get into the palm of the hand? 161. How many muscles from elbow to wrist? 162. What nerve lies in the substance of the Supinator brevis? 163. Pronators and flexors are attached to which condyle of humerus? 164. Extensors and supinators to which condyle? 165. What muscles attached to external or anterior bicipital ridge? 166. To the posterior or internal bicipital ridge? 167. What one is inserted in the groove? 168. The Musculo-spiral nerve divides into what branches? 1(19. What kind of nerve is the radial? 170. Give Anterior carpal arch. 171. Give Posterior carpal arch. 172. How does the posterior interosseous artery gel to the back of the forearm? 173. How many muscles in the hand? 124 ANATOMY IN A NUTSHELL. 171. What relation does the posterior interosseous artery bear to the deep layer of muscles of the forearm? I 7"). 1 describe the humerus. 176. With what does it articulate? PLATE XLIII. POSTERIOR LIMIT OF EXTERNAL OBLIQUE. INSERTION OF EXTERNAL OBLIQUE INTERNAL OBLIQUE LUTEUS KESIUS LATISSIMUS DORS!. CREST OF ILIUM TENSOR VAGINAE FEMORIS SAflTORIUS GLUTEUS MINIMUS PECTINEAL RIDGE "ECTINEUS RECTI S ABOOMINIS. PYRAMIOALIS • ODIir.TnR i 0NK5li'> REFLECTEO TENDON OF RECTUS INTERNA,. ILIAC NOTCH ADOIlCTfUl RRFVIS —-"""^ OESCFuomr. niMif. if "USES GRACILIS -fT a OBTURAT V'n \ \ THYROID ^^ T&- ■ ■ . \ ■ ■ '3 ' I {* • ' ■ . ' 1 — GLUTEUS MAXIMUS. POSTERIOR SUPERIOR ILIAC SPINE. POSTERIOR INFERIOR ILIAC SPINE GREATER SCIATIC (ILIO-SCIATIC) NOTCH CAPSULE. ISCHIUM SYNOVIAL MEMBRANE GEMELLUS SUPERIOR SPINE OF ISCHIUM - LESSER SCIATIC NOTCH -GEMELLUS INFERIOR OBTURATOR NOTCH SEMIMEMBRANOSUS QtlADRATUS FEMORIS 'SEMITENDINOSUS AND BICEPS. ADDUCTOR MAGNUS G8TURAT0R EXTERMUS External View of Left Innominate Hone. 177. How many and what muscles attached to humerus, ulna and radius? 17s. What is the tongesl muscle inserted on the humerus? 179. What muscles have attachment to both ulna and radius? L80. With how many bones does the radius articulate? 181. With how many bones doe- the ulna articulate? ANATOMY IN A NUTSHELL. 125 182. What are the two principal veins of the arm? 183. Which one passes through the Axilla? 184. What veins form each? 185. What is the longest nerve in the arm? 186. How many openings in the capsular ligament of the shoulder-joint? 187. Where are the greater and lesser sigmoid cavities? 188. With what does each articulate? 189. Why is the cephalic vein so called? 190. Why are the Lymphatics so called? 191. What is lymph? 192. What else are lymphatics called? 193. What does the lymphatic system include? 194. Over how much of the body does it extend? 195. How many coats have the lymphatics? 196. The lymphatic glands of the arm are divided into how many sets? 197. The lymphatic vessels are how divided? 198. Give blood supply and ossification of clavicle. 199. The same of Scapula. 200. The same of Humerus. 201. The same of Radius. 202. The same of Ulna. 203. The same of Carpus. 204. The same of Metacarpus. 205. The same of Phalanges. 206. What is the largest nerve of Brachial plexus? 207. What separates median basilic vein from brachial artery? 208. Give another name for Supinator longus. 209. Give another name for Extensor brevis pollicis. 210. Give another name for Extensor longus pollicis. 211. Give another name for First dorsal interosseous. 212. Give Acromial rete. 213. Deep branch of ulna passes between what muscles? 214. Give another name for lesser internal cutaneous nerve. 215. Give another name for the long thoracic artery. 216. On which side of the pisiform bone does the ulnar artery cross the anterior annular ligament? LESSON XXX II. Tin: [lium. (Plates XLIII-XL1V.) The ilium which forms less than two-fifths of the acetabulum is the superior expanded portion of the innominate bone. This portion is limited superiorly by the arched crest of the ilium, but anteriorly and posteriorly by margins which diverge at right angles from each other. The crest is concave inward in front and is concave outward behind. It is much narrower in its middle than near 126 ANATOMY IN A NUTSHELL. its extremities, and there is often a marked external projection in its anterior third. On the cresl are external and internal lips and an intermediate space. The anterior superior spine is the projection at the anterior extremity. below which is a concavity, the lesser iliac notch, and below this notch is the anterior Inferior spine. The posterior superior spine is the projection at the posterior extremity of the crest, and is separated by a small notch from the posterior inferior spine below which i- the great sciatic notch. To the external lip from before backward (Plate XLIII) are attached (1) Tensor vaginae femoris, (2) External oblique of abdomen, (3) Latissimus dorsi, P Gluteus maximus, (5) The fascia lata throughout the entire length of the lip. To the internal lip from before backward (Plate XLIV.) are attached (1) Transversalis abdominalis, (2) Quadratus lumborum, (3) Erector spina'. (4) The [liacus muscle and iliac fascia to that part of this lip corresponding to the interna] iliac fossa. To the intermediate space i> attached the Internal oblique of the abdomen. The anterior superior spine has attached 1 1 ) T< nsor vaginae femoris externally. (2) Sartorius in front. (3) Poupart's ligament internally. The straight head of the Rectus femoris arises from the anterior inferior spine of the Qii m. Tin external surface or dorsum ilii, has three curved lines called the gluteal !iii' -. The superior or POSTERIOR gluteal link begins two inches in front of the post< rior superior spine and curves down and forward to the hack part of the ilio-sciatic notch. The middle gluteal link begins in front about an inch and a half b< hind the ant< rior superior spine, and arches hack and down to the upper part of die notch. The inferior gluteal link, not so well marked. begins jusl above the anterior inferior spin< . and passes hack to the fore pari of the notch. The Gluteus maximus is attach* d bi hind th< superior gluteal line to a semi- lunararea which is rough above. The falciform space between the superior and middle curved lines and the iliac cresl is occupied by the Gluteus medius. The Gluteus minimus i< between the middle and inferior curved lines. The re- flected head of the Rectus femoris is attached just abov< tin cotyloid cavity to .•mi oblong mark. The iliac fossa or venter ilii is the ant( ro-sup< nor pari of the internal sur- face and is larger than the postero-inferior part. It ,/.4> 1 ^\ , I A c '(/-.;.• - : >Jfc • E?W *Tfc POST. INF. SPINE OF ILIUM. ;•'.' I v ' AURICULAR SURFACE; OBTURATOR INTERNUS. i ,. i GROOVE FOR PUDIC VESSELS AND NERVE GREAT SACRO-SCIATIC LIGAMENT ANT SUP SPINE OF ILIUM. ANT INF SPINE OF ILIUM. PSOAS PARVUS ILIO-PECTINEAL EMINENCE GROOVE FOR OBTURATOR NERVE AND VESSELS. ' ■ •' ^ ' /H ^"LEVATOR ANI SUBPUBIC LIGAMENT COMPRESSOR URETHRAL CRUS PENIS' ANO ERECTOR PENIS. [nternal View of Left [nnominate Bone. The ischium is supplied by the obturator, internal and ext< rnal circumflex. The pubis receives twigs from the obturator, internal and external circum- flex, deep epigastric, and pubic branch of the common femoral artery. These three bones form the is innominatum. 128 ANATOMY IN A NUTSHELL Ossification from eight centers. There is one primary center for the ilium which appears at the eighth or ninth week. One for the ischium at about the third month, and one for the os pubis between the fourth and fifth month. These three primary centers unite through a Y-shaped piece at about the age of puberty. There are five secondary centers- one for the crest of the ilium, one for the anterior inferior spin- 01 - proi ess, one for the tuberosity of the ischium, one for the symphysis pubis, and one or more for the bottom of the acetabulum. Epiphyses appear about the age of puberty and unite with the rest of the bone between the twentieth and twenty-fifth years. Articulates with its fellow of the opposite side, the sacrum and femur. Attachment ok muscles to the ilium, sixteen. To the outer lip of crest, the (1) Tensor vagina 1 femoris, (2) Obliquus externus abdominis, and (3) Lat- issimus dorsi; to the internal lip. the (4) Iliacus, (5) Transversalis, (6) Quad- rants lumborum, and (7) Erector spina?; to the interspace between the lips, the (8) Obliquus internus. To the outer surface of the ilium, the (9) Gluteus max- inii!-. (10) Gluteus medius, (11) Gluteus minimus, reflected tendon of the (12) Meet ns; to the upper part of the great sacro-sciatic notch, a portion of the (13) Pyriformis; to the internal surface, the Iliacus, to that portion of the internal surface below the linea ilio-pectinea, the (14) Obturator internus and the (15) Multifidus spina' to the internal surface of the posterior superior spine; to the .interior border, (16) the Sartorius and straight tendon of the Rectus. To the ischium, fourteen: — To the outer surface of the ramus, the (1) Ob- turator externus and (2) Adductor magnus; to the internal surface, the (3) Ob- turator internus and (4) Erector penis. To the spine, the (5) Gemellus superior, (6) Levator ani, ami (7) Coccygeus. To the tuberosity, the (8) Biceps, (9) Semi- tendinosug, (KM Semimembranosus, (11) Quadratus femoris, (12) Adductor magnus, (13) Gemellus inferior, (14) Transversus perinsei, Erector penis. To the os pubis, sixteen: (l)Obliquus externus, (2) Obliquus internus, (3) Transversalis. (4) Rectus, (5) Pvramidalis, (6) Psoas parvus, (7) Peetincus, (8) Adductor magnus. (9) Adductor longus, (10) Adductor brevis, (11) Gracilis, (12) Obturator externus, (13) Obturator internus, (14) Levator ani, (15) Com- pressor met In a', and occasionally a few filters of the (16) Accelerator urinae. LESSON XXXI II. Tin: Os Pubis. The os pubis which consists of a body and two rami forms the anterior wall of the pelvis, and bounds the obturator foramen above and partly in front. The SYMPHYSIS PUBIS is the junction of this bono with its fellow. It is the inner ex- tremity of the bone fat Lng inward b< ing of an oblong surface marked by trans- \ erse ridg< s. The des< ending r \.\us pass< s down and out from the symphysis. It is thin and Hat ami joins the ramus of the ischium at a point little more than half way from the body of the pelvis to the tuberosity of the ischium. The superior or ascending ramus is the upper part of the bone. This ramus ends ANATOMY IX A NUTSHELL. 129 externally at the cotyloid cavity and forms more than one-fifth of it. The su- perior border of this ramus forms the pubic portion of the ilio-pectineal line, running from the spine of the pubis to the internal aspect of the ilio-pectineal eminence. The part between the two rami is the body of the os pubis. Its anterior surface is rough and its pelvic surface is smooth. The Pectineus muscle has its origin from the ilio-pectineal line and the triangular surface in front of it. The obturator crest extends from the pubic spine to the acetabulum below the ilio-pectineal line. The obturator groove is on the inferior surface of the ramus behind the outer part of the crest. It is directed from behind forward and inward. The pubic crest gives origin to part of the (1) Conjoined tendon, (2) the Pyramidalis and (3) Rectus abdominis. To the pubic spine are inserted (1) Poupart's ligament and the (2) outer pillar of the external abdominal ring. From the front of the pubis, in the angle between the crest and the symphy- sis, arises the (1) Adductor longus muscle, and below this the (2) Adductor brevis and part of the (3) Adductor magnus. Internal to these the (1) Gracilis is attached, and external the (2) Obturator externus. Posteriorly the pubis gives attachment to the (1) Obturator internus; above this is some- times a flat line passing from the upper margin of the obturator foramen to the lower end of the symphysis; the (1) Levator ani muscle is attached to it. and (2) the Obturator and recto-vesical fasciae. The Ischium. The ischium forms the lower and back part of the innominate bone. It forms a little more than two-fifths of the cotyloid cavity and bounds the obtura- tor foramen below. This bone has a body, a tuberosity, and a ramus. The body has three sur- faces and three borders. The surfaces are external, internal and posterior. The borders are also external, internal and posterior. The external surface helps form the acetabulum, and this part is smooth and concave. Immediately below the acetabulum is a horizontal groove for the Ten i Ion of the Obturator externus. The internal surface forms part of the wall of the true pelvis. In shape it is roughly quadrilateral, also smooth and concave to a small degree. A ridge showing its junction with the ilium is its upper limit. Its anterior limit is its junction with the os pubis and the obturator foramen. Its posterior limit is the anterior margin of the great sciatic notch. Its lower limit is the tuberosity. A part of the Oubtrator internus muscle is attached to this surface. Posterior surface is limited in front by the margin of the cotyloid cavity. It is limited behind by the posterior margin of the bone. It is limited above by its connection with the ilium, and it is limited below by the tuberischii. This surface supports the two Gemelli, the Pyriformis and the Obturator internus. Below it presents a pari of the groove tor the Obturator externus. The external border is synonymous with that part of the rim of the Aceta- bulum which belongs to the ischium. 130 ANATOMY IN A NUTSHELL. The internal border is synoynmous with the outer boundary of the obtura- tor foramen. The posterior border has the spine of the ischium a little below its middle. This spine which extends backward and inward marks the lower limit of the greal sciatic notch. It gives attachment to the Levator ani and (occygeus muscles, externally to the Gemellus superior. Between this spine and the tuber- osity is the lesser sciatic notch. The tuberosity has three surfaces — ex- ternal, internal, and postero-inferior. The external SURFACE of the tuberosity is lost below in the ramus and above with the groove for the tendons of the Obturator externus. It is limited in front by posterior margin of the thyroid foramen, and externally by the pos- PLATE XLV. ARTICULAR PROCESS. SACRAL FORAMEN ERECTOR SPINA!. MULTIF1DUS SPINA!. GLUTEU MAXI HIATUS SACRALIS, LEADING INTO SACRAL CANAL SACRAL CORNU GLUTEUS MAXIMUS SPHINCTER ANI COCCYX. Posterior View of Sacrum and Coccyx. tero-inferior surface. The muscks attached to this surface are the Quadratus femoris on the posterior aspect, the Obturator externus on the antero-inferior aspect, and the Adductor magnUS below these two. The [NTERNAL SURFACE of the tuberosity extends to the thyroid foramen in front. Behind and below it ends in a prolongation tor the attachment of the greal sciatic ligament. The i'o-i bro-inferior surface of t he tuberosity has the Semimembranosus attached to its upper and outer portion, while the Biceps and Semitendinosus are attached to its lower and inner portion. The ramus of the ischium is not as long as the ramus of the OS pubis which ANATOMY IN A NUTSHELL. 131 it joins at a little less than half the distance between the body of the os pubis and the tuberosity of the ischium. The Obturator externus, the Adductor magnus and the Gracilis are attached to its outer surface. The Crus penis and Transversus perinei are attached to its inner border. The cotyloid cavity, or acetabulum, is cup shaped. It looks outward, for- ward and downward. The Ilium forms a little less than two-fifths of the aceta- bulum. The os pubis forms a little more than one-fifth of the acetabulum. The Ischium forms a little more than two-fifths of the acetabulum. The rim of this cavity is prominent, but it is slightly lower in front and behind and has a large notch below called the cotyloid notch. The depression in the center is called the cotyloid fossa, around which is the articular portion of the cotyloid cavity. The thyroid or obturator foramen — sometimes called foramen ovale is be- low and internal to the acetabulum. This foramen is closed by a fibrous mem- brane, leaving a space for the obturator groove in its upper margin. In the male this foramen is nearly oval, while in the female it is more triangular. LESSON XXXIV. The Pelvis as a Whole. The word pelvis means basin. It is composed of four bones, the sacrum, coccyx, and the two innominate. If we pass a plane through the sacral pro- montory, ilio-pectineal line and the upper border of the symphysis, we divide the pelvis into an upper or false pelvis and a lower or true pelvis. The upper pelvis really belongs to the abdomen. The sacrum looks downward and for- ward. Its anterior surface is broader than its posterior surface. It is held in place by ligaments and the projections into the iliac articular surface. The plane separating the true and false pelvis marks an angle of 60 degrees with the horizontal. The plane of this outlet makes an angle of 16 degrees with the hor- izontal. The base of the sacrum is about three and one-half inches above the upper margin of the symphysis. The tip of the coccyx is one-half inch above the apex of the subpubic arch. The ANTEROPOSTERIOR DIAMETER, CALLED THE CONJUGATE DIAMETER, LS measured from the sacro-vertebral angle to the symphysis. The transverse diameter represents the greatest width of the pelvic cav- ity. The oblique diamkteh is measured from the sacro-iliac joint of one side to the ilio-pectineal eminence of the other. The average measurements of the diameters of the pelvis in the three planes are as follows: antero-posterior. oblique. i i; \\s\ i:nsK. Inlet 4 1-4 inches 5 inches 5 1-1 inches Cavity 4 3-4 inches •"> 1-4 inches 5 :^-4 inches Outlet . , .3 3-4 inches . ..4 1-2 inches 4 1-4 inches 132 ANATOMY IN A NUTSHELL. THE FEMALE PELVIS DIFFERS FROM THE MALE PELVIS IN THE FOLLOWING RESPE' I s: I | The bones are more slender. (2) ilia more vertical, (3) iliac fossa is shallower, (4) false pelvis is relatively narrower, (5) the true pelvis is shallower, also (6) true pelvis is wider, (7) inlet is more oval, (8) symphysis is shallower, i'.ii tuberosities of ischia are everted. (10) pubic arch is wider and more round- ed, ill) margins of ischio-pubic rami are less everted, (12) obturator foramen is triangular, while in the male it is oval, (13) sacrum is wider and less curved, and (14) the capacity of the true pelvis is greater. The Sacrum. The sacrum is formed by the coalescence of five segments. It forms the upper and back part of the pelvis, being placed between the two innominate bones. It is a wedge shaped bone with its apex below, and its anterior surface wider than its posterior surface. The anterior border of the upper portion or base is called the promontory. It has four surfaces, a base, an apex, and a central canal. The anterior surface has four ridges marking the junction of the five seg- ments. This surface is concave, both vertically and transversely (less so.) The five segments or vertebras decrease from above downward. At the ends of the transverse ridges are foramina for the transmission of the sacral nerves. These f< »ramina are directed forward and outward. At the sides of the foramina are the lateral masses formed by the transverse processes of the vertebrae of the sacrum. The posterior surface is not as wide as the anterior one and is convex. It has rudimentary spinous processes in its median line. There are usually three orfour of these, the fifth one being undeveloped. External to the processes are the i.amive. the first three are well marked; the fourth is not well developed and the fifth is rarely so. The fifth ones are prolonged downward forming the sacral cornua. External to the laminae are the articular processes, the first pair are Large, the second and third small, and fourth and fifth are most always fused. Externa] to the articular processes are the foramina for the posterior divisions of the sacral nerves. External to the foramina are the transverse processes. The sacral groove is wide and shallow lodging the Erector spinas. It lies between the spinous and transverse processes. The lateral surface is narrow behind but broad above. The upper half of this surface is called the auricular surface. It articulates with the ilium and is covered with fibro-cartilage in the recent state. Behind this articular surface are deep impressions for the attachment of the posterior sacro-iliac ligaments. The lower half of this surface is called the tuberosity, and the borders of this half of the surface give attachment to the sacro-sciatic ligaments and part of the ( rluteus maxiinus. The base is the pari which articulates with the last lumbar vertebra. It is broad and look- upward and forward. Its anterior part is for the interarticular fibro-cartilage and is oval. Its posterior part has the sacral canal which is ANATOMY IN A NUTSHELL. 133 formed by the laminae and spinous process. The superior articular processes are oval and concave. They are situated on each side of the sacral canal and are directed backward and inward. The intervertebral notches are in front of these processes. The al.e are flat triangular areas on each side of the articular processes, and are continuous with the iliac fossa. The Iliacus muscle has a \'v\v fibers of origin from the ala. The apex articulates with the coccyx and is directed downward and for- ward. PLATE XLVI. PROMONTORY. ARTIC.WITH LAST LUMBAR. COCCYGE LEVATOR ANl Anterior View of Sacrum and Coccyx. The spinal canal is larger and triangular above, but*below it is ilattened from before backward. The lower part of its posterior wall is incomplete. This is caused by the non-development of the laminse and spinous processes. Ossification : — Thirty-five centers. Articulation: — With four bones; the lasl Lumbar vertebra, coccyx, and the two ossa innominata. Attachment of Muscles: — Eight pairs; in front, the Pyriformis and Coccygeus, and a portion of the Iliacus to the base of the bone: behind, the Gluteus maximus, Latissinnis dorsi. Multifidus spinse, and Erector spinae, and sometimes the Extensor coccveeus. i;^4 anatomy in a nutshell. The Coccyx. The coccyx is formed by four and sometimes five segments. It has no SPINAL CANAL, [NTERVERTEBRAL FORAMINA. SPINOUS PROCESSES, LAMIN.E, PED- [CLES. The firsl segmenl may be separate bu1 the rest are united and run to a point. This bone has an anterior and posterior surface, two borders, a base, and an apex. The anterior surface has three transverse grooves marking the union of the ments. This surface is concave. The posterior surface is convex and has grooves similar to those on the an- terior. The upper cornua are large and articulate with thecornua of the sacrum making the fifth posterior sacral foramina. The lateral borders are thin and present small eminences — the rudimentary transverse processes. The upper pair of the processes may articulate with the inferior lateral angles of the sacrum, thus forming the fifth anterior sacral for- amina. The other processes are small and may be absent. Blood Supply: — Sacra media. ( )ssification: — Four centers. Articulation: — With the sacrum. Attachment of Muscles: — Four pairs and one single muscle; on either side, the Coccygeus; behind, the Gluteus maximus and Extensor coccygeus, when preseni ; at the apex, the Sphincter ani; and in front, the Levator ani. LESSON XXXV. Psoas magnus. — Description. — (Plate LXXIII.) In the posterior part of the substance of this muscle, the lumbar plexus is situated. This muscle, which is placed on each side of the spine in the lumbar region and the margin of the pelvis, is a Long and fusiform one. It is attached by five slips to the interverte- bral substance and the adjacent parts of the vertebra above and below. Be- tween these slips are tendinous arches which with the concave part of the body of each lumbar vertebra make a passage for the lumbar vessels and filaments of the sympathetic nerve. As the muscle passes down it decreases in size and passing under Poupart's ligament, it terminates in a tendon after having re- reived nearly all the fibers of the Iliacus. Origin: — (Plate LXXIII.) (1) Front of bases of lumbar vertebrae by live fleshy slips; (2) -ides of bodies and intervertebral substances of last dorsal and all the Lumbar vertebrae. Insertion: (Plates XLVIII-XLIX.) Lesser trochanter of the femur. A( pion: 1'lexes thigh on pelvis; maintains erect posture. N i RVE Si I'i'iA : Anterior branches of second and third lumbar nerves. Blood Si pply: — Dio-lumbar from posterior branch of internal iliac, and lumbar from abdominal aorta. Psoas parvus. Description.— (Plate LXXIII.) This muscle may be absenl or double. It is situated in front of the Psoas and ends in a long flat tendon. It is well developed in those animals which are swift runners, in that it flexes the pelvis and arches the Lumbar spine. ANATOMY IN A NUTSHELL. 135 Origin: — (Plate LXXIII.) Sides of bodies of last dorsal and first Lumbar vertebra? and substance between. Insertion: — (Plate XLIV.) Ilio-pectineal eminence and by its outer border into the iliac fascia. Action: — Same as Psoas magnus, also makes tense the iliac fascia. Nerve Supply: — Anterior branch of first lumbar. Blood Supply: — Lumbar from abdominal aorta. Iliacus. — Description. — (Plate LXXIII.) The Iliacus and the Psoas magnus are sometimes regarded as one muscle, the Ilio-psoas, since they have one insertion. The Iliacus which is flat and triangular fills the whole of the iliac fossa. Origin. — (Plates XLIV-XLVL) — (1) Upper two-thirds of iliac fossa and inner margin of crest of ilium; (2) in front, anterior superior and inferior spin- ous process of ilium and notch between: (.'->) behind, ilio-lumbar ligament and base of sacrum; (4) fibers from capsule of hip-joint. Insertion. — (Plate XLVIII.) — Outer side of tendon of Psoas muscle and into oblique line extending from lesser trochanter to linea aspera. Action. — Flexes thigh on pelvis and rotates femur outward; also aids in maintaining erect posture. Nerve Supply. — Anterior branches of second and third lumbar through the anterior crural. Blood Supply. — Ilio-lumbar. Tensor vagina 3 femoris. — Description. — (Plate LXIV.) — This muscle lies along the outer side of the thigh and extends from the crest of the ilium to about one-fourth the distance to the knee. Origin. — (Plate XLIII.) — Anterior portion of outer lip of crest of ilium and outer surface of anterior superior spinous process between Gluteus medius and Sartorius muscle, and from fascia covering the Gluteus medius. Insertion. — (Plate LXIV.) — Between the two layers of the fascia lata. The fascia is continued downward to external tuberosity of the tibia as a thick- ened band, the ilio-tibial band. Action. — Tenses fascia lata. Nerve Supply. — Fourth and fifth lumbar and first sacral through the superior gluteal. Blood Supply. — Superior gluteal and external circumflex. Sartorius. — Description. — (Plate LXXIY.) — This muscle, which extends from the ilium to the tibia, is flat, narrow, ribbon-like, and i< the longest one in the body. In the upper part of its course it forms the outer boundary of Scar- pa's triangle. It passes downward, then obliquely inward, then downward to the insertion. Scarpa's triangle (Plates LXIV-LXXIV.) — Is bounded above by Pouparl 'a ligament. On the outer side by the Sartorius and on its inner side by the Ad- ductor longus. The femoral vessels and the anterior crural nerve pass through it- center from above down. Their position from within outward is femoral vein, artery, and anterior crural nerve (V. A. N.). The floor of this triangle from without inward is formed by the Iliacus, Psoas, IVctineus, (Adductor brevis?) 136 ANATOMY IN A NUTSHELL. and Adductor longus. In the middle third of the thigh the femoral artery lies first along the inner border and then behind the Sartorius. Origin. — (Plate XLIII). — Anterior superior spinous process of ilium and upper half of notch below. Insertion.- (Plate LI.) — The muscle passes behind the inner condyle of the femur and terminates in a tendon which, curving obliquely forward, ex- pands into a broad aponeurosis and is inserted into the upper part of the inner surface of the shaft of the tibia, nearly as far forward as the crest. An offset is PLATE XLVII. Anterior and Superior View of the Pelvis. derived from the upper margin of this aponeurosis which blends with the fi- brous capsule of the knee-joint, and another, given off from its lower border, blend.- with the fascia OH t lie inner side of the leg. A( i u )\. Flexes leu on thigh and continuing to act flexes the thigh on the pelvis; also rotates the thigh outward. \i.i;\ i. Si pply. Branch of anterior crural. Blood Supply.- Femora] artery. Rectus lemons. Description.— (Plates LXIV-LXV111-LXXIV.)— The Rectus fenioris together with the Vastus externus, Vastus interims, and the ANATOMY IN A NUTSHELL. 137 Crureus, form one muscle — the Quadriceps extensor, which is the great extensor of the leg. This might be called one muscle with four heads and one insertion. The Rectus is situated in the middle and anterior part of the group and has two heads. These heads join at an acute angle. Its superficial fibers are bipenni- form. and its deep ones run straight down to the deep aponeurosis. The broad and thick aponeurosis which occupies the lower two-thirds of the posterior sur- face of the muscle gradually ends in a flattened tendon. LESSON XXXVI. Origin. — (Plate XLIII.) — The anterior or straight tendon, from the an- terior inferior spinous process of ilium; the posterior, or reflected tendon, from a groove above the brim of the acetabulum. Insertion. — (Plate LXXIV.) — Into the patella in common with the Vasti and Crureus. Action. — Assists Psoas muscle to bend pelvis and trunk forward and sup- port them upon the femur. Nerve Supply. — Anterior crural. Blood Supply. — Femoral artery. Vastus externus. — Description. — (Plates LXIV-LXVIII-LXXIV.) — This muscle is the largest part of the Quadriceps extensor. The strong aponeurosis on the under surface at the lower part of this muscle receives the fillers which form a large fleshy mass. The tendon of this muscle gives an expansion to the capsule of the knee-joint. Origin. — (Plate XLVIII.) — By a broad aponeurosis attached to ihe upper half of anterior intertrochanteric line, to the anterior and inferior borders of the root of the great trochanter, to the outer lip of the gluteal ridge, and to the upper half of the outer lip of the linea aspera. This aponeurosis covers the upper three-fourths of the muscle and from its inner surface many fibers take origin. A few additional fibers arise from the tendon of the Gluteus maximus, and from the external intermuscular septum between the Vastus externus and short head of Biceps. Insertion. — (Plate LXXIV.) — Into patella. Action. — Extends knee. Nerve Supply. — Anterior crural. Blood Supply. — External circumflex. Vastus interims.— Description. — (Plates LXIV-LXVIII-LXXIV.) —If the Rectus is reflected a narrow space is seen between the Vastus interim- and the Crureus extending upward from the inner border of the patella. At this space they can lie separated, bin they arc in reality one muscle. The aponeuro- sis which lies on the deep surface of the muscle receives fibers from the muscle, which are directed downward and forward. Origin. — (Plate XLVIII.) — Lower one-half of anterior intertrochanteric line,, the spiral line, the inner lip of the linea aspera, the upper pari of the in- ternal supracondylar line, and the tendon of the Adductor magnus and internal intermuscular septum. 138 ANATOMY IN A NUTSHELL. Insertion. -(Plate LXXIV.) — By common extensor Tendon into the patella, an expansion being sent to capsule of knee-joint. A.< i ion. Extends leg and draws patella inward. N i i;\ e Suppli . Branches of anterior crural. Blood Supply. Femoral artery. Crurcus. Description. — Given with Vastus internus. Origin. (Plate XLIX.)— From front and outer aspect of shaft of femur in its upper two-thirds and from the lower part of the external intermuscular septum. Insertion.— (Plate LXXIV.) — Its fibers end in a superficial aponeurosis which forms the deep part of the Quadriceps extensor tendon. A. tion. Extends leg and draws patella inward. Nerve Si pply. Branches of anterior crural. BLOOD Si PPLY. — Femoral artery. Subcrureus. Description. — This muscle may consist of several muscular bundles, but it is a small muscle. It is most always distinct from the Crureus, bu1 may be attached to it. < Origin. I Plate XLIV.) — Anterior surface of lower part of shaft of femur. I\-i rtion. (Plate LXXIV.) — Upper part of eul de sac of capsular lig- ament. A< tion.— Lifts capsule. \'i.k\ i. Supply. — Branches of anterior crural. BlOod Supply. — Femoral artery. Gracilis.— Description.— (Plates LX1V-LXV1II-LXXIV.)— This muscle is broad above, narrow below, thin and flattened as a whole. Its fibers after passing downward end in a rounded tendon, then passes behind the internal condyle of femur to curve round the inner tuberosity of the tibia. It becomes flattened before its insertion. It is the most superficial muscle in the Internal Femora] Region. Its tendon which is just above that of the Semitendinosus and below that of the Sartorius joins the latter. It is separated from the in- ternal lateral ligament of the knee-joint by a synovial bursa which is common to it and the Semitendinosus. < Origin. I Plate X F I II.) — Lower half of margin of symphysis and anterior half of the pubic arch. Insertion. (Plate LI.)- Upper part of inner surface of shaft of tibia be- low the tuberosity. A< tion. Assists Sartorius in flexing leg; also adducts thigh. Nerve Si pply. Third and fourth lumbar through the obturator nerve. Blood Si pply. Obturator and femoral arteries. Pectineus. Description. (Plates LXIV-LXVIII-LXXIV.)— This mus- cle which is situated at the anterior part of the upper and inner aspect of the thigh is flat and quadrilateral. Origin. (Plate XLIII.)— (1) Uio-pectineaJ line; (2) surface of bone in front of it scia covering anterior surface of muscle. Insertion.- (Plate XLVIII.) Rough line between lesser trochanter and lines aspera. PLATE XLVIII. OBTURATOR EXTERNUS (I). GUITEOUS MEOIUS (I). TUBERCLE OF THE OUADRATUS FEMOfllS (I) .VASTUS EXTERNUS (0) GLUTEAL RIDGE. GLUTEUS MAXIMUS (I) LIGAMENTUM TERES. POST INTERTROCHANTERIC LIKE. PSOAS Jl). ADDUCTOR MAGNUS (I) OUTER LIP OF LINE* ASPERA. BICFJS (0). VASTUS EXTERNUS (0). CRUREUS (0) tXT. SUPRA CONDYLAR LINE. POPUTEAI SURFACE GASTROCNEMIUS (0) ANT CRUCIAL LIGAMENT EXT CONDYLE. INTERVENING SPACE OF THE LINEA ASPER*. ADDUCTOR LONGUS (I). INNER LIP OF LINEA ASPERA. FOR FEMORAL ARTERY INT. SUPRACONDYLAR LINE. ADDUCTOR MAGNUS II). ADDUCTOR TUBERCLE. GASTROCNEMIUS (0). CAPSULl. INT LATERAL LIGAMENT. INTERCONDYLAR NOTCH POST CRUCIAL LIGAMENT Posterior View of Left Femur. 139 140 ANATOMY IN A NUTSHELL. Action. Adducts thigh. Nerve Supply. — Anterior crural, obturator accessory, and occasionally a branch from the obturator. Blood Supply.— Femoral and obturator arteries. Adductor Longus — Description.— ( Plates LXIV-LXVIII-LXXI-LXXIV) —This muscle forms the inner boundary of Scarpa's triangle and is the most superficial one of the Adductors. It lies on the same plane as the Pectineus. It is a flat, triangular muscle. Origin. — (Plate XL111.) — Front of OS pubis, at junction of crest with symphysis. Insertion. — (Plate XLVIII.) — By aponeurosis into linea aspera. Action. Adducts thigh powerfully. \'i w\ r. Supply. — Obturator. Blood Supply. — Obturator and perforating branches of profunda. Adductor brevis. 1 Ascription.— (Plates LXIV-LXVIII-LXXI-LXXIV.) The Adductor brevis, which is somewhat triangular, is situated immediately beneath the Adductor longus and the Pectineus. The second and sometimes the first perforating branches of the profunda femoris artery pierces this muscle near it- insertion. Origin. — (Plate XLIII.) — Outer surface of body and descending ramus of os pubis, between Gracilis and Obturator extern us. Insertion. — (Plate XLVIII.) — By an aponeurosis into lower part of line Leading from the lesser trochanter to the linea aspera and the upper part of the same line, immediately behind the Pectineus and upper part of the Adductor longus. A( tion. Assists in flexing thigh upon pelvis; also in drawing leg forward in walking. \ki;\ i: Supply. — Third and fourth lumbar through the obturator. Blood Supply. — Obturator and perforating branches of the profunda. LESSON XXXVII. Adductor magnus.— Description.— (Plates LXIV-LXVIII-LXXI-LXXIV.) —The muscles of the Anterior Femoral Region are separated from the remain- ing muscles of the Internal Femoral Region by the Adductor magnus. Along the attachment of this muscle there are three and sometimes four open- Lngs Formed by tendinous arches attached to the femur for the passage of the three perforating branches of the profunda artery. The fourth one, when pres- ent, is for the terminal branch of the profunda. Origin. — (Plate XLIII.) — (1) Descending ramus of os pubis; (2) ascend- ing ramus of ischium ;(3) outer margin of under surface of tuberosity of ischium. [nseri con. | Plate XLVIII.) — The fibers from the ramus of the os pubis are vi'vy short, horizontal in direction, and are inserted into the rough line lead- ing from the greal trochanter to the linea aspera,internal to the Gluteus max- Lmus; those from the ramus of the ischium are directed downward and outward to be inserted by mean- of a broad aponeurosis into the linea aspera and the ANATOMY IN A NUTSHELL. 141 upper part of its internal prolongation below. The internal portion of the mus- cle, consisting principally of those fibers which arise from the tuberosity of the ischium, forms a thick, fleshy mass, descends almost vertically and terminates about the lower third of the thigh in a rounded tendon which is inserted into the adductor tubercle on the inner condyle of the femur, being connected by a fibrous expansion to the line leading upward from the tubercle to the linea aspera. Action. — Adductor of thigh. Nerve Supply.- — Obturator and branch of great sciatic. Blood Supply. — The femoral and perforating branches of profunda. Gluteus maximus. — Description. — (Plate LXV.) — This muscle, which is made up of fasciculi lying parallel with one another, is very coarse in structure. These fasciculi are collected together into large bundles, which are separated by deep cellular intervals. It is a thick and quadrilateral muscle and helps to hold the trunk erect. It is the most superficial muscle in the Gluteal Region. There is a synovial bursa between this muscle and the great trochanter, one between its tendon and the Vastus externus, and often one is situated on the tuberosity of the ischium. Origin. — (Plates XLIII-XLV.) — (1) Superior curved line and crest of ilium; (2) posterior surface of lower part of sacrum; (3) side of coccyx; (4) aponeurosis of Erector spina?; (5) great sacro-sciatic ligament and fascia cover- ing Gluteus medius. Insertion. — (Plate XLVIII.) — The fibers forming the upper and larger portion of the muscle, together with the superficial fibers of the lower portion, terminate in a thick tendinous lamina, which passes across the great trochanter and is inserted into the fascia lata covering the outer side of the thigh ; the deeper fibers of the lower portion are inserted into the rough line leading from the great trochanter to the linea aspera between the Vastus externus and Adductor mag- nus. Action. — Extends, adducts, and rotates the thigh outward. Nerve Supply. — Inferior gluteal and small sciatic. Blood Supply. — Superior and inferior gluteal. Gluteus medius. — Description. — (Plate LXV.) — The posterior border of this muscle lies parallel with the Pyriformis muscle but is separated from it by the gluteal vessels. The posterior one-third of its external surface lies under the Gluteus maximus, its anterior two-thirds under the fascia lata. This is a broad thick, radiating muscle situated on the outer surface of the ilium. A synovial bursa is situated between the tendon of this muscle and the surface of the great trochanter in front of its insertion. Origin. — (Plates XLIII-XLV.) — Outer surface of ilium between superior and middle curved lines; (2) crest of ilium; (3) fascia covering outer surface. Insertion. — (Plate XLIX.) — Oblique line of great trochanter. Action. — Adducts the extended thigh, rotates same and supports body on limb. Nerve Supply. — Superior gluteal. Blood Supply. — Superior gluteal. PLATE XLIX. OBTURATOR INTERNUS AND GEMELLI HI. GREATER TROCHANTER. PTRIFORMIS (I). -'»■■ <^''4Mi ^ - seck. ■•ji .",,>• ;ft\ CAPSULE OF "*"^^i^i \* ■i%( id Supply.— Sciatic LESSON XXXVIII. Gemellus superior. — Description. — (Plate LXY.) — This muscle is not always present. It is an aid to the Obturator internus. It has a common tendon with the Obturator internus. It is smaller than the Gemellus inferior. Origin. — (Plate XLIY.) — Outer surface of spine of ischium and blends with tendon of Obturator internus. I nsertion. — (Plate XLIX.)— Inner surface of great trochanter. A.< tion. — Rotates the extended thigh, abducts the flexed thigh. Nerve Supply. — Fifth lumbar, first and second sacral. Blood Supply. — Sciatic and external circumflex. Gemellus inferior. — Description. — (Plate LXY.) — This muscle is larger than the Gemellus superior and like that muscle is an aid to the Obturator in- terims. Origin. — (Plate LXIII.) — Upper part of tuberosity of ischium and blends with tendon of ( >bturator internus below. Insertion. — (Plate XLIX.) — Inner surface of great trochanter. Action. Rotates extended thigh, abducts flexed thigh. \'u;\ e Supply.— Fourth and fifth lumbar and first sacral. Blood Supply. — Sciatic and external circumflex. Quadrat us femoris.— 1 )ks directed upward. inward and a little forward, bein^ broad and compressed at the base Inn becomes rounded at its junction with the head. It is longer below and behind than above and in front. Posteriorly and above where it joins the greater tr< - chanter is a depression (digital fossa) for the insertion of the Obturator exter- nals. Where it joins the shaft between the two trochanters is tile POSTERIOR INTERTROCHANTERIC LINE. About half an inch above this line the capsular lig- ainent of the hip-joint is attached to the neck. The bead is an expanded portion of the neck, and forms more than a hem- isphere. It articulates witli the acetabulum of the innominate bone. The Fossa CAPITIS is a depression a little below and behind the center of the head. P LATE LI. INT. FIBRO CARTILAGE. CORONARY LIGAMENT ANT. CRUCIAL LIGAMENT SPINE. EXTERNAL FIBRO-CARTILAGE. CAPSULE. INNER TUBEROSITY. K»A< \ INT. LATERAL LIGAMENT LIGAMENTUM PATELLAE (l) ; (QUADRICEPS EXTENSOR). GRACILIS (I) SARTORIUS (ij SEMI-TENDINOSUS(/ EXT. SURFACE OF TIBIA. TIBIALIS ANTICUS (0) ANT. BORDEROR CREST OF TIBIA INT. SURFACE OF TIBIA. INTEROSSEOUS MEMBRANE ANT. LICAMENT OF ANKLE JOINT. INT. LATERAL LIGAMENT INTERNAL MALLEOLUS. OUTER TUBEROSITY. ). BICEPS AND ANT. TIBIO-FIBULAR LIGAMENT. EXT. LATERAL LIGAMENT. EXTENSOR LONGUS WGITORUM (0), PERONEUS LONGUS (0). EXTENSOR LONGUS DIGITORUM (0), PFRONEAL SURFACF flF FIBULA EXTENSOR SURFACE Of FIBULA '. EXTENSOR PROPRIUS HALLUCIS (0; PERONEUS BREVIS<0). FIBULA. - PERONEUS TERTIUS (0). - SUBCUTANEUS PORTION. ANT. TIBIO-FIBULAR LIGAMENT. EXTERNAL MALLEOUS. EXTERNAL LATERAL. LIGAMENT. (ANT. FASCICULUS). Anterior View of Left Tibia and Fibula. 148 ANATOMY IN A NUTSHELL. 149 The fore part of this depression gives attachment to the ligamentum teres of the hip-joint. The fossa capitis has one or two vascular foramina. The greater trochanter is an expanded portion of the upper part of the bone opposite the head, its upper limit being about half or two-thirds of an inch below the upper limit of the head. The word trochanter means, to turn. The Gluteus minimus is attached to its anterior surface in a broad depression. The Gluteus medius is attached to ax oblique link, which runs downward and forward from the posterior aspect of its upper border. On the anterior surface of the greater trochanter is the superior cervical tubercle of the femur. which marks the JUNCTION of the following muscles: Vastus externus. Gluteus minimus. Obturator interims, and the two Gemelli. Above and external to the insertion of the Obturator interims and the Gemelli is the INSERTION of the Pyriformis. About the center of the posterior intertrochanteric line is the tubercle of the Quadratus femoris. The linea quadkati, when present, passes vertically down from this tubercle. The lesser trochanter is a pyramidal projection at the junction of the lower part of the posterior intertrochanteric line and the diaphysis. Its direction is inward and backward, and its apex gives attachment to the Ilio-psoas muscle. In front the neck is separated from the shaft by the anterior intertro- chanteric line, which is the upper part of the spiral line. This line commences at the tubercle of the femur, and runs down in front of the lesser trochanter. It gives attachment to the capsular ligament and the Vastus interims and Cru- reus muscles. The shaft is arched forward; its middle is somewhat cylinderical, but below it is expanded. It has an anterior and two lateral surfaces which are not sep- arated by well defined lines. The two Yasti and the Crureus muscles cover these surfaces. The linea aspera separates the two surfaces posteriorly. This line is well marked in the middle third of the thigh, bifurcating both above and below. Of its two upper divisions the external one extends to the greater tro- chanter making the gluteal ridge for the attachment of the Gluteus maximus. The internal division winds around below the lesser trochanter, passing into the anterior intertrochanteric line, and forming the lower part of the spiral line. Another line passes from this line to the lesser trochanter for the attachment of the Pect incus. Below the linea aspera divides into two lines which extend to the two condyles, thus forming the supracondylar lines, which enclose the popliteal sur- face of the femur. The inner line ends at the Adductor tubercle, ami i- broken above this where the femoral vessels lie on the bone. Above the middle of the linea aspera is a NUTRIENT foramen, which is directed from the knee. (Page P.).) A SECOND foramen inav exist nearer the distal end of the bone. The inner lip of the linea aspera gives attachment to the Vasius interims, and the outer lip gives attachment to the Vastus externus. The Adductor magnus is attached between the two. Between the Adductor magnus ami the Vastus externus are the Gluteus maximus and the short head of the Biceps. Between the Adductor magnus and the Vastus internus are the Qiacus, Pecti neus, Adductor brevis, and Adductor Longus. At the lower pari of the poplitea 150 ANATOMY IN A NUTSHELL. space above each condyle is the origin of one head of the Gastrocnemius. The distal extremity has two condyles, which are united anteriorly but separated posteriorly by the intercondylar notch. The external condyle is broader and more prominenl anteriorly, while the internal one is more prominent internally, and it extends to a lower level, when the femur is taken from the body. When the femur articulates with the tibia the two condyles .,,,. (l|1 the -mum' level. Both condyles are convex for the articulation of the tibia, and between these two anteriorly is a concave strface for the articula- tion of the patella. The patellar surface has a vertical hollow and two lips. The external portion which is wider and more prominent than the internal por- tion rises higher. The tibial surfaces are almost parallel being a little closer anteriorly than posteriorly. The lateral surface of each condyle extends into :i tuberosity or epicondyle, which gives attachments to ligaments. Above the external condyle is a depression for the outer head of the Gastrocnemius. The inner head of the < hisirocnenhns arises from the upper part of the inner condyle. The [ntercondyleae fossa has two depressions for the crucial ligaments. The ONE FOE tin. wtkkiok ligament is on the posterior part of the inner sur- face of thf external condyle. The one for the posterior ligament is on the anterior part of the external surface of the inner condyle. The angle of the neck of femur with the shaft makes no changes after growth is completed. Blood Supply. — The head and neck of the femur receive branches from the sciatic, obturator and circumflex arteries. The trochanter receives twigs from the circumflex arteries. The nutrient vessel for the shaft is derived from second perforating; it enters near the linea aspera and is directed towards the head of the bone. Condyles are nourished by articular branches from the popliteal and the anastomotic of femoral. Ossifk \'i ION. - From five centers. The one for the shaft is a primary center and begins to ossify in the seventh week of intra-uterine life. The other four are epiphyseal centers. The one for the lower extremity appears in the NINTH MONTH and joins the bone in the twentieth year. This is the only epiphysis which ossifies before birth, although some observers say the proxifhal end of the tibia ossifies before birth. The one for the head appears in the first yi.ai; and joins the bone in the nineteenth year. The one for the greater tro- chanter appears the fourth yi.ai; and joins the bone in the eighteenth year. The • for the lesser trochanter appears in the thirteenth or fourteenth i eab and join- the bone the seventeenth year. Articulates.- With three bones: os innominatum, tibia and patella. \ii M HMENT "i MuS( LES. — Twenty-three. To the great trochanter, the Gluteus medius, Gluteus minimus, Pyriformis, Obturator externus. Obturator interim.-. Gemellus superior, Gemellus inferior, and Quadratus femoris. To the lesser trochanter, the Psoas magnus and the Iliacus below it. To the shaft, tin' Vastus externus, Gluteus maximus, short head of Biceps, Vastus internus, Adductor magnus, Pectineus, Adductor brevis, Adductor longus, Crureus and Subcrureus. To the condyles, the Gastrocnemius, Plantaris and Popliteus. PLATE LI I. EXTENSOR LONGUS DIGITOfillM (1) EXTENSOR LONGUS HALLUCIS (1). THIRD PHALANX -H fl SECOND PHALANX FIRST PHALANX EXTENSOR BficViS DIGITORUM (0) TENDO ACHILLIS. Dorsum of Left Foot. 151 152 ANATOMY IN A NUTSHELL. LESSON XL. Tibialis anticus. — Description. — (Plate LXXV.) — The anterior tibial vessels and nerve run along the outer border of this muscle, which is just be- neath the fascia on the outer side of the tibia. It is thick and fleshy above, but tendinous below where it passes through the innermost compartment of the anterior annular ligament. Origin. (Plate LI.) — (1) Outer tuberosity of tibia; (2) upper two-thirds of shafl of tibia; (•">) interosseous membrane adjoining; (4) deep surface of fascia; (5) intermuscular septum. Insertion. — (Plate LIII). — Inner and under surface of internal cuneiform bone and base of metatarsal of great toe. Action. Flexes tarsus upon leg and assists in inverting the foot. Nerve Supply. — Fourth and fifth lumbar and first sacral through anterior tibial. Blood Supply. — Anterior tibial artery. Extensor propius hallucls. — Description. — (Plate LXXV.) — This muscle lies between the Tibialis amicus and Extensor longus digitorum. It is a thin, Hat muscle and hs tendon occupies its anterior border below. This tendon passes through a distinct compartment in the lower portion of the annular lig- ament, it also crosses the anterior tibial vessels near the ankle-joint and then lies on the inner side of these vessels. It gives a thin prolongation on each side of the metatarso-phalangeal articulation, which covers the surface of the joint. Origin.- -(Plate LI.) — (1) Anterior surface of fibula, middle two-fourths of same; (2) part of interosseous membrane. Insertion. — (Plate I.I I.) — Base of last phalanx of great toe. It usually sends an expansion from the inner side of the tendon to be inserted into base of 6rs1 phalanx. Action.— Extends great toe and flexes tarsus. \'i.i;\ i: Supply.— Fourth and fifth lumbar and first sacral through anterior tibial. Blood Supply.— Anterior tibial. Extensor Longus digitorum.— Description.— (Plate LXXV.) — This muscle lies external to the other muscles in this region. It is enlongated and flat- tened. It and the Peroneus tertius enter the same canal in annular ligament. It divides into four slip-, one for each of the four inner toes. A tendon from the Extensor brevis digitorum join- the three inner of these tendons on their outer side opposite the metatarso-phalangeal articulation. All four slips re- ceive fibrous expansions from the Interossei and Lumbricales, after which they spread out into a broad aponeurosis which covers the dorsal surface of the first phalanx. This aponeursosis divides Into three slips at the articulation of the first with the second phalanx. Origin.— (Plate LI.) (1) Outer tuberosity of tibia; (2) upper three- fourths of anterior surface of shafl of fibula; (3) interosseous membrane; (4) deep surface of Fascia; (5) intermuscular septa. ANATOMY IN A NUTSHELL. 153 Insertion. — (Plate LII.) — The middle slip is Inserted into the base of the second phalanx: the two lateral slips, after uniting on the dorsal surface of the second phalanx, are continued onward and inserted into base of the third. Action. — Extends toes and flexes foot. Nekve Supply. — Fourth and fifth lumbar and first sacral through anterior tibial. Blood Supply. — Anterior tibial. Peroneus tertius. — Description. — (Plate LXXV.) — This muscle is some- times wanting. sometimes it is described as a fifth tendon of the Extensor longus digitorum with which it is joined, and their tendons pass through the same canal in the anterior annular ligament. Origin. — (Plate LI.) — (1) Lower fourth of anterior surface of fibula; 2 lower part of interosseous membrane: (o) intermuscular septum. Insertion. — (Plate LII.) — Inner side of dorsal surface at base of meta- tarsal of little toe. Action. — Flexes and everts foot. Nerve Supply. — Fourth and fifth lumbar and first sacral through anterior tibial. Blood Supply. — Anterior tibial. Gastrocnemius. — Description. — (Plate LXXVII.) — The Gastrocnemius has two heads the inner of which is the larger. This muscle forms the greater part of the calf of the leg and is the most superficial one in this region. An aponeurosis spreads out from each tendon to cover the posterior part of that portion of the muscle to which it belongs. The muscular fibers of the outer head are thinner and do not extend as low as those of the inner. Muscular fibers are given off from the anterior surface of these tendinous expansions. This muscle gradually gets smaller and its tendon with that of the Soleus forms the tendo Achillis. In the tendon of the outer head there is a sesamoid fibro-cartilage (very seldom osseous): and one is occasionally found in the ten- don of the inner head. Origin. — (Plate L.) — Inner and larger head from depression at upper and back part of inner condyle and from adjacent part of femur. The outer head from impression on outer side of external condyle and from posterior surface oi femur immediately above the condyle. Both heads also arise by a few fibers from the ridges which are continued upward from the condyle- to the linea a-- pera. Insertion. — (Plate LII.) — Os calcis by tendo Achillis. Actiox. — Extends foot and flexes leg. Nerve Supply. — First and second sacral through internal popliteal (from greal sciatic.) Blood Supply. — Popliteal. Soleus. — Description.— (Plate LXXVII.)— Situated beneath the Gastro- cnemius is the Soldi-, which i> a broad flat muscle. In shape it resembles a sole fish, hence its name. The deep transverse fascia of the leg, separates this mucle from the posterior vessels and nerve. A- -aid before the tendon of this muscle and that of the Gastrocnemius make the tendo Achillis. 154 ANATOMY IS A NUTSHELL. Origin. — (Plato L.) — (1) Back part of head of fibula ; (2) upper 'hird of rior surface of shaft of fibula; (3) oblique line of tibia; (4) middle third of internal border of tibia; (5) tendinous arch between the tibial and fibular ori- gin-, beneath which the popliteal vessels and internal popliteal nerve pass. [nsertion.— (Plate LII.) — Os calcis by tendo Achillis. A* HON.— Steadies leg on foot : prevents body from falling. N era i. Suppli . Internal popliteal and posterior tibial. 'u.oDi) Supply. — Popliteal. Plantaris.- Description. — (Plate LXXVII.) — This muscle is sometimes absent and again it may be double. It has the longest tendon of any muscle in the body. It takes its name because it is sometimes inserted into the plantar fascia. The muscular part of the Plantaris is a small fusiform belly about three or four inches in length. It is situated between the Gastrocnemius and Soleus and the tendon finally running along the inner side of the tendo Achillis. It may be lost in the fascia of the leg or the internal annular ligaments. Origin. — (Plate XLVIII.) — From the lower part of outer prolongation of linea aspera and from posterior ligament of knee-joint. Insertion. — (Plate LII.) — Os calcis with tendo Achillis. Action. — Flexes leu- and extends foot. Nerve Supply. — Internal popliteal. Blood Supply. — Popliteal. LESSON XLI. Popliteus.— Description. — (Plate LXXIX.) — This muscle forms part of the popliteal space. It is a thin flat triangular muscle, and is different from nio-t other muscles in that its origin is smaller than its insertion. The internal popliteal nerve and the popliteal vessels cross the superficial surface of this muscle. Origin. — (Plate XLIX.) — Deep depression on outer condyle of femur and posterior ligament of knee. Insertion.- (Plate L.) — Inner two-thirds of triangular surface above oblique line on posterior surface of shaft of tibia ami tendinous expansion cover- ing surface of muscle. Action. Flexes and rotates leg inward. Xi:i;\ i; Supply.- fourth and fifth lumbar and first sacral through internal popliteal. Blood Suppli . - Popliteal. Flexor longua hallucis. — Description. — (Plate LXXIX.) — This musch/is on the fibular side of the lei: although it passes to the great toe. Its tendon occupies most all of the posterior surface of the muscle, then it passes through three grooves in three different bono, first one is on the posterior surface of the lower end of the tibia; the second one is on the posterior surface of the astragalus; and the third one is beneath the sustentaculum tali of the os calcis. The tendon finally passes between the two heads of the Flexor brevis hallucis to its insertion. PLATE LIU. FLEXCI* L8NGUS HALLUCIS <1). k tf) FLEXOR LONGUS DIGITORUM (I). 4DQUCT0« H»LLUCIS ELEXOR BREVIS Ha LLUCISMi 'OUTER PORTION! (INNER PORTION ABDUCTOR HALLUCIS (l/ V 1 PERONEUS LONGUS H) TIBIALIS AUTICUS (1 TIBIALIS POSTICUS (1) ACCESSORIUS (INNER HEAD) FLEXOR BREVIS DIGITORUM (0) ABDUCTOR HALLUCIS \0) LANTAR INTEROSSEOUS (1). ABDUCTOR WIN I Ml DIGITI (1) FLEXOR BREVIS NTAR INTEROSSEOUS (0). DDUCTOR HALLUCIS (0). _FLEXOR BREVIS MINIMI DIGITI (0) FLEXOR BREVIS HALLUCIS (0) ACCESSORIUS (OUTER HEAD) (0) ABDUCTOR MINIMI DlGlTl ,0| POSTERO— INFERIOR SURFACE OF THE CALCANEUM. Plantar Surface of Left Foot. 155 156 ANATOMY IN A NUTSHELL. Origin.— (Plate L.) — (1) Lower two-thirds of posterior surface of shaft of fibula except an inch at lowest part: (2) lower part of interosseous mem- brane; (3) intermuscular septum; (4) fascia covering Tibialis posticus. Insertion. — (Plate LIII.) Base of last phalanx of great toe. Action. Flexes ureal toe and extends foot. Nerve Supply. Fifth lumbar and first and second sacral through pos- terior tibial. Blood Supply. — Posterior tibial. Flexor Longus digitorum.— Description. — (Plate LXXIX.) — This muscle is small at its origin but gradually increases in size as it descends. Its tendon occupies nearly all of the posterior surface of the muscle. The tendons of the Tibialis posticus and this muscle pass through a common groove behind the internal malleolus, but each tendon has its own synovial sheath. They are separated from each other by a fibrous septum. As the tendon crosses the sole of the foot obliquely forward and outward, it divides into four tendons each of which passes through the tendons of the Flexor brevis digitorum opposite the base of the first phalanx. Just before it divides it is joined by the Flexor ac- cessories. Origin.- -(Piatt 1 L.) — Posterior surface of shaft of tibia, immediately below i lie oblique line to within three inches of its extremity internal to the tibial origin of the Tibialis posticus. Insertion. — (Plate LIII.) — Into bases of last phalanges of the four lesser toes. A.CTION. — Flexes toes and extends foot. Nerve Supply. — Fifth lumbar and first sacral through posterior tibial. Blood Supply. — Posterior tibial. Tibialis posticus. — Description. — (Plate LXXIX.) — This muscle is the mosl deeply seated of all the muscles of the leg. and it lies between the Flexor Longus hallucis and the flexor longus digitorum. Between its two heads pass the anterior tibial vessels to the front of the leg. Its tendon passes through a groove behind the internal malleolus in its own sheath. It then passes through another sheath over the internal lateral ligament into the foot and then beneath the inferior calcaneonavicular ligament to its insertion. It sends fibers of in- sertion to all the bones of the tarsus except the astragalus, also to second, third, and fourth metatarsal bones. ( >rigin. ( Plate L.) — Whole of posterior surface of interosseous membrane, excepting lowesl part; from outer portion of posterior surface of shaft of tibia, between commencement of oblique line above and junction of middle and lower third of shaft below; from upper two-thirds of the internal surface of fibula; some fibers a bo from deep transverse fascia and intermuscular septa. I nsertion. (Plate bill.) —Tuberosity of navicular and internal cuneiform bono and bases of second, third, ami fourth metatarsal. Action. Extends tarsus; turns sole inward. Nerve Supply.— Fifth lumbar and first sacral through posterior tibial. Blood Si pply. Posterior tibial. Peroneus longus.- Description. — (Plate LXXIX.) — The Peroneus Ion- ANATOMY IN A NUTSHELL. 1 ")7 tins is superficial to the Peroneus brevis. It is situated at the upper part and outside of the leg. The external popliteal or peroneal nerve passes between the fibula and this muscle near the upper part of the bone between the head and the shaft. As its tendon passes behind the external malleolus it lies behind the tendon of the Peroneus brevis in a common groove which is converted into a canal by a fibrous band. These two tendons have synovial membranes. Its tendon passes across the outer side of the os calcis, below its peroneal tubercle, then it runs in a groove on the under surface of the cuboid bone after which it crosses the sole of the foot obliquely. Behind the external malleolus and on the outer side of the cuboid bone the tendon changes its direction, and in these places it is thickened. A sesamoid fibro-eartilage (sometimes a bone) is in its substance where it crosses the cuboid bone. Origin. — (Plate LI.) — (1) Head and upper two-thirds of outer surface of fibula; (2) deep surface of fascia; (3) intermuscular septa and occasionally by few fibers from outer tuberosity of tibia. Insertion. — (Plate LIII.) — Outer side of base of metatarsal of meat toe and internal cuneiform. Occasionally send- dip to base of second metatarsal bone. Action. — Extends and everts foot and steadies leg upon foot. Nerve Supply. — Fourth and fifth lumbar and first sacral through musculo- cutaneous branch of the external popliteal. Blood Supply. — Peroneal. Peroneus brevis. — Description. — (Plate LXXIX.) — This muscle is shorter and smaller than the Peroneus longus and lies behind it. Its tendon passes behind the external malleolus in front of that of the Peroneus longus. On the outer side of the os calcis it is separated from the tendon of the Peroneus longus by the peroneal tubercle. Origin. — (Plate L.) — Lower two-thirds of external surface of shaft of fibula, and intermuscular septa. Insertion. — (Plate LIII.) — Tuberosity at base of metatarsal of little tee on its outer side. Action. — Extends foot and helps to steady leg upon foot. \ki;\ e Supply. — Fourth and fifth lumbar and hist sacral through musculo- cutaneous branch of external popliteal. Blood Supply. — Peroneal. LESSON Xidl. Extensor brevis digitoruin. — Description.— (Plate LXXV.)— This is a broad, thin muscle which passes obliquely across the dorsum of the foot and divides into four tendons. Beneath this muscle lie the tarsal and metatarsal arteries and bones and the Dorsal interossei muscles. The innermost tendon crosses the dorsalis pedis artery. Origin. — (Plate LI I.) — (1) Fore part of upper and outer surface of < s calcis; (2) external calcaneo-astragaloid ligament; (3) horizontal portion of anterior annular ligament. 158 ANATOMY IN A NUTSHELL. [nsertion. — (Plato LIU.) — Innermost tendon into dorsal surface of base of first phalanx of great toe; the other three into outer sides of long extensor tendons of second, third and fourth toes. Action. Extends phalanges of four inner toes acting only on first phalanx of ilif great toe. N i kve Supply.— Anterior tibial. Blood Supply. — Dorsalis pedis. Abductor hallucis.— Description. — (Plate LV.) — This muscle is the inner one "t' the three muscles of the first layer of the plantar surface of the foot. It is protected by the plantar fascia. This fascia is beneath the muscle when one's fool is on the floor. Origin.- (Plate LI 11.) — (1) Inner tubercle of under surface of os calcis;(2) internal annular ligament; (3) plantar fascia; (4) intermuscular septum. Insertion. — (Plate LIII.) — Inner side of base of first phalanx of greattoe. Actiox. — Abducts great toe; flexes proximal phalanx. Nerve Supply. — Internal plantar. Blood Supply. — Internal plantar. Abductor minimi digiti. — Description. — (Plate LV.) — This muscle is separated from the Flexor brevis digitorum by a vertical septum of fascia, and has along its inner border the plantar vessels and nerve. All the muscles of the first Layer of the foot bear the same relation to the plantar fascia. Origin. — (Plate LIII.) — (1) Outer tubercle of os calcis; (2) under surface of os calcic in front of both tubercles; (3) fore part of inner tubercle; (4) plantar fascia: (5) intermsucular septum. Insertion. — (Plate LIII.) — Its tendon, after gliding over a smooth facet on the under surface of the base of the fifth metatarsal bone, is inserted, together with the short Plexor of the little toe, into the outer side of base of first phalanx of little toe. Action. — Abducts little toe; flexes proximal phalanx. Nerve Supply. — External plantar. Blood Supply. — External plantar. Flexor brevis digitorum. — (Perforatus.) — Description. — (Plate LV.) — This muscle is called Perforatus because its tendons are perforated by those of the Flexor longus digitorum (Perforans.) After the muscle divides into four tendons, one for cadi of the four outer toes, these tendons themselves divide opposite bases of the first phalanges for the passage of the tendons of the Flexor longus digitorum. They divide a second time to be inserted into the sides of the second phalanx of the four outer toes. This muscle is separated from the externa] plantar vessels and nerve by a thin layer of fascia. ORIGIN. (Plate bill.)— (1) Inner tubercle of os calcis; (2) central part of plant a i- fascia; (3) intermuscular septa. Insertion.- (Plate LIII.) Sides of second phalanges of four lesser toes. \ii [on. Flexes toes. \i:i;\ i: Supply. Internal plantar. P>!.(»oi> SUPPLY.- Plantar arteries. Adductor obliquus hallucis.- Description. — (Plate LX.) — This muscle PLATE LIV PHALANGES. TWO CENTERS FOR EACH BONE. ONE FOR SHAFT. ONE FOR METATARSAL EXTREM ITY THE CENTERS FOR THE BASE OF THE TERMINAL PHA- LANGES APPEAR AT THE SIXTH YEAR. CONSOLIDATE AT THE EIGHTEENTH YEAR. THE CENTERS FOR THE HEADS OF THE METATARSALS APPEAR AT THE THIRD YEAR, AND CONSOLIDATE AT THE TWENTIETH YEAR. METATARSUS TWO CENTERS FOR EACH BONE. ONE FOR SHAFT ONE FOR DIGITAL EXTREMITY EXCEPT FIRST THE CENTER hOR THE EPIPHYSIS FOR THE METATARSAL OF THE HALLUX APPEARS AT THE THIRD YEAR. CONSOLIDATES AT THE TWENTIETH YEAR. ONE CENTER FOR EACH BONE. EXCEPT OS CALCIS THE CENTER FOR THE EPIPHYSIS FOR THE CAL- CANEUM APPEARS AT THE TENTH YEAR. CONSOLIDATES AT SIXTEENTH YEAR. Showing the Direction op Nutrient Arteries of Bones of the Foot. 159 160 ANATOMY IN A NUTSHELL occupies the hollow space between the four inner metatarsal bones. It is a large, thick, fleshy mass passing obliquely across the foot. Origin. — (Plate LIII.) — Tarsal extremities of second, third, and fourth metatarsals and sheath of tendon of Peroneus longus. Insertion. — ( Plate LIII.) — Outer side of base of first phalanx of great toe, with outer portion of Flexor brevis hallucis. All the small muscles of the great toe give off fibrous expansions at their insertion to blend with the long extensor tendon. Action. — Abducts great toe. Nerve Supply. — External plantar. Blood Supply. — Plantar arteries. Adductor transversus hallucis. — Description. — (Plate LX.) — This muscle is narrow ami fiat, and crosses the heads of metatarsal bones, lying between them and the flexor tendons. Another name for this muscle is (Transversus pe< lis.) Origin. — (Plate LIII.) — Inferior metatarso-phalangeal ligaments of three outer toes. Insertion. — (Plate LIII.) — Outer side of first phalanx of great toe, its fibers being blended with the tendon of insertion of the Adductor obhquus hallucis. A< tion. — Adducts great toe. Xi;i;\ e Sipply. — External plantar. Blood Supply. — External plantar. Dorsal interossei. — Description. — (Plate LXI.) — The Dorsal interossei of the foot are similar to those in the hand with the exception that they are grouped around the middle line of the second toe, while those of the hand are grouped around the middle line of the middle finger. Each one lias two heads between which pass the perforating arteries to the dorsum of the foot, except in the hirst dorsal interosseous between the two heads of which passes the com- municating branch of the dorsalis pedis artery. ORIGIN. (Plate LXI.) — From adjacent sides of metatarsal bones. Insertion. — (Plate LXI.) — Bases of first phalanges and aponeurosis of common extensor tendon; first muscle inserted into inner side of second toe, the other three into outer side of second, third, and fourth toes. Action.— Flex first and extend second and third phalanges ; adduct second, third, ami fourth tin-. Nerve Supply. External plantar. First and second dorsal also receive extra filaments from anterior tibial nerve. Blood Supply. The Plantar interossei receive the external plantar, and the Dorsal interossei receive the plantar arteries both external and internal; ex- cept the third dorsal interosseous which receives the external only. Plantar interossei. DESCRIPTION.— (Plate LXII.) — The plantar inter- ""i i ;ire three in number, the same as the palmar interossei of the hand and also have one head apiece. They lie beneath the metatarsal bones. ORIGIN.— (Plate LXII.) Base ami inner side of shaft of third, fourth. and fifth metatarsal bones. ANATOMY IN A NUTSHELL. 161 Insertion. — (Plate LXII.) — Inner sides of bases of first phalanges of same toes and aponeurosis of common extensor tendon. Action. — Adduct first phalanges of three outer toes; also flex first phalanges, but extend the rest. Nerve Supply. — External plantar. Blood Supply. — Plantar arteries. PLATE LV. EXTERNAL NERVE .PLANTAR Plantar Fascia and First Layer of Muscles of Foot. LESSON XLII1. Flexor accessorius. — Description. (Plate LIX.) The two heads of this muscle are separated from each other by the Long plantar Ligament. The ex- ternal plantar vessels and nerve lie beneath it . when one is standing. 162 ANATOMY IN A NUTSHELL. Origin. — (Plate L1II.) — Inner or larger head from inner concave surface of os calcis below groove for tendon of Flexor longus hallucis. Outer head from outer surface of OS calcis and long plantar ligament. [nsertion. (Plate LIX.) — Outer margin, upper and under surfaces of tendon of Flexor Longus digitorum. A< pion. Assists long flexors of toes. Nerve Supply. — External plantar. Bl Si ppli . External plantar. Lumbricales.— Description. — (Plate LIX.) — These are accessory to ten- dons of the Flexor Longus digitorum. Origin. -(Plate LIX.) — Tendons of long flexors. Insertion. — (Plate LIX.) — Expansion of long extensors and base of first phalanx of corresponding toe. A< riON. Accessory to flexors and extensors. \i i;\ i. Supply. — Two inner muscles get the internal plantar. Two outer muscles gel the external plantar. Note. — The first inner lumbricalis has internal plantar and the three outer have external plantar in one out of ten cases. Blood Supply. — Plantar arteries. Flexor brevis hallucis. — Description. — (Plate LX.) — This muscle has one origin and two insertions, and is situated along the inner and under surfaces of the metatarsal of the great toe. The inner tendon joins that of the Abductor lialluci-. while the outer one joins the tendons of the Adductor transversus hallucis and the Adductor obliquus hallucis prior to their common insertion in a sesamoid bone. Between these two heads the Flexor longus hallucis lies in a ive. Origin. — (Plate LIII.) — (1) Inner border of cuboid bone; (2) external cuneiform; (3) prolongation of tendon of Tibialis posticus. Insertion. (Plate LIII.) — Inner and outer sides of base of first phalanx of greal toe. Action. —Flexes and abducts great toe. N i:i;\ i. Supply. Internal plantar. Blood Supply.— Internal plantar. Astragalus, supplied by dorsalis pedis. One or two centers of ossification. Artici LATION. With four bones: (1) tibia, (2) fibula; (3) os calcis, and navicular. Astragalus has no muscles attached. Os calcis, supplied by posterior tibial, internal and external malleolar. Two centers of ossifk moN. For ossification of tarsus see Plate LIY. Artk i LATION. With two bones: (1) the astragalus and (2) cuboid. Attachment oi Muscles. Eight: (1) part of the Tibialis posticus; (2) the tendon Achillis; (3) Plantaris; (4) Abductor hallucis; (5) Abductor minimi digiti; (6) Flexor brevis digitorum; (7) Plexor accessorius, and (8) Extensor brevis digitorum. Cuboid, supplied by the dorsalis pedis, as are the remaining bones of tarsus. ( >ssn [( vi [on. ( me center. ANATOMY IN A NUTSHELL. 163 Articulation. — With four bones; (1) the os calcis; (2) external cunei- form, and (3) the fourth and (4) fifth metatarsal bones; occasionally with the navicular. Attachment of Muscles.— (1) part of the Flexor brevis hallucis and (2) PLATE LVI. First Layer of Muscles of the Foot, Also [nternal wi> External Plantar Arteri es. a slip from the tendon of the Tibialis posticus. Navicular, supplied by dorsalis pedis. ( Ossification. — One center. Articulation.— With four hones: (1) astragalus and three cuneiform; occasionally the cuboid. Attachment of Muscles. Pari of the Tibialis posticus. Internal cuneiform, supplied by dorsalis pedis. 164 ANATOMY IN A NUTSHELL. Ossification. — One center. Articulation. — With four bones: (1) navicular, (2) middle cuneiform; (3) first and (4) second metatarsal bones. Attachment of Muscles. — (1) Tibialis anticus and (2) posticus and (3) Peroneus longus. Middle cuneiform, supplied by dorsalis pedis. i >ssification. — One center. Ai;ii< qlation. — With four bones, navicular, internal and external cunei- form and second metatarsal bone. Attachment of Muscles. — A slip from the tendon of the Tibialis posticus is attached to this bone. External cuneiform, supplied by dorsalis pedis. Ossification. — One center. Articulation. — With six bones; the navicular, middle cuneiform, cuboid, second, third, and fourth metatarsal bones. Attachment of Muscles. — Two: part of Tibialis posticus, Flexor brevis hallucis. Metatarsus. Plates LII-LIII. Blood Supply. — They all have small nutrient branches from interosseous. Ossification. — Each metatarsal bone has two centers. Plate LIV. Articulation. — Each bone articulates with the tarsal bones by one ex- tremity, and by the other with the first row of phalanges. The number of tarsal bones with which each metatarsal articulates is one for the first, three for the second, one for the third, two for the fourth, and one for the fifth. Attachment of Muscles. — To the first metatarsal bone, three, part of the Tibialis anticus, the Peroneus longus, and First dorsal interosseous. To the second, four, the Adductor obliquus hallucis and First and Second dorsal inter- osseous, and silp from the tendon of the Tibialis posticus, and occasionally a slip from the Peroneus longus. To the third, five, the Adductor obliquus hallucis, Second and Third dorsal and Plrst plantar interosseous, and a slip from the tendon of the Tibialis posticus. To the fourth, five, the Adductor obliquus hallucis. Third and fourth dorsal, and Second plantar interosseous, and a slip from the tendon of the Tibialis posticus. To the fifth, six, the Peroneus brevis Peroneus tertius, Flexor brevis minimi digiti, Adductor transversus hallucis. Fourth dorsal and Third plantar interosseous. Phalanges. Plates LII-LIII. Blood Supply. — They all have small nutrient branches from digital. Ossification.- From two centers. Plate LIV. Artk i LATION. The first row, with the metatarsal bones behind and sec- ond phalanges in front ;the second row of the four outer toes, with the first and third phalanges; of the great toe, with the first phalanx: the third row of the loin- outer toes, with the second phalanges. Attachment ok Muscles.- To the first phalanges. Great toe, five mus- cles; innermosl tendon of Extensor brevis digitorum, Abductor hallucis, Ad- ductor obliquus hallucis, flexor brevis hallucis, Adductor transversus hallucis. ANATOMY IN A NUTSHELL. 165 Second toe, three muscles ; First and Second dorsal interosseous and First lumbrical. Third toe, three muscles ; Third dorsal and First plantar interosseous and Second lumbrical. Fourth toe, three muscles; Fourth dorsal and Second plantar interosseous and Third lumbrical. Fifth toe, four muscles; Flexor brevis minimi digiti. Abductor minimi digiti, and Third plantar interosseous, and PLATE LVII. INTERNAL PLANTAR LUMBRICALES ARTERY INTERNAL PLANTAR NERVE. ARTERY. POST. TIBIAL NERVE EXTERNAL PLANTAR COMMUNICATING TO INTERNAL PLANTAR NERVE EXTERNAL PLANTAR ARTERY LUMBRICALES, INTERNAL AND EXTERNAL PLANTAH VESSELS AND NERVES. Fourth lumbrical. Second phalanges. Great toe; Extensor Longus hallucis, Flexor longus hallucis. Other toes; Flexor brevis digitorum; one slip ol the common tendon of the Extensor longus and brevis digitorum. Third phalanges; two slips from the common tendon of the Extensor longus and Extensor brevis digitorum, and the Flexor longus digitorum. 166 ANATOMY IN A NUTSHELL. LESSON XL1Y. The Tibia. The word tibia means flute. It is also called the shin bone and is situated on a plane anterior to and on the inner side of the fibula. It articulates with the lemur above, tin 1 astragalus below, and the fibula externally. It sustains the uri'Jn of the entire body above the knee-joint as the fibula does not enter into this articulation. The superior expanded portion is called the head, each side of which is a tuberosity. These tuberosities are continuous in front but are separated be- hind by the popliteal notch. The upper surface of each tuberosity is concave to receive the condyles of the femur. The internal tuberosity is larger than the external one, and its articular surface is more concave and Longer. A horizontal groove for the Semimem- branosus muscle is behind this articular surface close to its inner border. The external tuberosity gives attachment to the ilio-tibial band at the junc- tion of the anterior and outer surfaces, at which place there is a prominent tuber- cle. The Extensor Longus digitorum and the Biceps have a \'v\\ fibers of at- tachment immediately below and in front. The fibula articulates with the posterior and under part in a flat facet which looks downward, outward, and backward. The articular surface of this tuberosity is concave from side to side, but convex from before backward, and its circumference is almost circular. The semilunar fibro-cartilages are situated around the circumference of each of these articular surfaces where they are flattened. The spine is an elevation between these articular surfaces. The summit of the spine has two tubercles with an intervening space. The depressions in iVi .lit and behind the spine are for the attachment of the crucial ligaments. This posterior depression is continuous into the popliteal notch, which separates the tuberosities posteriorly. The anterior tuberosity or tubercle is at the junc- tion of the head and the -haft anteriorly. The lower half of this tubercle gives attachment to the ligamentum patellae. The shaft which is triangular on cross section is smallest at the junction of the upper two-thirds with the lower one-third. It has three borders and three surfaces. The anterior border separates the internal and external surfaces and extends from the anterior tuberosity or tubercle to the front of the inner mal- leolus. The crest of the tibia i> the upper two-thirds of this border. The lower one-third of this border is smooth. The internal border separates the internal and posterior surfaces. It commences above at the back of the inner tuberosity and extends below to the posterior border of the internal malleolus. This border ie rnos1 distind in the middle third of the bone. The external border, also called interosseous ridge, separate- the external and posterior surfaces. It gives attachment to the interosseous membrane and is thin and sharp in its middle portion. The internal surface is nearly subcutaneous and is convex. The insertion ANATOMY IN A NUTSHELL. 167 of the Gracilis is at the inner side of the tubercle, having the insertion of the Semitendinosus below it. the two being surrounded by the double insertion of the Sartorius. except below. The external surface has on it- upper two-thirds, which is concave, the Tibialis anticus. The lower part of its surface runs for- ward and is covered by the extensor tendons. The posterior surface has an PLATE LVIII. Accessorius Muscle and Plantar Vessels. oblique line running down and inward a1 the junction of the upper and middle one-third of the bone. This line giv< - the origin of the Soleus. The popliteus muscle is attached to the triangular area above this line. The middle one- third of the bone is divided into two portion- by a longitudinal ridge, the inner one of which is for the origin of the Flexor longus digitorum, and the outer one 168 ANATOMY IN A NUTSHELL. is for the origin of the Tibialis posticus. A nutrient foramen is on this portion of the bone and is directed towards the distal extremity. The lower portion of the bone is broad transversely, and extends downward internally to form the inner malleolus. On the posterior portion of this malleo- lus is a groove for the tendon of the Tibialis posticus, and externally to this is one for the tendon of the Flexor longus hallucis. The fibula articulates with the external portion of the lower extremity of the bone in a concave surface, which is rough for the attachment of ligaments, except along its lower border. The lower end of the tibia has an articular surface which is concave, being broader in front than behind. It articulates with the astragalus. In the middle of thi> surface is a slight elevation separating two lateral depression-. The tibia is a very vascular bone. The nutrient artery for the shaft is furnished by the posterior tibial, it enters the bone near the interosseous border at the junction of the upper and middle third, and is directed downward. The head of the bone receives numerous branches from the inferior articular arteries of the popliteal, and the recurrent branches of the anterior and posterior tibial arteries. The lower extremity receives twigs from the posterior and anterior tibial, the anterior peroneal, and the internal malleolar arteries. Ossificatiox. — From three centers. The center for the shaft appears in the eighth week of intra-uterine life. The center for the proximal extremity appears at the end of the ninth month of intra-uterine life, and joins the shaft at the twenty-first year or even later. The center for the distal extremity ap- pears during the second year and unites with the shaft at the eighteenth year. Articulation. — With three bones; femur, fibula and astragalus. Attachment of Muscles. — Twelve; to the inner tuberosity, the Semi- membranosus; to the outer tuberosity, the Tibialis anticus and Extensor longus digitorum and Biceps; to the shaft, its internal surface, the Sartorius, Gracilis, and Semitendinosus; to its external surface, the Tibialis anticus; to its posterior surface, the Popliteus, Soleus, Flexor longus digitorum, and Tibialis posticus; to the tubercle, the hgamentum patellae. LESSON XLY. The Patella. The sesamoid bone which is developed in the tendon of the Quadriceps extensor muscle is the patella (knee-pan.) Its anterior surface is pierced by vascular foramina. h> superior border has the Rectus and Crureus attached to it. The posterior margin of this border is higher than the anterior margin. The externa] part of the posterior surface is concave transversely, and the interna] pari i- convex. When the leg is extended the lower one-sixth of articular surface is in contact withthe femur. When it is mid-flexed the middle three-sixths of the articular surface is in contact with the femur. When fully flexed the upper two-sixths of the articular surface is in contact with the femur, also in this position the marginal facet is in contact with the inner condyle. The Ugamentum patellae springs from the apex. If the patella is placed upon a ANATOMY IN A NUTSHELL. 169 plain surface, its apex away from you and its anterior surface up, it will tip to the side to which it belong?. Blood Supply.— The patella receives twigs from the superficial branch of the anastomotica, anterior tibial recurrent, and the inferior articular of the popliteal. 'ft j |t / •' LUMBRICALIS_ V / | 1 iff Flexor Lonqtjs Digitorum Tendon and Foub Lumbricales. Ossification. — One center. It begins during the third year and is com- pleted aboul the age of puberty. Articulation.— With two condyles of femur. Attachment of Muscles.— Four : the Rectus, Crureus, Vastus interims and Vastus externus. These muscles, joined at their insertion, constitute the Quadriceps extensor cruris. 170 anatomy in a nutshell. The Fibula. The word fibula means clasp or pin. It is also called the peroneal bone, and Lies almost parallel with the tibia. It is not quite as long as the tibia, but extends to a Lower Level. Its main purpose is to give elasticity to the leg. 1 1- upper expanded portion is called the head, which is prolonged upward at its posterior part into the styloid process. The inner surface of the head and styloid process has a facet which looks upward, inward, and forward to articulate with the tibia. This styloid processgives attachment to the Biceps. The Soleus muscle is attached behind and the Peroneus longus is attached in front. The neck is the constricted part below the head. The lower extremity extends into the external malleolus which is lower than the internal malleolus. .Man i- the only animal in which this is true. It articulates with the astragalus internally, and behind there is a depression for the posterior fasciculus of the external lateral ligament. There is a slight groove posteriorly for the Peroneus longus and brevis. This extremity is convex and subcutaneous externally. The shaft has four surfaces which are anterior, internal, posterior, and external; and it has four borders which are antero-external, antero-in- ternal, postero-external, and postero-internal. To its anterior surface are attached the Extensor proprius hallucis, Extensor longus digitorum, and Peroneus tertius. This surface is broad and grooved below but narrow above. The internal surface is grooved for the Tibialis posticus. The posterior surface has attached to its upper third the Soleus, below this the Flexor longus hallucis. The nutrient canal is on this surface and is directed downward. The Peroneus brevis and longus are attached to the external surface, which is directed out- ward above and backward below. The antero-external border is between the peroneal muscles and the ex- tensor muscles, and extends from the front of the head of the fibula to the ex- ternal malleolus, where it divides to embrace a triangular subcutaneous sur- face. The antero-internal border, called interosseous ridge, gives attachment to the interosseous membrane and separates the extensor muscles in front from the Tibialis posticus behind. It lies parallel with the antero-external border in it- upper third. It ends below just above the articular facet. The pos- tero-external border separate- the peroneal muscles from theflexor muscles. It commences a1 the base of the styloid process and ends below in the posterior border of the external malleolus. This is not a straight line for at first it is directed outward, then backward, then inward. The postero-internal border, called the oblique line, commences above the inner side of the heads and ends below in the lower one-fourth of the bone where it joins the interosseous ridge, or antero-internal border. lb > Supply. The fibula receives the nutrient artery of its shaft from the peroneal branch of the posterior tibial. The head is nourished by branches from the inferior external articular branch of the popliteal artery, and the malleolus i- supplied mainly by the peroneal and external malleolar arteries. Ossification. From three centers. The center for the shaft appears in the eighth week of intra-uterine life. The center for the proximal extremity AXATOMY IN A NUTSHELL. 171 appears in the fourth or fifth year, and joins the shaft at the twenty-second year or later. The center for the distal extremity appears during the second year, and unites with the shaft at the twentieth year. Articulation-.— With two bones: the tibia and the astragalus. Attachment of Muscles.— Nine ; to the head, the Biceps. Sol.-us. and PLATE LX. FLEXOR LONGUS HALLUCIS SESAMOID BONE: - . & ec • £j fV t? >N i i, / ' FLEXOR BREVIS HALLUCIS - ■ ?- \ TIBIALIS POSTICUS FLEXOR LONGUS DIGITORUM - FLEXOR LONGUS HALLUCIS . GROOVE FOR PERONEUS LONGUS Third Later of Must les of the Foot. Peroneus Iongus; to the shaft, its anterior surface, the Extensor longus digi- torum, Peroneus tertius, and Extensor proprius hallucis; to the internal surface, the Tibialis posticus; to the posterior surface, the Soleus and Flexor longus hal- lucis: to the external surface, the Peroneus longus and brevis. The fibula is a vestigial bone in man and survives mainly on account of the excessive development of its malleolus. This accounts for the fad thai the 172 ANATOMY IN A NUTSHELL. lower epiphysis, through appearing first, unites with the shaft before the upper epiphysis. In birds, the head of the bone is large, and enters into the formation of the knee-joint, while the lower end atrophies. The rule is this: Those ephy- ses which are the last to form are first to join the bone. The fibula is an excep- tion. Rule 1, page 19. LESSOX XLVI. Arteries The abdominal aorta (Plates LXXII-XC) divides into the right and left common iliac arteries a little to the left side of the median line of the fourth lumbar vertebra. This division is on a level with the highest points of the crest of the ilii. Each of these common iliac arteries divides into an external and an internal iliac branch at the lumbo-sacral joint. The branches of these com- mon iliac arteries supply the peritoneum, ureter. Psoas magnus. The internal iliac branch (Plates LXXII-XCI) is about an inch and a half long and divides into an anterior and posterior trunk at the upper margin of the great sacro-sciatic foramen. The posterior trunk gives off the three fol- lowing branches: (1) Ilio-hmibar, (2) lateral sacral, (3) gluteal. The ilio- lumbar branch divides into an iliac branch for the Iliacus muscle and the ilium and a lumbar branch for the Psoas magnus and Quadratus lumborum. The branch to the Quadratus lumborum semis a spinal branch to the spinal cord through the last intervertebral foramen. The lateral sacral branch divides into a superior and inferior division. The superior one, after anastomosing with the sacro-media, passes through the first or second anterior sacral foramen to supply the canal, after which it passes through the corresponding posterior foramen to the back. The inferior branch, after descending on the sacrum and coccyx, anastomoses with the sacro-media and has a similar route as the super- ior branch. The gluteal branch passes out of the pelvis through the great sacro-sciatic foramen, above the Pyriformis muscle. While in the pelvis, it gives branches to the ilium and adjacent muscles. Outside of the pelvis it divides into super- ficial branch which passes undes the Gluteus maximus, and deep branch which passes between the Gluteus medius and Gluteus minimus, and then divides into an upper branch which runs along the upper border of the Gluteus minimus, and a lower branch which runs downward. The anterior trunk (Plate- LXXII-XC) uives off the following branches: (!) Superior vesical, (2) middle vesical, (3) inferior vesical. (4) middle hem- orrhoidal. (.">) obturator. (Co internal pudic, (7) sciatic; and in the female (8) uterine, ami (9) vaginal. The superior vesical branch is that portion of the fetal hypogastric artery which is still used alter birth. It runs to the side of the bladder and gives off the artery to the vas deferens, which artery runs with tin- spermatic cord. In the fetus the external iliac artery is only about one- half as large a- this hypogastric artery (umbilical). This artery in the fetus runs to the bladder and from there along the abominal wall to pass through the ANATOMY IN A NUTSHELL 173 umbilicus to the umbilical cord and the placenta, (Plate IX). The middle vesical branch passes to the base of the bladder and is generally a branch of the superior vesical. The inferior vesical branch runs to the base of the bladder, prostate gland and seminal vesicales in the male and to the vagina, rectum, and neck of the bladder in the female. In the female it is called vaginal. The middle hemorrhoidal branch passes to the rectum and generally arises with the PLATE LXI. The Four Dorsal Interossei. inferior vesical. The obturator branch lies inferior to the obturator nerve, and after passing through the obturator canal it divide s into an internal and an ex- ternal branch, which branches wind around either margin of the obturator foramen under the Obturator externns muscle. This branch arises from the d( ep epigastric once in three and a half cases, and pass* > over the outer margin of the femoral ring to the obturator foramen. Inside the pelvis it sends branches to the Iliacus muscle and iliac fossa, branches to the bladder, and pubic branches to the back of the OS pubis. The internal puttie branch is the -mailer of the terminal branches of the anterior trunk, and passes ou1 of the pelvis below the 174 ANATOMY IN A NUTSHELL. Pyriformis muscle, lying between this muscle and the Cuccygeus. After cross- ing the spine of the ischium, external to the nerve, it passes through the lesser sacro-sciatic foramen into the pelvis, it now passes through Aleock's canal about an inch and a half above the tuberosity of the ischium, it now pierces the triangular ligament where it divides into the dorsal artery of the penis and the artery of the corpus cavernosum. Besides these two terminal branches it has the (1) muscular, (2) inferior hemorrhoidal. (3) superficial perineal, (4) trans- perineal, (5) artery of the bulb. The sciatic branch is the larger of the terminal branches of the anterior trunk and passes through the great sacro- sciatic foramen below the Pyriformis, then descends between the tuberosity of the ischium and the trochanter of the femur under the Gluteus maximus, and then helps to form the crucial anastomosis which is made by four branches, the first three of which are branches of the profunda artery and the fourth is the S< [atii BRANCH. The first three branches are named internal circumflex, external circumflex, and superior perforating. Inside the pelvis the sciatic artery gives branches to the rectum, neck and base of bladder, prostate gland, and muscle- of the floor of the pelvis. Outside the pelvis the sciatic artery gives anastomotic and coccygeal branches, which run through the great sacro-sciatic ligament to the back of the coccyx, and inferior gluteal branches (which are three or four) to the Gluteus maximus. and muscular branches to the muscles on the back of the hip. It sends articular branches to the hip-joint and comes nekyi ischiadici to the great sciatic nerve. The uterine branch runs to the cervix of the uterus and then along its sides in the broad ligament to anastomose with the ovarian. This artery is above and in front of the ureter. The Relations of the Common Iliac Arteries. (Plates LXXII-XCI.) The right common iliac artery has the following relations: In Front. — (1) Peritoneum, (2) Small intestine, (3) Sympathetic nerves, and (4) Ureter. Behind.— (1) Fourth and fifth lumbar vertebrae, (2) Right common iliac vein, (3) Lef1 common iliac vein. Outer Side. — (1) Vena cava. (2) Right common iliac vein, (3) Psoas muscle. Inner Side.— (1) Left common iliac vein. The Left Common Iliac Artery has the following relations: I\ Front.- (1) Peritoneum, (2) Small intestine, (3) Sympathetic nerves, I Superior hemorrhoidal artery. (5) Ureter. Behind." (1) Fourth and fifth lumbar vertebra?, (2) Left common iliac vein. ( >i m.i; Side. — Psoas magnus muscle. Iwi.i; Side. Left common iliac vein. The Relations of the Internal Iliac Artery.— (Plates LXXII-XCT.) In Front. — (1) Peritoneum, and (2) Ureter. Behind. — (1) Interna] iliac vein, (2) Lumbo-sacral cord. (3) Pyriformis muscle. ( )ii i;i; Side.— Psoas magnus. The Relations of the External Iliac Artery. (Plate XCI.) ANATOMY IN A NUTSHELL. 175 In Front. — (1) Peritoneum, (2) Intestines, (3) Fascia, (4) Lymphatic vessels, (5) Lymphatic glands, (6) Spermatic vessels, (7) Genito-crural nerve (genital branch.) (8) Deep circumflex iliac vein. Behind. — (1) External iliac vein, _ Psoas magnus. Outer Side. — (1) Psoas magnus, (2) Iliac fascia. Inner Side. — (1) External Iliac vein, (2) vas deferens near Poupart's lig- ament. PLATE LXII. Tin. Three Plantah 1 m i rossi i. LESSON XLVII. The external iliac artery passes from its origin, which i- a1 the lumbo-sacral articulation, along the inner border of the Psoas magnus muscle to pass under Poupart's ligamenl after which it is called the common femoral artery. 11 gives branches to the Psoas magnus and the lymphatic nodes. The deep epi- gastric is a branch of this artery and after descending i<> Poupart's ligamenl it 176 ANATOMY IN A NUTSHELL. lies between the peritoneum and the transversalis fascia. After passing under the vas deferens in the male or the round ligament in the female it curves around the lower and inner margin of the internal abdominal ring, then ascending it pierce- the transversalis fascia and the sheath of the Rectus muscle to enter inin the longesl arterial anastomosis in the body by anastomosing with the superior epigastric branch of internal mammary artery. It gives the cremas- ii.i.ii branch t<> the Cremasteric muscle on spermatic cord, pubic branch to the hack of the pubes, and MUSCULAR branches to the adjacent muscles and integument. The deep circumflex iliac artery is also a branch of the external iliac and alter passing along Poupart's ligament to the anterior superior spine it con- tinues to the crest of the ilium. The femoral artery is a continuation of the ex- ternal iliac and passes through the middle of Scarpa's triangle just internal to the head of the femur. This artery is an inch or two in length and here it gives off the profunda artery and continues as the superficial femoral. The superficial femoral passes to the apex of Scarpa's triangle then through Hunter's canal, and after passing through an opening in the Adductor magnus, at the junction of the middle and lower third of the thigh close to the bone, it is called the popliteal artery. Scarpa's triangle. — (Plate LXXIV.) is bounded above by Poupart's lig- ament, externally by the Sartorius muscle, and internally by the Adductor longus. Its floor is formed from without inward by the Iliacus, Psoas, Pectineus, Adductor brevis (?) and Adductor longus. The femoral vein lies "ii the inner side of the femoral artery and the anterior crural nerve lies on ii< outer side. Lymphatics and fat are behind the nerve. Hunter's canal.— (Plates LXIV-LXXVUI.) occupies the middle third of the thigh, while Scarpa's triangle occupies the upper third. This canal is bounded externally by the Vastus internus and antero-internally by ax aponeurosis passing from the Vastus internus to the Adductor longus and magnus which form its posterior boundary. This aponeurosis has above it the Sartorius. The femoral vessels and long saphenous nerve pass through tins canal. The nerve is external to and the vein postero-external to the artery. The Relations of the Common Femoral Artery. (Plates LXXII-LXIV- LXVIII-) [n Front.- (1) Skin, (2) Superficial fascia, (3) Superficial inguinal glands, (4) Iliac portion of fascia lata, (5) Prolongation of transversalis fascia, (6) Crural branch of genito-crural nerve, (7) Superficial circumflex iliac vein, (8) Superficial epigastric vein. Behind. — (1) Prolongation of fascia covering Iliacus muscle, (2) Pubic portion of fascia lata, (3) Nerve to Pectineus, (4) Psoas muscle, (5) Pectineus muscle. (6) Capsule of hip-joint. OUTEB SlDE. (1) Anterior crural nerve, (2) Small part of Psoas muscle. Inner Side. — Femoral vein. The Relations of the Superficial Femoral Artery. (Plates LXXII-LXIV.) In Front. (1) Skin, (2) Superficial and deep fasciae, (3) Internal cutane- PLATE LXIII. TWELFTH THORACIC EXTERNAL CUTANEOUS SOLEUS TIBIALIS POSTICUS FLEXOR LONGUS DIGITORUM FLFXriR LONGUS HALLUCIS THE TWO INNER LUMBRICALES. FLEXOR BREVIS .HALLUCIS. ABDUCTOR MINIMI OIGITI. THE TWO OUTER LUMBRICALES FLEXOR ACCESSORIUS FLEXOR BREVIS MINIMI OIGITI SEVEN INTEROSSEI. ACO. TRANS. HALLUCIS. AOD. npi . HALtuClS. Lumbar, Sacral and Coccygeal Plexuses. 177 178 ANATOMY IN A NUTSHELL. mis nerve, (4) Sartorius muscle, (5) Aponeurostic covering of Hunter's canal, (6) Internal saphenous nerve. Behind.— (1) Femoral vein, (2) Profunda artery. (3) Profunda vein, (4) Pectineus muscle, (5) Adductor longus, (6) Adductor magnus. Outer Side.— (1) Long saphenous nerve, (2) Nerve to Vastus interims, ,:: Vastus internus, (4) Femoral vein (below.) Inner Side. — (1) Adductor longus, (2) Adductor magnus, (3) Sartorius. The Relations of the Profunda Artery. (Plates LXXII-LXIV.) I\ Front. — (1) Femoral vein. (2) Profunda vein, (3) Superficial femoral arten\ (4) Adductor longus muscle. Behind. (1) Qiacus, (2) Pectineus, (3) Adductor brevis, (4) Adductor magnus. Outer Side.— Vastus internus. 1 \\ ER SlDE.- Pectineus. The Relations of the Popliteal Artery. (Plates LXXII-LXIX-LXX.) In Front. — (1) Femur, (2) Ligamentum posticum, (3) Popliteus. Behind. — (1) Semimembranosus, (2) Fascia, (3) Popliteal vein, (4) In- ternal popliteal artery, (5) Gastrocnemius, (6) Plantaris, (7) Soleus. Outer Side. — (1) Biceps, (2) Outer condyle. (3) Gastrocnemius (outer head,) (4) Plantaris, (5) Internal popliteal nerve (above.) Inner Side. — (1) Semimembranosus. (2) Internal condyle. (3) Gas- trocnemius (inner head.) LESSOX XL VI II. The branches of the common femoral artery are, (1) superficial epigastric, _' superficial circumflex iliac, (3) superficial external pudic, (4) deep external pudic. The branches of the superficial femoral are, (1) muscular branches, (2) anastomotica magna. The branches of the profunda femoral are, (1) internal circumflex, (2) external circumflex. (3) perforating. The superficial epigastric artery passes through the saphenous opening and . ascends almost to the umbilicus, lying in the superficial fascia on the external oblique muscle. It anastomoses with branches of the deep epigastric artery. The superficial circumflex iliac artery, after piercing the fascia lata, runs to the anterior superior spine and crest of the ilium below Poupart's ligament. It anastomoses with the deep circumflex iliac and with the gluteal and external circumflex arteries. The superficial external pudic artery, also called superior, passes through the saphenous opening across the spermatic cord in the male and round ligament in the female to the lower part of the abdominal wall, penis, scrotum in the male, and the labium in the female. It anastomoses with branches of the internal pudic. The deep external pudic artery, also called in- ferior, crosses the Pectineus muscle then pierces the fascia lata to pass to the slrin of perineum and scrotum in the male or labium in the female. It anasto- moses with branches of superficial perineal artery. The muscular branches of the superficial femoral artery vary in number from two to seven and go mainly to the Sartorius and Vastus internus muscles. The anastomotica magna which PLATE LXIV SUPERFICIAL EPIGASTR SUPERFICIAL EXTERNAL PUDIC ARTERr ADDUCTOR BREVIS DEEP EXTERNAL PUDIC SCROTUM JNTERNAL OR LONG SAPHENOUS ANASTOMOTICA MAGNA ANASTOMOTICA MAGNA SUP. INT. ANTICULAR INF. INT ARTICULAR A SUPERFICIAL CIRCUMFLEX ilIAC ANT CRUAL NERVE COMMON FEMORAL FEMORAL VEIN EXTERNAL CIRCUMFLEX - ILIO-TIBIAL BAND OF FASCIA LATA SUP. EXT. ARTICULAR A. INF. EXT. ARTICULAR A. Common, Superficial and Profunda Femoral Arteries. 179 ISO ANATOMY IN A NUTSHELL. arises near the end of the femoral divides into a superficial branch which passes with the long saphenous nerve, and adeep branch which runs in front of the tendon of the Adductor magnus to the inner side of the knee-joint, where it anastomoses with the anterior tibial recurrent and the superior internal artic- ular arteries. The profunda artery itself passes behind the superficial femoral vessels od the inner side of the femur and then behind the Adductor longus to pierce the Adductor magnus at the lower third of the thigh. This is sometimes called the fourth perforating branch. The internal circumflex of the profunda passes between the Psoas magnus and the Pectineus to the upper border of the Adductor brevis, at this point it sends one branch inward to the Adductor muscles and another branch downward under the Adductor brevis. The in- ternal circumflex artery itself now passes between the Quadratus femoris and the Adductor magnus to join the crucial anastomosis which is formed by the [NTERNAL CIRCUMFLEX ARTERY, THE EXTERNAL CIRCUMFLEX ARTERY and THE Si periob perforating all of which are branches of the profunda, and the BCIATIC arter*s which is one of the terminal branches of the anterior trunk of the internal iliac. The external circumflex of the profunda passes outward under the Sartorius and Rectus muscles where it divides into ascending branches, descending branches, transverse branches. The ascending branches run up- ward under the Tensor vagina femoris. The descending branches run under the Rectus as far asthe kneeto enter into the circumpatellar anastomosis. The trans^ erse branches pass outward over the Crureus muscle and through the Vastus externus to the back of the thigh to enter into the crucial anastomosis. This external circumflex artery passes between the anterior and posterior divis- ions of the anterior crural nerve. The three perforating branches of the pro- funda pierce the tendon of the Adductor magnus to reach the back of the thigh. The supeRiob ONE passes above the Adductor brevis to join the crucial anas- tomosis. The middle one pienes the Adductor brevis. The inferior one passes below the Adductor brevis. The popliteal artery is a continuation of the femoral and passes through the popliteal space downward and outward. At the lower border of the Popliteus mi scle it gives off the anterior tibial artery and continues as the posterior tibial artery. The popliteal space lies b< hind the knee-joint and is diamond shaped. This -pace has \ FLOOR, A ROOF, and LATERAL BOUNDARIES. It IS bounded above the knee-joinl externally by the Biceps, and below the joint by the Plantaris and the outer h< ad of the Gastrocnemius. It is bounded above the joint internally by the Sen in < 1 1 branosus and below the joint by the inner head of the Gas- trocnemius, lis floor is formed by bones, ligament and muscle. The bones are the femur and tibia, the ligament is the posterior ligament of the knee-joint, and the muscle is the Popliteus. The popliteal artery passes obliquely across the spa< e b< ing surrounded by popliteal nodes, and has the articular branch of the obturator nerve lying upon it. The popliteal veins are superficial and ex- ternal to the artery. An articular filament of the great sciatic nerve is often found deep in this space. The internal popliteal or popliteal nerve crosses all PLATE LXY GEMEUiJS If fJ ^'^4~ INFERI0R GLorEAL - CRUREUS SHORT HEAD OF BICEPS PUNTARIS SUPERIOR GLUTEAL Of GASTROCNEMIUS Muscles in thk Gluteal Region and Back of Thigh. 181 182 ANATOMY IN A NUTSHELL. these structures superficially in the median lint', and the external popliteal or peroneal nerve lies close to the tendon of the Biceps. The branches of the popliteal artery are, (1) cutaneous branches, three in number which descend in the median line and on each side run across the Gast- rocnemius to the calf of the leg. These branches may arise from other branches. (•_») Superior muscular branches, two or three in number pass to the Vastus externus ami flexors of the thigh. (3) Inferior muscular or sural branches generally two branches pass to the Gastrocnemius and Plantaris muscles. (4) Superior internal articular branch which passes under the tendon of the Ad- ductor magnus muscle divides, one of the branches joining the superior external articular artery and the other branch joining the anastomotic^ magna and the inferior internal articular artery. (5) Superior external articular artery which passes above the outer condyle under the tendon of the Biceps divides into a dt ep branch which joins the inferior internal articular artery, and anastomotic^ magna artery and a superficial branch which joins the inferior external artic- ular and the descending branch of the external circumflex artery. (6) The azygos articular pierces the posterior ligament of the knee-joint to supply thai joint. ( 7) Inferior internal articular passes below the inner tuber- osity of the tibia under the internal lateral ligament to join the inferior external and superior internal articular arteries. (8) Inferior external articular artery passes above the fibula under the tendon of the Biceps and external lateral ligament to join the anterior tibial recurrent ami the inferior internal articular and the superior external articular arteries. The circumpatellar anastomosis (Plates LXXII-LXXYI) is formed by the (1) superior external articular, (2) superior internal articular, (3) inferior external articular. (4) inferior internal articular, (5) fourth perforating or terminal branch of the profunda, (6) anastomotica magna, (7) descending branch of the external circumflex, and (8) the anterior tibial recurrent. This anastomosis has superficial and deep portions. If we substitute in this anas- tomosis the fourth perforating or terminal branch of the profunda for the pos- terior tibial recurrent and azygos articular, we will have the blood supply to the knee-joint. LESSON XLIX. The anterior tibial artery (Plates LXXII-LXXVI) runs forward between the two heads of the Tibialis posticus above the interosseous membrane. It now descends on the anterior surface of this membrane and crosses the anterior surface of the tibia distally and the anterior ligament of the ankle-joint. Below this joint it i- called dorsalis pedis artery. The branches of the anterior tibial artery are, I muscular, 1 which go to the muscles of the leg. (2) Posterior tibial recurrent branch (which i> not always present | passes under the Popliteus muscle. (3) Superior fibular branch which passes around the neck of the fibula and through the Soleus muscle to the Peroneus longus. (4) Anterior tibial recurrent which passesupward through the Tibialis anticus to go to the circum- patellar anastomosis. (5) Internal malleolar branch passes under the tendons PLATE LXVI. SUPERFICIAL EPIGASTRIC SUPERFICIAL INGUINAL NODES SUPERF.CIAL CIRCUMFLEX ILIAC VEIN. EXTERNAL FEMORAL CUTANEOUS VEIN Superficial Lymphatic Vessels \\i> Veins <>f Leg 183 184 ANATOMY IN A NUTSHELL. of the Extensor proprius hallucis and Tibialis anticus to the inner malleolus. 6) The cMcrnal malleolar passes under the tendons of the Extensor longus digitorum and Peroneus tertius to the outer malleolus. The Relations of the Anterior Tibial Artery. l.\ Front.- -(1) Integument, (2) Superficial and deep fascia, (3) An- terior tibial nerve, (4) Tibialis anticus (overlaps it in the upper part of the leg), (5) Extensor longus digitorum (overlaps it slightly,) (6) Extensor proprius hallucis (overlaps it slightly). (7) Anterior annular ligament. BEHIND. — (1) Interosseous membrane, (2) Tibia, (3) Anterior ligament of ankle-joint. Outeb Side. — (1) Anterior tibial nerve, (2) Extensor longus digitorum, (3) 1 Jxtensor proprius hallucis. Iwii; Side. — (1) Tibialis anticus, (2) Extensor proprius hallucis (crosses it at it- lower part). The dorsalis pedis artery (Plates LXXII-LXXYI.) is the continuation of the anterior tibial. It passes along the inner side of the foot from the ankle- joint to the first intermetatarsal space, where it divides into dorsalis hallucis artery and the communicating artery. The dorsalis hallucis artery, also called firsi dorsal interosseous, passes in the first interosseous space to the base of the mvat toe where it divides into two branches which pass to the dorsal aspect of the adjacent sides of the great and second toes. Prior to this division it gives off a branch which passes under the Extensor proprius hallucis tendon and runs along the dorsal aspect of the inner side of the great toe. The communicating branch, also called the plantar digital, passes between the two heads of the First dorsal interosseous muscle to join the external plantar artery, thus completing the plantar arch, it now gives off the arteria princeps hallucis which runs along the plantar surface of the first interosseous space and divides at the base of the toes into two branches for the plantar aspect of the sides of the great toe. Besides these terminal branches it gives off (1) external tarsal, (2) internal tarsal. These branches run outward and inward across the cuboid and scaphoid bones. (3) Metatarsal which passes across the base of the metatarsal bones ex- ternally. This artery gives off three interosseous arteries which pass in the three outer interosseous spaces to the base of the toes where they divide into internaland external branches for the dorsalaspect of adjacentsides of the four outer toes. The outer interosseous branch before its division at the base ofthetoes sends :i branch along the dorsal aspect of the outer side of the little toe. These three arterieseach receives aposterior perforating branch from the plantar arch a1 the base of the space, also an anterior perforating branch from the digital artery ;it the front of the space. The Relations of the Dorsalis Pedis Artery. I\ Front. (1) [ntegument, (2) Fascia, (3) Anterior annular ligament, I Innermost tendon of Extensor brevis digitorum. Behind.- (1) Astragalus, (2) Navicular, (3) Middle cuneiform, (4) The ligament- to these bones. Outeb Side. — (1) Extensor longus digitorum, (2) Anterior tibial nerve. Iwii; Side. Extensor proprius hallucis. ANATOMY IN A NUTSHELL. LESSON L. 185 The posterior tibial artery (Plates LXIX-LXX) is a continuatioD of the popliteal artery and commences at the lower border of the Popliteus muscle, from here it passes to the interval between the heel and the internal malleolus PLATE LXVII. v : Jii External or Shout Sapiienoi s Vein. where it divides into the internal and external plantar arteries. Along its course it lies upon the Tibialis posticus. Flexor longus digitorum, tibia, and ankle-joint. The branches of the posterior tibial artery are. (1) The peroneal 186 ANATOMY IN A NUTSHELL. artery which arises about an inch below the Popliteus and passes along the inner side of the fibula to the lower third of the leg where it divides into an anterior and posterior peroneal. The peroneal artery itself gives off (a) mus- culab branches to the muscles at the hack and outer side of the leg, (b) nutri- ent to fibula, (c) INTERIOR PERONEAL which runs through the interosseous membrane and then descends to the outer ankle, (d) Communicating branch runs inward to unite with a similar branch of the posterior tibial, (e) Pos- terior PERONEAL continues with the main artery to the outer side of the os calcis. (f) The external calcanean sends several branches to the outer side of the heel. (2) Muscular branch* s which pass to the muscles on the back of the leg. (3) Nutrient to the tibia. This branch also gives off muscular branches. (4) Communicating branch which runs across the tibia and unites with a similar branch from the peroneal. (5) Internal calcanean which sends several branches to the internal side of the heel. Flu external plantar artery (Plates LV-LVI-LVIII) passes between the Flexor brevis digitorum and Flexor accessorius to the base of the fifth meta- tarsal bone. It now bends inward and arches across the bases of the fourth, third, ami second metatarsals to the interval between the second and first meta- tarsal, where it joins the communicating branch of the dorsalis pedis to com- plete the plantar arch. The branches of the external plantar are (1) posterior perforating: which are three in number and run between the heads of the three outer Dorsal mterossei to join the interosseous branches of the metatarsal arteries. (2) Digital branches are four. The first runs along the outer side and plantar aspect of the little toe, the outer branches run along the three outer in- terosseous spaces to the base of the toes where each one sends an anterior per- forating branch to join an interosseous branch of the metatarsal, and then divides into two brandies for the adjacent sides and plantar aspects of the toes. The internal plantar artery (Plates LV-LVI-LVIII) passes above the Ab- ductor hallucis, then between it and the Flexor brevis digitorum, and from here along the inner side of the great toe to anastomose with the digital branch from the princeps hallucis. The Relations of the Posterior Tibial Artery. 1\ Front. — (1) Tibialis posticus, (2) Flexor longus digitorum, (3) Tibia, I Ankle-joint. Behind. (1) Integument, (2) Fascia. (3) Gastrocnemius, (4) Soleus, (5 Deep transverse fascia, (6) Posterior tibial nerve, (7) Abductor hallucis. Outer Side. Posterior tibial nerve, lower two-thirds. Inner Side. Posterior tibial nerve, upper third. The Relations of the Peroneal Artery. (Plate LXIX.) In Front, fit Tibialis posticus, (2) Flexor longus hallucis. Behind. (1) Soleus, (2) Deep transverse fascia, (3) Flexor longus hallucis Outer Side. (1) Fibula, (2) flexor longus hallucis. Inner Side. Flexor longus hallucis. Veins. The external iliac vein (Plate XC) is a continuation of the femoral vein PLATE LXVIII. SPERMATIC CORD PECTINEUS ADDUCTOR LONGUS SCROTUM OBTURATOR. ADDUCTOR MAGNUS SUB- SARTORIAL PLEXUS PATELLAR BRANCH OF LONG SAPHENOUS INTtHNAL CUTANEOUS SARTORIUS LONG SAPHENOUS. THE ANTERIOR TIBIAL ARTERY AND NERVE ANT. ANNULAR LIG. EXTERNAL CUTANEOUS NERVI ANTERIOR CURAL NERVE -EMORAL ARTERY FEMORAL VEIN INTERNAL CUTANEOUS EXTERNAL POPLITEAL OR PERONEAL MUSCULOCUTANEOUS PERONEUS 1LONGUS EXTENSOR LONGUS DIGITORUM CUTANEOUS BRANCH OF MUSCULO -CUTANEOUS PERONEUS. BREVIS PERONEUS TERTIUS Anterior View of Entire Lower Limp.. L87 1SS ANATOMY IN" A NUTSHELL. above Poupart's ligament to the sacro-iliac articulation, where it joins the in- ternal iliac vein to make the common iliac vein. The right common iliac vein is on the outer side of the right common iliac artery, but as it passes upward it goes behind the artery. The left common iliac vein is on the inner side of the left common iliac artery throughout its course. The radicles of the external iliac vein arc the deep epigastric and the deep circumflex iliac veins, and a small pubic vein. The external iliac vein may have one or two valves. The internal iliac vein, which unites with the external iliac vein at the sacro-iliac articulation to form the common iliac vein, lies at first on the inner side of ami then behind the artery. It receives radicles corresponding to all the branches of the internal iliac artery except the umbilical (hypogastric.) Jt drain- the viscera in the pelvis in the following manner: (1) the internal pudlc vein receives radicles which corresponds to all the branches of the internal pudic artery except the dorsal artery of the penis. (2) Around the lower end of the rectum there is a hemorrhoidal plexus which is formed by the hem- orrhoidal veins. (3) The blood which passes through the superior hemorrhoidal vein empties into the inferior mesenteric vein, while the blood which empties into the middle ami inferior veins passes into the internal iliac vein, thus is established a free communication between the portal venous system and the general venous system. (4) The plexus, which surrounds the vaginal mucous membrane and is well developed near the orifice, and anastomoses with the vesical and hemorrhoidal plexuses before it joins the internal iliac vein. (5) The plexus which lies at the sides and upper angles of the uterus between the layers of the broad ligament is called uterine plexus, and it drains the sub- stance of 4ie uterus and communicates with the ovarian veins before it joins the internal iliac vein. The common iliac veins are formed by the external and internal iliac veins at the sacro-iliac articulation from which point they ascend obliquely upward to the righl >ide of the median line of the spine between the fourth and fifth lum- bal- vertebra where they join one another to form the inferior vena cava. The right one, which is more vertical than the left, passes at first behind and then to the outer side of the cuimnon iliac artery. The left one, which is more ob- lique and longer than the right, passes, for the most part, to the right side of the left common iliac artery but passes behind its artery above. Each of these veins receives the ilio-lumbar vein and occasionally the lateral sacral vein. The left one. in addition, receives the middle sacral vein. No valves are found in these veins. The inferior vena cava, (Plate XC) which ends in the lower and back part of the righl auricle of the heart near the Eustachian valve, has no length above the Diaphragm. It passes from the fifth lumbar vertebra where it is formed by the righl and lefi common iliac veins upward in front of the spine on the right side of the aorta, and in it> course it passe^ in a groove on the posterior surface of the liver and pierces the central tendon of the Diaphragm. At this point it enters the fibrous pericardium and is partially invested by the serous peri- cardium. The lumbar veins, (Plate XC) which drain the structures of the abdominal PLATE LXIX. BICEPS SUPERIOR EXTERNAL ARTICULAR ARTERY CUTER HEAD GASTROCNEMIUS A2YG0S ARTICULAR ARTERY INFERIOR EXTERNAL ARTICULAR ARTERY A' T ERIOr TIBIAL ARTERY w///h si ; &i -,POPL'TEAL I\ LEXC.1 LOnUS HALLUCIS PERONEUS LONGUS PERONEAL ARTERY FL£XOR LONGUS HALLUCIS PEBCMEOUS LONGUS PEROHEOUS BREVIS CONTINUATION OF PERONEAL ARTERY- SUPERIOR INTERNAL ARTICULAR ARTERY INNER HEAD GASTROCNEMIUS GRACILIS SEMI-TENOINOSUS SEMIMEMBRANOSUS INFERIOR INTERNAL ARTICULAR POSTERIOR TIBIAL NERVE FLEXOR LONGUS DIGITORIUM POSTERIOR TIBIAL ARTERY INTERNAL ANNULAR LIGAMENT" TENDO ACHILLIS INTERNAL CALCANEAL ARTERY Showing Arteries and Nerves of Back of Leo. 189 HJO ANATOMY IN A NUTSHELL. walls and the loins, arc four on each side, and they arc all connected by longi- tudinal ascending lumbar veins. This ascending vein passes in front of the transverse processes in the lumbar region and gives origin to the azygos vein of it s own side. The left lumbar veins pass behindthe aorta. The pampini- form plexus lies around the spermatic cord in front of the vas deferens and is formed by the spermatic veins which drain the testis and epididymis. This plexus forms three or four main trunks which pass through the inguinal canal to form two veins. These veins accompany the spermatic artery and finally make one trunk. The SPERMATIC VEINS ox the right side empties into the inferior vena cava, while the one ox the left side passes behind the sig- moid flexure to enter the left renal vein. The one on the right side has a valve. The plexus in the broad ligament near the ovary and around the fallopian tube i> formed by the ovarian veins and communicates with the uterine plexus. These ovarian veins are similar to tin- spermatic veins, that is the one on the light side empties into the inferior vena cava, while the one on the left side empties into the left renal vein. The renal veins lie in front of their companion arteries which is an exception for the veins below the Diaphragm. The left vein passes in front of the aorta w lute it empiii s into the inft rior vena cava at a higher level than the right, and is the longer of tin- two renal veins. Its radicles are the left spermatic or ovar- ian, Li f1 inferior phrenic, and most always the left suprarenal. The left suprarenal vein empties into the left renal or phrenic while the tight empties into the inferior vena cava. The two superior phrenic veins end in the internal mammary vein, after accompanying the phrenic nerve and comes nervi phrenici artery. The two im'i rior phrenic veins accompany the phrenic arteries and join the inferior vena cava on the righl side and the left renal V( in on the left side. LESSON LI. The hepatic veins begin in the liver in the capillaries of the intralobular v< in- and form three main v< ins which empty into the inferior vena cava as it lies in the groove on the posterior surface of the liver. There are' no valves in these v< ins. The blood which passes Lhrough the portal vein goes through the following vessels: those on the' left; before it reaches the inferior vena cava: while i hoe i n the righl represent the vessels used by the Hepatic artery. 1. Portal vein 1. Hepatic artery 2. Interlobular vein 2. Interlobular artery .'!. Intralobular capillary plexus 3. Its own intralobular capillaries 4. Intralobular vein 4. Portal intralobular capillary plexus 5. Sublobular vein 5. Intralobular vein 6. Hepatic vein 6. Sublobular vein 7. Inferior vena cava 7. Hepatic vein 8. Inferior vena cava. It will be noticed that the blood which passe-s through the Portal vein and t he 1 h pat ic artery has a similar route through the> last five vessels. PLATE LXX SUPERIOR EXTERNAL ARTICULAR ARTtHT POPLITEAL NERVE INFERIOR EXTERNAL ARTICULAR ARTERY ANTERIOR TIBIAL ARTERY PERONEAL ARTERY PERONEUS BREVIS — CONTINUATION OF PERONEAL ARTERY SUPERIOR INTERNAL ARTICULAR ARTEt. v POPITEAL ARTERY. POSTERIOR LIGAM: ,'T OF KNEE — SEMI-MEMBRANOStl* INFERIOR INTERNAL ARTICULAR POSTERIOR TIBIAL ?:ERVE POSTERIOR TIBIAL ARTERY FLEXOR LONGUS DIGITORUn TIBI4LIS POSTICUS COMMUNICATING BRANCH INTERNAL ANNULAR LIGAMENT -TEN00 ACHILLIS INTERNAL CALCANEAL AST^RY Showing Muscles of Back of Leg. 191 192 ANATOMY IN A NUTSHELL. The veins of the lower extremity are divided into a superficial and deep set like those of the upper extremity, but the valves are more numerous. The superficial veins of the lower extremity lie between the two layers of the super- ficial fascia. The veins on the dorsum of the foot form a venous arch, which has ii- concavity backward. This arch receives digital radicles from the dorsum of the iocs, and ii crosses the anterior extremities of the metatarsal bones. This arch ends externally in the short saphenous vein and internally in the long saphenous. The external or short saphenous vein (Plate LXVII) is a continuation of this arch and ascends behind the outer malleolus along the outer border of the tendo Achillis, from here it crosses to the inner border in the median line of the leg posteriorly to perforate the deep fascia in the lower part of the popliteal space where it ends in the popliteal vein between the two heads of theGastroc- nemius. It receives cutaneous radicles in its course and it sends a communi- cating branch from near its end upward and inward to the long saphenous vein. It communicates with the dee}) veins below and accompanies the external saphenous uerve. This vein has from nine to fourteen valves in it. The internal or long saphenous vein (Plate LXVI) is a continuation of the arch and ascends in front of the internal malleolus along the inner side of the leg. From this point it accompanies the internal saphenous nerve behind the inner margin of the tibia and at the knee it runs backward behind the inner con- dyle of the femur. From here it passes along the inner side of the thigh to pass through the saphenous opening where it ends in the femoral vein about an inch and a half below 1'oiipart's ligament. It communicates with the deep veins and receives cutaneous radicles in its course. It receives the superficial epigas- tric, superficial circumflex iliac, and external pudic veins at the saphenous opening. This vein maybe doubleand it has fromseven to twenty valves in it. The deep veins of the lower extremity accompany their arteries and are called venae co mites and have numerous valves. Yeme comites are not found from the knee to the hip. for in this region there is but one vein for the artery. The posterior tibial veins are formed by the internal and external plantar, and are joined by the peroneal veins. The anterior tibial veins accompany the anterior tibial artery and join the posterior tibial veins to form the popliteal vein. The popliteal vein passes through the popliteal space, passing from the lower to the upper boundary obliquely outward ami becomes the femoral vein at the aperature in the Adductor magnus muscle. This vein receives the ex- ternal saphenous vein, articular and sural veins. The femoral vein accompanies the femora! artery and passes under the artery from its outer to its inner side. This vein continues as the external iliac after it passes under Poupart's ligament. It has four or five valves and receives radicle- corresponding to the arterial branches and the internal saphen- ous vein. Talipes comes from two words, talus which means ankle, and pes which means foot. Tin- deformity, called club-foot, depends upon the contraction of muscles or tendons, and this contraction may either be congenital or acquired. PLATE LX.\r. LUMBAR LIGAMENT LAST LUMBAR VERTEBRA, GREATER SACRO- SCIATIC LIGAMENT RECTUS TENDON RECTUS TENDON GLUTEUS MEOIUS GLUTEUS MINIMUS VASTUS EXTERNUS VASTUS INTERNUS RECTUS FEMORIS ILIO-TIBIAL BAND LIGAMENTUM PATELLAE Showing Muscles of I.wki; and Anterior Part op the Thigh. 193 194 ANATOMY IN A NUTSHELL. We have the following forms of club-foot: (1) Talipes equinus in which the heel is elevated and the weight of the body thrown upon the anterior portion of the foot. (2) Talipes calcaneus in which the patient walks upon the heel. (3) Talipes cavus or arcuatus in which there is an increased curvature in the arch of the foot. (4) Talipes varus in which the footis turned inward the patient walk- ing on the outer border. (5) Talipes valgus (flat or splay foot) in which the foot is everted or distorted outward. Combinations of these may occur, such as Talipes equino-varus, Talipes ealcaneo-varus, Talipes calcaneo-valgus, Talipes equino-valgus. (Plate LXXXIX.) The following are some of the principal amputations of the whole or part of the foot. (1) Syme's amputation is made at the ankle-joint, leaving a large heel flap and removing the internal malleolus and the external malleolus and sometimes a slice from the lower part of the tibia. (2) Roux's amputation is made at the ankle-joint, leaving a large internal flap. (3) Pirogoff's amputa- tion is made by removing all the tarsal bones, except the posterior part of the os calcis, and a thin slice from the tibia and fibula including the two malleoli. The small portion of the os calcis which remains is then turned up and united to the lower surface of the tibia. (4) Sub-astragaloid amputation is made by removing all the bones of the foot except the astragalus. This operation is rarely per- formed. (5) Chopart's amputation is made by removing all the bones of the foot except the os calcis and astragulas. (6) Lisfranc's amputation is made by removing all the metatarsals and phalanges, but not cutting any of the bones. (7) Hey's amputation is a modification of Lisfranc's amputation by sawing through the internal cuneiform bone. (8) Skey's amputation is a modification of Lisfranc's amputation by sawing off the base of the second metatarsal bone. A combination of Pirogoff's and the sub-astragaloid is Hancock's amputation. LESSON LI I. Hip-Joint. (Plate LXXXII.) This joint is a diarthrodial joint and belongs to the subclass enarthrodial. It has five ligaments. (1) The capsular ligament, which is very strong and fibrous, surrounds the brim of the acetabulum, beingjust external to the coty- loid ligament. Below it is attached to the neck of the femur into the anterior intertrochanteric line anteriorly, to the root of the neck of the femur superiorly, and to the middle of the neck of the femur posteriorly. It has two sets of fi- bers, circular and longitudinal. The circular are best developed at the lower and posterior part where they form a collar called the zona orbicularis or liga- ment of Bertin. The longitudinal fibers form the accessory ligaments. Some- time- there is an opening in the front of the capsular ligament for the passage of synovial membrane to form a bursa under the Psoas magnus. (2) The ilio- femoral or V ligament is accessory to the capsular ligament, it is bifurcated below and is connected to the anterior intertrochanteric line at its outer and inner portions and it is attached above to the anterior inferior spine of the ilium. (a) The ischio-capsulab ligament is an accessory ligament being attached to the ischium below the acetabulum and passing through the circular fibers ABDOMINAL AORTA COMMON ILIAC A. SACRA MEDIA INTERNAL ILIAC A. EXTERNAL ILIAC A. OBTURATOR A. SCIATIC A. PUDIC ARTERY INTERNAL CIRCUMFLEX A SUPERFICIAL FEMORAL A. PERFORATING ANASTOMOTICA MAGNA TERMINAL BRANCH OF PROFUNDA ANASTOMOSING WITH POPLITEAL SUP. INT. ANT1CULAR INT. LATERAL UG. INF. INT. ARTICULAR POPLITEAL SOP EXT. AflTICULAR POST. TIBIAL A. INT. MALLEOLAR TARSAL BRANCH DORSALIS PEDIS METATARSAL PLATE LXXII. DEEP EPIGASTRIC A LIO LUMBAR A. DEEP CIRCUMFLEX ILIAC A GLUTEAL A. COMMON FEMORAL PROFUNDA FEMORAL EXTERNAL CIRCUMFLEX CRUCIAL ANASTOMOSIS EXT. LATERAL LIG, INF. EXT. ARTICULAR. TIBIAL RECURRENT PERONEAL A. EXT. MALLEOLI ANT. PERONEAL A. POST. PERONEAL A. EXT. PLANTAR The Arteries of the Entire Lower Extremity 195 196 ANATOMY IN A NUTSHELL. at the lower and hack part of the capsular ligament, (b) The pubofemoral ligament is an accessory ligament and passes from the ilio-pectineal eminence to the rough tubercle in fronl of the lesser trochanter. :; The ligamentum teres passes from the margins of the notch at the bottom of the acetabulum to a depression on the head of the femur. It is covered by a n flection of synovial membrane and consists of connective tissue and vessels. 1 1 The cotyloid ligament surrounds the brim of the acetabulum, making this cavity deeper. It is broad at its point of attachment and runs to apoint, thus making it triangular on cross section. 5) The transverse ligament is a portion of the cotyloid ligament which crossi - the notch at the lower portion of the acetabulum. The nutrient vessels to the joint pass under this ligament. The synovial membrane of the hip-joint is reflected over the inner surface of the capsular ligament on to the neck of the femur, and from here over to the ligamentum teres to the bottom of the acetabulum. At this point it covers some fat. As said before it frequently communicates with the bursa which is under the Psoas muscle. The flexors of the hip-joint are all the muscles in the floor of Scarpa's tri- angle, viz.. the Qiacus, Psoas magnus, Pectineus, Adductor brevis, Adductor longus. The Sartorius, the R( ctus and the anterior fibers of the Gluteus niedius and ( Uuteus minimus are also flexors of the hip-joint. The extensors of this joint are the Gluteus maximus, Biceps, Semimem- branosus, and Sen itendinosus. '1 Ik adductors are the Addu< t< r 1< ngus, Adductor brevis, Adductor magnus plus the Bic< ps, Gracilis, and lower part of the Gluteus maximus. Tin abductors of this joint are the Gluteus medius, and Gluteus minimus. and the up] < r pan i f tin Glut< us maximus. Th< internal rotators an the anterior fibers of the Gluteus medius, Gluteus minimus, and T< nsor fas< ia f< moris. Th( external rotators < f this joint are all the muscles in the gluteal region excepl tin posterior fibers cf the Gluteus medius and Gluteus minimus, plus tin lliacus, tin three Adductors, the Feetineus and the Sartorius. The tendino-trochanteric band is a str< ngthening band of the hip-joint. Thi ligamentum teres is an incorporated tendon of the P< ctineus muscle. Neiaton's line is a line drawn fr< m the anterior superior spineof the ilium to tin tuberischii. Bryant's triangle is a triangle mad< by N< lat< n's line and a line drawn from tin ant* i tor su] < i tor s] in< — of the ilium whi< h nn < ts a third line cor- responding to the long axis of the f< mur continued. Th( blood supply of the hip-joint is theinternal circumflex, gluteal, sciatic, and ob Th< nerve supply is the anterior crural, the obturator, the obturator access- ory, greal sciatic, and branches from the sacral plexus. PLATE LXXIII. ILIO INGUINAL EXTERNAL CUTANEOUS The Diaphragm, Psoas Magnus \m> Parvus. 197 198 ANATOMY IN A NUTSHELL. LESSON LI II. Knee-Joint. (Plates LXXXIII.) The knee-joint is a diarthrodial joint and belongs to the subclass ginglymus. It is a modified ginglymus joint. This joint lias flexion, extension, and a slight rotation externally and internally. Ligainentus muscles are those that cross a joint, they are also called elastic ligaments of the joint. The ligamentous muscles of the knee-joint are Biceps, Quadriceps, Semimembranosus, Semitendinosus, Gracilis, Sartorius, Gastrocne- mius, Plantaris, and Popliteus. The nerve supply of this joint is the anterior crural, the obturator, the in- ternal and external popliteal. The blood supply of the knee-joint is the anastomotica magna, the five articular branches of the popliteal, the anterior and posterior tibial recurrent, and the terminal branches of the profunda. The flexors of this joint are the Biceps, the Semimembranosus, Semitendi- nous. Gracilis, Sartorius, and indirectly the Gastrocnemius, Popliteus, and Plantaris. The extensors of this joint are the Quadriceps, plus outer rotation by the Biceps and inner rotation by the Popliteus and Semitendinosus, and to a slight degree by the Semimembranosus, Sartorius and Gracilis. The strengthening bands are the Biceps, Sartorius, and Semimembranosus. The incorporated tendons are the Peroneus longus and Adductor magnus. The incorporated tendon of thePeroneus longus makesthe external lateral lig- ament of the knee-joint, and that of the Adductor magnus makes the internal lateral ligament. The knee-joint is formed by the condyles of the femur, the head of the tibia, and the patella, It has fourteen ligaments, an external set in which there are six, and an interna] set hi which there are eight. The first of the external Ligaments is the anterior or ligamentum patella, which is a continuation of the tendon of the Quadriceps extensor. (Plate LXXXIII.) It is attached above to the apex ami rough surface on the lower and posterior portions of the patella, and below it is attached to the lower part of the tubercle of the tibia. A bursa is found bei w< en the upper pail of the tubercle and the ligament. The second ligamenl of this set is the posterior ligament, called the liga- mentum posticum Winslowii, which is broad and thin and covers the back of the knee-joint. (Plate LXXXVI.) It has a central and two lateral portions, the lateral portion- are attached above the condyles of the femur superiorly, and to the head of the tibia inferiorly. The central portion which is derived from an expansion of the Semimembranosus tendon and passes from the inner tuberosity of the tibia to the inner side of the upper part of the outer condyle of the femur. The third ligamenl ni thissel is the internal lateral ligament, which is broad and flat and i- attached above to the inner condyle of the femur and below to the margin of the inner tuberosity, to the internal fibro-cartilage, and to the PLATK LXXIY. SPERMATIC CORD ADDUCTOR GLUTEUS MEDIUS GLUTEUS MINIMUS ILIO-TIBiAL BANO OF FASCIA LATA \ H V' lIM LIGAMENTUM PATELLAE The .Muscles ix Front of the Thigh. 199 200 ANATOMY IN A NUTSHELL. inner surface of the shaft of the fibula extending one and one-half inches. (Plates LXXXIII-LXXXVL) The fourth ligamenl of this set is the Ions external lateral ligament, which is the divorced tendon of the Peroneus longus and is nowa rounded cord, being attached above to the external condyle of the femur and below to the external pari of the head of the fibula. It divides the tendon of the Biceps into two portions. (Plates LXXXIV-LXXXVI.) The fifth ligament of this set is the short external lateral ligament, which lies behind and almost parallel with the long external lateral ligament and it is very indistinct, being attached above to the outer condyle of the femur and below to the styloid process of the fibula. The sixth ligament of this set is a capsular ligament. It fills the spaces left by the>e other ligaments. It is thin and is attached to the margins of the articular surfaces of the bones. It blends with the fascia of the thigh and re- ceives expansions from the Vast! muscles above, called lateral patellar liga- ments. (Plate LXXXIII.) 'The following structures are on the head of the tibia from before backward in the median line. (Plate LXXXY.) 1. Transverse ligament. 2. Anterior extremity of internal semilunar cartilage. 3. Anterior crucial ligament. 4. Anterior extremity of external semilunar cartilage. 5. The spine of tibia. 6. Posterior extremity of external semilunar cartilage. 7. Posterior extremity of internal semilunar cartilage. 8. Posterior crucial ligament. The ligaments of the internal set are eight in number. The first ligament is the anterior or external crucial, which is attached to the depression in front of the spine of the tibia and to the external semilunar fibro-cartilage. It now passes upward, backward, and outward to the pos- terior pint of the inner side of the external condyle of the femur. (Plate LXXXV.) The second ligament of this set is the posterior or internal crucial, which is attached to a depression behind the spine of the tibia, to the popliteal notch, and also to the posterior border of the external semilunar fibro-cartilage. From here it passes upward, forward, and inward to be attached to the oblique curve of the inui )■ condyle, to the fore part of the intercondylar fossa, also to the an- terior part of the outer surface of the inner condyle. The semilunar fibro-cartilages help to deepen the cavities which receive the condyle of the femur. They are thicker at the circumference than at the central portion. The internal semilunar fibro-cartilage is longer antero-pos- teriorly than transversely. lis anterior extremity is attached in front of the anterior crucial ligamenl to the tibia and the posterior extremity is attached in front of the posterior crucial ligament. The external semilunar fibro-cartil- age is nearly circular, and its anterior extremity is attached in front of the spine to the tibia, its posterior extremity is attached to the back of the spine. (Plate LXXXV.) PLATE LXXV GASTROCNEMIUS SOLEUS. EXTENSOR KKUHRIUS HALLUCIS *NT. ANNULAR LIG DORSAL INTER02SB. \\ ■patIllaCj ' / U W v, V! V\ PERONEUS LONGUS PERONEUS TERTIUS PERONEUS TERTIUS XTENSOR BREVIS WGITORUM Muscles ix Front oi Leg. 201 202 ANATOMY IN A NUTSHELL. The transverse ligament passes between the anterior extremities of the semilunar fibro-cartilages and is a hand of broad fibers. (Plate LXXXIV.) The coronary ligaments hold the circumferences of the semilunar fibro- cartilages bo the head of the tibia. (Plate LXXXIV.) The synovial membrane of the knee-joint is the largest in the body. It ex- tends over two inches above the joint under the extensor muscles and it passes over the crucial ligaments to the head of the tibia. It covers both surfaces of the semilunar fibro-cartilages and lines the capsular ligament. It gives a cover- ing to the tendon of the Popliteus muscle. The ligamentum mucosum is a fold of this membrane. It is triangular in shape, being attached to the intercondylar notch and extending to the patella. The ligamenta alalia are two processes of this membrane which are on either side of the ligamentum mucosum. LESSON LIV. The Superior Tibio-Fibular Joint. This joint is an arthro dial joint. Its anterior superior ligament extends from the head of the fibula upward and inward to the external tuberosity of the tibia. Its posterior superior ligament extends from the back part of the head of the fibula upward and inward under the tendon of the Popliteus muscle to the back part of the outer tuberosity of the tibia. (Plate LXXXVI.) The middle tibio-flbular articulation is formed by the interosseous membrane which is attached to the interosseous ridges of the tibia and fibula. The fibers of this membrane pass down from the tibia to the fibula. Above this mem- brane there is an opening for the anterior tibial vessels, and below it one for the anterior peroneal vessels. The inferior tibio-flbular arctiulation is a syndesmosis joint. The inferior interosseous (igament which passes between the adjacent rough surfaces of the tibia and fibula is continuous above with the interosseous membrane. The anterior ligament of this joint passes between the adjacent margins of the tibia and fibula and is triangular in shape. The posterior ligament is a similar hand posteriorly. It is smaller than the anterior one. The transverse or inferior ligament of this joint is a narrow band which is continuous with these two ligaments and extends from the back of the external malleolus nearly to the internal malleolus and helps to deepen the ankle-joint. (Plate LXXXYII.) The Ankle-Joint. (Plates LXXXVII-LXXXVIII.) This joint is a ginglymus or hinge-joint, and is formed by the lower ends of the tibia and fibula and the upper surface of the astragalus. The anterior ligament of this joint is connected above with the edge of the articular surface of the tibia, and below with the margin of the superior articu- lar surface of the astragalus. This ligament is thin and broad. The posterior ligament is attached above to the transverse ligament of the inferior tibio-fibular articulation and below to the back of the upper articu- lar surface of the astragalus, most of the fibers of this ligament are transverse. The internal lateral ligament is called the deltoid ligament and consists PLATE LXXVI. SUPERIOR INTERNAL ARTICULAR ARTERY INFERIOR INTERNAL ARTICULAR ARTERY ANTERIOR TIBIAL RECURRENT ARTERY SUPERIOR EXTERNAL ARTICULAR APTERY INFERIOR EXTERNAL ARTICULAR ARTERY GASTROCNEMIUS SOLEUS m i i til \S ')°'i^^ l"-i LONGUS H ANTERIOR TIBIAL ARTERY INTERNAL MALLEOLAR ARTERY BREVIS TERTIUS ANTERIOR PERONEAL ARTERY M -AfilMLARi. >EDIS ARTERY- | [^ Hh' COMMUNICATING BRANCH DORSALIS HALLUCIS ARTERY TENDON OF EXTENSOR BREVIS DIGITORUM TARSAL BRANCH . METATARSAL 3RANCH DORSAL INTEROSSEUS ARTERY Arteries and Nerves in Front of Leg. 203 21)4 ANATOMY IN A NUTSHELL. of two main parts. First a superficial part which is attached by its apex to the internal malleolus and by its base to the inner side of the astragalus and the sustentaculum tali posteriorly, while anteriorly it is attached to the tuberosity of the scaphoid and blends with the inferior calcaneo-scaphoid ligament. The second, a deep portion which passes from the apex of the malleolus to the side of the astragalus. The external lateral ligament consists of three portions. The first is an anterior fasciculus which passes between the front of the external malleolus and the side of the astragalus in front of the superior articular process. The second is a middle fasciculus which passes from the apex of the external malleolus to the outer side of the os calcis. The third is a posterior fasciculus which is attached behind the deep groove on the posterior part of the outer malleous and from this point passes inward to a depression on the posterior surface of the astragalus. The synovial membrane of the ankle-joint lines the inner surfaces of its ligaments, and from there it is reflected on the two articular surfaces of the hones forming the joint. It sends a prolongation into the inferior tibio-fibular articulation. The ligamentous muscles of the ankle-joint are all the muscles from the knee to the ankle except the Popliteus. The nerve supply is the anterior tibial, posterior tibial and internal saphen- ous. The blood supply is the anterior tibial, posterior tibial and peroneal. LESSOX l.V. Tin. Joints of the Tarsus. (Plates LXXXVII-LXXXVIII.) All these joints are arthrodial except the articulation between the navicu- lar and the astragalus, which is an enarthrodia! joint. Till. LIG WIE.XTS BETWEEN THE < >S CALCIS AND THE ASTRAGALUS ARE: 1 Anterior calcaneo-astragaloid ligament. I : ' sseous calcaneo-astragaloid ligament. (3) Externa] calcaneo-astragaloid ligament. THE LIGAMENTS BETWEEN THE OS CALCIS AND SCAPHOID ARE: (1) Superior or dorsal calcaneo-scaphoid ligament. (2) Inferior calcaneo-scaphoid ligament. Ib.TU l.l.X THE ASTRAGALUS AXH THE SCAPHOID THERE IS RUT ONE LIGAMENT. 1 I The superior or dorsal astragalo-scaphoid ligament. Till. LIGAMENTS BETWEEN THE SCAPHOID, CUBOID, AND THE THREE CUNEI- I ORM are: (1) Superior or Dorsal scapho-cuboid ligament. -' Superior or Dorsal scapho-cuneiform ligament. (3) Superior or Dorsal intercuneiform ligament. 1 Superior or Dorsal cubo-cuneiform ligament. (5) Internal lateral scapho-cuneiform ligament. The plantar ligaments are similarly arranged upon the bottom of the foot. PLATE LXXVII. GASTROCNEMIUS / INNER HEAD / 7 SEMI-MEM3RAN0SUS t — POSTERIOR TIBIAL NERVE PERONEJS LONtiUS Muscles in Hack of Leg (Superficial Laykkj 205 206 ANATOMY IN A NUTSHELL. (7) There are four strong interosseous ligaments passing between the rough non-articular surfaces of these bones. THE LIGAMENTS BETWEEN THE OS CALCIS AND CUBOID ARE: (1) Superior or dorsal calcaneo-cuboid ligament. Inferior calcaneo-cuboid ligament. (3) Internal calcaneo-cuboid ligament. (4) External calcaneo-cuboid ligament. There is the long calcaneo-cuboid ligament also called ligamentum longum plantar. This ligament passes between the under surface of the os calcis in front of the tuberosities to the posterior margin of the peroneal groove of the cuboid. Sonic of the fibers pass over the sheath of the tendon of the Peroneus longus and are attached to the bases of the second, third, and fourth meta- carpal bones. The short calcaneo-cuboid ligament passes from the tubercle and depression uii the under surface of the os calcis to the under surface of the cuboid behind the peroneal groove. The Joints of the Tarsus and Metatarsus. The ligaments of these joints are: (1) Dorsal tarso-metatarsal ligament. (2) Dorsal intermetatarsal ligaments. (3) Internal lateral tarso-metatarsal ligaments. (4) The plantar ligaments are arranged irregularly between these bones. The [nterosseous ligaments which are strong bands are three in number: (1) The internal one passes from internal cuneiform to the second meta- tarsal. (2) The middle one passes between the external cuneiform and the second metatarsal. (3) The external one connects the external cuneiform and the third meta- tarsal. There auk six synovial membranes of the tarsus and metatarsus: (1) One for the posterior calcaneo-astragaloid articulation. (2) One for the anterior calcaneo-astragaloid articulation and the scapho- as1 ragaloid articulation. (3) One for the calcaneo-cuboid artciulation. (4) ( )ne for the articulation of the scaphoid and the three cuneiform bones; the cuneiform bones with each other; the external cuneiform and the cuboid; and the middle and external cuneiform bones with the bases of the second and third metatarsal bones. < me 1 >et ween the first metatarsal and internal cuneiform bones. ()')) One for fourth and fifth metatarsal with the cuboid. The bases of the metatarsal bones are joined by dorsal, plantar, and in- terosseous Ligaments! The digital ends are joined by the transverse metatarsal ligament, which connect- the firsl metatarsal with the others, similar to those in the hand. The metatarso-phalangeal and phalangeal articulation are similar to the corresponding parts of the hand. PLATK LXXVUI- GLUTEUS MINIMUS SUPERIOR GLUTEAL ARTERY SUPERIOR GLUTEAL NERVE OBTURATOR INTERNUS INFERIOR GLUTEAL SMALL SCIATIC GREAT_ SCIATIC NERVE GLUTEUS MAXIMUS PUDIC ARTERY PUDIC NERVE. nglj — —SCIATIC ARTERY -- COCCYGEAL BRANCH TUBERISCHII INFERIOR PUDENDAL ADDUCTOR MAGNUS DESCENDING CUTANEOUS EXTERNAL POPLITEAL OR PERONEAL SOLEUi PERONEAL ARTERY GRACILIS NTERNAL POPLITEAL POSTERIOR TIBIAL NERVE SOLEUS POSTERIOR TIBIAL ARTERY INTERNAL CALCANEAN PLANTAR CUTANEOUS Posterior View <»k Entire Leg. 207 208 ANATOMY IN A NUTSHELL. LESSON LVI. Lumbar Plexus. (Plates LXIII-LXXIII.) The lumbar plexus is made of the anterior branches of the first, second, third, and a greater part of the fourth lumbar nerves. The twelfth dorsal nerve scuds a communicating branch to the first lumbar nerve. This plexus lies in the posterior pari of the Psoas magnus muscle in front of the transverse processes of the lumbar vertebrae. The first lumbar nerve divides into two branches, the ilio-hypogastric and the ilio-inguinal. (Plate LXX11I.) The ilio-hypogastric nerve passes through the outer border of the Psoas magnus in front of the Quadratus iumborum and behind the kidney and the large intestine. It pierces the Transversalis muscle at the outer border of the Quadratus Iumborum to enter the areolar tissue be- tween the transversalis muscle and the Internal oblique. At this point it fre- quently joins the last dorsal and inguinal nerve. It divides into a hypogastric branch and an iliac branch. The hypogastric branch passes between the Trans- versalis and the Internal oblique muscles forward and downward and gives branches to each of these muscles. It joins the ilio-inguinal nerve and pierces the Internal oblique muscle near the anterior superior spine of the ilium and passes beneath the aponeurosis of the External oblique towards the median line. It pierces the aponeurosis of the External oblique muscle about an inch above the externa] abdominal ring and .becomes cutaneous to supply the skin over the symphysis. The iliac branch pierces both the Internal oblique muscle and the Externa] oblique. The point where it pierces the External oblique muscle is above the crest of the ilium a little in front of its middle portion. It supplies the integument near the Gluteus medius muscle and the Tensor fascia femoris. The ilio-inguinal nerve passes out of the Psoas magnus muscle a little below the hypogastric, and thin crosses the Quadratus Iumborum to pass behind the large intestine, after which it crosses the inner lip of the crest of the ilium pos- teriorly. It now takes a forward course on the upper part of the Iliacus muscle to pierce the Transversalis muscle near the anterior part of the crest of the ilium where it communicates with the hypogastric branch of the ilio-hypogastric nerve. It pass< s through the inguinal canal and gives a branch to the sper- matic cord, and to the skin of the upper and middle part of the thigh and to the scrotum and penis in the male, or to the mons veneris and the major lip in 1 1n' female. The second nerve of the lumbar plexus is the genito-crural, which conies from the firsl and second lumbar nerves, mostly from the second. It passes through the Psoas magnus muscle coming out on the anterior surface of this muscle at the level of the lower border of the third lumbar vertebra. It now passes downward on the outer side of the abdominal aorta and the common iliac artery, then behind the meter where it divides into an external or genital branch and an internal or crural branch. The EXTERNAL or GENITAL BRANCH gives a branch to the external iliac artery ami it turns round the deep epigas- tric artery at Poupart's ligament. It now enters the inguinal canal with the spermatic cord in the male or the round ligament in the female. The Cremas- PLATE LXXIX. PtANTARIS OUTER HEAD OF GASTROCNEMIUS BICEPS ANTERIOR TIBIAL ARTERY INNER HEAD OF GASTROCNEMIUS i TENDON OF SEMIMEMBRANOSUS PERONEUS BREVIS TIBIALIS POSTICUS. POSTERIOR TIBIAL NERVE POSTERIOR TIBIAL ARTERY TENOO ACHILLIS Muscles of Back of Leg (Deel Layer). 209 210 ANATOMY IN A NUTSHELL. tciic muscle is supplied by this nerve, it also sends branches to the integument of the scrotum in the male or the major lip in the female. The internal or crural branch passes beneath Poupart's ligament on the outer side of the femoral artery. It pierces the fascia lata to supply the integument in the middle of the upper third of the thigh. The third nerve of the lumbar plexus is the external cutaneous, which conies from the second and third lumbar nerves. After passing from the outer border of the Psoas magiius muscle it crosses the Iliacus muscle, prior to this it pa>ses behind the caecum on the right side and the iliac colon on the left. Below the anterior superior spine of the ilium it passes under Poupart's liga iniiii in the outer border of Scarpa's triangle. It now crosses in front of the Sartorius muscle where it divides into two branches, an anterior and a posterior brunch. Tin: anterior BRANCH, after passing in the deep fascia for about four inches, becomes cutaneous, and most always divides into an external branch which supplies the skin of the lower half of the outer side of the thigh. and an internal branch which is distributed to the skin of the outer side of the front of the thigh as far as the knee. The posterior branch supplies the in- tegument of the outer side of the thigh from the greater trochanter to the middle of the thigh. The patellar plexus is formed by branches from the long saphenous and internal cutaneous and middle cutaneous, and external cutaneous. LESSON LVII. Tlu fourth nerve of the lumbar plexus is the anterior crural, which is the largesl n< rve of this plexus. It comes from the anterior branches of the sec- ond, third, and fourth nerve, and after passing through the outer border of the Psoas magnus muscle, it passes tinder Poupart's ligament in a groove between the Psoas magnus and Iliacus muscle into Scarpa's triangle. In this triangle it lit s io the outer side of the femora! artery from which it is separated by part of the P>o;i> magnus. Hue it divides into superficial and deep branches, be- twi i n which pass< s die external circumflex artery. The superficial branches supply the Pectineus and Sartorius muscle and give off two cutaneous branches, middle and internal. The deep branches supply the Iliacus. the Rectus femoris, Vastus interims. Vastus externus, Crueus and Subcrureus muscle, and gives off the internal or long saphenous nerve which is cutaneous. This an- terior crural nerve passes to eight muscles, all the muscles on the front of the leg except tin Tensor fascia femoris, and in its place it supplies the Iliacus of the deep abdominal region. It supplies the Pectineus of the internal femoral region. The nerve to the Pectineus passes behind the femoral sheath and in fiont of the Psoas magnus to end in the anterior surface of the Pectineus. The nerve to the Sartorius ends in the upper part of the muscle. The middle < utaneoi - \i u\ i; divides into two branches, the outer one of which pierces the Sartorius and it together with the inner branch becomes cutaneous at the upper third of the thigh, and the two pass down as far as the knee-joint where they < nt( r into the patellar plexus. Tin; internal cutaneous branch divides into an ai i d post< rior division and supplies integument on the inner side of PLATE LXXX. THORACIC MUSCULOCUTANEOUS INTERNAL CALCANEAN SHORT SAPHENOUS EXTERNAL PLANTAR S IHUSLULUCUIANbOUS ANTERIOR TIBIAL internal plantar Cutaneous Nerve Supply of the Lowkf. Extremity 211 212 ANATOMY IN A NUTSHELL. the thigh from the middle of the thigh to the knee. The posterior one of these branches helps to form the subsartorial plexus which lies on the roof of Hunter's canal. The other nerves in the subsartorial plexus are the long saphenous, and branches from the obturator. The muscular branch which passes to the Rectus muscle sends an articu- lar branch to the hip-joint, while the muscular branch to the Vastus internus sends an articular branch to the knee-joint. The long saphenous nerve sends an articular branch to the ankle-joint. The blood supply of the lumbar plexus comes from the ilio-lumbar arteries. The obturator nerve is derived from the second, third and fourth sacral nerves. Its largest root is from the third nerve. After it passes from the sub- si ance of the inner border of the Psoas magnus muscle at the posterior part of the brim of the pelvis, the ilio-lumbar artery separates it from the lumbo-sacral cord. It now crosses the internal iliac vessels and the ureter, passing in the extraperitoneal fat below the obliterated umbilical (hypogastric) artery, along the inner surface and upper part of the Obturator internus muscle. It now passes through the obturator foramen above the obturator membrane. In the pelvis it lies above the obturator artery. After passing out of the pelvis it divides into two branches, an anterior and a posterior division. The anterior division crosses the Obturator externus muscle and passes between the Pectineus and Adductor brevis. It sends (1) an articular branch to the hip-joint. (2) a branch to the femoral artery, which is an example of the gray rami. (3) Cutane- ous branch to the subsartorial plexus. (4) muscular branches to the Adductor longus, Adductor brevis, the Gracilis and the Pectineus muscle. The pos- terior division passes between the Adductor brevis and Adductor magnus after piercing the upper part of the Obturator externus. It gives off (a) muscu- lar 1 'ranches to the Obturator externus and Adductor magnus, and (b) articu- lar branches to the hip-joint and knee-joint. Obturator accessory nerve, which is present in a little more than one-fourth of the cases, comes from the second and third lumbar nerves. It passes along the inner border of the Psoas muscle between the roots of the anterior crural and obturator nerves. It does not pass through the obturator foramen, but passes in front of the brim of the pelvis beneath the Pectineus muscle. Its branches are (1) a communicating branch to the obturator nerve. (2) an artic- ular branch to the hip-joint, and (3) a muscular branch to the Pectineus. LESSON LVI1I. Sacral Plexus. (Plates LXIII-LXXIII.) The sacral plexus is formed by the lumbo-sacral cord and the anterior branches of the first, second, third, and a part of the fourth sacral nerves. Tin- lumbi -sacral cord is formed by a part of the fourth lumbar nerve and all i f the fifth lumbar nerve. This plexus is situated < n the anterior surface of the Piriformis muscle and behind the pelvic fascia and the branches of the internal iliac artery. It gives >>^ (A) viscera] branches, (B) muscular. (C) cutaneous, (D) terminal branches. (E) Greal sciatic and its branches. ANATOMY IN A NUTSHELL. 213 Under (A) visceral branches, we have branches to the pelvic viscera from the second, third, and fourth sacral nerves. Under (B) muscular branches. (1) The nerve to the Pyriformis comes from the first and second sacral nerves. This nerve leaves the pelvis through the great sacro-sciatic foramen, and after crossing the spine of the ischium enters the Pyriformis muscle on its internal surface. PLATE LXXX1. Cutaneous Nerve Supply of the Plantab Surface of the Foot. (2) The superior gluteal nerve is derived from the fourth and fifth lumbar and first sacral nerve. It leaves the pelvis above the Pyriformis muscle with the gluteal vessles. It supplies the Gluteus medius, Gluteus minimus and Tensor fascia femoris. It also sends sympathetic branches, which are gray rami, to the bone, ligament, fascia, and vessels - see sympathetic nerve. 214 ANATOMY IN A NUTSHELL. (3) The inferior gluteal nerve is derived from the fifth lumbar, first and second sacral nerves. It leaves the pelvis below the Pyriformis muscle with the sciatic and pudic vessels and nerves. It gives muscular branches to the ( Huteus maximus. (4) The nerve to the Quadratus femoris is derived from the fourth, fifth lumbar, and first sacral nerves. It leaves the pelvis below the Pyriformis muscle. It sends a branch to the Gemellus inferior, and also one to the hip- joint. i.")i The nerve i<» the Obturator interims is derived from the fifth lumbar, tirst and second sacral nerves. It leaves the pelvis below the Pyriformis mus- cle and re-enters the pelvis through the lesser sacrc -sciatic foramen to be dis- tributed to the inner surface of this muscle. It gives a branch to the Gemellus superior. Under ((') cutaneous branches we have, (Plate LXXYIII.) (1) The small sciatic is derived from the first, second, and third sacral nerves. It leaves the pelvis through the great sacro-sciatic foramen below the Pyriformis muscle with the sciatic vessels and the great sciatic nerve, inferior gluteal nerve, internal pudic nerve and vessels. At the lower border of the Glutens maximus it passes behind the long head of the Biceps and descends beneath the deep fascia to the popliteal space. Some say it supplies the Gluteus maximus, bu1 outside of supplying this one muscle it is cutaneous. Its branches are first; peroneal cutaneous which supplies the skin of the upper, inner, and posterior aspects of the thigh and perineum. One of these branches, the in- ferior or long pudendal nerve, crosses the tuberosity of the ischium and per- forates the fascia lata and Colles' fascia to enter the anterior compartment of the perineum. In the perineum it communicates with the superficial perineal nerves and sends branches to the skin of the scrotum in the male, and to the major lip in the female. Second; Femoral cutaneous branch which supplies the integumenl on the central, inner and outer aspects of the posterior partof the thigh. Third; Gluteal or ascending cutaneous branches to supply the skin over the lower and outer part of the Gluteus maximus. (2) Perforating cutaneous nerve is derived from the second and third sacral nerves. It perforates the greater sacro-sciatic ligament and supplies the skin over the lower and inner part of the Gluteus maximus. Under I D) terminal branches we have. (1) The pudic nerve is derived from the second, third and fourth sacral nerves. It haves the pelvis below the Pyrifomis muscle. It now crosses the spine of the ischium, being on the inner side of the internal pudic artery, which it accompanies through the lesser sacro-sciatic notch into Alcock's canal where it divides into three branches. First; the inferior hemorrhoidal nerve which passes through the inner wall of Alcock's canal towards the anus to supply the sphincter ani and the adjacent integument. Second; the perineal branch which has a cutaneous branch called the superficial perineal. It leaves Alcock's canal ami pierces the base of the triangular ligament and is distributed to the skin of the scrotum in the mule or the major lip in the female. Third; the dor- sal nerve of the penis, pierces the posterior layer of the triangular ligament and ANATOMY IN A NUTSHELL. 215 passes through the deep perineal space along the inner margin of the ramus of the pubic bone. It now pierces the anterior layer of the triangular ligament, Lying between the cms penis and the pubic hone, and gives a vaso-motor branch to the corpus cavernosum, and passes to the dorsum of the penis to supply the integument, glans and prepuce in the maleor clitoris in the female. It is called the dorsal nerve of the clitoris in the female and is much smaller. PLATE LXXXII. CAPSU LAR LIGAMENT DIVIDED UUI SURFACE OF CAPSULAR LIGAMENT Ligaments of Hip-Joint. LESSON LIX. Under (E) great sciatic nerve and its branches we have, (Plate LX Will.) (1) The great sciatic nerve and its branches which supply both muscles ami integument below the knee-joint but muscles only above this joint. It sup- plies thirty-seven muscles in all. It isthe largest nerve in the body and is a con- tinuation of the sacral plexus, except the fourth sacral nerve, since thegreal sciatic isformed by thelumbo-sacral cord and the anterior branches of the first, second and third sacral nerves. After passing out of the pelvis below the Pyriformis muscle it passes between the great trochanter and the tuberosity ^i the ischium. It may perforate the Pyriformis muscle. It generally divides at the lower one- third of the thigh into an external popliteal or peroneal and an internal popliteal or popliteal nerve. This division may take place immediately after the nerve leaves the pelvis. In its course down the hack of the thigh (Plate LXXVIII) it 216 ANATOMY IX A NUTSHELL. lies upon the l>ack of the ischium, the nerve to Quadratus femoris. the Gemelli muscles, Obturator interims. Quadratus femoris. and Adductor magnus muscles. It i- accompanied by the sciatic artery and the small sciatic nerve. In the tipper part of its course it is covered by the Gluteus maximus and in its lower part by the long head of the Biceps. Before it divides it gives, (a) articular branches t<> the hip-joint which perforates the capsular ligament posteriorly. (b) MUS< ri. ak branches beneath the long head of the Biceps to the Biceps. Semitendinosus, Semimembranosus, and Adductor magnus. The fibers in the internal popliteal or popliteal are from the fourth and fifth Lumbar, first, second. ami third sacral. (Plate LXXVII.) This is the larger of the two divisions, it passes through the popliteal space. At the lower border of the Popliteus muscle it is called the posterior tibial nerve. It is like the median nerve of arm in that it lies at first on the outer side of the artery, then crosses it to lie on its inner side. It gives off the following branches. (1) articular branches to the knee-joint which are three in number: first, superior internal; second, superior external, and third, azygos. (2) Muscular branches to the Gastrocnemius. Plantaris, Popliteus. and Soleus. (3) Communicans poplitei which joins the communicans peronei to form the short saphenous nerve, which supplies integument on the posterior part of the Leg and on the outer side of the foot. (4) This nerve continues as the posterior tibial after it passes the lower border of the Popliteus muscle. The posterior tibial nerve crosses the posterior tibial vessels from within out. just the opposite from the median and popliteal nerves. (Plate LXXVIII.) In the lower part of the leg these posterior tibial vessels and the nerve lie parallel with the inner border of the tendo Achillis. The branches of this nerve are. (1) mus- cular to the Soleus. Tibialis posticus. Flexor longus hallucis. Flexor longus digitorum. (2) Internal calcanean (cutaneous) which passes with the in- ternal calcaneal) artery. It supplies the integument and fascia of the heel and a part of the sole. (3) Articular branches to the ankle. (4) Internal axd external plantar nerves, which are formed by the division of the pos- terior tibial nerve at a point midway between the internal malleolus and inner tubercle of the os calcis. These nerves accompany the internal and external arteries. While the internal plantar nerve islarger than the external plantar, the arteries are just the reverse. the external being Larger than the internal. The in- ternal nerve supplies the following five muscles. (1) Abductor hallucis, (2) Flexor brevis digitorum, (3) and (4) the two inner Lumbricales. (5) Flexor brevis hallucis. It also supplies integument on the inner aspect of the plantar sur- face of the fo«.t. (Plate LXXXI.) The external plantar nerve supplies the following fourteen muscles. (1) Abductor minimi digiti, (2) and (3) the two outer Lumbricales, (4) Flexor accessorius, (5) Flexor brevis minimi digiti. the seven [nterossei make twelve. (13) the Adductor transversus hallucis. and 1 I the Adductor obliquus hallucis. This nerve also supplies integument on the plantar surface of the foot. ANATOMY IN A NUTSHELL. 217 LESSON LX. The external popliteal or peroneal nerve passes along the outer part of the popliteal space close to the tendon of the Biceps muscle as far as the head of the fibula. (Plate LXXVIII.) It is about half as large as the popliteal nerve. It gives (1) articular branches to the knee-joint (superior and inferior ex- ternal) also recurrent articular branch to the superior tibio-fibular articulation (2) Cutaneous branches which supply the integument along the back part and outer side of the leg. (3) Communicans peronei which joins the com- municans poplitei to form the short saphenous nerve. Museulo-eutaneous PLATE LXXXIIL INTERNAL TUBEROSITY EXT LATERAL LIGAMENT LlG AMENTUM PATELLA. which begins on the head of the fibula and passes down between the Peronei muscles and the Extensor brevis digitorum pierces the deep fascia a1 the lower one-third of the leg on its front and outer side. This nerve supplies the I'er- oneus Longus, Peroneus brevis, and the integumenl mi the dorsum of the foot. The INTERNAL TERMINAL BRANCH of the nuiselilo-rutaneous nerve passes in front of the ankle-joint and divides into two branches. The inner branch passes to the inner side of the great toe and sends twigs to the integumenl on the inner side of the foot. The outer branch passes to the base of the cleft 218 ANATOMY IX A NUTSHELL. between the second and third toes and divides to supply the adjacent sides of the cleft. The external terminal branch is the smaller of the two and passes along the outer side of the dorsum of the toot and divides into two branches. The inner one suppli* s t he integument of the adjacent sides of the third and fourth toes. The outer one supplies the integument on the adjacent sides of the fourth and fifth toes. The outer side of the fifth toe receives the short saphenous nerve. The anterior tibial nerve comes from the end of the peroneal nerve just internal to the musculo-cutaneous between the Peroneus longus and the neck of the fibula. It passe- forward and inward beneath the Extensor longus dig- itorum to lie in the interval between this muscle and the Tibialis anticus. It descends on the interosseous membrane with the anterior tibial artery to the front of the ankle-joinl where it divides into an inner and an outer terminal branch. The inner terminal branch passes down along the dorsalis pedis artery and supplies the integument along the adjacent sides of the first and second toes. It also supplies the periosteum of the adjacent bones, the metatarso- phalangeal and inter-phalangeal joints. It helps to supply the First dorsal interosseous muscle. The outer terminal branch passes under the Extensor brevis digitorum outward. This branch has a ganglion upon it which supplies the Extensor brevis digitorum, tarsal joints and the bones, periosteum, and joints of the three outer intermetatarsal spaces. It helps to supply the Second dorsal interosseous muscle. The anterior tibial nerve gives ( 1 ) muscular branches to Tibialis anticus. Extensor longus digitorum, Extensor proprius hallucis, Peroneus tertius, Ex- tensor brevis digitorum, and as said before helps to supply two inner Dorsal interossei. (2) Articular branches to the inferior tibio-fibular articulation and the ankle-joint. (Plate LXXY1.) The coccygeal plexus (Plate LXIII-LXXIII.) is formed by the anterior branches of part of the fourth sacral nerve, the fifth sacral and the coccygeal nerve. It is situated on the inner surface of the Coccygeus muscle and behind the Second portion of the rectum. Its muscular branches supply the Coccygeus muscle and Levator aid. while its visceral branches together with the sympa- thetic supply the pelvis viscera. For the complete distribution of the cutan- eous nerve supply of the lower limb see (Plates LXXX-LXXXI.) LESSOX LXI. Thk Superficial Fascia of the Thigh. The superficial fascia i> continuous with that of the leg below and that of the abdomen above. It has an superficial and a deep layer, between which layers are die superficial vessels and nerves. Really these structures are in the deep layer but the line of distinction cannot be closely drawn between the superficial deep layers. This fascia is beneath 1 he integument and forms an investment for the entire thigh. It is attached (1) to the margin of the saph- enous opening, (2) to the femoral sheath through the saphenous opening, (3) to the fascia lata below Poupart's ligament. The cribriform fascia, which form- one of the coverings of ;) femoral hernia, is that part of the superficial ANATOMY IX A NUTSHELL. 219 fascia which covers the saphenous opening. This fascia is perforated by the long saphenous vein and a number <>f vessels. The superficial fascia has a very intimate attachment to the deep fascia below Poupart's Ligament, thus in ex- travasation of urine, it cannot pass down into the superficial fascia of the thigh. PLATK LXXXIV PLANTARIS OUTER HEAD OF GASTROCNEMIUS TENDON OF POPLITEUS v A • ' \ . EXTERNAL LATE LIGAMENTS - .;:.*7V- TENDON OF ADDUCTOR MAGN05 TENDON OF BICEPS "al m\ ' Q *^^^ fl f4 NNER HEAD OF GASTROCNEMIUS ~~TEf;20'J OF SEMI-MEWSRANOSUS WITH ITS SLIP TD THICKENED THE POSTERIOR LIGAMENT /HEAD P mi ' ' TIBIOFIBULAR LIGAMENT^ ,',| \\\ } T ' B ' A ■ POSTERIOR SUPERIOR INTEROSSEOUS MEMBRNE Posterior Ligament of Knee-Joint. Deep Fascia of the Thigh. The deep fascia of the thigh is called fascia lata, and form- a strong cover- ing lor the thigh beneath the skin and superficial fascia. It is thick in front and externally, but thin behind and internally. The Gluteus maximus, the Tensor fascia femoris, the Biceps, the Sartorius, and Quadriceps extensor mus- cles give expansions to the fascia lata. The fascia lata is attached to Poupart's ligament and the body of the pubic bone anteriorly, to the tuberosity of the ischium and the rami of the pubes and ischium internally, to the back of the sacrum and coccyx posteriorly, to the head of the fibula, tuberosities of the tibia, and condyles of the femur distally. The external Intermuscular septum 220 ANATOMY IN A NUTSHELL. is attached to the linea aspera and extends from the insertion of the Gluteus maximus to the outer condyle of the femur. It separates the Vastus externus from the short head of the Biceps and gives attachment to both of these mus- cles. The internal intermuscular septum is attached to the linea aspera and extends from the lesser trochanter to the adductor tubercle, thus separating the Vastus in tenuis from the Pectineus and Adductors. This intermuscular septum is perforated by branches of the profunda artery which pass to the hamstring muscles and by the superficial femoral artery which passes into the popliteal space through an opening in the Adductor magnus. Smaller septa are given off from the fascia lata to ensheath each muscle. The ilio-tibial band (Plate LXXIV.) is a special part of the fascia lata which passes from the front part of the crest of the ilium down the thigh as two layers, one superficial to and the other beneath the Tensor fascia femoris, at the lower end of which muscle these two layers become blended and having received the insertion of this muscle it passes down to be inserted into the ex- ternal tuberosity of the tibia. Another special portion of the fascia lata is called the gluteal aponeurosis and takes its origin from the outer lip of the crest of the ilium posterior to the ilio-tibial band. This fascia covers the Gluteus medius muscle and divides at the anterior border of the Gluteus maximus to enclose it. The iliac portion of the fascia lata is behind the femoral vessels but in front of the pubic portion. This portion is attached to the crest of the ilium and to the whole length of Poupart's ligament and to the ilio-pectineal line with Gimbernat's ligament where ^continuous with the iliac fascia. The pubic por- tion of the fascia is attached above to the ilio-pectineal line. It passes beneath the femoral vessels to which it is attached and crosses the Gracilis, Adductor longus and Pectineus muscles. The saphenous opening is between the iliac and pubic portions of the fascia lata and leads from the space of the superficial fascia to the femoral vessels. It is an oval shaped aperature which is about an inch and a half in length and half an inch in width. It is directed obliquely downward and outward at the upper and inner part of the thigh just below Poupart's ligament. The inner boundary of the opening is posterior to the outer margin and behind the femoral vessels. It is through the saphenous opening that a femoral hernia passes after descending along the crural canal. The outer margin of this opening forms the falciform process which passes in fronl of the femoral vessels and is attached to Poupart's ligament and the spine of the os pubes and the pectineal line where it is continuous with the pubic portion. LESSON LXII. The Fascia of the Leg. The superficial fascia of the leg is continuous with that of the thigh and beneath it i- the deep fascia of the leg, which forms an investment for the mus- cles but is not continued over the subcutaneous surfaces of the bone. Above it joins the fascia lata and receives an expansion from the tendon of the Biceps externally and from the tendons of the Sartorius, Gracilis, Semitendinosus in- ternally. Anteriorly it blends with the periosteum covering the subcutaneous surface of the tibia and with that covering the head and the external malleolus AXATOMY IX A XUTSHELL. 221 of the fibula. Below it is continuous with the anterior annular ligament of the ankle. It is thin where it covers the Gastrocnemius and Soleus but thick and dense in the upper and anterior part of the leg where it gives attachment to the Tibialis amicus and Extensor longus digitorum. At the lower part of the pop- liteal space it is strengthened by transverse fibers and is perforated by the short saphenous vein. The deep fascia of the leg gives off several small septa which enclose each muscle and externally it gives off two strong intermuscular septa which enclose PLATE LXXXV. APERTURE LEADING INTO THE BURSA BENEATH THE QUADRICEPS EXTENSOR. ATTACHMENT OF CAPSULAR. OR ' ANTERIOR LIGAMENT TO FEMUR ANTERIOR CRUCIAL- LIGAMENT INTERNAL SEMILUNAR INTERNAL LATERAL LIGAMENT POSTERIOR CRUCIAL LIGAMENT EXTERNAL LATERAL LIGAMENT EXTERNAL SEMILUNAR TRANSVERSE LIGAMENT Showing Condyles and Ligaments of Knee-Joint — Anterior View. the peronei muscles, thus separating them from the muscles on the anterior tibial region and the muscles on the posterior tibial region. It also gives off a deep transverse fascia of the leg which passes between the superficial and deep muscles in the posterior tibio-fibular region. The anterior annular ligament (Plate LXXV.) consists of two portions, a superior or a vertical portion, and an inferior or horizontal portion. The superior portion passes across the front of the leg between the anterior borders 222 ANATOMY IN A XITSHELL. of the tibia and the fibula just above the malleoli and binds down the extensor tendons as they descend on the front of the tibia and fibula. The inferior portion begins on the outer side of the calcaneum and divides into two layers at the outer border of the Peroneus tertius, one passing in front, the other be- hind ami at the inner border of the Extensor longus digitorum these layers mute thus forming a canal through which these muscles pass. This inferior portion of the anterior annular ligament now divides into two branches one of which passes upward to be inserted in the front of the internal malleolus and the other passes across to be inserted on the scaphoid and internal cuneiform bon< s and the plantar fascia. The tendon of the Tibialis anticus has a synovial PLATE LXXXYI EXPANSION FROM QUADRICEPS EXTENSOR TENDON ANTERIOR CRUCIAL POSTERIOR CRUCIAL LIGAMENT EXTERNAL LATERAL LIGAMENT Semilunab Fibro-Cartjlage of Knee-Joint. -heath in the superior portion of the anterior annular ligament and also one in the upper limb of the inferior portion, but is passes under the lower limb of the inferior portion. | The external annular Ligament runs from the extremity of the outer malleo- lus to the outer side of the os calcis binding down the Peroneus longus and Peroneus brevis, which are enclosed in a single synovial membrane. The internal annular Ligament (Plate LXIX.) passes from the internal malleolus to the internal margin of the os calcis. It thus makes the grooves over which it passes into canals for the passage of the tendons of the flexor muscles and vessels into the sole of the foot. It joins the deep fascia of the leg above and the plantar fascia below at the origin of the Abductor hallucis. It has three canals which from within outward transmit (1) the Tibialis posticus, ■ udon of the Flexor longus digitorum, then the posterior tibial vessels and nerve, (3) the tendon of the Flexor longus hallucis. Each of these canals is lined by synovial m< mbrane. ANATOMY IX A NUTSHELL. 223 The fascia on the sole of the foot is called the plantar fascia (Plate LV.) and is the densest of all the fibrous membranes. It is divided into three por- tions. (1) A central portion which is attached to the inner tuberosity of the OS calcis and runs forward below the Flexor brevis digitorum and ends in front in a process for each toe and in slips for the skin. At its sides it joins the lateral portions which extends around the margins of the foot. At the junction of the central with the two lateral portions expansions pass upward. (2) The ex- PLATE LXXXVII. ANTERIOR LIGAMENT OF ANKLE CALCANEO- SCAPHOID- LIGAMENT DORSAL SCAPHO-CUBOID- LIGAMENTS DORSAL SCAPHO-CUNEIFORM LIGAMENTS DORSAL INTER CUNEIFORM-LIGAMENTS. DORSAL CUBO-CUNEIFORM LIGAMENT DORSAL TARSO- METATARSAL LIGAMENTS DORSAL INTER METATARSAL LIGAMENTS ANT INF IIBin- FIBULAR LIGAMENT. POST INF TIBIOFIBULAR LIGAMENT. ANTERIOR FASCICULUS OF EXTERNAL LATERAL LIGAMENT POST. LIGAMENT OF ANKLE JOINT * WV EXT. LATERAL LIGAMENT (POST. FASCICULUS) TENDO ACHILLIS INTERNAL CALCANEOCUBOID LIGAMENT DORSAL CALCANEOCUBOID LIGAMENT INFERIOR CALCANEO- CUBOID LIGAMENT EXTERNAL CALCANEO- CUBOID LIGAMENT MIDDLE FASCICULUS OF EXTERNAL LATERAL LIGAMENT ANTERIOR CALCANEO-ASTRAGALOID LIGAMENT INTEROSSEOUS CALCANEO-ASTRAGALOID LIGAMENT EXTERNAL CALCANEO-AS TRAGALOIU LIGAMENT Ligaments of Ankle — External View. tenia] portion which is thin in front and thick behind extends from the os calcis io the base of the fifth metacarpal hone. It coversthe nude'- surface ofthe Ab- ductor minimi digiti. It is continuous with the fascia on the hack of the fool and with the central portion of the plantar fascia. (3) The internal lateral portion covers the Abductor hallucis muscle and is quite thin. Posteriorly it is attached to the internal annular ligamenl and continues around the side of the foot with the dorsal fascia, and e\l< rnally with the middle portion of the plantar fascia. 224 ANATOMY IX A NUTSHELL. REVIEW QUESTIONS. 1. How many muscles in the Gluteal region? 2. How many of them are attached to the great trochanter? 3. Name the muscles in the Gluteal region. 4. What nerves supplies the Gluteus maximus? .">. What nerve supplies the Gluteus minimus and medius? ('). What other muscle does this nerve supply? 7. Nerve to the Quadratus femoris comes from which ones? 8. What other muscle does it supply? 9. Nerve to Obturator interims comes from which ones? 10. What other muscle does it supply? 11. What ligaments make the greater and lesser Sacro-sciatic foramina? 12. What muscle goes through the Greater? 13. What goes through above the Pyriformis muscle? OS CALCIS PLATE LXXXV1II. DORSAL ASTRAGALO- SCAPHOID LIGAMENT DORSAL AND INT. LATERAL SCAPH0-CUNEIF0RM LIGAMENTS DORSAL INTERCUNEIFORM LIGAMENTS DORSAL AND INT. LATERAL TARSO- METATARSAL LIGAMENT DORSAL AND INT. LATERAL METATARSO- PHALANGEAL LIGAMENTS DORSAL AND INTERNAL LATERAL INTER PHALANGEAL LIGAMENTS TIBIO-ASTRAGALOID INF.CALCANEO- LIGAMENT scaphoid ligament Ligaments of Ankle — Internal View. 1 1. Wha1 ]>:i>ses through below the Pyriformis muscle? 15. What muscle passes through the lesser Sacro-sciatic foramen? 16. The Obturator interims is supplied from what plexus? 17. The 5th lumbal- nerve belongs to what plexus? 18. The Obturator externus is supplied from what plexus? 19. How many muscles are attached to the Ischium? 20. How many muscles are attached to the Ilium? 21. How many muscles are attached to the Os Pubis? 22. How many bones in the pelvis? •_':;. Name them. 24. Name the divisions of the Innominate. _'.">. What bones form the acetabulum? 26. Name the ligaments of the hip-joint. 27. How many muscles are attached to the femur? ANATOMY IN A NUTSHELL. 225 28. What nerve supplies the muscles in the anterior femoral region? 29. What nerve supples the muscles in the internal femoral region? 30. What nerve supplies the muscles in the posterior femoral region? 31. The anterior crural and obturator nerves come from what plexus? 32. All the muscles on the posterior part of femur and from knee down are supplied by what nerve and its branches? 33. How many muscles are there from the knee to the ankle? 34. How many on the anterior tibio-fibular region? 35. How many in the outer fibular region? 36. How many in the posterior region? 37. How many layers in the posterior region? 38. What separates these two layers? 39. Name the seven muscles. 40. Name the deep layer. 41. Give nerve supply. 42. Name those in superficial layer. 43. Give nerve supply. 44. Which muscles are attached to the tibia and fibula? 45. What long bone has the insertion of only one muscle? 46. What is that muscle? 47. Name the outer hamstring. 48. Name the inner hamstring. 49. Bound Scarpa's triangle. 50. Who was Scarpa? Italian Anatomist. 1747-1832. He was physician to Napoleon. 51. Give the floor of Scarpa's triangle from without inward. 52. What structure passes through the center of this triangle? 53. How long is the common femoral artery? 54. It gives off what branch? 55. Passes through what canal? 56. Then through what space? 57. Then gives off what branches? 58. Where does this division take place? 59. Anterior tibial passes to the front of the leg between the two heads of what muscle? 60. Anterior tibial continues below the ankle as what artery? 61. The posterior tibial artery gives off what large branch? (i2. The posterior artery divides into what as it passes into the plantar surface of the foot? 63. Describe the Anterior annular Ligament. 64. Describe the Internal annular ligament. 65. Describe the External annular Ligament. (if). Describe the Plantar fascia. ()7. Name the muscles the Great Sciatic supplies on posterior part of the Leg. 68. It divides into what branches? PLATE L XX XIX. TALI PES"" CAVUS-OR-ARC^U A TUS TAL I P E S E~QU INO-VALG.U'S* Forms of Cub Foot. 220 ANATOMY IX A NUTSHELL. 227 69. The external popliteal nerve divides into what branches? 70. The anterior tibial supplies what muscle-'.' 71. What else dues it supply besides these five muscle-? 72. Musculo-cutaneous nerve supplies how many muse 73. Name them. 74. 'What else does it supply besides these muscle-'.' 75. What nerve supplies the integument on external border of the foot? 76. From what plexu.-? 77. How is the short saphenous formed? 78. The internal popliteal nerve supplies how many muscles? 79. The posterior tibial supplies how many? 80. The posterior tibial divides into how many branches? 81. How many muscles does the internal plantar supply? 82. Xame those it supplies in the 1st, 2nd and 3rd layers. 83. Xame those supplied by the external plantar. 84. Give the cutaneous nerve supply of the foot. 85. What muscle arises just below the insertion of the Gluteus maximus? 86. The small sciatic comes from what nerve-? 87. The pudic comes from what nerves? 88. The great sciatic comes from what nerves? 89. The superior gluteal comes from what nerves? 90. The inferior gluteal comes from what nerves? 91. What other nerve comes from the same? 92. What other one comes from the same one as the superior gluteal? 93. Give the relations of the common femoral artery. 94. (Jive the relations of the superficial femoral artery. 95. Give the relations of the profunda artery. 96. What are the divisions of the abdominal aorta? 97. The common iliac divides into what branches? 98. The internal iliac divides into what? 99. Xame the branches of the anterior trunk. 100. Xame the branches of the posterior trunk. 101. The external iliac continues as what? 102. What structures ]>a>- out of the Greater and into the Lesser sacro- sciatic foramen? 103. What passes through the obturator foramen? 104. What is inserted into the digital fossa? 105. Xame the ligaments of the knee-joint. loti. What structures pass under Poupart's ligament? 107. "Who was Poupart? Ih was a Frenchman. Lived 1661-1709. 108. What structures pass through Hunter's canal? K i'.i. Who was Hunter? Wa- British, 172s-17'.i::. 110. Hound Hunter's canal. 111. Hound the popliteal space. 228 ANATOMY IN A NUTSHELL. 112. WhyJ called popliteal? 113. Give contents. 114. Name the Ligaments of the ankle. 115. What forms the crucial anastomosis? 116. What muscles form the tendo Achillis? 117. Why is the Plantaris so called? 118. How many bones in the foot? Hi). Describe the fascia lata. PLATE XC. HEPATIC SPERMATIC VEIN SPERMATIC ARTERY RIGHT LUMBAR ARTERY LEFT PHRENIC GASTRIC ARTERY -SPLENIC ARTERY LEFT SUPRARENAL RENAL ARTERY, RENAL VEIN SUPERIOR MESENTERY, ' INFERIOR MESENTERY ARTERY EXTERNAL ILIAC^ ^INTERNAL ILIAC ' Showing the Great Vessels Below the Diaphragm. L20. Describe the deep fascia of the leg. l_'l. Describe the ilio-tibia) band. 122. What muscles compose the Quadriceps extensor cruris? 1 J.'!. The tendon of what long muscle passes directly across the sole of the foot? L24. Describe the saphenous opening. 125. Why called saphenous? 120. Describe the external abdominal ring. ANATOMY IN A NUTSHELL. 229 127. Describe Poupart's ligament, 128. Describe Gimbernat's ligament. PLATE X(T. SUPRARENAL CAPSULE EXTERNAL ILIAC GLANDS LUMBAR GLANDS COMMON ILIAC ARTERY SACRAL GLANDS. t! INTERNAL ILIAC GLANDS. ,DEEP INGUINAL GLANDS V LYMPHATICS OF PENIS Showing the Abdominal Aorta and its Terminal Branches. 129. Describe Petit 's triangle. 130. Describe the trianglar ligament of the abdomen. 131. What muscles are attached to the intermuscular septa of ' fascia' lata? 230 WAToMY IX A NUTSHELL. 1 :'.'_'. Describe interna] abdominal ring. 133. What does the word hernia mean? 134. What muscles make the external rotators of hip? 135. What muscles make the internal rotators of hip? L36. Show how the external popliteal nerve gets to the front of the leg. 137. The length of the femur is what part of the [< agth of the body? 138. Describe the linca asju ra and what muscles are attached to it. 139. At what angle dots tin neck join with shaft of femur? 1 li). Give function and location of patella. 141. Describe the knee-joint. 1 l'_\ What passes through the Obturator forami n? I 13. Why so called? ! II. Give dimensions of pelvic cavity. 1 lo. 1 )escribe the lumbal' fascia. 1 Hi. The sacral plexus continu.es as what'.' 147. Great sciatic divides into what nerves? 1 IV .Name four kinds of hernia. 149. Name the different kind of joints found in the body. 1 50. Why does the arm admit of greatf r motion than the leu'.' 151. What is the sustentaculum tali? 152. What is the receptaculum chyli? 153. Where are the anterior and posterior circumflex arteries? 154. Where are the internal and externa! circumflex arteries? 1.")."). What is the Biceps cubiti? 156. What muscle is attached to all tarsal bones but one? 157. -Name the muscles attached to each tarsal bone. 158. Give articulation of each tarsal bone. 159. Name the spinous processes of the ilium. 160. What is attached to each? ltd. Give meaning of trochanter. 162. (live blood supply, ossification, articulation and attachment of mus- cle,- io the os innominatum. lii:i. Same for femur. 164. Sin ne for tibia. 165. Same for fibula. 166. Same for tarsus. 167. Same for metatarsus. L68. Same for phalanges. 169. Same tor patella. 170. Same for sacrum. 171. Same for coccyx. 172. Give branches of femoral artery. 1 7:;. ( rive branches of popliteal artery. 17-1. Give branches of anterior tibial artery. 175. Give branches of posterior tibial. 176. Give branches of dorsalis pedis. ANATOMY IN A NUTSHELL. 231 177. Give branches of peroneal artery. 178. Give plantar arch. 179. This arch gives off what branches? PLATE XCII. INTERCLAVICULAR NOTCH. STERNO-MASTUIU. COSTAL CARTILAGE APONEUROSES OF ABDOMINAL MUSCLES. Anterior View of Sternum. L80. Which is the larger external or internal plantar artery? 181. Which is the larger the external or internal plantar nerve? 182. Give relation of popliteal artery. 232 ANATOMY IN A NUTSHELL. 183. Give relation of anterior tibial artery. 184. Give relation of posterior tibial artery. 185. Give relation of peroneal artery. 186. Give relations of dorsalis pedis artery. LESSON LXIII. The Thorax. (Plate XC1V.) The thorax is formed by thirty-seven bones, namely, the twenty-four ribs the twelve dorsal vertebrae, and the sternum. The thorax is a conical cavity, broad below, narrow above, flattened from before backward, and longest pos- teriorly. Its posterior boundary is formed by the bodies of the dorsal ver- tebrae and the posterior portion of the ribs, thus making it concave verti- cally with a high ridges on either side. The lateral boundaries are convex, being formed by the ribs and Intercostal muscles. The anterior boundary, which slopes down and forward, is formed by the sternum and the costal car- tilages. The upper opening of the thorax is broadest transversely and is formed by the first dorsal vertebra posteriorly, first ribs laterally, and the upper margin of the manubrium anteriorly. The upper border of the manubrium is on a level with the second dorsal vertebra. In the female the sternum is shorter than in the male, the ribs more movable, and the thorax is smaller. The upper margin of the manubrium is on a lower level than in the male. There are forty structures passing through the superior opening of the thorax. There are three pairs of muscles that pass through this upper opening in the thorax. Sterno-thyroid, Sterno-hyoid and Longus colli muscles, making six muscles. The arteries that pass through the superior opening of the thorax are the (1) innominate, (2) left common carotid and (3) left subclavian, (4) and (5) the two internal mammary and (6) and (7) the two superior intercostal. There are fifteen nerves that pass through this opening: (1) and (2) the two Pneumo- gastric, (3) and (4) the two phrenic, the six cardiac and the two sympathetic nerves, the anterior branches of the two first dorsal nerves, and the recurrent laryngeal nerve of the left side make fifteen. The veins that pass through this superior opening are the right and left innominate and the inferior thyroid veins, making four veins. There are eight unclassified structures that pass through this opening in the thorax: Remains of thymus gland, trachea, oesoph- agus, thoracic duct, apex of each lung, and pleurae. Then the six muscles, fifteen nerves, seven arteries, four veins, and eight unclassified structures make the forty structures which pass through the superior opening of the thorax. The Lower opening of the thorax is widest transversely and slopes down- ward and backward. It is formed by the last dorsal vertebra posteriorly, and the seventh to the eleventh costal cartilages laterally, and the ensiform car- tilage anteriorly. The Diaphragm separates the thoracic cavity from the abdominal cavity. ANATOMY IN A XUTSHELL. 233 Diaphragm. (Plate LXXII.) The word diaphragm is a Greek word meaning a partition wall. It is a musculo-fibrous septum, situated between the upper one-third and the lower two-thirds of the trunk. It separates the thoracic cavity from the abdominal cavity/ It is the floor of the former and the roof of the latter, its general shape PLATE XCTII. CLAVICULAR NOTCH STERNO HYOID, STERNO THYRO FIRST COSTAL CARTILAGE TRIANGULARIS STERNI ENSIFORM APPENDIX Posterior View of Sternum. is somewhat like that of an umbrella or an irregular dome. The upper surface of it is covered with the right and left pleura, he! ween the two pleura' it is cover- ed with the pericardium. Its circumference is elliptical in form, highesl at the ensiform cartilage. The highest part of all the diaphragm is od the righl side ANATOMY IX A NUTSHELL. immediately above the liver. This is a litth higher than the left side. The lowest part of it is the righl crus which reaches in the fourth lumbar vertebra. The under surface is cov< red with p( ritone um. 1 1 is One of the so-called double Ik Ui< (I musch s. 1 1 has its origin in frorrt from th< < asiform cartilage, from the sides, from the under surfaces of the cartilages and bony portion of the six or seven lower ribs interdigitating with the Transversalis muscle, also from the two aponeurotic arches called the ligamentum arcuatum externum el internum. The last one is the covering of the Psoas magnus, the first one is the covering of the Quadratus lumborum. Behind ii is connected to the spine by two crura or legs, the right one is the longer i xtending from the anterior surface of the bodi< s and intervertebral substance of the thrc e or four upp< r lumbar vertebrae; tin left one from the anterior surfaces of th< two upper ones. From this origin it - to the central or cordiform tendon which consists of three leaflets, the righl one is the largest, the left on< the smallest, and the middle one is inter- im diate in size. On each sid( of tin ensiform attachment tin re is a weak place which may be brok< n; th< n we nay have what is called a phrenic or diaphrag- matic hernia. Some of the contents of the abdomen protrude into the chest, or ptts in the mediastinum may descend through it into the abdominal cavity. The diaphragm has three large and several small natural foramina. The one mosl posterior is really not in the diaphragm bui between the two crura which arc joined posteriorly by a tendinous band. This is called the aortic opening, and transmits the aorta, vena azygos major, the thoracic duct, and sometimes the left sympathetic nerve; when this nerve does not pass through this open- ing it goes through the left crus. The vena azygos major occasionally goes through the right crus. The second large opening is in front, and a little to the left of the aortic opening; it transmits the oesophagus and the pneumogastric oerves. Th< left pneumogastric passes in front of the oesophagus. The right one, which passes b; hind it, goes into the solar plexus, which is situated behind the stomach. The third large opening is farther in front than the others and lies in the c< ntral tendon. Ii is son u what quadrilateral in form and is called the foramen quadratum; the inf< rior v< na cava passes through it. The smaller openings are through the crura. Those in the right crus transmit the great* r and less* r splanchnics and the sympathetic nerves of the right side, occasionally the vena azygos major. The left cms transmit the vena azygos minor, the greater or lesser splanchnic nerves of the left side and the sympathe- tic nerve of the left side when it does not pass through the aortic opening. The blood supply of the diaphragm is derived from the two phrenic, the internal mammary, and the lower intercostal arteries. The phrenic arteries are two small arteries which may arise separately from the aorta above the coeliac axis. < hien .me is derived from the aorta and the other from the renal arteries. They very rarely arise as two separate vessels from the aorta. The nerve supply is the phrenic which comes from the third, fourth, and fifth cervical nerves. The phrenic plexus also helps to supply it. This plexus is made by the phrenic nerve and branches from the semilunar ganglion of the solar plexus. The laity call the diaphragm the midriff, which comes from the Saxon words which mean the middle of the belly. The solar plexus or abdominal brain and the ANATOMY IV A NUTSHELL 235 phrenic plexus are situated near the diaphragm. The former behind the stomach and the latter formed by branches from it. These plexus or plexuses belong to the great sympathetic system, which govt rns tl ritary actions. PLATE XClV. FLOA- Boxes of i he Thorax. ere blow on the head may knock a man senseless bul he Mill lives. His heart ami lungs still ad. being governed by the sympathetic system, but if he receive^ a severe blow upon the diaphragm it may produce instant death. The pugilist has learned this much about anatomy and if he were not trained to the 236 ANATOMY IN A NUTSHELL. hour more would be killed than are by this so-called solar plexus blow. The diaphragm is the chief muscle of respiration. The lower ribs may fall down thus drawing the diaphragm out of its natural position, in this way somewhat obstructing the passing of the blood through the aorta. I have known of one case in which the diaphragm was pulled down by the lower ribs causing an irregular action of the heart. As soon as they were replaced the heart acted in a natural manner. Tight lacing, or any cause whatsoever which will impair the natural action of the diaphragm will cause much pain. Man is the only animal in which the transverse diameter of the diaphragm is greater than the antero-posterior. It begins to be developed about the ninth week of fetal life and grows from the circumference to the central tendon. All mammals or milk-giving animals have a diaphragm. Man and horse are examples of land animals, the whale and the sea cow are examples of water animals which have diaphragms. Birds possess a rudimentary form, which is best shown in the abteryx. LESSON LXIV. The muscles which help the Diaphragm in tranquil inspiration are (1) Intercostals, (2) Levatores costarum, and (3) The Scaleni. Those which help it in forced inspiration are (1) Trapezius, (2) Pectoralis minor, (3) Pectoralis major (?) (4) Serratus posticus superior, (5) Serratus posticus inferior, (6) Rhomboideus major, (7) Rhomboideus minor, (8) Serratus magnus, (9) Sterno- cleido-mastoid, (10) Ilio-costalis, (11) Quadratus lumborum. Tranquil expiration is caused by the elasticity of the lungs and that of the chest walls. The muscles of forced expiration are (1) External oblique, (2) In- ternal oblique, (3) Transversalis, (4) Rectus abdominis, (5) Internal inter- costals, (6) Triangularis sterni. The sternum (Plates XCTI-XCIII.) is about six inches long and is situated in the median line of the thorax in front. It is flat anteriorly and concave pos- teriorly. It is broadest above and pointed below, and constricted at the junc- tion of the manubrium with the gladiolus. The manubrium or first piece of the sternum is narrow below, but broad above. The anterior surface of the manu- brium is concave vertically but convex transversely. The Pectoralis major and Sterno-cleido-mastoid are attached to the lateral aspect of this surface. The upper border of this part forms the interclavicular notch, on each side of which is an oval facet for the articulation of the clavicle. The lateral border articulates above with the cartilage of the first rib and below with the upper poit ion of the cartilage of the second rib. The low r er border articulates with the gladiolus. The posterior surface is concave and gives attachment to the Sterno-hyoid and Sterno-thyroid muscles. The gladiolus or second portion is longer, narrower and thinner than the manubrium. It is broadest below. The anterior surface gives attachment to the Pectoralis major. Three trans- verse lines, indicating the original divisions of the gladiolus into four portions, pass from the third, fourth, and fifth articular facets across the bone. These lines are not so well marked on the posterior surface. This surface is concave ANATOMY IN A NUTSHELL. 237 and gives attachment to the Triangularis sterni muscle. The lateral border of the gladiolus articulates with the cartilages of the second, third, fourth, fifth, sixth, and seventh rib; however the second and seventh cartilages articulate partly with the bones above and below. This portion of the bone articulates with the manubrium above and the ensiform or xiphoid appendix below. The ensiform appendix, cartilaginous hi youth but is partly ossified above in the adult. The chondro-xiphoid ligament is attached to its anterior surface, while the Diaphragm and the Triangularis sterni are attached to its posterior surface. It articulates above with the gladiolus. Laterally the aponeurosis of the abdominal muscles are attached. The superior angle of the lateral border has a demi-facet for the cartilage of the seventh rib. Its apex may be bifid below or may present a foramen, and it gives attachment to the linea alba. Attachment of Muscles: — Nine pairs and one single muscle. The Pectoralis major, Sterno-cleido-mastoid, Sterno-hyoid, Sterno-thyroid, Tri- PLATE XCV. LATERAL MASS COSTOTRANSVERSE FORAMEN SURFACE FORAMEN FOR VERTEBRAL ARTERY The Atlas annularis sterni, aponeurosis of the External oblique, Internal oblique, Trans- versalis, Rectus muscles, and Diaphragm. Ossification: — From six centers. One for the manubrium (fifth or sixth month.) One for each of the four pieces of the gladiolus. The ones for the first two pieces of the gladiolus appear at the sixth or SEVENTH month. The one for the third piece appears at the ninth month, and the one for the fourth piece appears during the first year after birth. The one for the ensiform appendix appears between the SECOND and eighteenth years. The manubrium and the lower three pieces of the gladiolus may have two centers each, thus making ten centers of ossification for the sternum. The pieces of the gladiolus join at about the age of puberty, while the glad- iolus rarely joins the manubrium and the ensiform remains cartilaginous even in advance life. Articulation. — With the clavicles and seven costal cartilages on each side. 238 ANATOMY IN A NUTSHELL. Blood Supply. — Internal mammary arteries through its sternal and per- foratum branches, also twigs from the aortic intercostal arteries. Heart. The covering of the heart is called the Pericardium. Besides covering the lu ait it encloses the origin of the great vessels. It is situated behind the sternum from the third to the seventh costal cartilages (inclusive) and between the two pleurae. It forms a closed sac. the base of which is attached to the central tendon and adjoining muscular substance of the Diaphragm, and it extends more to the 1< ft than to the right. The apex of the pericardium is directed up- ward and surrounds the great vessels for about two inches. Behind the per- icardium are (1) the two bronchi. (2) the esophagus, (3) descending aorta. In front are f 1 ) the margin of the lungs, (2) remains of the thymus gland (above), (3) areolar tissue (below). (4) the sternum. On the sides it is covered by the pleura and the phrenic nerve. The pericardium is composed of two layers, first a fibrous, second a serous. Tin: fibrous OB external layer is strong and dense. It sends prolongations around the gr< at vessels which join their external coats. It also sends a diverti- culum upward on each side of the ascending aorta. The one on the left side of the ascending aorta passes between the left pulmonary artery and the arch of the aorta to the ductus arteriosus where it ends in a blind extremity. The one on the light side of the ascending aorta passes between this vessel and the super- ior vena cava, and it also ends in a blind extremity. This fibrous layer is at- tached below to the central tendon and muscular substance of the Diaphragm. Two ligaments, the superior sterno-pericardial and the inferior sterno-peri- cardial, connect it with the sternum anteriorly. Tin. serous ok internal layer consists of two portions, first a visceral, and second a paiital. The visceral layer covers the heart and the great v< ssels for about an inch and a half and then is reflected upon the inner surface of the fibrous layer forming the parietal portion. The pulmonary artery and the aorta are enclosed in a single tube of pericardium. Behind this tube there is a passagi called the transv< rse p< ricardial sinus. The pericardium only partially covers the vena cava and pulmonary veins, so that on each si le of these struc- tures iIk re i- a cul-de-sac. The one on the left side is known as the oblique .-iin s, the one (.n the righi as the straight sinus. The vestigial fold of Marshall lies between the left pulmonary artery and the subadjacent pulmonary vein, thus enclosing the remains of the lefl superior vena cava. This left superior vena cava is a fibrous cord which may be traced upward te> the left superior intercostal vein and downward to the coronary sinus and known as the oblique v< in of Marshall. Blood Supply. — The art< ri< s to the pericardium come from the descending thoracic aorta and the internal mammary with its musculo-phrenic branch. Nerve Supply. Xerxes to the pericardium are from the tenth, phrenic, and sympath) tic. The' nerve supply to the pericardium, the heart, the pleurae, and the lungs, is derived from these three sources. As said above' they all go tei the | ( ricardium. The- tenth, the sympathetic and pe>ssibly the phrenic pass ANATOMY IN A NUTSHELL. 239 to the heart. The tenth and sympathetic go to the lungs substance, while the phrenic and sympatheic pass to the pleura. LESSON LXV. The heart (Plate CXXVIII.) is situated in the middle mediastinum be- tween the spinous processes of the fourth dorsal and eighth dorsal vertebra posteriorly. Its apex is directed downward and forward to the left, and lies against the fifth intercostal space three -quarters of an inch to the inn< r sid of PLATE XCVI. ROUGH SURFACE FOR CHECK LJGAMEW. SUP. ARTIC. PROC. ODONTOID PROC. ARTIC. GROOVE FOR TRANSVERSE LIG. LAMI SPINOUS PROC Posterior View of Axis. the left nipple and an inch and a half below the same. The heart lies obliquely behind the lower tw< -thirds of the sternum, extending about three inches to the left of the median line and one and a half inches to the right. Its anterior surface consists mostly of the light ventricle and a part of the left ventricle. It is convex and looks upward and forward. Its posterior surface consists mostly of the left ventricle and rests upon the Diaphragm. This surface is flattened. The right border of the heart is long and thin, while the left is short and thick. The average weight of the heart is about eleven ounces. In the male it weighs from ten to twelve ounces, while in the female its weight is from eight to ten. The adult heart is five inches long by three and a half wide, by two and a half thick. It is divided into four chambers, namely, the right and left auricles and the right and left ventricles. The right side of the heart, which is more superficial and is called the venous heart, is separated from the left side of the heart, which is deeper and is called the arterial heart, by a longitudinal septum, and each of these lateral halves are divi led bya transverse septum,thus making the auricles and ventricles. These four divisions of the heart are indicated by grooves on its surface. The apex of the heart is formed entirely by the left ventricle. These grooves on the surface of the heart contain the coronary arteries, cardiac veins, lymphat- ics, nerves and fat. 240 ANATOMY IN A NUTSHELL. The right auricle has a capacity of about two ounces. It is larger than the left auricle but its walls arc thinner. It consists of two main parts, first a sinus or atrium which is large and lies between the superior vena cava above and the inferior vena cava below and has postero-internally to it the left auricle. The second pari is the auricular appendix, which is small and conical projecting for- ward and to the left over the root of the aorta. The inner surface of the auricle is smooth except in this auricular appendix and the adjacent part of the right wall of the sinus. At this point it is thrown into parallel ridges called musculi pectinati. (Plate CXXIX.) The right auricle has the following points for consideration: 1. The opening of the superior vena cava, which is at the upper and back part of the auricle and is directed downward and forward. The blood from the superior vena cava flows toward the auriculo-ventricular opening. 2. The opening of the inferior vena cava is larger than the superior and is at the lower part of the auricle near the auricular septum. The blood from the inferior vena cava is directed upward and inward towards the auricular septum. 3. There is small projection between the superior vena cava and the in- ferior vena cava called the tubercle of Lower. Its function is to direct the blood from the superior vena cava towards the auriculo-ventricular opening. 4. There is an opening between the inferior vena cava and the auriculo- ventricular opening called the coronary sinus. It is guarded by a valve called coronary or Thebesii. It receives blood from the substance of the heart and it is constricted where it joins the great coronary vein. 5. The auriculo-ventricular opening is somewhat oval and about an inch in diameter and lies between the right auricle and right ventricle. It is sur- rounded by a fibrous ring covered by the lining membrane and is guarded by the Tricuspid valve. 6. The foramina of Thebesii are small openings of the venae cordis minima? which return blood from the substance of the heart. 7. A semilunar fold of the endocardium which lies between the auriculo- ventricular opening and the anterior margin of the opening of the inferior vena cava is called the Eustachian valve. In the fetus this valve is large and directs the blood from the inferior vena cava through the foramen ovale into the left auricle. It may be present or it may be absent in the adult. 8. The coronary valve also called Thebesii is a semicircular fold of endo- cardium which guards the opening of the coronary sinus. This valve may be double and it prevents regurgitation into it (hiring systole 1 of the auricle. 9. The fossa ovalis is a remains of fetal life. It is an oval depression lying on the lower part of the auricular septum marking the position of the foramen ovale. There may be a small foramen in this fossa throughout life. 10. The annulus ovalis is a prominent margin of the foramen ovale and is best marked above and at the sides, while below it is wanting. 11. The musculi pectinati are small muscular folds which are found in the auricular appendix and the adjacent pari of the sinus venosum. They end in a vertical ridge posteriorly called the crista terminalis of His. The right venrtiele extends from the right auricle nearly to the apex of the ANATOMY IN A NUTSHELL. 241 heart. Its walls are one-third as thick as those of the left ventricle, and it holds about three ounces. Its posterior surface rests upon the Diaphragm forming a small part of the back of the heart, while its anterior surface forms most of the front of the heart. 1. The conus arteriosus or infundibulum is a conical pouch at the upper and left angle of the ventricle, from which the pulmonary artery arises. 2. The auriculo-ventrieular opening has been described with the auricle. 3. The opening of the pulmonary artery which lies at the summit of the infundibulum is circular. It is guarded by the pulmonary semilunar valves. 4. The tricuspid valve consists of three portions. The largest of these segments, called the left or infundibular flap, lies at the left and front of the opening. The right flap is to the front and right, while the third, called the posterior or septal flap, is posteriorly. The center of each of these flaps is thick, the lateral margins are thin. 5. The chorda? tendinae are fibrous cords which are attached to the mar- PLATE XCVII. A, ARTIC.WVTH U^t? ANT. ARCH 0FA7LA5. BODY. Anterior View of Axis. gins and ventricular surfaces of each of these flaps. Three or four are attached t<> the liases of each flap and are continuous with the fibrous ring which surrounds the auriculo-ventrieular opening. Four to six pass to the central part of these flaps, and the finest and most numerous go to the free margins of these flaps. 6. Column;? earneae project from the walls of the ventricle except near the pulmonary opening. They are divided into three sets, the first set are at- tached throughout their length thus forming mere ridges. The second sel called trabecular, are attached to their ends only, thus forming arches, while the third 3e1 . <;tlled musculi papillares, are attached to one end only, thus forming pillars. These musculi papillares are two in number, an anterior and a posterior, and they give attachment by their free ends to the chor.hr tendinae. Those from the anterior one pass to the right and left flaps, while those from the posterior one pass to the right and septal flaps. A few of the chordae tendinae pass to the left and septal flaps from the septum. 7. The semilunar valves (Plate XCXXX.) (pulmonary) are three in num- ber. Two anterior, (a righl and left), and one posterior. They are formed by 242 ANATOMY IN A NUTSHELL. folds of fibrous membrane, covered by endocardium below and by the inner arterial coat above. The convex margin of each valve is attached to the inner coal of the artery where it joins the ventricle, while its double crescentic border is free and is directed upward. The corpus arantii are small nodules situated at the center of each free margin. Tendinous fibers radiate from the corpus arantii to the attached margin of the valve, passing throughout the entire valve excepting a small portion on each side of the corpus arantii called the lunula. At this point the valve consists of lining membrane only. When the valve closes the surfaces of the lunula come in contact and the copora arantii fill the interval at the center. Sinus of valsalva is a pouch behind each valve. 8. The moderator band is a muscular beam running across the left ventricle obliquely. LESSON LXVI The left auricle like the right auricle has two parts, a sinus or atrium and an auricular appendix. This auricle is smaller but has thicker walls than the right one. The atrium lies behind the aorta and the pulmonary artery and is separated from the right auricle by the auricular septum internally. The left auricular appendix is longer and narrower, and more curved than the right one, and it projects forward to the right over the root of the pulmonary artery. The left auricle presents the following points: 1 . The openings of the four pulmonary veins, two on each side. These veins have no valves and carry pure blood. There may be five pulmonary veins or only three. 2. The auriculo-ventricular opening is smaller than the one on the right side. It is surrounded by a fibrous ring covered by endocardium and guarded by the mitral valve. 3. The musculi pectinati are fewer and smaller than those on the right side and are confined to the auricular appendix. 4. On the auricular septum, just above the fossa ovalis of the right auricle, there is an impression which is bounded below by a crescentic ridge whose con- cavity looks upward. The left ventricle is longer than the right and its walls are about three times as thick. It forms most of the posterior surface of the heart, all the apex, and a small part of the left side of the anterior surface. The left ventricle presents the following points: 1. The auriculo-ventricular opening which is below and to the left of the aortic opening is described with the left auricle. 2. The aortic opening is circular and is guarded by the semilunar valves. It i> situated in front and to the right of the auriculo-ventricular opening. 3. The mitral or bicuspid valve is attached to the margin of the auriculo- ventricular opening similar to the tricuspid valve on the right side of the heart, luit is stronger and thicker than the tricuspid valve. Its segments or flaps are covered by < ndocardium ami contain a few muscle fibers. The larger flap lies to the right and in front between the auriculo-ventricular opening and the ANATOMY EN A NUTSHELL. 243 aortic opening. The smaller flap lies to the left and behind. The smaller flaps are usually found where the two larger flaps meet. 4. The chordae tendinae are thicker, stronger, and less numerous, but have a similar attachment as those on the right side 5. The semilunar valves (aortic) are three in number, a right posterior, a left posterior, and an anterior one. They are larger, thicker, and stronger than those on the right side, but are similar in structure and attachment. Their corpora arantii and lunula are more distinct than those of the pulmonary semi- lunar valves. Their sinuses of valsalva are larger than those on the right side. The right coronary artery arises from the anterior sinus and the left coronary artery arises from the left posterior sinus. 6. The columns? carnea? are smaller and more numerous than those on the PLATE XCVIII. ANT. TUBERCLE TRANSVERSE PROC. fORAUEN FOP VERTEBRAL ARTERY. PEDICLE. SPINOUS PROC. The Fifth Cervical Vertebra. right side and are arranged in a similar manner. On the posterior wall and at the apex they are interlaced. The musculi papillares are larger than those on the right side, one of which comes from the anterior wall, the other from the posterior wall. The chorda' tendinae arise from their free ends. 7. Just under the aortic opening there is a small cavity called the aortic vestibule. 8. The ventricular septum is thick below but above it becomes thinner and losing its muscular fibers consists only of fibrous tissue covered by endothelium. For position of valves of the heart in reference to the chest wall, see Plate XVII. The structures of the heart consists of muscular fiber- and fibrous rii gs The muscular structure called myocardium Ls formed from small striated, and quadrangular muscular cells which have nude i joined end to end to form fibers and tend to branch, anastomosing with other cells. Some say the heart Is a voluntary muscle because it has striated fiber-, but l1 is governed by the sym- pathetic nerve thus making it involuntary in action. The fibrous rings are stronger on the left side than on the right. Thev 244 ANATOMY IN A NUTSHELL. surround the auriculo-ventricular openings and the arterial openings, giving attachment: to the muscle fibers, valves, and great vessels. The endocardium is a smooth, thin membrane which lines the heart and is more opaque on the left side and is thickest in the auricles, being thicker in the left auricle than in the right, Blood Supply. — The arteries are the right and left coronary. The right coronary artery arises from the anterior sinus of valsalva and passes forward between the pulmonary artery and the auricular appendix. From this point it runs in the right auriculo-ventricular groove to the posterior interventricular groove, and here it divides into a transverse branch which runs in the left auricu- lo-ventricular groove and a descending branch which runs in the posterior interventricular groove to the apex of the heart. A marginal branch which comes from this artery runs along the margin of the right ventricle. It also gives infundibular branches to the right auricle and right ventricle and the pul- monary artery. (Plate CXXVIII.) The left coronary artery, which is larger than the right, arises from the left posterior sinus of valsalva and passes forward between the pulmonary artery and the left auricular appendix. At this point it divides into a transverse branch, which runs outward in the left auriculo-ventricular groove and a de- scending branch which runs to the apex of the heart in the anterior interven- tricular groove. The coronary arteries may come from a common trunk and there may be one or two small additional branches. (Plate CXXVII.) The cardiac veins return the blood from the substance of the heart into the righl auricle. 1. The anterior cardiac vein, also called great cardiac vein, ascends from the apex of the heart to the base of the ventricle in the anterior interventri- cular groove. It turns to the left into the left auriculo-ventricular groove and opens at the back of the heart into the great coronary sinus where it has two valves, it drains both ventricles (more the left than the right), and the left auricle. 2. The middle cardiac vein ends in the great coronary sinus after running from the apex of the heart to its base in the posterior interventricular groove. It has one valve at its orifice and it drains the posterior part of both ventri- cles. :;. The posterior surface of the left ventricle is drained by the left or pos- terior cardiac veins which empty into the great coronary sinus. 1. The right or anterior cardiac veins receive the blood from the anterior surface of the right ventricle and open separately into the lower part of the righl auricle. The largest one of these veins, which runs along the right border of the heart, is called the vein of Galen. 5. The right or small coronary sinus drains the back part of the right auricle and right ventricle and it runs in the right auriculo-ventricular groove and end- in the righl end of the gr< at coronary sinus. ('). The left or great coronary sinus is then a portion of the great cardiac vein which is about an inch long and occupies the posterior part of the left auri- culo-ventricular groove. It receives the veins just mentioned and also an ANATOMY IX A NUTSHELL. 245 oblique vein from the back of the left auricle which is the remnant of the obliter- ated left vena cava called duct of Cuvier. This great coronary sinus ends in the right auricle between the inferior vena cava and the auriculo-ventricular opening. The opening of this sinus is guarded by a semilunar fold of the lining membrane of the heart called the coronary valve or Thebesii. 7. Venae Thebesii are minute veins which drain the cardiac muscular sub- stance and open directly into the right auricle by the foramina of Thebesii. LESSON LXVII. Nerve Supply. — The nerves to the heart are derived from the cardiac plexuses, formed by the pneumogastric and sympathetic nerves. Its actions are involuntary. The nerves of the heart are derived from three sources: PLATE XCIX. UPPER INTER- VERTEBRAL NOTCH SUP.ARTICPROC'S. TRANSVERSE PROC'S. OEMIFACET FUR HEAD OF RIB. LOWER INTERVERTEBRAL NOTCH. A Dorsal Vertebra, With Long Spine. 1. From nerve cells buried in its own substance and known as the intrinsic ganglia. 2. From the tenth pair (pneumogastric) of cranial nerves. 3. From the sympathetic nervous system. The intrinsic ganglia keep the heart beating, and the other two sets of nerves control the rate and force of the beat. Systole is contraction of the heart and arteries tor propelling the blood and thus carrying on circulation. The expansion of the hearl is called diastole. The heart has two sounds. The first is longer in duration and lower in pitch than the second. It is made by those sounds which take place during ventri- cular systole. (1) Muscular contractions. (2) friction of blood rushing through 24') ANATOMY IN A NUTSHELL. the s< n.ilunar valves, (3) friction of the heart within the pericardium, (4) fric- tion of heart against neighboring structures. It is of importance to study the norma] hi art sounds for any of these four factors may be modified by various dis< ases. The second sound of the heart is made by those sounds which occur during the closure of the aortic semilunar valves and the pulmonary semilunar valves. The position for hearing the first sound is at the apex, while the sec- ond sound is more easily heard over the base of the heart. The tricuspid and pulmonary valves are on a superficial plane to the aortic and bicuspid valves, thus a circle of one inch in diameter includes a part of all the valves of the healthy heart. The tricuspid valve is situated behind the median line of the sternum between the fourth costo-sternal articulations. The sound of this valve is best heard at the base of the ensiform cartilage. The aortic valve is situated behind the left edge of the sternum on a level with the lower border of the third rib, and although this valve is on the left side of the heart we listen to its sounds in the second right or aortic interspace where they are conveyed. The pulmonary valve is situated behind the junc- tion of the third costal cartilage with the sternum, and although it is situated on the righl side of the heart its sounds are best heard in the second left or pulmonary interspace where the sounds are conveyed. The mitral valve is situated between the left edge of the sternum and the third and fourth costal cartilages. We listen at the apex for this sound. Plate XVII. The Thyroid Gland. (Plates CXXI-CXXII-CXXXII.) There are several organs in the body that are called ductless glands or bodies. They are the thymus gland, the thyroid gland, the spleen, and the suprarenal capsules. Some anatomists name the additional organs as duct- less "lands; the tonsils, the epiphysis, the hypophysis, the coccygeal glands and carotid glands. A gland is an organ which secrets and pours forth fluid from one or more ducts, and since these bodies just named have no ducts it would seem that they could not be called glands, however they have an internal se- cretion. The thyroid gland has a duct in the fetus which leads to the base of the tongue. This gland is very vascular and is situated upon the larynx and upper part of the trachea. Although closely associated with the trachea, yet it takes no pari in respiration. It is the seat of the disease known as bron- chocele or goiter. The following are the main forms of goiter: 1. Exophthalmic (Grave's disease.) Where there is a great vascularity and often pulsation, accompanied by exophthalmus, palpitation, and rapid pulse. 2. Fibroid. Where there is an increase of the interstitial tissue. 3. Cystic. Where there are one or more cysts formed from dilatation and possibly coalescence of adjacent follicles. 4. Pulsating. Where vascular changes predominate. ."). Parenchymatous. Where the follicles are enlarged. This gland consists of two lobes, which are pyriform in shape, and an isthmus. The dimensions of the lobes are two inches in length, three-quarters ANATOMY IX A NUTSHELL. 247 of an inch in thickness, and an inch and a quarter in breadth. It extends from the middle of the thyroid cartilage to the sixth ring of the trachea, and the isthmus crosses the trachea about the third ring. The isthmus may. in rare cases, pass behind the trachea in front of the oesophagus. This gland weighs from one to two ounces. It is larger in the female and is increased in size dur- ing menstruation. Blood Supply. — The superior thyroid arteries, which are branches of the external carotid, supply the apex and inner and fore parts of the lateral lobes. The inferior thyroid arteries, which come from the thyroid axis, supply the PLATE C. A Lumbar Vertebra. outer and posterior portion of the lateral lobes. The thyroidea ima. which is derived either from the innominate artery or from the arch of the anna, ascends on the front of the trachea to anastomose with the superior and inferior thy- roid arteries and helps to supply the isthmus. The veins arc the superior thyroid which empties into the internal jugular, and the middle thyroid which empties into the same, and the inferior thyroid which empties into the innom- inate of the corresponding side. Nerve Supply. — From the superior and middle cervical ganglion of the sympathetic, and possibly a branch from the tenth. A goiter may be distinguished from a cervical tumor by the fact thai it rises ami falls on deglutition. 248 ANATOMY IN A NUTSHELL. The Spleen. (Plate CXLVI1.) The dimensions of the spleen are one by three by five inches, and it weighs aboul five ounces. It consists of an external portion called cortex, and an in- ternal portion called the medullary portion. This internal portion consists of a honey-combed arrangement and in these cells are the MaJpighian corpuscles •which arc about one-twenty-fifth of an inch in diameter. The spleen manu- factures white blood corpuscles and has no true set of capillaries, the blood emptying into these spaces from which it is collected into the veins. There may be numerous accessory spleens. The spleen has no excretory duct and therefore no proper secretion. The Ancients thought the spleen to be the seat of various emotions. It is situated in the left hypochondriac region. The relations of the spleen are as follows: In Front. — Stomach and splenic flexor of colon. Behind. — The Diaphragm. Outer Side. — Diaphragm, ninth to eleventh ribs between the axillary line. Inner Side. — Stomach, pancreas, left kidney, and suprarenal capsule. Blood Supply. — The splenic artery, which is a branch of the cceliac axis, divides before entering the spleen into about six branches. This artery is tortuous and large in porpotion to the body it supplies. The spleen is en- tirely covered by peritoneum beneath which there is a plexus of lymphatic vessels. The lymphatics of the spleen are divided into a superficial and a deep set. The veins of the spleen form one main vein called the splenic which empties into the portal vein. Nerve Supply. — The splenic plexus which comes from the solar plexus and passes along the splenic artery. LESSON LXVIII. The Thymus Gland. (Plate CXXXII.) This gland is situated within the thorax behind the sternum near the neck. It is a fetal structure and begins to disappear about the second year after birth. The thymus gland of the sheep is called throat, or neck, sweet bread to distin- guish it from the pancreas, or stomach sweet breath This gland reaches its highest development about the second year and its weight it is six drachms. Blood Supply. — Internal mammary, superior and inferior thyroid. The veins empty into the left innominate vein and thyroid veins. Nerve Supply. Sympathetic and pneumogastric. Suprarenal Capsules. (Adrenal Bodies.) (Plate CXLVII.) These bodies are solid viscera situated on the upper extremity of each kid- ney. They are richly supplied with vessels and nerves. Dimensions are two inches by one-half by one-half. Weight is one drachm. They are not in- vested by peritoneum. Blood Supply. Suprarenal, phrenic, and renal arteries, which pierce the organs chiefly on the anterior surface along a furrow called the hilum. The veins empty on the rigb.1 side into the vena cava and occasionally by means of ANATOMY IN A NUTSHELL. 249 small branches into the phrenic and renal veins. Those on the left side empty into the renal vein. The lymphatics of this organ pass into the renal glands. The renal glands, as well as the suprarenal capsule, contain a good deal of pig- ment. Nerve Supply. — Solar and renal plexuses, and possibly the splanchnic, phrenic, and the pneumogastric nerves. The other ductless glands mentioned will be described in their proper places. PLATE CI. DORSI-SPINAL VEINS INTERCOSTAL VEI ANTERIOR LONGITUDINAL MENINGO-RACHIDIAN. INTERCOSTAL VEIN VENAE BASIS VERTEBRARUM. Veins of Spinal Cord and Column (Transverse View.) Larynx. (Plate CXXIL) The larynx (the organ of phonation) is thai part of the trachea in which vocal sound is made and modulated. It is the upper end of the trachea which is enlarged and modified. It opens by the glottis into (he pharynx and is con- tinuous below with the trachea. The larynx is larger in men than in women by about one-third. In some animals the larynx may be situated any where along the wind pipe or even in the bronchial tubes. In birds there are two larynges, one at the top of the trachea ami the other, at the bottom of the trachea, which is called syrinx. The opening of the trachea is called the glottis. The word glottis is sometimes applied to this opening with the contiguous 250 ANATOMY IN A NUTSHELL. structures as one mighl say oedema of the glottis just as he would say mouth to include the lips. The anterior part of the glottis is called glottis vocalis and is hounded by the true vocal cords, while the posterior part is called glottis res- piratoria and is hounded by the internal margins of the arytenoid cartilages. The epiglottis (Plates CXXII-CXXXIV-CXXXV-CXXXVI-CXXXVIL) i> a valve-like organ which prevents the food from entering into the glottis during deglutition. The superior or false vocal cords are two folds of mucous mem- Inane which enclose a delicate rounded hand, the superior thyro-arytenoid ligament. They are called false vocal cords because they are not directly con- cerned in the production of the voice. The inferior or true vocal cords are two strong fibrous bands, inferior thyrc-arytenoid ligament, which are covered by a thin layer of mucous membrane. They are called true vocal cords because they are concerned in the production of the voice. The sinus of the larynx, (Plate CXXXVII) which is situated between the false and true vocal cords on each side, leads into the sacculus laryngis (sinus Morgagni.) There are nine cartilages of the larynx, three of which are single and three are in pairs. The single ones are (1) epiglottis, (2) thyroid, (3) cri- coid. (Plate CXXXVI.) Those in paris are (1) the two arytenoid, (2) two cornicula laryngis, and (3) the two cuneiform, The cricoid and thyroid and the arytenoid (excepting tin tip) are hyaline in structure. The tip of the arytenoid, the epiglottis, the cornicula laryngis, and the cuneiform are yellow elastic. The ligaments of the larynx are arranged in two sets, the extrinsic which are three in number, connect the larynx to the hyoid bone, and the in- trinsic, which are sixteen in number, connect the cartilages of the larynx to one another. The extrinsic ones are: Thyro-hyoid membrane. (Plate CXXXIV.) Two lateral thyro-hyoid ligaments, each of which contains a nodule cartil- age, (the cartilage triticea.) The sixteen intrinsic ligaments are: Crico- thyroid membrane. (Plate CXXXIV.) Two crico-thyroid capsular ligaments. Two crico-arytenoid ligaments. Two crico-arytenoid capsular ligaments. Two superior thyro-arytenoid (situated in the false vocal cords.) Two inferior thyro-arytenoid (situated in the true vocal cords.) Hyo-epiglottic ligament. Thyro-epiglottic ligament. Three glosso-epiglottic folds. The muscles of the larynx are as follows; (1) Crico-thyroid, (2) Crico- arytenoideus posticus. (3) Crico-arytenoideus lateralis, (4) Thyro-aryte- Doideus (5) Arytenoideus, (6) Thyro-epiglottideus, (7) Aryteno epiglottideus superior. (8) Aryteno-epiglottideus inferior. All these muscles are in pairs excepi the Arytenoideus, which is a single muscle. Three of these muscles be- long to the epiglottis. (Plate CXXXVI.) ANATOMY IN A NUTSHELL. 251 LESSON LXIX. Cricothyroid Muscle. Origin. — From the side of the cricoid cartilage. Insertion. — Into the interior border and lower cornu of thyroid cartil age. Action. — Rotates the posterior part of cricoid cartilage downward and backward, and thus tightens the vocal cords. Nerve Supply. — External laryngeal from the superior laryngeal. Blood Supply. — The superior laryngeal from the superior thyroid, and the inferior larvngeal from the inferior thyroid. The veins have the same name PLATE CTI. ANTERIOR LONGITUDINAL WENINGO-RACHIDIAN. POSTERIOR LONGITUDINAL. YENINCO-RACHIDIAN VENAE BASIS VERTEBRARUM Veins of Spinal Cord axd Column (Sagittal View.) as the arteries and accompany them. This is the blood supply of all the mus- cles of the larynx. Crico-arytenoideus Posticus. Origin. — From posterior surface of the cricoid cartilage. Insertion. — Into the outer angle of the base of the arytenoid cartilage. Action. — It dilates the glottis bv rotating the arytenoid cartilage out- ward. Nerve Supply'. — Recurrent laryngeal from the pneumogastric nerve. Crico-arytenoideus Lateralis. Origin. — From the upper border of the sides of the cricoid cartilage. 252 ANATOMY IN A NUTSHELL. Insertion. — Into the external angle of the base of the arytenoid cartilage in front of the Crico-arytenoideus posticus. Action. — T<> contract the glottis by rotating the arytenoid cartilage in- ward. \i i;\ e Supply. — Recurrent laryngeal from the pneumogastric. Thyro -arytenoideus. Origin. — From the side of the angle of the thyroid cartilage and the crico- thyroid membrane. [nsertion.- Into the anterior surface and base of the arytenoid cartilage. Action. — Relaxes the vocal cords by drawing the arytenoid cartilage for- ward. Nerve Supply. — Recurrent laryngeal from the pneumogastric. Arytenoideus Muscle. Origin. — This is the single muscle of the larynx and comes from the pos- terior surface of the arytenoid cartilage, its fillers running in a transverse direc- tion pass from one cartilage to the other. Insertion. — Into the posterior surface of the arytenoid cartilage. Action. — It assists in contracting the glottis by approximating the aryten- noid cartilages. Nerve Supply. — Recurrent laryngeal from the pneumogastric, and the superior laryngeal. Thyro-Epiglottideus. Origin. — From the angle of the thyroid cartilage just above the Thyro- arytenoideus. Insertion. — Into the lower border of the epiglottis and into the aryteno- epiglottic fold. Action. — To compress the sacculus laryngis and to depress the epiglottis. Nerve Supply. — Recurrent laryngeal nerve. Aryteno-Epiglottideus Superior. Origin. — From the tip of the arytenoid cartilage. [nsertion. Into the mucous membrane attached to the side of the epi- glottic Action. — Contracts the superior opening of the larynx. Nerve Supply. — Recurrent laryngeal. Aryteno-Epiglottideus Inferior. Origin. — From the anterior surface of the arytenoid cartilage. [nsertion.— Into the upper and inner part of the epiglottis. This muscle is separated from the superior muscle by a distinct interval. It is often called the Compressor sacculus laryngis of Hilton. The Triticeo-glottis muscle is a small muscle which is frequently present. Its origin is from the corpus tri- ticeuni, and after passing forward and upward to join the Cerato-glossus, it is inserted into the tongue. PLATE CIII. m> VC. ;, 4n T tf? The Spinal Column. 253 254 ANATOMY IN A NUTSHELL. A< tii in. - Contracts the superior opening of the larynx. Nerve Supply. — Recurrent laryngeal nerve. Nerve Supply. — The Crico-thyroid muscles and mucous membrane of the larynx receive the superior laryngeal nerves, all the remaining muscles receive the inferior <>r recurrent laryngeal nerves. The Arytenoideus receives both superior and inferior laryngeal nerves. 1 ;;.oi in Supply. The laryngeal branches from the superior thyroid and inferior thyroid arteries pass to the larynx. The veins, which accompany the superior laryngeal artery, join the superior thyroid vein which empties into the internal jugular vein. The veins which accompany the inferior laryngeal artery join the interior thyroid vein which empties into the innominate vein. The lymphatics pass into the deep cervical nodes. Trachea. (Plate CXX.) The word trachea comes from a Greek word which means rough. It is also called the wind pipe and is the air passage of the body beginning at the larynx and ending in the bronchial tubes. It is composed of sixteen to twenty car- tilages or osseous rings. The first ring is called the cricoid cartilage, and the last one is called the pessulus. This last one is situated at the forking of the trachea into the right and left bronchial tubes. The trachea is a musculo- membranous tube and it communicates with the mouth and nose through the larynx, and with the lungs through the bronchial tubes. All vertebrates, which breathe air with lungs, have a trachea which is subject to very little variation in character. The human trachea is about four and one-half inches long, ex- tending from the sixth cervical vertebra to the fourth dorsal vertebra where it branches into the two bronchi. The oesophagus is between the trachea and the spinal column. The average diameter of the trachea is about four-fifths of an inch in the cadaver. The antero-posterior diameter is somewhat less. Dur- ing life these dimensions are smaller. The rings of the trachea are incomplete behind where they join the (esophagus. Blood Supply. —Inferior thyroid arteries. The veins terminate in the thyroid venous plexus. Nerve Supply.— Pneumogastric and sympathetic. The right bronchus is about an inch in length and in direction is more hor- izontal in its passage to the rool of the lung than the left bronchus. It is wider than lie Nft and divi les into three branches to the lung. The left bronchus is nearly tun inches in length and is smaller, longer, and more oblique than the righl one. It enters the root of the lung opposite the sixth dorsal vertebra, which is alioiii an inch lower than the point whe'e the right bronchus enters i In lung. It divides into two branches. It has above it the arch of the aorta. behind it the (esophagus, thoracic duct, and the descending aorta. The left pulmonary artery is a1 first above, then in front of the left bronchus. LESSON LXX. Lungs. (Plates CXXI-CXXII-CXXIII.) Tin word Lung comes from the Latin pulmones, from which comes pul- ANATOMY IX A NUTSHELL. 255 monary. The lungs are two large organs which occupy a great part of the chest cavity. The heart, oesophagus, and the great vessels separate them. They are the organs of respiration in air breathing vertebrates and communicate with the pharynx through the trachea. The air cells (alveoli) are from one fiftieth to one-seventieth of an inch in diameter. The lungs are formed by re- peated subdivisions of the bronchial tubes which finally end in saccular dilata- tions called infundibula. The air cells are in the infundibula and the air pass- UPPER FASCICULUS MIDDLE FASCICULUS. .OWER FASCICULUS. PLATE CIV. _-*-> THREE SLIPS OF THE STELLATE LIGAMENT ANTERIOR COSTOVERTEBRAL LIGAMENT ANTERIOR OR SUPERIOR COSTOTRANSVERSE LIGAMENT Ligaments of Spinal Column. ages leading to them. These cells have a capillary net-work in which the branches of the pulmonary art< ry < nd and In re the blood is s< parat< d from the air by the capillary wall and the thin alveolar epithelium of the air cells. The lung is comparatively compact, being composed of air breathing tubes bound tip by connective tissue. Blood Supply. — From the bronchial arteries which vary in number, size. and origin. The one on the right side may conic from (1) the first aortic in- tercostal. (2) by a common trunk with the lefl bronchial from the f I of the thoracic aorta. On the left side ther< are generally two which conic from the thoracic aorta. The bronchial veins do not return all the blood carried to the 256 ANATOMY IN A NUTSHELL. lungs by the bronchial arteries, for that part which is distributed to the smaller bronchial tubes and alveolae is brought back by the pulmonary veins. The right bronchial vein empties into the vena azygos major just before that vein empties into the superior vena cava. The left bronchial vein empties into the lower left superior intercostal vein or into the vena azygos tertius. Small veins from the bronchial glands, from the trachea, and from the posterior med- iastinum empty into the bronchial veins at the root of the lung. The lymphatics of the lungs are numerous. The base of each lung rests upon the Diaphragm and its apex passes through the superior opening of the thorax about an inch above the clavicle. Each lung is pyramidal in form and the right one is divided into an upper lobe, a middle lobe, and a lower lobe, while the left lung is divided into an upper lobe and a lower lobe. The root of each lung is little above the middle at the inner side and except for this attachment the lung lies free in the pleural cavity which it completely fills. The lung is elastic and always on a tension. The blood in passing through the lungs gives off carbon dioxide to the air in the alveolae and receives oxygen. This process which takes place in the lung is a simple physical change and has nothing to do with any secreting or other activity of the epi- thelial cells. Nerve Supply. — It is from the anterior and posterior pulmonary plexuses, which are formed from the sympathetic and pneumogastric. Filaments from these plexuses accompany the bronchial tubes upon which they are lost. Small ganglia are formed upon these nerves. The right lung (Plates CXXI-CXXII-CXXIII.) weighs twenty-two ounces and the left one twenty. Their capacity is nearly seven and a half pints. The entire respiratory surface is more than eight hundred and seventy square feet. At birth the lungs are a reddish brown and change to a rose pink on inflation. They are grayish white in adult life and brownish in middle life and bluish black in old age. The specific gravity varies from 345 to 746, water being 1000. The serous membrane which covers the lung is the pleura . (Plates CXXY-CXXVL) Each pleura is an inclosed sac and they do not touch each other. Each has a parietal layer called a costal, and a visceral layer called pulmonary. The movements of the lungs in the chest are facilitated by serous secretion in the pleura. The parietal pleura has different names for its various portions. 1. Tin-: costal pleura is that which lines the ribs, costal cartilages, and intermediate muscles. 2. The diaphragm \tic pleura is that which is attached to the Diaphragm. 3. The mediastinal pleura is that which is attached to the adjacent structures in the mediastinum. 4. The < i;k\ ecal pleura is that which covers the dome of the lung. Blood Supply. — Internal mammary, intercostal, musculo-phrenic, thymic, pericardiac, bronchial. The veins correspond to the arteries. The lymphatics are numerous. Nerve Supply. — Sympathetic and phrenic. The broad ligamenl of the lung is a fold of the visceral layer of the pleura which after covering the root of the lung comes together directly beneath it ANATOMY IX A NUTSHELL. 257 forming a triangular sheet, passing vertically from the root of the lung to the Diaphragm, and laterally from the lung to the mediastinal pleura. The root of the lung is composed of (1) the pulmonary artery, (2) pulmonary veins, (3) bronchial tube, (4) bronchial vessels, (5) anterior pulmonary plexus, PLATE CV. ANTERIOR TUBERCLE OF ATLAS TO WHICH THE LONGU COLLI IS INSERTED THE ORIGIN OF THE UPPER OBLIQUE PORTION OFLONGUS COLLI INSERTION OF INFERIOR OBLIQUE PORTION OF LONGUS COLLI RECTUS CAPITIS ANTICUS MINOR ORIGIN THIS AND THE THREE SUCCEEDING PROCESSES GIVE ORIGIN TO THE RECTUS CAPITIS ANTICUS MAJOR AND THE SCALENUS ANTICUS ORIGIN OF VERTICAL PORTION OF THE LONGUS COLLI. ITS INSERTION IS INTO THE SECOND. THIRD AND FOURTH VERTEBRAE Anterior View of Cervical Vertebra. (6) posterior pulmonary plexus, (7) bronchial lymphatic nodes, (8) areola! tissue. All these are enclosed in the pleural covering. The first three of these are the main structures in the root of the lung and bear the following relations from before backward in each lung: Vein, artery, and bronchus. From above down in the left root we have artery, bronchus, and vein. In the righl one from above down we have bronchus, artery and vein. Relations of the root of the right lung. (Plate CXXVII.) 258 ANATOMY IN A NUTSHELL. In Front. — (1) .Superior vena cava. (2) upper portion of right auricle of heart. (3) anterior pulmonary plexus, (4) right phrenic nerve. Behind. — (1) Posterior pulmonary plexus, (2) pneumogastric nerve, (3) vena azygos major. Above. — (1) Vena azygos major. Below. — Broad ligament (ligamentum latum pulmonis.) Relations of the left root. (Plate CXXVIL) In Front. — (1) The anterior pulmonary plexus. (2) the left phrenic nerve. Behind. — The descending aorta, (2) pneumogastric nerve, (3) posterior pulmonary plexus. Above. — The arch of the aorta. Below. — The broad ligament (ligamentum latum pulmonis.) About one hundred cubic inches of air remains in the lungs which cannot be expelled. (Plate CXXIY.) This is called residual air. After an ordinary expiration one hundred cubic inches of air can be expelled by forced expira- tion, this is called reserve air. About twenty or thirty cubic inches of air which passes in and out during the ordinary breathing is called tidal air. After an ordinary inspiration one can inhale one hundred and twenty cubic inches of air, which is called eomplemental air. After the complemental air has been taken into the lungs then one may expell all the air, except the residual air, and this is called vital capacity. LESSON LXXI. A vertebra (Plate XC1X) consists of a body and an arch, the latter being formed by two pedicles ami two laminae which support the seven processes. The body is thick and spongy, convex in front from side to side and concave vertically on the upper and lower surfaces which are surrounded by bony rims. Anteriorly are small foramina for nutrient vessels, posteriorly a large foramen for the exit of the venae basis vertebrarum. The pedicles project backward from the body, inclining outward; they are noticed above and below, thus forming, with the adjacent notches, the intervertebral foramina for the entrance of ves- sels and the exit of spinal nerves. The laminae are two broad plates meeting in the spinous process belaud and rough on the upper and lower borders for the attachment of the ligamenta subfiava. The transverse processes, one on each vide, project outward. The articular processes, two on each side, superior and inferior, project from the junction of the lamina? and the pedicles, articulating above and below with the articular processes of the adjacent vertebrae. Their superior facets look upward in the cervical region, outward in the dorsal region, and inward in the lumbar. The spinous process projects backward from the junction of the lamina?, sometimes very obliquely. The spinal foramen is the -pace enclosed by the body, pedicles, and lamina?, and each foramen when the vertebrae are articulated, form part of the spinal canal. There are thirty-three vertebra? in number, exclusive of those which form the skull, having received the names of cervical, dorsal, lumbar, sacral, and coccygeal, according to the position which they occupy, seven being found in ANATOMY IN A NUTSHELL. 259 the cervical region, twelve in the dorsal, five in the lumbar, five in the sacral, and four in the coccygeal. (Plate CIII.) Their number is sometimes increased by an additional vertebra in one region, or the number may be diminished in one region, the deficiency being supplied by an additional vertebra in another. These observations do not apply to the cervical portion of the spine, the number PLATE CVI. RECTUS CAPITIS POSTICUS MINOR TRANSVERSE PROCESS OF ATLAS LEVATOR ANGULI SCAPULAE ORIGIN SPLENIUS COLLI .INSERTION LEVATOR ANGULI SCAPULAE SPLENIC COLLI SCALENUS MEDIUS .INSERTION LEVATOR ANGULI SCAPULAE SPlfNIUS COLLI SCALENUS MEDIUS COMPLEXUS LEVATOR ANGULI SCAPULAE SPLENIUS COLLI ■SOMETIMES SCALENUS MEDIUS COMPLEXUS AND MULTIFIDUS SPINAE SCALENUS MEDIUS SCALENUS POSTICUS COMPLEXUS AND TRACHELO MASTOID. MULTIFIDUS SPINAE SCALENUS MEDIUS SCALENUS POSTICUS COMPLEXUS AND TRACHELO- MASTOID. MULTIFIDUS SPINAE SCALENUS MEDIUS SCALENUS POSTICUS j&j£* ' ,' COMPLEXUS AND TRACHELO- MASTOID. MULTIFIDUS SPINAE MULTIFIDUS SPINAE lAND TO EACH SPINOUS PROCESS AS HIGH AS THE SECOND RECTUS CAPITIS LATERALIS SUPERIOR OBLIQUE - INFERIOR OBLIQUE RECTUS CAPITIS POSTICUS MAJOR THE POINTER CROSSES THE ORIGIN OF THE INFERIOR OBLIQUE SEMISPINALS COLLI CERVICAUS TRANSVERSUS SEMISPINALS COLLI CERVICAUS TRANSVERSUS CERVICAUS ASCENDENS SEMISPINALS COLLI CERVICAUS ASCENDENS CERVICAUS TRANSVERSUS CERVICAUS TRANSVERSUS CERViCALiS ASCE\0ENS - 3 COLLI LEVATOR COSTAE ORIGIN ACCESSORIUS INSERTION INTERSPINALES TRAPEZIUS. RHOMBOIDEUS MINOR. SERRATUS POSTICUS SUPERIOR. SPLENIUS. COMPLEXUS Postekiob View uf Cervical Vertebrae. of bones forming which is seldom incr< ased or diminished. The peculiar vertebra' are the first cervical or atlas, SE< OND CERVU al or AXIS, and THE SEVENTH CERVICAL Or VERTEBRA PROMINENS. (Plates XCV- XCVI-XCVII.) The great modifications in the form of the atlas and axis arc d( signed to admit of nodding and rotary movements of the head. The peculiar vertebra* in the dorsal region are the first, ninth, tenth, Eleventh, and twelfth. (Plate CVII.) In the lumbar region the fifth is 260 ANATOMY IN A NUTSHELL. peculiar. The peculiarity of the first dorsal is that it has one facet and a demi- facet. The ninth dorsal has a demi-facet only. The tenth has but one facet mi its body and one on the transverse process. The eleventh and twelfth have each but one facet on the body, and none on the transverse process. The twelfth resembles a lumbar vertebra in size and shape. The fifth lumbar is much deeper in front than behind. Its spinous process is small, but its transverse processes are large and thick and point slightly upward. The atlas has ten pairs of muscles attached to it. I'm anterior arch. Longus Colli. 1 Ant. vertebral region. To posterior arch. Rectus capitis posticus minor. 2 Fifth layer of back. Rectus capitis anticus minor. 3 Ant. vertebral region. Rectus capitis lateralis. 4 Ant. vertebral region. Inferior oblique. 5 Fifth layer of back. To transverse pro- Superior oblique. 6 Fifth layer of back, cess. Splenius colli. 7 Third layer of back. Levator anguli scapula?. 8 Second layer of back- Anterior intertransversalis. 9 Fifth layer of back. Posterior intertransversalis. 10 Fifth layer of back. The atlas has a small spinous process, large lateral masses, and no body. The anterior arch forms one-fifth of the circumference, the posterior arch two- fifths of the circumference, and the lateral masses one-fifth each. The attach- ment of muscles is given above. There is a groove on the posterior surface of the anterior arch for the articulation of the odontoid process of the axis. This process is held in place by the transverse ligament which passes across it pos- teriorly, being attached to the inner surface of the lateral masses. Where the posterior arch joins the lateral masses there is a groove (sinus atlantis) for the vertebral artery and suboccipital nerve (first spinal nerve), the nerve lying be- neath the artery. The articulation of the atlas with the occiput is a diarthrosis joint, subclass double condylar arthrosis, having all the movements of the ball- and socket joint (enarthrosis) except axial rotation. (Plate XCV.) The blood supply of this joint is the vertebral artery and sometimes the ascending pharyngeal artery. The nerve supply is the anterior division of the suboccipital (first cervical.) The ligaments are the anterior occipito-atlantal, posterior occipito-atlantal, two capsular, two anterior oblique or lateral occipito-atlantal. (Plate CIX.) The anterior occipito-atlantal ligament is attached above to the anterior margin of the foramen magnum, below to the upper margin of the anterior arch of the atlas. The central part, which is a continuation of the anterior common ligamenl of the vertebral column, is sometimes called the superficial part of this ligament. The lateral portions, which are continuous with the capsular ligament, form the deep part. In front of this ligament are the Recti capitis antici minores muscles. H( hind is the central odontoid or suspensory ligament. ANATOMY IN A NUTSHELL. 261 LESSON LXXII. The posterior oceipito-atlantal ligament is attached above to the posterior margin of the foramen magnum from condyle to condyle, below to the pos- PLATE CVII. AN ENTIRE PACET ABOVE A DEMI-FACET BELOW A DEMI-FACET ABOVE ONE ENTIRE FACET AN ENTIRE FACET. NO FACET ON TRANSVERSE PROCESS. WHICH IS RUDIMENTARY AN ENTIRE FACE1 NO FACET ON TRANSVERSE PROCESS INFERIOR ARTICULA PROCESS CONVEX AND TURNED OUTWARD The Peculiar Dorsal Vert k hi; b. terior surface and upper margin of the posterior arch of the atlas. This liga- ment is incomplete on each side for the passage of the vertebra] artery into, and the suboccipital nerve from, the spinal canal. In position ii corresponds 262 ANATOMY IN A NUTSHELL. to the ligamenta subflava which are below the axis but has no elastic tissue in its composition. In front this ligament is attached to the dura mater and be- hind are the Rectus capitis posticus minor and Superior oblique muscles. The two capsular ligaments are attached above to the margins of the con- dyL - of the occipital bone and below to the margins of the articular surfaces of the atlas. Each capsular ligament is lined with synovial membrane which sometimes communicates with the synovial membrane of the transverse odon- toid ligament. The two anterior oblique or lateral occipito-atlantal ligaments are situated in front of the external part of the capsular ligament. They are attached above to the jugular process of the occipital bone, and below to the base of the trans- verse process of the atlas. Their direction is forward, upward, and inward. The articulation of the lower part of the atlas with the upper part of the axis is a diarthrodiaJ joint, subclass arthrodial. The nerve supply is the loop between the first and second cervical nerves. The blood supply is the vertebral artery. The ligaments are anterior atlanto-axial, posterior atlanto-axial, transverse, and two capsular. The anterior atlanto-axial ligament is attached above to the anterior sur- face and lower border of the anterior arch of the atlas, and below to the base of the odontoid process and the transverse ridge on the front of the body of the axis. It is continuous on each side with the capsular ligaments. In front in the median line is the anterior common ligament of the vertebral column which is sometimes called the superficial anterior atlanto-axial ligament. It has im- mediately in front the Longus colli, then the Recti capitis antici minores. The posterior atlanto-axial ligament takes the place of the ligamenta sub- flava of the joints below the axis. It is attached above to the posterior surface and lower edge of the posterior arch of the atlas and below to the dorsal aspect of the upper edge of the lamina of the axis. It is continuous with the capsular Ligament on each side. It is perforated on each side by the second cervical nerve. In front it is connected to the dura mater, behind is the Inferior ob- lique muscle. The two capsular ligaments. These articulations are between the superior articular surfaces of the axis and inferior articular surface of the atlas. Each joint has a loose capsular ligament and synovial sac. These ligaments are strengthened in front and behind by the anterior and posterior atlanto-axial ligaments. The transverse ligament is a strong fibrous band passing from the tubercles on the inner side of the lateral masses of the atlas, holding the odontoid process in place. It is thicker in the center and gives fibers which pass above to the basilar process of the occipital and some passing below to the base of the odon- toid process and body of the axis, thus forming a crucial ligament. This liga- ment divides the canal of the atlas into two parts, a small anterior one which is for the odontoid process and a large posterior one for the spinal cord, the spinal acci ssory nerves, the spinal arteries, vertebral arteries, and the meninges of the cord. The articulation of the posterior surface of the anterior arch of the atlas PLATE CVIII. TUBERCLE ARTICULAR PART OF TUBERCLE SECOND AND THIRD DICTATIONS OF SERRATUS MAGNUS (0) STERNAL END FOR COSTAL CARTILAGE The Second and Skykxth Ribs. 263 264 ANATOMY IN A NUTSHELL. with the odontoid process is a diarthrosis joint, subclass trochoides. Blood supply, vertebral and ascending pharyngeal arteries. Nerve supply, loop be- tween the first and second cervical nerves. The part between the posterior surface of the odontoid process and the transverse ligament is a syndesmo- odontoid joint. Each of these joints has a synovial membrane. The synovial membrane of the atlanto-odontoid is surrounded by a capsular ligament of the same name and is continued with the occipito-atlantal capsular ligament. It blends with the anterior occipito-atlantal, atlanto-axial, and the central odon- toid ligaments. The synovial sac of the syndesmo-odontoid joint is surrounded by a capsule. This sac often communicates with the occipito-atlantal synovial sac. The ligaments attached to the odontoid process are (1) Occipito-axial lig- ament (apparatus ligamentosus colli) which is a continuation of the posterior common Ligament of the vertebral column, some of the fibers continuing to the anterior margin of the foramen magnum to be continued by the dura mater. This cuvcrs the odontoid process and its ligaments. (2) Crucial ligament, the same as the transverse ligament. (3) Two lateral odontoid or check ligaments passing from the sides of the apex of the odontoid process to the inner surface of the condyles of the occipital bone, their direction being outward, upward, and forward. (4) The central odontoid or suspensory ligament is attached to the tip of the odontoid process below, and to the under surface of the anterior margin of the foramen magnum above. It has in front the anterior occipito-atlantal lig- ament ami behind is the upper division of the crucial ligament. LESSON LXXIII. The axis is the second cervical vertebra. (Plates XCVI-XCVII.) Its peculiarity is that it has an odontoid process which is in reality the body of the atlas. Its spinous process is bifid. It has fourteen pairs of muscles attached. To body Longus colli 1 Ant. vertebral region. Inferior oblique 2 Fifth layer of back. Rectus capitis posticus major 3 Fifth layer of back. Semispinals colli 4 Fifth layer of back. To spinous process Spinalis colli 5 Fourth layer of back. [nterspinales 6 Fifth layer of back. Multifidus spinae 7 Fifth layer of back. Supraspinales 8 Fifth layer of back. Splenitis colli 9 Third layer of back. Anterior intertransversalis 10 Fifth layer of back. To transverse pro- Posterior intertransversalis 11 Fifth layer of back. cess. Levator anguli scapulae 12 Second layer of back. Transversalis colli or cervicis 13 Fourth layer of back. Scalenus medius 14 Lateral vertebral region. The seventh cervical is the last cervical and has characteristics of both cer- vical and dorsal vertebrae. It is called vertebra prominens on account of its ANATOMY IN A NUTSHELL. 265 large spinous process. Its transverse process may, or may not, have the costo- transverse foramina. The vertebral artery and vein more often pass in front of the transverse process than through its foramen: they more often pass through the left foramen than the right one and the vein more often than the artery. The anterior tubercle of the transverse process, which is an analogue of the rib, may be enlarged, making a rudely developed cervical rib. This vertebra has eighteen pairs of muscles attached to it. PLATE CIX. POST. 0CC1PIT0-AXIAL LIG. VERTICAL LIG. ACCESSORY ATLANTO- AXIAL LIG. Ligaments of Upper Cervical Ykktebr.e. To bodv Longus colli Trapezius Rhomboideus minor Serratus posticus superior To spinous process Splenius capitis Mnltifidus spina' [nterspinales S( mispinalis dorsi Spinalis colli Anterior inter! ransversalis Posterior Lntertransversalis Levatores costarum To transverse Scalenus posticus process Scalenus medius 1 Ant. vertebral region. 2 First layer of back. .'! Second layer of hack. 4 Third layer of back, f) Third layer of back, (i Fifth layer of hack. 7 Fifth layer of hack. 8 fifth layer of hack. !> Fourth layer of back. 10 Fifth layer of back. 1 1 Fifth layer of hack. 12 Thoracic region. 13 Lateral vertebral region 11 Lateral vertebral region. 266 ANATOMY IN A NUTSHELL. To transverse Musculus accessories 15 Fourth layer of back. process. Complexus 16 Fourth layer of back. To art icular Multifidus spina? 17 Fifth layer of back. process Trachelo-mastoid 18 Fourth layer of back. LESSON LXIV. The ligaments of the vertebral column are: (Plate CIV.) 1. Ligaments of the body: a. Anterior common. 1). Posterior common. c. Intervertebral substance. el. Lateral or short ligament. 2. Ligaments connecting the laminae: a. Ligamenta subflava. 3. Ligaments connecting the articular processes: a. Capsular. 4. Ligaments connecting the spinous processes. a. Supraspinous. b. Interspinous. 5. Ligaments connecting the transverse processes : a. Intertransverse. The anterior common ligament is a fibrous band extending from the an- terior tubercle of the atlas to the base of the sacrum. Its upper part makes the anterior atlanto-axial ligament and its lower part extends to make the anterior sacro-coccygeal ligament. It is broader below than above and thickest in the dorsal region and thinnest in the cervical. It is thicker over the bodies of the vertebra? than over the intervertebral substance. The interarticular substance and the margins of the bodies of the vertebra? give attachment to the ligament more than the anterior surface of the bodies. There are aperatures at the sides of the median position of the body for the passage of vessels. This ligament consists of three layers of various lengths closely intermingled; the superficial layer passes from one vertebra to the fourth or fifth above; the second layer from one vertebra to the second or third above; and the third layer connect adjacent vertebra?. The posterior common ligament is situated along the anterior part of the spinal canal upon the posterior surface of the bodies of the vertebra?, extending from the basilar process of the occipital above, to the coccyx below, its upper pari making the posterior occipito-axial ligament. It is broader above (which is the reverse of the .'interior common Ligament,) thickest in the dorsal region, and, like t he anterior one, ii is attached to the intervertebral discs and adjacent margins of the vertebrae. It is narrow and thick over the bodies from which it is separated by adipose tissue and the venae basis vertebrarum. Opposite the in- tervertebral substance it gives off dentated processes. The filum terminale of the spinal cord blends with this ligament at the back of the base of the coccyx. Its fibers nre not so bitenningled as those of the anterior common ligament and ANATOMY IN A NUTSHELL. 267 consist of two layers; the superficial extends from one vertebra to the third or fourth, and the deeper connect adjacent vertebrae. The intervertebral substance or discs forms about one-fourth of the spinal column. They conform to the shape of the bones adjacent. They are thicker at the anterior than at the posterior border in the cervical and lumbar regions, PLATE CX. BASILAR PROCESS OF OCCIPITAL RECTUS CAPITIS _\ ANTICUS MINOR RECTUS CAPITIS LATERALIS 2ND RIB SCALENUS ANTICUS Muscles of Anterior Vertebral Region. thus helping to form the curve in these regions, while in the dorsal or thoracic region they are of a uniform thickness, the difference in the thickness of the bodies of the vertebra? making the curve in this region. They form the main bond between the bodies of the vertebra?; they are compressible, elastic, and tough. In number they are twenty-three, extending from the axis to the sacrum. They consist of an outer ring and an inner substance, the ring is com- posed of fibro-cartilagenous tissue of concentric layers. The fibers of the layers are not parallel but pass into the layers above and below. The central sub- stance has cartilage cells set in fine connective tissue matrix. The lateral or short vertebral Ligaments connect the adjacent margins of. the bodies of the vertebra? between the anterior and posterior common liga- ments with which they are continuous. In the dorsal region they overlie the stellate ligaments and in the lumbar they radiate towards the transverse pro- cesses. In the cervical region they are less well marked. The Ligamenta subflava conned the lamina between the axis and the sac- 268 ANATOMY IN A NUTSHELL. rum. They arc very thin, but broad and long in the cervical region; they are thicker in the dorsal, being very thick in the lumbar region. They consist of Yellow elastic tissue. Their fibers are almost perpendicular. They are at- tached above to the inner surface of the inferior articular process and the inner surface of the lower margin of the lamina of the vertebrae; below to the inner surface of the superior articular process and the upper margin of the lamina. They are continuous with the interspinous ligament at the root of the spinous processes and help to form the capsular ligament. The capsular ligaments connect the articular processes, being attached along the margins of the articular surfaces; the lateral part of the ligamenta subflava forms their inner portion. Each joint is lined by a synovial membrane. These ligaments are short and tight in the thoracic region, loose in the cervical, and intermediate in the lumbar. The supraspinous ligaments are fibrous bands connecting the tips of the processes, extending from the tip of the vertebra prominens to the first sacral. It is continued above as the ligamentum nuchae and below along the spines of the sacrum. The interspinous ligaments extend in all regions of the vertebral column betweeB the spinous processes of the vertebrae, running from root to apex. In the cervical region they are very delicate and are separated by the Inter 1 spinales muscles. They are stronger in the lumbar than in the dorsal region. The intertransverse ligaments extend between the transverse processes of the vertebrae; in the cervical region they are often absent, the Intertransversales muscles taking their place. They are better marked in the dorsal region; in the lumbar region thev are weak and membranous. LESSON LXXV. Each rib has the following points: (Plate CVIII.) Head which is divided by a ridge into two facets, and these articulate with the facets on the bodies of the dorsal vertebrae ;the ridge giving attachment to the interarticular ligament. Neck, about an inch long, having attached to its upper border the anterior costo-transverse ligament, to its posterior surface the middle costo-transverse ligament; its anterior surface is smooth. Tuberosity, at the junction of the neck with the shaft, has a facet for artic- ulation with the transverse process of the next lower vertebra, and a rough surface for the posterior costo-transverse ligament. Shaft, twisted on itself, is concave internally, convex externally, its upper border round and smooth, its lower border grooved for the intercostal vessels and nerves. A.1 its external extremity is an oval depression for the insertion of the costal cartilage. Angle, just in front of the tuberosity, is marked by a rough line, to which nre attached the muscles of the deep layer of the back. Bach rib is developed in the following manner: Each rib has thri e centers, one for the head, one for the shaft, and one for PLATE CXI. BIVENTER CERVICIS RECTUS CAPITIS POSTICUS MINOR OBLIQUES CAPITIS SUPERIOR RECTUS CAPITUS POSTICUS MAJOR OBLIQUES CAPITIS INFERIOR TRACHELO MASTOID SCALENI MEDIUS AND POSTICUS VERTEBRAL APONEUROSIS OBLIQUE INTERNUS ABDOMINIS ORIGIN OF ERECTOR SPINAE Muscles of Back (Deep Layer). 269 270 ANATOMY IN A NUTSHELL. the tuberosity. The last two ribs, having no tuberosity, are developed each by two centers. The peculiar ribs are the first, second, tenth, eleventh, and twelfth. They respectively present the following peculiarities, viz: First Rib is broad, short, not twisted, has no angle, only one facet on the head, but on its upper surface are seen two grooves for the subclavian artery and vein, and between them a tubercle for the Scalenus anticus muscle. Second Rib is not twisted, its tuberosity and angle are very close to- gether, and its upper surface presents rough surfaces for the Serratus magnus and Scalenus posticus muscles. Tenth Rib has but one facet on its head. Eleventh Rib has no neck, no tuberosity, and but one facet on its head. Twelfth Rib has neither neck, angle, tuberosity nor groove, and but one facet. Muscles of the Back. The muscles of the back are arranged in five layers. (Plates XVIII-CXI) Those in the fourth layer get both the internal and external divisions of the posterior 1 tranches of the spinal nerves. The external divisions supply those in the third layer. The internal divisions together with the sub-occipital and great occipital supply those in the fifth layer. (Plates XVIII-CXI.) First layer. 1 Trapezius. See page 45. 2 Latissimus dorsi. See page 52. Second layer. 1 Levator angulae scapulae. Page 54. 2 Rhombodideus minor. Page .1."). :'> Rhomboideus major. Page 55. Third layer. 1 Serratus posticus superior. 2 Serratus posticus inferior. 3 Splenius capitis. I Splenius colli. Fourth layer. S \cr.\l AND LUMBAR REGIONS. 1 Erector spina'. DORSAL REGION. 2 Dio-costalis. .'5 Musculus accessorius ad ilio-costalem I Longissimus dorsi. 5 Spinalis dorsi. I i.i;\ [CAL REGION. 6 Cervicalis ascendens. 7 Transversalia colli. 8 Trachelo-mastoid. !» Complexus. NERYKS. Spinal accessory; 3rd and 4th cervical. Middle or long subscapular. 3rd and 4th cervical; sometimes 5th. 5th cervical. 5th cervical. External divisions of the posterior branches of the spinal nerves, in their k spective regions. All the muscles in the fourth layer get the external divisions of posterior branches except the Spinalis dorsi and Spinalis colli and the Complexus. They get the internal divisions of the posterior branches. The Com- plexus also gets the sub-occipital and the great oc( ipital nerves. ANATOMY IX A NUTSHELL. 271 10 Biventer cervicis. 11 .Spinalis colli. Fifth layer. 1 Semispinalis dorsi. 2 Semispinalis colli. 3 Multifidus spinae. 4 Rotatores spina?. 5 Supraspinales. 6 Interspinales. 7 Extensor coccygis. 8 Intertransversales. 9 Rectus capitis posticus major. 10 Rectus capitis posticus minor. 11 Obliquus capitis superior. 12 Obliquus capitis inferior. All these muscles in the fifth layer are supplied by the internal divisions of the posterior branches of the spinal nerves in their respective regions, ex- cept the Recti andObliqui, and they are supplied by the sub-occipital. The Inferior oblique also takes the great occipital nerve. CUTANEOUS WITH OCCIPITALIS Ml SUPERIOR OBLIQUE COMPLEXUS RECTUS CAP. POSTERIOR DIV ST. CERVICAL PLATE CXI I. TO SCALP AURICULAR INF. OBLIQUE POSTERIOR DIVISION OF -ND. CERVICAL POSTERIOR DIVISION OF RD CERVICAL SPLENIUS ssss^-ti COMPLEXUS. =3^ TRACHELO-MASTdlO SKIN OVER TRAPEZIUS The Posterior Cervical Plexus. Muscles of the Third L wi:i;. Serratus posticus superior. — Description. This muscle is quadrilateral and has a serrated outer margin. The inner half of the muscle is tendinous and theouter half isfleshy. It takes its name from its serrated edgeand its position. Origin. — (1) Ligamentum nuchse, (2) spinous processes of the seventh 272 ANATOMY IN A NUTSHELL. cervical and first, second, third, and fourth dorsal vertebrae, (3) supraspinous ligament. Insertion. — Into the upper borders of the second, third, fourth, and fifth ribs beyond their angles. Action. — To assist in inspiration by raising the ribs into which it is in- serted. \i:i;\ i: Supply. — External divisions of the posterior branches of the spinal nerves. Blood Supply. — The muscles in the back are supplied by (1) occipital, (2) vertebral, (3) intercostal, (4) subclavian (thyroid axis), (5) lumbar arter- ies. This applies to all the muscles in the back. Serratus posticus inferior. — Description. — This muscle takes its name from its serrated edge and its position. More than half of this muscle is apon- eurosis, which blends with the posterior layer of the lumbar fascia. Its outer portion is fleshy. Origin. — (1) Spinous processes of the eleventh and twelfth dorsal, and first, second, and third lumbar vertebrae, (2) supraspinous ligament. Insertion. — Into the lower borders of the ninth, tenth, eleventh, and twelfth ribs beyond their angles. Action. — It assists in inspiration by depressing the lower ribs, and making them a fixed point so the diaphragm can contract. Nerve Supply. — External divisions of the posterior branches of the spinal nerves. The nerve supply of the remaining muscles of the back is given in the first part of this lesson. Splenius capitis and Splenius colli. — Description. — This is a broad muscle which divides above into two portions for insertion. It takes its name (band- age) on account of it holding down the Complexus and other muscles. Origin. — This muscle has one origin and two insertions and may be called two muscles. (1) Lower one-half of the ligamentum nuchas, (2) spinous pro- cesses of the seventh cervical, and upper six dorsal vertebrae, (3) supraspinous ligament. Insertion. — (Capitis portion). (1) mastoid process of temporal bone, (2) occipital bone beneath the superior curved line. (Colli portion) into the transverse processes of the first, second, and third cervical vertebra? (posterior tubercles. I Action.— It flexes the head and neck, laterally, extends them, and rotates the face to same side. LESSON LXXVI. Muscles of the Fourth Layer of the Back. Erector Spinae. — Description. — This muscle and its continuations fill up the vertebral groove on each side of the spine. In the sacral region this muscle is primed and tendinous. In the lumbar region it is larger and fleshy. In the dorsal region it divides into its branches, and these sub-divide. This muscle is covered in the lumbar region bythe lumbar fascia; in the dorsal region ANATOMY IN A NUTSHELL. 273 by the Serrati muscles, and the vertebral fascia, and in the cervical region by a laver of cervical fascia. +. . Origin. — (1) Spines of the eleventh and twelfth dorsal vertebrae, (2) all the lumbar and sacral spines, (3) supraspinous ligament of all these, (4) back RECTUS LAKIIUS ANTICUS MAJOR RECTUS CAPITIS ANTICUS MINOR RECTUS CAPITIS LATERALIS LONGUS COLLI RECTUS CAPITIS ANTICUS MAJOR GENIO-HYOID THYRO-HYOID LONGUS COLLI RECTUS CAPITIS A'.TlCLiS MAJOR DESCENnENS CERVICIS COMMUNICANS CERVICIS OMO-HYOID LONGUS COLL RECTUS CAPITIS ANTICUS MAJOR SCALENUS ANTICUS STERNO-HYOID STERNO THYROIO PLATE CXI 1 1. TWEIPTH NERVE FIRST CERVICAL NERVE. TRAPEZIUS TRAPEZIUS SUPRA supra-sternal clavicular The Cervical Plexus. SUPRA- ACROMIAL part of the inner lip of i lie cresl of the ilium . (.">) posterior surface of the sacrum external to the spinous processes. Insertion.- This muscle extends clear to the head by it- numerous sub- divisions ami these are its insertion. Action. — To extend the Lumbar spine on the pelvis. Iilo-costalis. — (Sacro-lumbalis.) Description. This muscle take- its name from its attachments to the ilium and the ril>s. Origin. — From the outer part of the Erector spina'. 274 ANATOMY IN A NUTSHELL. Insertion. — Into the inferior borders of the angles of the six or seven Lower ribs. It sometimes may include all the ribs. Action. — To draw down the chest and spine. Musculus accessorius ad ilio-costalom (ad sacro-lumbalem.) — Description. —This muscle is narrow with a serrated margin on each side. It takes its name from being an accessory to the Ilio-costalis. Ork;ix. — From the upper borders of the angles of the six lower ribs by separate tendons. Insertion. — (1) Upper borders of the angles of the six upper ribs, (2) back of transverse process of the seventh cervical vertebra. Action. — To assist the Erector spina 3 . Longissimus dorsi. — Description. — This muscle takes its name from its length and position. Origin. — (1) From the middle part of the Erector spina?, (2) transverse processes of the lumbar vertebra*, (3) middle lamina of lumbar fascia. Insertion. — (1) Tips of transverse processes of all the dorsal vertebras, (2) between the tubercles and angles of the lower ribs (seventh to eleventh.) Action. — To draw down the chest and spine. Spinalis dorsi. — Description. — This muscle takes its name from its at- tachment to the spines in the dorsal region. Origin. — From spinous processes of eleventh and twelfth dorsal and first and second lumbar vertebra?. Insertion. — Into the spinous processes of the six or eight upper dorsal vertebra 1 . Action. — To extend the dorsal region of the spine. Cervicalis ascendens. — Description. — This muscle takes its name from its position and direction. Origin. — From angles of the four or five upper ribs. Insertion. — Posterior tubercles of transverse processes of fourth, fifth and sixth cervical vertebrae. Action. — Elevates the ribs, if the cervical vertebrae are the fixed point. It extends the neck, if the ribs are the fixed point. If only one acts it pulls the neck to its own side. Transversalis colli (cervicis.) — Description. — This muscle takes its name from its attachment to the transverse processes, and its insertion in the neck. Origin. — From upper portion of transverse processes of six upper dorsal vertebrae. Insertion.— Posterior tubercles of transverse processes of the second to the sixth cervical vertebrae (inclusive.) Action. — If both ad, and the fixed point is below, they extend the neck backward. Trachelo-mastoid. — DESCRIPTION. — This muscle takes its name from its origin and its insertion. Origin. — (1) Transverse processes of first five or six dorsal vertebrae, (2) articular processes of the three or four lower cervical vertebra?. Insertion.- Posterior margin of mastoid process of temporal bone be- ANATOMY IX A NUTSHELL. 275 neath the insertion of the Splenitis capitis and the Sterno-cleido-mastoid. Action. — If both act, they extend the head backward. If only one acts it turns the face toward the shoulder of same side. Complexus. — Description. — This muscle takes its name from the com- plicated arrangement of its muscular bundles. Origix. — Tips of transverse processes of from two to seven upper dorsal vertebra? and seventh cervical vertebra 1 , (2) articular processes of fourth, fifth, and sixth cervical vertebrae. PLATE CXIV. PHRENIC NERVE SUPaAST'PULAR HERVE PNEUMOGASTRIC SUBCLAVIAN ARTERY INNOMINATE ARTERY EXTERNAL JUGULAR VEIN MEDIAN *WSOil 0-SP1RAL N AXILLARY ARTERY MUSCULOCUTANEOUS ■SUBSCAPULAR ARTERY. vpROFimni ARTERY Thyroid Axis axd Cords of Brachial Plexus. Insertion. — Into the innermost depression between the two curved lines of the occipital bone ACTION. — If both act they draw the head backward, if only one ads it draws the head to one side, and with the face turned to the opposite side. Biventer cervicis. — Description. — This muscle is one of the so-called double bellied muscles, and is situated on the Inner side of the Complexus. Origin. — Transverse processes of from two to four upper dorsal vertebrae. Insertion. — Superior curved line of the occipital bone. Action. — This muscle is a helper to the Complexus. Spinalis colli. — Description. — This muscle is snail and connects tic 276 ANATOMY IN A NUTSHELL. spinous processes in the cervical region. This muscle is absent in about twenty per cent of the cases. Origin. — (1) Spinous processes of the fifth, sixth, and seventh cervical vertebrae, (2) and occasionally from the first and second dorsal vertebras. Insertion. — Spine of axis and third and fourth cervical vertebrae. Action. — To approximate the spines of the vertebrae. LESSON LXXVII. Fifth Layer of Muscles of Back. Semispinalis dorsi. — Description. — This muscle takes its name on account of its inner half being attached to the spine, and its situation in the dorsal region. Origin. — From transverse processes of fifth, sixth, seventh, eighth, ninth, and tenth dorsal vertebra?. Ixskrtion. — Into the spinous processes of seventh and eighth cervical, first, second, third, and fourth dorsal vertebrse. Action. — To erect the spinal column. Semispinalis colli. — Description. — This muscle takes its name from the attachment of its one-half to the spines in the cervical region. Origin. — Transverse processes of the upper five or six dorsal vertebra?. Insertion. — Into the spinous processes of the second, third, fourth, and fifth cervical vertebrse. Action. — To erect the spinal column. Multindus spinas — Description. — This muscle takes its name from its many clefts. Origin. — (1) Back of sacrum as far as the fourth sacral foramen, (2) aponeurosis of the Erector spina? muscle, (3) Posterior superior spine of the ilium, (4) posterior sacrc-iliac ligament, (5) articular processes of lumbar ver- tebras (6) transverse processes of dorsal vertebras, (7) articular prosesses of three or four lower cervical vertebra?. Insertion. — Into the lamina?, and spinous processes of all the vertebra? except the atlas. Action. — To preserve the erect position of the spine and to rotate it. Rotatores spinae. — Description. — This muscle takes its name from its functions. There are generally eleven pairs, but they may be found in the cervical and lumbar regions. Origin.- Upper and hack parts of the transverse processes in the dorsal region i I t he S] inc. Insertion.- Lower border and outer surface of the first lamina above the oi igin. Action. — Assists the Mrlli.idus spina? to rotate the spine, turning the trunk to i he opposite si le. Suprasplnales.— Description.- These muscles lie on the spinous pro- c( sses in t he cervical r< eion. PLATE CXV. FRONTAL SUPRAORBITAL COMMUNICATING WITH OPHTHALMIC ANGULAR LATERAL NASAL- TRANSVERSE FACIAL INFERIOR u- CORONARY ANT, TEMPORAL POST. TEMPORAL DEEP TEMPORAL INTERNAL MAXILLARY OCCIPITAL TEMPORO- MAXILLARY JUGULO -CEPHALIC Lymphatics and Veins of Neck \\i> Kace. 277 278 ANATOMY IN A NUTSHELL. Origin. — Spinous process and external to the process immediately above. Insertion. — Spinous processes immediately above. Action. — Approximate the spinous processes. Interspinales. — Description. — These muscles are six pairs in the cervical region (first pair between axis and third cervical.) They are in the upper and lower dorsal, but absent in the middle dorsal. There are four pairs between the five lumbar vertebrae, sometimes one above and one below these pairs. Origin. — Spinous process below. Insertion. — Spinous process above. Action. — Approximate the spinous processes. Intertransversales. — Description. — In the cervical region these are best developed, and are in pairs (anterior and posterior) passing between the anter- ior and posterior tubercles of the tranverse processes. Between these muscles pass the anterior division of the spinal nerve. There are seven pairs in the cer- vical region. In the dorsal region they are not well developed. They are absent in the middle dorsal. In the lumbar region they are in pairs — one set called the intertransversales laterales, which are situated between the transverse pro- cesses. The other set called intertransversales mediales are situated between the accessory process of one vertebra and the mammillary process of the next. Origin. — In a transverse process below. Insertion. — Transverse process immediately above. Action. — Approximate the transverse processes. Extensor coccygis. — Description. — This muscle extends over the lower part of the posterior surface of sacrum and coccyx. Origin. — Last sacral or first coccygeal vertebra. Insertion. — Lower part of the coccyx. Action. — To extend the coccyx. Rectus capitis posticus major. — Description. — This muscle becomes broad as it ascends. Origin. — Spinous process of axis. Insertion. — Inferior curved line of the occipital bone and surface of bone below. Action. — To rotate the cranium with atlas, around the odontoid process of the axis. Rectus capitis posticus minor. — Description. — This muscle is the smallest of the muscles in this region. Origin. — Tubercle on posterior arch of atlas. Insertion. — Occipital bone beneath the inferior curved line. Action. — To draw the head backward. Obliquus capitis superior. — Description. — This muscle is narrow below but wide above. Origin. — Upper surface of transverse process of atlas. Insertion. — Occipital bone between the superior and inferior curved lines external to the Complexus. ACTION. — To draw the head backward and rotate cranium. PLATE CXVI. ORBICULARIS PALPEBRASUM ANGULAR LATERALIS NASI ORBICULARIS .N^- ORIS #§Hs Mmm Ir^T HYPO-GLOSSAL N STERNO HYOID- CRICOID THYROID A. STERNO THYROID- WWi'M -'7 i.'-V 'A V ' *~ < Or "l\\\ \C ASCENDING PHARYNGEAL LOOP OF COMMUNICATION BETWEEN HYPO- GLOSSAL N. AND CERVICAL PLEXU! The External Carotid Artery. 279 280 ANATOMY IX A NUTSHELL. Obliquus capitis inferior. — Description. — This muscle is larger than the superior one. Origin.— Apex of axis. Insertion. - Lower and back part of transverse process of atlas. A.< riON. — To rotate the arias with cranium. The -kin of the back is supplied by posterior divisions of spinal nerves. The internal branch of the posterior divisions of the upper six dorsal uerves are cutaneous, while the external branches of the posterior divisions of the lower six dorsal nerves are cutaneous. The external divisions of the upper and the internal divisions of the lower six have no cutaneous distribution. The sacro-vertebral articulation is supplied by the fourth and fifth lumbar and sympathetic nerves. The costo-central articulations are supplied by the an- terior divisions of the spinal nerves. The costotransverse articulations are sup- plied by the posterior division- of the spinal nerves. The sacro-iliac articu- lations are supplied by the posterior divisions of the first and second sacral nerves, the superior gluteal nerve, and sacral plexus. The saero-eoccygeal articulation is supplied by the fourth and fifth sacral and coccygeal nerves. The ribs and vertebra' an- supplied by the gray rami communicantes. LESSON LXXVIII. Triaxoles of the Neck. (Plate XIV.) The side of the neck is in the form of a rectangle, bounded, above by the lower margin of the jaw-bone and a line continued from the angle of the jaw to the mastoid process; below, by the clavicle; posteriorly, by the Trapezius; and anteriorly by the median line of the neck. This rectangle is divided into two triangles by the Sterno-cleido-mastoid. The anterior one is bounded in front by an imaginary line behind by the Sterno-cleido-mastoid. and above by the lower jaw-bone. The posterior one i- bounded in front by the Sterno-cleido- mastoid, behind by the Trapezius, and below by the clavicle. The Omo-hyoid divide- these triangles into two others and the Digastric divides the upper one of the anterior triangles into two other triangles. The Digastric pierces the Stylo-hyoid which help- to make the boundary line of the sub-maxillary tri- angle. Then these muscles divide the rectangle on the side of the neck into five triangles, (li Tin. [nferiok carotid triangle, or triangle of necessity, of Ml -( ! I.\i; TRIANGLE. (2) TtlE SUPERIOR CAROTID TRIANGLE, or TRIANGLE 01 ELECTION. (3) Till. SUBMAXILLARY, Or DIGASTRIC TRIANGLE. (4) THE OCCIPITAL TRIANGLE. (5) Till. SUBCLAVIAN, Or SUPRACLAVICULAR TRIANGLE. All these five triangles have a roof, boundary lines, and contents. The roof of them b made by skin, superficial fascia. Platysma myoides, and deep fascia. The Inferior carotid triangle in addition to this has the superficial cervical nerve ramifying in it- roof. Righl beneath this roof are the Sterno-hyoid and Sterno- thyroid. By -one these two muscles are called the floor, hut the Longus colli and Scalenus amicus and pari of the Rectus capitis anticus major form the floor. This triangle is bounded in fhont by the median line. above by the anterior PLATE CXVII. FRONTAL SINUS PRINCIPES CERVK.S A BRANCH OF OCC.PITAL ASCENDING PHARYNGEAL PROFUNDA CERVi:iS STERNO-MAS'OiD CRICOID CARTILAGE TRACHEA FIRST RIB SUP. INTERCOSTAL 1ST AORTIC INTERCObML SECOND RIB. Til E [NTERNAL ( ' VROTID A.RTERY. 2. SI 282 ANATOMY IN A NUTSHELL. belly nf the Omohyoid, and below by the inferior part of the Sterno-cleido- mastoid. .lust beneath the anterior border of the Sterno-cleido-mastoid is the common carotid sheath which is described in connection with this triangle, although it is under this muscle. This sheath contains the common carotid artery internally, the internal jugular vein externally, and the pneumogastric nerve between the two but on a plane posterior to them. This sheath is bound- ed i\ front by branches from the loop of communication; on the inner side by the trachea, thyroid gland, and the lower part of the larynx; behind by the inferior thyroid artery, re< urrent laryngeal nerve and the sympathetic nerve. The second triangle, superior carotid, or triangle of election, is bounded below by the anterior belly of the Omo-hyoid; behind by the Sterno-cleido - mastoid; above by the Digastric. Its roof is made of skin, superficial fascia, Platysma myoides, and deep fascia. Its floor is made of four muscles, Thyro- hyoid. Hyo-glossus, Inferior constrictor, and Middle constrictor. The external carotid artery has eight branches, five of which are in this triangle, viz., superior thyroid, lingual, facial, ascending pharyngeal, and occipital, with their corres- ponding veins, all of which empty into the internal jugular, except the occipital which may empty into the external jugular. The third triangle, or digastric, or submaxillary niangle, is bounded in fkont by the anterior belly of the Digastric; behind by the Stylo-hyoid perforated by the posterior belly of the Digastric; and above by the mandible and a line drawn from the angle of the jaw to the mastoid process. Its roof is made of the skin, superficial fascia, Platysma myoides, deep fascia, with the seventh nerve ram- ifying in it. Its Moor is formed by the Mylo-hyoid ami Hyo-glossus. This triangle is divided into two other triangles by the Stylo-maxillary ligament, the anterior one of which contains the submaxillary gland and the posterior one contains the parotid gland. The occipital triangle is bounded in front by the Sterno-cleido-mastoid, below by the posterior belly of the Omo-hyoid, and behind by the Trapezius. Its roof is made of the skin, superficial fascia, Platysma myoides, and deep fascia. Its floor from above downward and inward is formed by the Splenius capitis, Levator anguli scapulae, Scalenus posticus and Scalenus medius. The spinal accessory nerve crosses this triangle from the Sterno-cleido-mastoid to the Trapezius. A row of lymphatic nodes lie along the posterior border of the Sterno-cleido-mastoid in this triangle. The subclavian or supraclavicular triangle is bounded above by the pos- terior belly of the < )mo-h void. in front by the Sterno-cleido-mastoid, and below by the clavicle. Its roof is made by the skin, superficial fascia, Platysma myoides, and deep fascia and has the suprascapular vessels and nerve lying in it. Its floor is made of the digitations of the Serratus magnus, Scalenus pos- ticus. Scalenus medius, and part of the first rib. It has a few lymphatic glands in it. Tiir. Suboccipital Triangle. (Plate CXI.) The suboccipital triangle is bounded EXTENALLY by the Superior oblique; below by the Inferior oblique,and internally by the Rectus capitis posticus major. The floor of this triangle is formed by the posterior occipito-atlantal PLATE CXVIII. RIGHT POSTERIOR CEREBRAL LEFT POSTERIOR CEREBRAL POSTERIOR COMMUNICATING MIDDLE CEREBRAL RIGHT ANTERIOR CEREBRAL OPHTHALMIC ARTERY OCCIPITAL ARTERY PRINCEPS CERVICIS SUPERFICIAL BRANCH OF PRINCEPS CERVICIS ASCENDING CERVICAL TRANSVERSE CERVICAL POSTERIOR SCAPULAR ACROMIAL BRANCH SUBSCAPULAR BRANCH SUPRASPINOUS BRANCH ANTERIOR CIRCUMFLEX INFRASPINOUS BRANCH '" POSTERIOR CIRCUMFLEX LONG THORACIC SUBSCAPULAR DORSAL SCAPULAR INFRA SCAPULAR BRANCH SUBSCAPULAR SECOND AORTIC NTERCOSTAL THIRD AORTIC INTERCOSTAL. The Arteries From Arch of Aokta to Circle of Willis. 283 284 ANATOMY IN A NUTSHELL. ligament and the posterior arch of the atlas, and its roof is made by the Com- plexus muscle. The vertebral artery lies in a groove on the upper surface of the posterior arch of the atlas in this triangle. The suboccipital nerve enters this triangle between the vertebral artery and the arch of the atlas. The deep cervical vein begins in this triangle. LESSON LXXIX. Arteries. The pulmonary artery (Plate ( 'XXVIII) arises from the left side of the base of the right ventricle in front of the aorta. It passes upward and back- ward,beingtotheleftsideandin front of the ascending aorta. It is about two inches long and ends under the transverse aorta where it divides into the right pulmonary artery and the left pulmonary artery. This artery and the ascend- ing aorta are enclosed in a common prolongation of the serous pericardium. The right pulmonary artery, which is larger and longer than the left, passes behind the ascending aorta and the superior vena cava where it pierces the pericardium. It divides into the branches at the root of the lung, one branch being for the upper lobe of the light lung and the other for the lower lobe. The branch which passes to the middle lobe is derived from the upper branch. The left pulmonary artery passes in front of the descending aorta and the left bronchus to end in the root of the left lung where it divides into an upper branch for the upper lobe and a lower branch for the lower lobe. The remains of the ductus arteriosus passes from the left pulmonary artery to the inferior surface of the transverse aorta. The aorta begins at the upper part e>f the left ventricle and passes upward to the right, it then arches to the left and backward. It now elescends on the lefl side of the vertebral column to pass through the aortic opening of the Diaphragm and it ends opposite the' fourth lumbar vertebra where it elivides into a right and left common iliac artery. The aorta has the following divi- sions; 1 ' Ascending, (2) Transverse, (3) Descending, and this elescending por- tion is divided into thoracic and abdominal. The part above the Diaphragm is the thoracic aorta and the pari below the Diaphragm is the abdominal aorta. The ascending portion commences behind the left half of the sternum at the level of the lower border of the third costal cartilage. It passes obliquely up- ward and forward to the righl where it ends at the upper boreler of the second righl chondro-sternal articulation. It is about two inches in length. The Relations of the Ascending Aorta are: I.\ Front.— (1) Pulmonary artery, (2) Right auricular appendix. (3) Pericardium, i 1 Righl pleura and lung, (5) Remains of thymus gland. Behind. — (1) Righl pulmonary artery. (2) Left auricle. Righi Side. (1) Superior vena cava, (2) Right auricle. Left Side.- Pulmonary artery. The Transverse aorta (arch) (Plate CXXVIII) is a continuation of the ascending aorta from the upper bonier of the second right e'hondro-sternal articulation. It arches to the left and backward with its e-onvexity upward ANATOMY IN A NUTSHELL. 2v") and ends at the left side of the lower border of the fourth dorsal vertebra from which place it is called thoracic aorta. The upper border of the arch is about an inch below the upper margin of the sternum. Relations of the Arch of the Aorta. Above. — (1) Left innominate vein. (2) Innominate artery. (3) Left caro- tid artery. (4) Left subclavian artery. PLATE CXIX. ANTERIOR JUGULAR VEIN COMMON CAROTID ARTERY INTERNAL JUGULAR VE OUTER CERVICAL FASCIA. MIDDLE CERVICAL FASCIA. .COMMON CAROTID ARTERY UGULAR VEIN PNEUMOGASTRIC NERVE The Cervical Fascia. Below.— (1) Eifurcaticn cf pulircnary artery. (2) Remains cf .hums arteriosus, (3) Superficial cardiac plexus, (4) Lef1 recurrent laryngeal nerve, and (5) L< f1 bronchus. [n Front.— (1) Pleurae and lungs, (2) Remains of thymus gland, (3) Left, 286 ANATOMY IN A NUTSHELL. pneumogastric nerve, (4) Left phrenic nerve, (5) Superficial cardiac nerves (6) Left superior intercostal vein. Behind. — (1) Trachea, (2) Deep cardiac plexus, (3) Oesophagus, (4) Thoracic duct. (5) Left recurrent laryngeal nerve. The Relations of the Thoracic Aorta are: (Plate CXXVIII.) I\ Front. — (1) Root of left lung, (2) Pericardium, (3) Oesophagus, (4) ] Haphragm. Behind. — (1) Vertebral column, (2) Superior and inferior azygos minor veins. Right Side. — (1) Oesophagus (above), (2) Vena azygos major, (3) Thorac- ic dud. Left Side. — (1) Pleura, (2) Left lung, (3) Oesophagus (below.) The ascending aorta has the right coronary and the left coronary artery which have been described with the heart. The branches of the arch of the aorta arc (1) innominate, (2) left common carotid, (3) left subclavian. The branches of the thoracic aorta are (1) pericardiac, (2) bronchial, (3) oesopha- geal. (4) posterior mediastinal, (o) intercostal. LESSON LXXX. The innominate artery often called brachio-cephalic has its beginning opposite the fourth dorsal vertebra just in front of the left common carotid. It is the largest of the branches of the arch of the aorta. At the upper border of the right sterno-clavicular articulation it divides into the right common carotid and the right subclavian. It is from an inch and a half to two inches long and has no branches as a rule, but the thyroidea ima may arise from it. The Relations of the innominate artery are as follows; 1\ Front. — (1) Sternum. (2) Sterno-hyoid and (3) Sterno-thyroid muscles, (4) Remains of the thymus gland. (5) Left innominate vein, (6) Right inferior thyroid vein, (7) Inferior cervical cardiac branch from right pneumogastric nerve. Behind. — Trachea. Right Side. — (1) Right innominate vein, (2) Right pneumogastric nerve. Pleura. Left Side. — (1) Remains of thymus gland. (2) Left carotid artery, (3) Lef1 inferior thyroid vein, (4) Trachea. The rijrht common carotid artery (Plates CXVI-CXVII) arises from the innominate at the upper border of the right sterno-clavicular articulation. It passes obliquely upward and divides into the external carotid and internal carotid at the upper border of the thyroid cartilage opposite the fourth cervical vertebra. The left common carotid artery comes from the highest part of the arch of the aorta and passes upward behind the left slerno-calvicular articulation to divide into the external carotid and internal carotid at the upper border of the thyroid cartilage opposite the fourth cervical vertebra. These arteries are enclosed in a common sheath of cervical fascia with the internal jugular vein ANATOMY IX A NUTSHELL. 287 and pneumogastric nerve. The internal jugular vein lies external to the artery while the pneumogastric nerve is between the internal jugular vein and com- mon carotid artery but on a plane posterior to them. Occasionally a thyroid branch passes from this artery. The Relations of the Left Common Carotid Artery in the thorax is as fol- lows: Ix Front. — (1) Sternum, (2) Sterno-hyoid and (3) Sterno-thyroid muscles. PLATE CXX. SUPERIOR CORNU OF THYROID CARTILAGE CRICOID CARTILAGE The Trachea. (4) Left innominate vein, (5) Remains of thymus gland. Behind.— (1) Trachea. (2) Oesophagus, (3) Thoracic duct. (4) Left sub- clavian artery. Internally. — (1) Innominate artery, (2) Inferior thyroid veins. (3) (3) Remains of thymus gland. Externally. — (1) Left pneumogastric nerve, (2) Left pleura, (.'!) Left lung. (4) Left subclavian artery. 288 ANATOMY IN A NUTSHELL LESSON LXXXI The Relations of the Right Common Carotid and the Left Common Carotid arteries tin the neck). I\ Front. — (1) Integument, (2) Superficial fascia, (3) Deep cervical fascia, (4) Platysma myoides, (5) Sterno-mastoid, (6) Sternohyoid. (7) Sterno- thyroid. (8) Omo -hyoid, (9) Descendens and Communicans nerves. (10 Sterno-mastoid artery. (11) Superior thyroid vein, (12) Middle thyroid vein.. 13) Anterior jugular vein. Behind. — (1) Longus colli, (2) Rectus capitis amicus major, (3) Sym- pathetic nerve, (4) Inferior thyroid artery. (.">) Recurrent laryngeal nerve. Externally.— (1) Internal jugular vein. (2) Pneumogastric nerve. Internally. — (1) Trachea, (2) Thyroid gland, (3) Recurrent laryngeal nerve. (4) Inferior thyroid artery. (5) Larynx. (6) Pharynx. The common carotid arteries at the root of the neck are close together and ■ iii ply situated, but higher in the neck they become separated and are more superficial. The common carotid artery, internal jugular vein and the pneu- mogastric nerve all lie in a common sheath. The external carotid artery is a branch from the common carotid artery at the upper border of the thyroid cartilage, from which place it runs upward and forward, then backward between the external auditory meatus and the neck of the c< ndyle of the mandible (lower jaw). It now divides into a super- ficial temporal and internal maxillary arteries. It lies in the superior caroitd triangle (triangle of (lection) and passes through the substance of the parotid gland. It is superficial to and nearer to the median line of the neck than the internal carotid artery at its beginning. The branches < f the external carotid artey are, (1) superior thyroid. (2) lingual. (3) facial, which are anterior branches; (4) occipital ,(5) posterior auricular, which are posterior branches; -rending pharyngeal, which is an ascending branch; (7) superficial tem- poral, (8) interna] maxillary, which are' terminal branches. LESSON LXXXI I. The superior thyroid branch (Plate CXVI.) arises just below the great cornu of the hyoid bone, and passes inward and upward across the superior carotid triangle from which place it passes downward and forward to the upper part of the thyroid gland, after passing under the Sterno-hyoid, Sterno-thyroid and Omo-hyoid muscles. Besides giving branches to these muscle's and the thyroid gland, it gives off (1) a hyoid branch which passes along the' lower border of the' hyoid bone'. (2) Sterno-mastoid branch, also called super- ficial des< ending, which passes to the Sterno-mastoid muscle after running downward and outward across the sheath of the' common carotid artery. (3) Superior laryngeal, which passes with the superior laryngeal nerve to the PLATE CXXI. BAND CONNECTING THYMUS WITH HTOID BONE The Heart, Thyroid Gland (and Lungs Turned Outward). 289 290 ANATOMY IX A NUTSHELL. larynx under the Thyro-hyoid muscle. (4) Cricothyroid branch which runs across the cricothyroid membrane. The lingual artery (Plate CXVI.) first passes obliquely upward and in- ward across the Middle constrictor muscle to the greater cornu of the hyoid bone. It now passes horizontally forward on the Middle constrictor muscle PLATE CXXII. GRFATER CORNU OF HYOID BONE- K'F> G HIT!- S // LESSER CORNU OF HYOID BONE MEDIAN PORTION OF THYRO-HYOID MEMBRANE POMUN ADAM GROOVE FOR SUBCLAVIAN ARTERY INTERNAL LARYNGEAL NERVE SUPERIOR LARYNGEAL ARTERY SUPERIOR THYROID ARTERY THYROID CARTILAGE CRICO-THYROID MEMBRANE LEVATOR GLANDULAE THYROIDEA MUSCLE GROOVE FOR SUBCLAVIAN ARTERY Anterior View of Lungs. under the tendon of the Digastric muscle. Stylo-hyoid and the Hyo-glossus muscle. The Hyo-glossus muscle separates the lingual artery and the twelfth cranial nerve (hypoglossal). The artery now passes vertically upward between the Hyo-glossus and Genio-hyo-glossus to the under surface of the tongue where it takes the name of ranine artery. In this position it accompanies the lingual nerve, lying on or internal to the Lingualis muscle. It gives off (1) a hyoid ANATOMY IN A NUTSHELL. 291 branch, which runs along the upper border of the hyoid bone, (2) dorsalis lingile branch, which passes upward under the Hyo-glossus muscle to the dorsum of the tongue, (3) a sublingual branch, which passes on the Genio- hyo-glossus muscle to the sublingual gland, (4) the ranine branch. The fascial artery (Plate CXVI.) comes from the external carotid just above the origin of the lingual artery and passes obliquely upward under the Digastric and Stylo-hyoid muscles, it then passes forward in a groove on the posterior surface of the submaxillary gland. This much of the artery is called the cer- vical portion. It then passes upward over the lower jaw at the anterior margin of the Masseter muscle to the angle of the mouth. This portion of the artery is called the facial portion. It now runs upward along the nose and ends at the PLATE CXXIII. , fe't^ . ' UPPER LOB . Rft&nefl '" . ' k /Vj-OWER LOBE J, f, will Posterior. View of Lungs. inner canthus of the eye. This portion of the artery is called angular por- tion. The facial artery lies just under the superficial muscles and has a very tortuous course. The branches of the facial artery given off in the neck arc (I) [NFERIOR or ascending palatine, which passes between the Stylo-glossus and Stylo- pharyngeus muscles to the outer side of the pharynx where it divides into two branches, one of which runs through the Superior constrictor muscle and the other branch passes over this muscle. (2) The tonsillar branch which passes between the Internal pterygoid and Stylo-glossus muscles and after piercing the Superior constrictor passes to the tonsil. (3) The submaxillary 292 ANATOMY IN A NUTSHELL. branches, which are three or four in number, pass to the submaxillary gland. (4) the submental branch, which runs forward on the Mylo-hyoid muscle and under the Digastric muscle to the symphysis where it divides into a super- ficial and deep branch which pass over and under the Depressor labii inferioria muscle to the lip. (5) Muscular branches which pass to the adjacent muscles. The branches of the facial artery given off on the face are, (1) inferior lab] \i. which runs under the Depressor anguli oris muscle to the lower lip, (2) [NFERIOR CORONARY which runs in a very tortuous course along the edge of PLATE CXXIV. COMPLEMENTAl A|R 12 CUBIC INCHES AIR THAT CAN BE.BUT SELDOM IS.TAKEN IN TIDAL AIR 20 T0 30 CUBIC INCHES AIR TAKEN AND SENT OUT AT EACH BREATH RESERVE AIR 1 CUBIC INCHES AIR THAT CAN BE.BUT SELDOM IS DRIVEN OUT S I D U A L AIR. J0 CUBIC INCHES AIR THAT CANNOT BE DRIVEN OUT Showing tin: Capacity of the Luncs. the lower lip, (3) SUPERIOR CORONARY, which is larger anil more tortuous even than the inferior coronary, runsalong the edge of the upper lip andgives branches (a) to tIi* nose, (b) the inferior artery of the septum, and (c) the artery of the ala. il' Lateralis nasi which passes to the ala and dorsum of the nose. (5) angular which passes to the inner angle of the orbit, (6) muscular which pass to the adjacent muscles. ANATOMY IN A NUTSHELL. 293 LESSON LXXXIII. The occipital artery (Plate CXVI) is a branch from the external carotid opposite the facial artery and it passes under the Stylo-hyoid muscle and the posterior belly of the Digastric muscle. The twelfth cranial nerve (hypo- glossal) winds around it. This artery passes upward across the spinal acces- sory nerve and the internal carotid sheath to the space between the mastoid process of the temporal bone and the transverse process of the atlas. It now runs backward in the occipital groove on the mastoid process and pierces the origin of the Trapezius muscle and passes upward in a tortuous course to the PLATE CXXV. PLEURA Showing Pleur.e and Root of the Lungs. vertex, being accompanied by the greal occipital nerve in the last part of its course, while the Complexus muscle separates the artery and nerve at the beginninu'. Its branches are, (1) sterno-mastoid, which passes over the hypo- glossal nerve to the Sterno-cleido-mastoid muscle, (2) AURICULAR, which passes to the hack of the concha, and it may send a branch through the mastoid fora- men to the dura mater. (3) meningeal, which passes through the jugular foramen to the dura mater. | t) ARTERIA PRIN< EPS CERVIGIS, which descends along the back of the neck ami divides into two branches, (a) the superficial cess, (c) the- occipital branches which passover the Occipitalis muscle and are distributed to the' skin of the scalp. ( Plate' (X 1 II). These branches communicate with the great occipital, small occipital. great auricular, all of the cervical plexus, and with the posterior auricular of the fifth nerve-. (2) A branch helps to form the greal auricular, its other branch comes from the cervical nerve. The meat auricular nerve passes with the small occipital nerve to the posterior border of the Sterno-cleido-mastoid, 302 ANATOMY IN A NUTSHELL. whore it leaves this nerve and passes across the muscle towards the angle of the mandible. While crossing the muscle it lies in the deep fascia almost parallel with but behind the external jugular vein. It divides into (a) the mastoid branch which is distributed to the skin on the mastoid process, (b) the auricular branches which are distributed to the integument on the pin a at Its upper part, some of these branches are distributed to the integu- ment on the outer surface of the lobule and the outer surface of the lower part of the helix and antihelix, (c) the facial branches pass to the superficial lobules of the parotid gland and the integument over and in front of the gland. In the substance of the gland they unite with the cervico-facial division of the facial PLATE (XXXIV. CRICO-THYROID MEMBRANE INFERIOR CORNU OF THYROID CARTILAGE. MEDIAN PORTION OF THYRO-HYG MEMBRANE y\ SUPERIOR CORNU OF THYROID CARTILAGE FORAMEN FOR SUPERIOR LARYNGEAL NERVE 1 _ MEDIAN NOTCH OF THYROID CARTILAGE II void Bone, Thyroid and Cricoid Cartilages. (Anterior View.) nerve. (3) It gives v. branch to help from the superficial cervical nerve which com< - from the second and third cervical nerves. It appears a little below the great auricular at the posterior border of the Sterno-cleido-mastoid and crosses tld- muscle lying under the external jugular vein, although it may perforate it or pass in front. This nerve divides into ascending and descending branches. Tin' ascending branches supply the integument on the upper half of the neck as high as the chin. It sends a branch which accompanies the external jugular vein and another which unites with the facial. The descending branches sup- ply the integument <>n the lower half of the neck as far as the sternum. (4) One of the communicans hypoglossi, and a filament to the Sterno- CLEIDO-mastoid. This filament communicates with the spinal accessory in the substance of the muscle. ANATOMY IN A NUTSHELL. 303 The posterior branch of the second cervical nerve leaves the spinal (anal below the Inferior oblique between the posterior arch of the atlas and the lamina of the axis. This branch is larger than any other posterior branch in the cervical region and is three or four times as large as the anterior branches. It sends a twig to the Inferior and receives a branch from the first cervical nerve. It divides into a small external division wihch supplies tin- Complexus and Trachelo-mastoid and Splenius and gives a twig to the Inferior oblique, and a PLATE (XXXV. EPIGLOTTIS CRICOID CARTILAGE THYROID ARYTENO-EPIGLOjTTIDEAN FOLD^t"^ /~f CARTILAGE I \ k ^ ^C^- ^ ) ( i SANTORINI ARYTENOIDEUS OBLIQUUS \ i ARYTENOIDEUS TRANSVERSUS? MUSCULAR PROCESS OF ARYTENOID CARTILAGE. \ o ■ ; ' - & / CR1C0- ARYTENOIDEUS ' - x -., ■"' -'//^ POSTICUS ==« y Thyroid Cartilages. (Posterior View.) very large internal division which is the great occipital nerve — the internal division of the posterior branch of the second cervical nerve. After this nerve crosses the Inferor oblique it pierces the Complexus, the Trapezius and the deep fascia beneath the superior curved line of the occipital bone. It joins a filament from the posterior branch of the third cervical nerve and ascends on the back of the head with the occiptial artery and supplies the integument as far as the vertex, communicating with the small occipital. It gives a muscular branch to the Complexus and an auricular branch to the back part of the ear. (Plate CCXVI). The superficial origin of the third cervical nerve may be as high as a little below THE POSTERIOR ARCH OF THE ATLAS OT as low as THE 3\ NOTION OF THE upper two-thirds and lower third of spine of \xis. The anterior branch of this nerve is larger than the posterior one. (Principle [I,Page 26). It is also larger than the anterior branch of the second cervical nerve (double the size.) After leaving the intervertebral foramen, it passes downward and out- ward beneath the Sterno-cleido-mastoid and divides into an ascending branch and a descending one. The ascending branch joins the anterior branch of second cervical nerve, in front of the Scalenus anticus. The most of the great 304 ANATOMY IX A NUTSHELL. auricular, superficial cervical, one of the communicans hypoglossi, a branch to the supraclavicular nerves, a filament to the phrenic, and muscular branches to the Levator anguli scapula 1 and Trapezius, and sometimes a branch to the Scalenus medius. all come from this nerve. The posterior branch of the third cervical nerve is smaller than that of the second, but larger than that of the fourth. It divides at the outer border of the Semispinalis colli into internal and external divisions. The greater portion of the internal division of the posterior branch of the third cervical nerve is the smallest or third occipital. The internal division runs between the Complexus and Semispinalis muscles, supplying them, th< n pierces the Trapezius to supply the integumenl of the back of tin n< ck. It communicates with the great occipi- PLATE CXXXVI. THYRO-EPIGLOTTlDEAN LIGAMENT CARTILAGO TRITICEA SUPERIOR CORNU OF THYROID CARTILAGE CARTILAGE OF SAN-TOR Nl SCULAR PROCESS OF RYTEN0I0 CARTILAGE INFERIOR CORNU OF THYROID CARTILAGE Arytenoid Caktilage and Epiglottis. tal nerve and supplies the skin of the scalp in the region of the external occipital protuberance. The external division joins the posterior branch of the second to supply the Splenius, Trachelo-mastoid and Complexus. (Plate CXII.) LESSON LXXXVI. t' pregnancy, often the caecum, appendix vermiformis, sigmoid flexure of the colon, and the upper part of the rectum. Left hypochondriac contains the fundus of the stomach, greater part of the spleen, tail of the pancreas, splenic flexure of the colon, upper part of the left kidney, and part of the left lobe of the liver. Left lumbar contains the descending colon, part of the omentum, sigmoid flexure, lower part of the left kidney, and some coils of the jejunum. Left inguinal (iliac) contains the sigmoid flexure of the colon and convo- lutions of the jejunum and ileum. Alimentary Canal. (Plate CXXXVIII). The alimentary canal is about thirty feet in length, extending from the mouth to the anus. It is a musculo-membranous tube and consists of the fol- lowing portions: mouth, pharynx, cesophagus. stomach, small intestine which has the following divisions, (1) duodenum, (2) jejunum, and (3) ileum, and then comes the large intestine which has the caecum, ascending colon, hep- atic flexure, transverse colon, splenic flexure, descending colon, sigmoid flexure, and rectum. The accessory organs to the alimentary canal are the teeth, salivary glands, liver, spleen, and pancreas. A viscus is any internal organ of the body. The viscera are situated in the cranium, thorax, abdomen, and pelvis. The Diaphragm lies immediately above the stomach. All of the canal above the Diaphragm has three coats which are from within outward the mucous membrane, areolar tissue or sub- mucous and muscular. That portion of the canal which lies below the 1 >ia- phragm has a fourth coat called the serous membrane, which is external to the muscular coat. The teeth (Plate CCXXVI) are dense white structures firmly implanted in sockets in the alveolar processes of the jaw bones. Each consists of three por- tions — A ROOT or PANG, \ NECK, and A CROWN. The teeth grow in two sets, one in infancy, the other in childhood and youth. The first set are called tem- porary, milk, deciduous teeth and are twenty in number, there being five in each lateral half jaw, namely two incisors, one canine, and two molars. In this set there are no bicuspids and no third molar. The bicuspids of the per- manent set take the place of the temporary molars. In the second or permanent set there are thirty-two teeth: eighl in each lateral half jaw, two incisors, one canine, two bicuspids, and three molars. 310 ANATOMY IN A NUTSHELL. The arteries to the teeth are derived from the inferior dental and from the alveolar and infraorbital branches of the internal maxillary. The nerves are from the inferior dental branch of the inferior maxillary PLATE CXXXIX. ORIFICE OF LACHRYMAL CANAL GROOVE ON ANTERIOR BORDER OF SEPTAL CARTILAGE. ACCESSORY CARTILAGE. LATERAL CARTILAGE SEPTAL CARTILAGE SESAMOID CARTILAGF ALAR CARTILAGE CELLULAR TISSUE OF ALA The Anterior and Posterior Pillars of the Fauces and Cartilages of Nose. division of the fifth, and also from the anterior and posterior dental branches of the superior maxillary division of the same nerve. Just before the six-year molars are erupted from the gum, forty-eight teeth in various stages of formation and retrogression can be recognized in the ANATOMY IN A NUTSHELL. 311 two jaws — twenty of the temporary set and twenty-eight of the permanent set. The four wisdom teeth at this time are only embryonic buds. In a sagittal sectionof a tooth we see first the enamel (Plate CCXXVII) which is the hardest structure in the body, consisting of 96.5 per cent earthy and 3.5 per cent animal matter. Its individual tubules are 55V0 of an inch in dia- meter. Beneath the enamel is the dentine or ivory. The amount of earthy matter is 72 per cent and the animal matter 28 per cent. Its tubules are 4^70 of an inch in diameter and are covered by the sheath of Neumann, which protects it from the action of acids. The cavity in the tooth is called the pulp cavity and contains the blood vessels but no lymphatics. The tissue in the cavity is called myxomatous. The part which surrounds the root as the enamel surrounds the crowm is called the crusta petrosa (Plate CCXXVII). There are two kinds of muscles found in the tongue (Plate CXLV) intrin- sic and extrinsic. The intrinsic are the Superior lingualis, Inferior lingualis, Transverse lingualis, and Vertical lingualis. They are all supplied by the hypoglossal nerve. Some say the Inferior lingualis gets the Chorda-tympani branch of the the seventh nerve. The extrinsic muscles are the Genio-hyo- glossus, Palato-glossus, Hyo-glossus, Stylo-glossus, and Chondro-glossus. The nerve to these is the hypoglossal. Papilla means a bud, a nipple, a teat, a pimple. The lingual mucous membrane of the dorsum of the tongue is peculiar in several respects. It con- sists of a layer of connective tissue forming a corium supporting special papilla? covered with epithelium. The corium is a network in which ramify numerous vessels and nerves. The papillae are of three kinds. LESSON LXXXVIII. 1. Large circumvallate ("walled around") papillae seven in number set in an inverted V at the back of the tongue and shaped like truncated cones set on end in cup-like depressions, whence the name. (Plate CXLIII). 2. Middie-sized fungiform ("mushroom shaped") papillae scattered irreg- ularly over the surface, forming rounded red eminences like mushrooms, whence their name. 3. Small conical or filiform ("thread-shaped") papillae covering the an- terior two-thirds of the surface, each ending in a number of little processes. It is these that are concerned in the whitish coating or furring of the tongue. Be- sides these papilla? there are several other simple ones. Occupying the entire thickness of the epithelium of the lateral surface of the papilla? is a multitude of flack-shaped bodies, called tatse-buds. They are composed of two kinds of epithelial cells, gustatory and sustentacular, packed closely together. The microscopic structure of some papillae include certain bodies called taste-buds. Taste-buds are scattered also over the dorsal surface independently of papilla?, and are especially numerous in the posterior part. The nerves of the tongue are in four pairs. 1. The hypoglossal is the motor nerve to the tongue. 312 AXATOMr IX A NUTriHKLL. 2. The lingual (gustatory) of trifacial is distributed to the anterior two- thirds of the dorsum of tongue and also to sides of tongue. This nerve is one of sensation, Formerly it was thought to be a nerve of taste, whence the name (gustatory,) which it still retains. 3. The lingual branch of glosso-pharyngeal is especially concerned in gus- PLATE CXL. FRAENUM LINGUAL DUCT. OF RiVINUS ANTERIOR BELLr DIGASTRIC Showing the Salivary Glands tatlon (taste) and is distributed to the posterior one-third of dorsum and sides of tongue. (Plate CXLIII). 4. The function of the lingual branch of the facial (Chorda-tympani) is still in (p lest ion. Its distribution is about the same as the lingual -branch of the fifth. Some say it is a nerve of taste for the anterior two-thirds of the tongue. Others say that it supplies the Inferior lingualis muscle. Still others say that ANATOMY IN A NUTSHELL. 313 the anterior two-thirds of the tongue is supplied by the glosso-pharyngeal through the chroda-tympani. The blood supply of the tongue is derived from the lingual, the facial, and ascending pharyngeal arteries. The veins of the tongue accompany the arter- ies. There are two kinds of glands in the tongue. (Plate CXL). the mucous and serous. The mucous glands are found all over the surface of the mucous mem- brane of the tongue. The serous are found only at the back of the tongue. The fraenum linguae is a fold of the mucous membrane of the mouth which binds down the under surface of the tongue and sometimes requires to be cut from too great restriction or from extension too far forward, causing the sub- ject to be tongue-tied. Fraenum linguae means bridle of tongue. The dorsum of the tongue is convex, marked along the middle line by a raphe, which divides it into symmetrical halves; this raphe terminates behind, about an inch, from the base of the organ, in a depression, the foramen caecum, The tongue is not the only organ of taste as taste-buds are found on the back part of the hard palate, on anterior part of the soft palate, and to some extent in other parts of the pharynx. The lymphatic vessels from the tongue pass to one or two small glands sit- uated on the Hyo-glossus muscle in the sub-maxillary region, and from thence to the deep glands of the neck. The pharynx (Plate CXLII)is bounded above by(l)the base of the sephnoid bone and (2) the basilar process of the occipital; behind by (1) the vertebral column. (2) Longus colli and (3) the Recti capitis antici muscles: it is incom- plete in front being bounded by the (1) internal pterygoid plate, (2) pterygo- maxillary ligament. (3) the lower jaw. (4) the tongue, (5) the hyoid bone, (6) the thyroid and (7) cricoid cartilages. On the sides by (1) the styloid process and (2) its muscles, (3) the common carotid and (4) internal carotid arteries, (5) the internal jugular vein, (6) ninth, (7) tenth, (8) twelfth, and (9) sympa- thetic nerves and (10) a portion of the Internal pterygoid muscle. It has seven openings, two posterior nares, two Eustachian tubes, the oesophagus, the mouth, and the larynx. On its posterior wail between the two Eustachian tubes there is a collection of lymphoid tissue similar to that found in the tonsils which forms the pharyngeal tonsil or the third tonsil. Above this is the bursa pharyngea, which some authors think has something to do with the develop- ment of the anterior part of the pituitary body and others think it has some- thing to do with the development of the third tonsil. The pharnyx, the throat, technically the joint opening of the gullet and the windpipe, is a musculo-membranons pouch situated at the back of the nasal cavities, mouth and larynx and extending from base of skull to the cricoid car- tilage. It is about five inches long. It i- widest (nearly one inch and a half 1 ) in the upper pharyngeal portion, and narrow above and below, having its least diameter (half an inch) at its junction with the gullet. Ventro-dorsally its measurement is everywhere small, only opposite the mouth being more than four-fifths of an inch. It is a cavity situated in front of the upper live cervical 314 ANATOMY IN A NUTSHELL. vertebrae. The pharynx also belongs to the respiratory system. The middle segmenl of the pharynx is common to the alimentary and respiratory systems, and the tracts followed by the food and air cross obliquely in it. The pharynx lias three tunics, the mucous, areolar, and muscular. PLATE CXI. I. TENSOR PALATI. EUSTACHIAN TUBE LEVATOR PALATI PTERYGOMANDIBULAR LIGAMENT STYLO-PHARYNGEUS. 9TH NERVE-GLOSS O-PHARYNGEAL "STYLO-GLOSSUS MYLO-HYOID HYO-GLOSSUS S T YL0-HYOID D I GASTRIC THYROID CARTILAGE STYLOHYOID LIGAMENT HYPOGLOSSAL SUPERIOR LARYNGEAL N. CURRENT LARYNGEAL NERVE Showing the Muscles of the Pharynx. The muscles of the pharnyx ( Plate CXLI) arc Superior constrictor, Middle constrictor, Inferior constrictor, Stylo-pharyngeus, Palato-pharyngeus, and Salpingo-pharyngeus. The Constrictors are supplied by branches from the pharyngeal plexus. The Stylo-pharyngeus by the glosso-pharyngeal nerve ANATOMY IX A NUTSHELL. 315 and the Inferior constrictor gets, in addition, branches from the external laryn- geal nerve and the recurrent laryngeal. The Palato-pharyngeus probably gets its nerve supply from the internal branch of the spinal accessory, whose fibers are distributed along with certain branches of the pneumogastric through the pharyngeal plexus. The pharyngeal plexus is formed by branches of the vagus, sympathetic and glossc-pharyngeal. It supplies the muscles and mucous membrane of the pharynx. The blood supply of the pharynx is from the superior thyroid branches, ascending pharyngeal, pterygopalatine, and descending palatine. The first two are branches of the external carotid, the last two are branches of the internal maxillary. The sinus of 3Iorgagni is a space at the upper and back part of the Superior constrictor of the pharynx, just under the base of the skull where the muscular fibers of the Constrictor are deficient, the pharynx being consequently walled in behind by its own aponeurosis. Here the Eustachian tube opens into the pharynx, one on each side. LESSON LXXXIX. The tonsils (Plate CXXXIX) are two prominent oval bodies situated in there- cesses formed one on each side of the fauces, between the anterior and pos- terior palatine arches. They are composed of lymphoid follicles, surrounded by less dense lymphoid tissue arranged around the walls of crypts. They lie near the internal carotid artery. The blood supply is from the dorsalis lingua? from the lingual; ascending pharyngeal from external carotid; ascending palatine from facial ; tonsillar from facial : descending palatine from internal maxillary. (Plate CXVI) The veins of the tonsil form a plexus which lies upon the outer side of the gland and opens externally into the pharyngeal plexus. The nerves to the tonsils come from the fifth by means of Meckel's ganglion and from the glosso-pharyngeal nerve. Steno's duct (Stenson's) (Plate CXL) is a duct of the parotid gland convey- ing saliva into the mouth; so named from the Danish anatomist, Nicholas Steno, of Copenhagen (1638-86). This duct is also called parotid duct. Wharton's duct named from Thomas Wharton, an English physician, 1656. The duct of the submaxillary gland, conveying saliva into the mouth, about two inches long, opening on a papilla at the sideof the fraenum linguae, or bridle of the tongue. The ducts of Rivinus are those ducts of the sublingual gland which open apart from one another and from Wharton's duct. The duct of Bartholin is one of the ducts of the sublingual gland running along side of Wharton's duct, and opening into it or close to its orifice into the mouth. Thehardpalate(PlateCC.WYIII) isin the roof of the mouth and is formed by the palate processes of the superior maxillary and palate bones. The soft palate is a movable fold suspended from the posterior bonier of the hard palate, form- ANATOMY IX A NUTSHELL • , u incomplete septum between the mouth and pharynx. The muscles oi the sofl palate are the Levator palati, Tensor palati, AzygOs uvula, Palato- glossus and Palato-pharyngeus. The Tensor palati is supplied by the Otafl ganglion. The remaining muscles of this group are in all probability supplied PLATE CX LI I PROBE PASSED FROM FRONTAL^SINUS THROUGH INFL'NDIBULUM Hi 0PE\;NGS OF POSTERIOR ETHMO VESTIGULE Sagittal Section of the Head and Neck Showing the Pharynx. by the internal branch of the spinal accessory, whose fibers are distributed along with certain branches of the pneumogastic through the pharyngeal plexus. The isthmus of the fauces is called the throat. The anterior pillars of the fan.-.- art in:. Me by two muscles covered with mucous membrane, the two Pala- to-glossi, and the posterior pillars are made by the two Palato-pharyngei. ANATOMY IN A NUTSHELL. 317 The next part of the alimentary canal is called the oesophagus (Plate CXLVI) which extends from the spinous process of the sixth cervical vertebra to the cardiac end of the stomach opposite the spinous process of the ninth dorsal. It consists of three coats, an outer or muscular, a middle or areolar, and an internal or mucous. All of the alimentary canal above the diaphragm has three coats, and all below it has four coats, these three just mentioned and a serous coat or peritoneum. The oesophagus (Plate CXLVI) in the neck, is boundeb! in front by the trachea, the thyroid gland, and the thoracic duct. On each side by the common carotid artery, the lateral part of the lobes of the thyroid gland, and the re- current laryngeal nerve. Behind by the vertebral column and the Longus colli. In the thorax it is bounded in front by the trachea, arch of the aorta, left common carotid artery, left subclavian artery, left bronchus, pericardium, and Diaphragm. Behind by the vertebral column, Longus colli, vena azygos minor, right intercostal arteries, thoracic duct, aorta, and the abdominal aorta. On the right side by the right lung and pleura, vena azygos major, and the thoracic duct. On the left side by the left lung and pleura, and thoracic aorta. The left pneumogastric and right pneumogastric surround the oesophagus, the right being situated behind it and the left in front, forming the plexus of Gula? in the muscular coat. The muscular coat consists at first of three perpendicular bands, the anterior one being attached to the posterior part of the cricoid cartilage and the lateral ones being continuous with the Inferior constrictor of the pharynx. These three bands gradually blend and make a circular muscular band around the oesophagus. The next coat is the circular coat which is continuous with the fibers of the Inferior constrictor and at the upper part of the oesophagus they are parallel and at the lower part they are parallel, but in the intermediate portion they are oblique. The upper ones are striped or voluntary muscles, while the lower ones are involuntary. The glands of the esophagus are compound race- mose glands which empty by long tubes on the mucous membrane. The oesophagus (carrying eatables) or gullet is a tube connecting the pharynx and stomach. It is about ten inches long. The blood supply is from the Infer- ior thyroid which comes from the thyroid axis of the subclavian; branches from t he d( sc< oding thora< ic aorta ; and from the gast i ic branches of the coeliac axis of abdominal aorta. The nerve supply is from th< pneumogastric and sympa- thetic. They form a plexus in which are groups of ganglion-cells between the two layers of the muscular coats, and also a second plexus in the submucous tissue. 318 ANATOMY IN A NUTSHELL. LESSON XC. The stomach ( Plate CXLYI) is the most dilated and most distensible part of the alimentary canal. It occupies parts of the left hypochondriac and epigas- tric regions of the abdomen, immediately within the abdominal walls below the diaphragm and partly under the liver to the right of the spleen and above the transverse colon. In form it is irregularly conoidal and curved upon itself. When moderately distended it is about twelve inches long and four inches wide; it weighs three or four ounces. The size, shape, and hence anatomical rela- tion.^, differ greatly in different states of distension. It is somewhat like a pear with the large end up and the small end bent side wise to the right. The fundus or splenic end is connected to the spleen by the gastro-splenic omentum. We niiuht mention that an omentum is a special mesentery connecting the stomach with the liver, spleen, and colon respectively. The one that connects it to the spleen is called gastro-splenic omentum. The one that connects it to the liver is called the gastro-hepatic omentum, and the one to the colon is called the gastro-colic omentum. The pylorus or lesser end lies near the cartilage of the eighth rib, in contact with the under surface of the liver. The stomach has two curves, a greater and a lesser. The greater is convex and is connected to the colon by the gastro-colic omentum. The lesser one is concave and is connected to the liver by the gastro-hepatic omentum, and to the Diaphragm by the gas- trophrenic ligament. The oesophageal or cardiac orifice is situated between the fundus and the lesser curvature. The pyloric (janitor) is situated at the extreme right and is more anterior in position than the cardiac orifice. The stomach has four tunics, serous, mus- cular, areolar or submucous, and mucous. The serous coat (peritoneum) en- closes the stomach between two layers, derived from the lesser omentum. Tha lesser omentum, omentum minimus, or gastro-hepatic is a single fold (two layers) of peritoneum, extending between the transverse fissure of the liver and the lessee curvature of the stomach. It might be well to explain the greater omentum, omentum magnus or gastro-colic omentum also called epiploon, It is the largest of all peritoneal duplications, and consists of four layers of peri- toneum attached to the greater curvature of the stomach and to the transverse colon, whence it is looped down freely upon the intestines, forming a great flap or apron. The muscular coat has two distinct layers — an outer, longitudinal, and an inner, circular. Besides these two distinct layers some oblique fasci- culi are found internal to the circular. The areolar, submucous, also called vascular, is loose, and its meshes are largely occupied with the vessels and nerves going to and from the coats between which it lies. The mucous coat is thrown into irregular Longitudinal folds called rugae. The rugse invade the mucous and submucous coats. There are two kinds of glands in the stomach, the cardiac or proper gastric glands also called peptic (digest), and the pyloric glands The aerve supply to the stomach is the right and left pneumogastric and branches from the solar plexus of sympathetic nerves. The blood supply to stomach (Plate CXLVIII) is from the coeliac axis. ANATOMY IN A NUTSHELL. 319 (1) the gastric artery which runs along the lesser curve from left to right anas- tomosing with the (2) pyloric branch of the hepatic. Along the greater curve run the (3) right and (4) left gastro-epiploic arteries, anastomosing at the middle of the border, the left being a branch of the splenic, the right a branch of the hepatic through the gastro-duodenalis artery. The stomach also receives branches from the splenic (5) vasa brevia at the fundus. The blood of the stomach is returned into the portal vein; the right gastro-epiploic vein opens into the superior mesenteric, the left into the splenic. The lymphatics are PLATE CXLIII. PHARYNX .■.••■•.•:-. :, - ; / CAPSULE aV-PANCREAS l. \plEEN w c GREAT VESSELS -» a/ SOLAR PLEXUS t oVTRANSVERSE MESO COLON Z «*- CRURA OF DIAPHRAGM BELOW 'eat omentum transverse colon 3astr0- splenic omeutum Showing the Muscular Coats and Relations of the Stomach. run outward from the left lobe to the left lateral ligament, and thence through the Diaphragm to the anterior mediastinal glands. Those on the under surface form three groups, viz., (1) branches arising to the right of the gall-bladder and passing to the lumbar glands; (2) branches Burroduning the gall-bladder in a plexus and passing, with the hepatic Vessels to glands in the lesser omentum : and (3) branches arising to the left of the gall- bladder and passing to the oesophageal glands or glands along the lesser curva- ture of the stomach. The deep vessels of the liver accompany the branches of the portal vein and hepatic duct and artery: they escape a1 the transverse fissure and either enter glands placed along the lesser curvature or the stomach and behind the pancreas, or join a lacteal before it enters the thoracic duct. 330 ANATOMY IX A NUTSHELL. LESSON XCIV. Spinal Cord. (Plates 1V-V-CXCII-CXCIII-CXCIV). The spinal cord belongs to the cerebrospinal or central nervous sys- tem, which ('(insists of the brain and spinal cord. The twelve pairs of cranial nerves, and thirty-one pairs of spinal nerves make the peripheral system. Besides these two systems there is the sympathetic system which is connected with these two and closely associated with the vessels, viscera, and glands. The spinal cord extends from the level of the foramen magnum (below the decussation of the pyramids of the medulla) to the level of the upper border of the second lumbar vertebra, sometimes only to the first lumbar vertebrae. Its length is from fifteen to eighteen inches and its average weight about one and one-half ounces. It is a somewhat flattened cylinder, wider in the transverse diameter. It follows the curves of the spinal column in which it is lodged. It is composed of white and gray matter, the white on the exterior, and the gray on the interior. The gray matter of the cord consists of two kinds. (1) SUB- STANTIA GELATINOSA (RoLAXDI and CENTRALIS) and (2) SUBSTANTIA SPON- GIOSA. Rolandi forms A cap to the posterior horn. It extends the whole length of the cord into the medulla where it becomes enlarged and has large PLATE CL. SMALL INTESTINE Ot'SCENDISG COLON ASCENDING COLON AORTA NFERIOR VENA CAVA THEMESSENTERY Showing the Peritoneum as a Closed Sac. nerve cells and forms one of the end stations for the sensory divisions of the fifth nerve. The substantia gelatinosa Rolandi was formerly thought to be rich in neruoglia tissue, but in fad it is vert poor in this tissue. The cord has two enlargements, i he < i:i;\ ecal ami the lumbar. The former is between the third cervical and the second thoracic vertebra, reaching its greatest diameter, which is transverse, in the sixth cervical, The latter is between the ninth thor- acic and 6rs1 lumbar; its greatesl diameter, which is antero-posterior, is opposite the twelfth thoracic vertebra. These enlargements occur where the nerves are given off to supply the extremities. A- the cord is shorter than the canal, the lumbar, sacral, and coccygeal nerve roots have a longer course than the nerve ANATOMY IN A NUTSHELL. 331 roots above them. The last nerve roots have the appearance of a horse's tail (cam la equina). The neuroglia consists of a homogenous transparent matrix of a network of very (1) delicate fibrillar and of (2) small stellate or branched cells, the neuroglia cells. Formerly it was considered connective tissue but neuroglia PLATE CLI. LESSER OMENTUM PARIETAL PERITONEUM /ISCERAL PERITONEUM GREAT OMENTUM GREAT CAVITY OF PERITONEUM FORAMEN OF WINSLOW SPINAL COLUMN KANCREAS OUOCENUM TRANSVERSE MESOCOLON TRANSVERSE COLON THE MESSENTERY POUCH OF (I (i L A S A Sagittal Section of the Trunk Showing the Peritoneum. is developed from the epiblast and connective tissue from mesoblast. In addi- tion to forming a ground substance in which the nerve fibers, nerve cells, and blood vessels are imbedded, a considerable accumulation of neuroglia takes place in these situations; (1) ox the OUTER SURFACE OF the CORD, beneath the pia mater, (2) around the central canal, and (3) i\ the anterior born. The conus inedullaris is the coin-like termination of the cord, and this 332 ANATOMY IN A NUTSHELL. terminates in a .slender thread, the filum terminale. The filum terminate is a continuation of the pia mater as far as the base of the coccyx, to the periosteum of which it is attached. It contains very litttle nervous matter, and is distin- guished from the nerves of the cauda equina by its glistening white appearance. The membranes of the cord are the same as those of the brain, viz., dura mater, arachnoid, and pia mater. The dura mater of the cord differs from that of the brain, in that it does not form (1) the internal periosteum, does not adhere (2) to the walls, does not contain (3) sinuses, and does not send (4) infoldings into the fissures of the cord. The nerve supply of the dura mater is from the spinal nerves and filaments from the sympathetic. The dura mater of both brain and cord send tubular prolongations over the nerves. PLATE CLII. DIAPHRAGM AND ANTERIOR WALL OF ABDOMEN behind TENTH AND ELEVENTH THORACIC VERTEBRAE RIGHT SUPRARENAL CAPSULE GREAT VESSELS CARDIAC END OF STOMACH HEPATIC FLEXURE OF COLON RIP^- KIDNEY FIRST AND SECOND PORTIONS OF DUODENUM The Relations of the Liver. It is separated from the walls of the spinal canal by fat, loose areolar tissue, and anterior and posterior plexuses of veins. It is attached above to the foramen magnum, to the axis and the third cervical vertebra, and below to the posterior surface of BASE of the cocgyx. The subdural space is between the dura mater and the arachnoid and contains a small quantity of cerebro-spinal fluid. The inner surface of the dura mater is lined with endothelium, and is abundantly supplied with nerves and blood vessels. The arachnoid of the cord is more delicate than that of the brain, but re- sembles it in sending tubular prolongations over the nerves. It is devoid of nerves and has bu1 a slight blood supply. It extends as far as the second or third sacral vertebra. It forms a long sac and the space between it and the pia mater is called the subarachnoid space. This space contains cerebro-spinal fluid, which is about one ounce in this space and two ounces in the ventricles. ANATOMY IN A NUTSHELL. 333 The pia mater is the inner membrane of the cord. It is closely adherent to the cord and sends septa into the anterior and posterior fissures of the cord. The linea splendens is the thickened line of pia mater along the anterior median line. The ligamenta denticulata are fibrous bands which are attached to the median lateral aspect of the pia mater from the level of the foramen magnum to the level of the first lumbar vertebra. The ligaments are midway between the anterior and posterior nerve roots. There are about twenty-one ligaments on each side, extending from the pia mater to the dura mater, carrying the arach- noid along which it, not piercing it. The highest one of the processes is placed between the hypoglossal nerve and the vertebral artery. PLATE CLIII. LEFT LATERAL LIGAMENT SITE OF THE SPIGELIAN LOBE INFERIOR VENA CAVA The Superior Surface of the Liver. The reticula is a network of gray matter, enclosing white fibers in its meshes. It is situated at the base of the posterior horn externally, directly opposite the columns of Clarke. The columns of Clarke are two symmetrically placed tracts of medium sized nerve cells of thespinal cord, latero-dorsal of the central canal, confined chiefly to the dorsal region, but also extending a little above and below it. LESSON XCV. ' The anterior and posterior nerve roots of the spinal cord emerge from the antero-lateral and postore -lateral aspects of the cord respectively, and form a double row on each side of it. The anterior roots arise from the anterior horn of the gray matter and contain motor fibers; the posterior roots arise from the posterior horn and contain sensory fibers. The central canal is in the centre of the gray commissure, and is lined with 334 ANATOMY IN A NUTSHELL. columnar ciliated epithelium in the fetus, but in the adult the cilia have dis- appeared and fill the canal with their remains. It is continuous above with the fourth ventricle of the brain. This canal is the remains of the original neural canal of the embryo, from the walls of which the spinal cord is formed. The sinus rhomboidalis inferior or ventricularis terminalis is a dilatation of the cen- tral canal in the conus medullaris. Diseases of the spinal cord may affect its entire transverse area, or certain portions of it in varying lengths, or it may begin at any level and extend up- ward or downward, in which case, being designated as ascending or descending. PLATE CL1V. RIGHT LOBE' BILE DUCT The Inferior Surface of the Liver. A tumor would be an example of a focal disease, or disease of one of the seg- ments (a portion of the cord with a pair of nerves). Locomotor ataxia is an example of a systemic disease. Fractures of the spinal column above the fifth cervical vertebra — above the origirj of the phrenic nerve, are almost always fatal because of paralysis of the diaphragm. Fractures of the fifth, sixth, and seventh vertebrae cause paraly- sis of the intercostal and abdominal muscles and death usually results. In fractures of the Lower part of the thoracic region the prognosis is not so unfavorable. Degenerations in motor tracts of the cord descend, and the sensory tracts ascend. This is due to the fact that the trophic centers of the m«>ti»r tracts are in the okay matter of the brain, while those of the sen- sory iraci- arc in the G \m.li \ upon the posterior roots of the spinal nerves. In the crossed pyramidal tracts we find three sets of fibers, motor, vasomotor, ANATOMY IN A NUTSHELL. 335 and fibers which carry impulses for inhibition of reflex action. The vasomotor and inhibitory fibers pass to the motor cells of the anterior horn. When the crossed pyramidal tract degenerates these inhibitory and vasomotor fibers are included, and dilatation of the blood vessels and increased reflexes result. In spina bifida there is an overbundance of cerebro-spinal fluid with faulty development of the posterior walls of the lumbar portion of the spinal canal. In this condition the membranes are pushed through the opening in the spinal canal by the weight of the cerebro-spinal fluid. The subarachnoid spaces of the cord and brain are continuous and connected PLATE CLY. 3. PLEXIUS OF CAPILLARY BLOOD-VESSELS WITHIN THE LOBULE. 1. INTERLOBULAR VEINS . « R 1 V. 2. INTRALOBULAR VEIN. 4. TWIGS OF INTERLOBULAR VEIN, PASSING TO THE ADJACENT LOBULES. The Vessels of a Lobule of the Liver. with the fourth ventricle by the foramina of Magendie, Key, and Retzius. The opening of a spina bifida may drain the cerebro-spinal fluid from the brain and result in fatal convulsions. The fissures of the cord are antero-median. postero-median, two antero- lateral, two postero-lateral. and two dorso-intermediate fissures. These fissures divide the cord into eight columns, viz.. ventral, lateral, "Goll, ami Burdack (posterior.)" These are on each side. The ascending and descending fibers of the white matter of the cord arranged in tracts, but these tract- are not recognizable in the adult cord, but only during development or when affected with disease or degeneration. The facts concerning the tracts have been ascertained by embryologies! and path- ological research. This division of fissures is somewhat arbitrary, a- the place where the anterior nerve roots leave the cord i> not always called a fissure, and the dorso-intermediate one is only in the cervical region. If we lake this di- vision there are only eight fissures and eighl columns in the spinal cord. The antero-median fissure extends about one-third the diameter of the cord, toward 336 ANATOMY IN A NUTSHELL. the anterior white commissure. It has in it a pro cess of pia mater which conducts blood to the cord. Although there are only eight columns in the whole cord, there are ten tracts in the white matter of each lateral half of the cord. As a rule the tracts are much smaller than the columns, but sometimes they are equal, as in Goll and Burdack. Tracts one, two, three, four, and five are ascend- PLATE CLVI. Showing the Blood Supply to the Small Intestine. ing tracts; eight, nine, and ten are descending tracts, and six and seven are association tracts. (Plate IV). The gray matter in the cord is in the form of a capital letter "H;" the horizontal portion is called the gray commissure, and the portion in front of the central canal is the anterior gray commissure, and the portion behind it the posterior gray commissure. The portion of white matter in front of the gray commissure is the white commissure. The blood supply of the spinal cord and its membranes is (1) from the lateral spinal, which are branches from the subclavian, from thoracic intercostals of the aorta, from ANATOMY IN A NUTSHELL. 337 the lumbar, and from the internal iliac arteries. (2) From the anterior and posterior spinal branches of the vertebral arteries. The anterior spinal arter- ies are two in number; and come from the vertebrate, just before they unite to make the basilar at the foramen magnum, the anterior spinals unite to make one artery, the anterior median artery. This artery lies in the pia mater, which it PLATE CLVII. LEFT COMMON ILIAC VEIN MIDDLE SACRAL ARTERY AND VEIN Showing the Blood Supply to the Large [ntestine. supplies, and extends the wholelength of the cord. It recieves branches from the lateral spinal arteries, and it sends branches into thesubstance oi the spinal cord. The posterior spinals are also two in number; they come from the vertebral arteries a, the side of the medulla (occasionally from the posterior inferior cerebellar); they pass down behind the posterior nerve roots (occasionally there is another branch in front of the posterior nerve roots) to the cauda equina. Each Beg- PLATE CLVIH. NO. 2. NO. 3. Showing the Vermiform Appendix and Four Forms of the Cecum, 338 ANATOMY IN A NUTSHELL. 339 nient ( a part of the cord with a pair or nerves ) has a blood supply which is made by the anterior and posterior spinal, reinforced by the lateral spinal, making a ring around the segment. Branches are given from each segment to the segment above and below. The blood supply of the vertebral column and its ariculation is the vertebral, occipital, ascending pharyngeal, ascending cervical, intercostal, lumbar, ilio-lumbar, sacra media, and lateral sacral. The nerve supply is from the spinal nerves. LESSON XCVI. Brain. (Plates CLXVIII -CLXXXIII.) There is but one nervous system, consisting of three great divisions. The brain and spinal cord make the central system, the twelve pairs of cranial and the thirty-one pairs of spinal nerves make the peripheral system, and the third division is called the sympathktic system. This last svsteni is called PLATE CLIX. ASCENDING COLON CAECUM. ' ^§^-=^^5^ 4PPFN0IX The Ileo-Ctecal Valve. the nerve of organic life while the central one is called the nervous system of animal life. The specific gravity of the nervous system is L.036, the brain 1.038 and the spinal cord 1.034. The reaction is alkaline, which is Lessened by activity, owing to lactic acid being developed. The white matter is more alkaline than the gray. The brain is a collection of gray ganglia connected by white commissures. The following are the principal transverse commissures! 1. Anterior commissure. 2. Middle commissure. 3. Posterior commissure; 4. Corpus callosum. 5. Optic commissure. 6. Pons Varolii. 340 ANATOMY IN A NUTSHELL. 7. Fornix, which is a longitudinal commissure also. 8. Posterior or inferior medullary velum. 9. Valve of Vieussens, anterior or superior medullary velum. The following are the principal longitudinal commissures: 1. Olfactory tracts. 2. Taenia semicircularis. 3. Crura cerebri. 4. Processus-e-cerebello ad testes. 5. Peduncles of the pineal gland. 6. Fornix. 7. Infundibuluni. 8. Lamina Cinerea. 0. Gyrus fornicatus. 10. Fasciculus unciformis. LESSON XCVII. The extensor of the brain, Avhich is called cortex, is gray, while the interior is white. The average weight of the brain is forty-nine and one-half-ounces. in the male, while it is a little lighter in the female. PLATE CLX. MUSCULAR BANDS — TAENIAfc COLI Transverse Skction of the Large Ixtkstine. The nervous system is developed from the neural tube. (Plates CLXIV- CLXV-CLXVI-CLXV1 ! ). The substance of the brain and cord are made from a thickening of the walls of the tube; the hollow of the tube makes the central canal of the cord and the ventricles of the brain. The rooms, or ventricles in the brain are filled with cerebro-S] Lnal fluid which acts as a cushion for the brain and cord. There are five ventricles in the brain. The central canal in the cord is dilated as it passes into the brain, between the cerebellum behind, and the pons wi) medulla i x front; this dilatation is called the fourth ven- ANATOMY IN A NUTSHELL 341 tricle; as this passage goes forward between the crura cerebri in front, and the corpora quadrigemina behind, it is contracted and is called the aque- duct of Sylvius (iter e tertio ad quartum ventriculum) ; from here it passes into a narrow but high room, called the third ventricle, which is between the optic thalami; these two ventricles are in the median line of the brain. There are two lateral ventricles, one in each hemisphere, which are connected with the third one by the foramen of Monro. There is the fifth ventricle not con- nected with the others; it is situated in the septum lucidum. The brain consists of four main parts, (1) fore-brain, (2) inter-brain, (3) mid-brain, and (4) hind-brain. The brain is called encephalon; the cerebral PLATE CLXI. CYSTIC DUCT SUPRARENAL CAPSULE SPLENIC ARTERY ORIFICE OF ACCESSORY PANCREATIC DUCT. ORIFICE OF BILE AND PANCREATIC DUCTS SUP. MESENTERIC ARTERY interior vena cava. Pancreas, Duodenum and Kidney. hemispheres are called prosencephalon; the parts around the third ventricle are called the thalamencephalon ; the parts around the aqueduct of Sylvius arc called the mesencephalon; the pons and cerebellum, are called the epencephalon; the medulla is called the metencephalon ; the olfactory tract is called the rhin- encephalon. The spinal cord is called the myelon. The encephalon and the myelon constitute the neuron. The brain, like the spinal cord, has three coats. viz., dura mater, arachnoid, and pia mater. The arteries which supply the dura mater are derived chiefly from the anterior, middle, and posterior menin- geal. The nerve supply of the dura mater is the sympathetic,* rasserian ganglion, fourth, fifth, tenth, and twelfth. The arachnoid has but a limited blood sup- ply, and the nerve supply is from the motor division of the fifth, the seventh, and the spinal accessory. The pia mater receives blood supply from the ni- 342 ANATOMY IX A NUTSHELL. ternal carotid and vertebral arteries. The nerve supply is from the sympathetic, the third, fifth, sixth, seventh, ninth, tenth, and eleventh cranial nerves. The exterior of the cerebrum is uneven, having hills and valleys. The hills are called gyri, or convolutions; the valleys are called sulci, or Assures. The larger fissures are called primary, the others secondary. The primary are either complete or incomplete. A complete Assure makes an impression in a ventricle of the brain. They are all on the mesial surface of the brain. They are (1) the dentate, which makes the hippocampus major in the descending lioiii ; (2) the ealcarine, which makes the hippocampus minor in the posterior PLATECLXII. UUCTUS VENOSUS FISSURE LEFT LOBE RIGHT LOBE VENA CAVA FISSURE UM B,LICAL FISSURE -GALLBLADDER F.-SSl). Lobes and Fissuses of the Liver. horn; and (3) the collateral, which makes the eminentia collaterals in the de- scending horn. There are two others which are sometimes called complete fissures, the transverse, which has opposite it the choroid plexus, and the fissure of Sylvius, which has opposite it the corpora striata. The last two are not on the mesial surface. LESSON XCVIII. The right and left lobes of the cerebrum are connected by the corpus CALLOSUM. There are five lobes in each hemisphere of the brain. The brain is the encephalon; the part of the cerebro-spinal axis which is contained in the cranium. Its divisions are the cerebrum or brain proper, the cerebellum or little brain, the pons Varolii, and the medulla oblongata. The average weighl of the brain in the male is forty-nine and one-half ounces, in the female forty-four ounces. Cuvier's brain weighed more than sixty-four ounces. The human brain weighs more than that of any other animal, except the elephant and whale. The elephant's brain weighs about ten pounds; that of the whale five pounds. Like the bark (cortex) of a tree the cortical layer of the brain covers the surfaces of the brain. It is composed of cellular nerve-material. ANATOMY IN A NUTSHELL. 343 The Assures or sulci of the brain are infoldings of the cortex and the more numerous and deeper they are, the greater is the amount of the peripheral gray substance. The gray matter of the brain which invests the cerebellum and cerebrum, is also called the cortical substance, in distinction from the white or medullary substance of the interior. There are several ganglia or collections of gray mat- ter in the interior, as the corpora striata, the optic thalami, the optic lobes or corpora quadrigemina,the corpora dentata of the cerebellum, and the corpora olivaria of the medulla oblongata. There are two non-nerv- ous structures connected with the brain, the conarium or epiphpsis cerebri and the pituitary body or hypophysis cerebri. The principal fissures of the cerebrum are: (Plates CLXXV-CLXIX), (a) The longitudinal fissure which separates the two hemispheres. PLATE CLXIII. DUODENUM SEROUS COAT LONGITUDINAL MUSCULAR LAYER CIRCULAR MUSCULAR LAYER AREOLAR COAT MUCOUS COAT The Four Coats of the Stomach and the Pyloric Orifice. (b) The Sylvian fissure is the largest, deepest, and most constant of the fissures of the brain. It has a short anterior and long posterior branch, the latter separating the temporal from the parietal lobes. It has the middle cere- bral artery in it, lesser wing of sphenoid and central lobe or isle of Reil. (c) The fissure of Rolando or central fissure is a deep sulcus separating the frontal and parietal lobes of the cerebrum on each side. (d) Parieto-occipital fissure extends from the longitudinal fissure outwards for about, one inch between the parietal and occipital lobes. (e) The transverse fissure is a crevice through which the invagination of the pia mater is effected, it starts from the porta (foramen of Monro) nearly to the distal end of the middle horn on each side. It is at the base of the brain. It is also called choroid fissure. (f) Calloso -marginal fissure is nearly concentric with the callosal and also with that of the margin of the hemisphere until a point above the hind end of the callosum is reached, at which the fissure turns and runs upward and back- ward to the upper border. 344 ANATOMY IN A NUTSHELL. (g) Calcarine fissure (from calcar, "a spur"), runs from near the rather pointed hind end of the hemisphere upward and forward, and just beyond the middle at the point where it receives the parieto-occipital, binds downward and terminates beneath the rear end of the callosum. Encircling the callosum is a fissure, called the callosal. (h) First tempro-sphenc tidal fissure is below the fissure of Sylvius on the lateral surface of the brain. LESSON XCIX TllK PRINCIPAL LOBES OF THE CEREBRUM ARE: (Plates CLXXV). 1. Frontal lobe is the anterior one of the cerebrum, separated from the parietal by the fissure of Rolando or central fissure. 2. Parietal lobe is the middle one of the vault of the cerebrum, separated PLATE CLXIV GERMINAL AREA NEURAL GROOVE PRIMITIVE STREAK FORE- BRAIN (RUDIMENT OF CEREBRAL HEMISPrtEKtS OPTIC VESICLE FIRST CEREBRAL VESICLE SECOND CEREBRAL VESICLE THIRD CEREBRAL VESICLE MESODERM NEURAL CREST Showing Germinal Area. from the frontal by the central fissure. or fissureof Rolando and marked off from the occipital by the parito-occipital fissure. It is divided by an intra-parietal fissure int" a superior and inferior parietal lobe. '■'<. Occipital lobe is the posterior portion of the cerebrum marked off from tin parietal lobe by the parieto-< iccipital fissure. 4. Temporo-sphenoidal lobe, also called temporal, is the lobe of cerebrum which occupies the middle cerebral fossa of the skull, it is separated from the frontal and parietal lobes by the fissure of Sylvius. .">. The Central lobe or island of lb il is also called the lobule of the Sylvian fissure, lobule of the corpus striatum is a portion of the cerebral cortex con- ANATOMY IN A NUTSHELL. 345 cealed in the Sylvian fissure, consisting of five or six radiations, convolutions, or the gyri operti ("covered gyrus"). Different human brains vary in details of the gyri. and the same brain may differ on its opposite sides. The gyri are best marked when one reaches his highest mental development. The principal gyri or convolutions are: (Plate CLXXV-CLXXXIII- CLXXXIV). 1. Angular gyrus is a short one, arching over the upper extremity of the superior temporal fissure, the hindmost one of the four parietal gyri, separated by a short vertical sulcus from the supra-marginal gyrus. 2. Annectent gyrus is a small fold wich may connect large or primary con- volutions; applied to several such gyri on the occipital lobe, as those forming the connections of the cuneus or occipital lobule. 3 Ascending frontal gyrus is the one bounding the fissure of Rolando in front. PLATE CLXV. SURFACE ECTODERM ^^ NEURAL CREST (DISAPPEARING) TJEURAL CREST GANGLION POSTERIOR NERve SPINAL GANGLION SYMPATHETIC GANGLION / ANTERIOR NERVE ROOT Showing the Development of the Sympathetic Nerve. As ascending parietal is the one bounding the fissure of Rolando behind. 5. Calossal gyrus is a convolution of the median surface of the cerebrum immedately over the corpus callosum and below the calloso-marginal fissure. It is continuous behind with the gyrus hippocampi, and ends in the gyrus un- cinatus, also called gyrus fornicatus, convolution of the corpus callosum. 6. Cuneate gyrus is one of the occipital lobe appealing as a wedge-shaped figure on the median aspect of the cerebrum in the fork between the parieto- occipital sulcus and the calcarine sulcus, also called occipital lobule and cuneus. 7. External orbital gyrus is that part of the orbital surface which lies out- side of the triradiate sulcus. 8. The frontal gyri, three gyri which compose the superior and lateral surface of the frontal lobe of the cerebrum, all lying in front of the ascending frontal gyrus. They are denned by the superior and inferior frontal sulci, and by the vertical fissure or precental sulcus. 9. The hippocampal gyrus is the continuation of the gyrus fornicatus where it dips down behind and below the corpus callosum, and continues for- ward to the uncinate gyrus: so-called from its relation to the hippocampus. 346 ANATOMY IN A NUTSHELL. 10. That part of the first frontal convolution which appears on the median side of the hemisphere is the marginal gyrus, or it is that gyrus which arches over the extremity of the fissure of Sylvius. 11. Occipital gvri are the three principal convolutions of the occipital lobe of the cerebrum, separated by two small transverse sulci, and distinguished as first, second, and third; from above downward, superior, middle, and inferior. 12. The orbital gyri are upon the under or orbital surface of the frontal Lobe <>!' the cerebrum, which rest upon the orbital plate of the frontal bone. They are three in number, directly continuous with and corresponding to the frontal gyri. The two which are best marked are sometimes called internal and external. 13. The parietal gyri are four well-marked convolutions upon the superior PLATE CLXVI. MEDULLA OBLONGATA OPTIC THALAMUS EPENCEPHALON TERMINALS \ OLFACTORY DIVERTICULUM CEREBRAL HEMISPHERE & MID BRAIN FORAMEN OF MONRO A Horizontal Section of a Vertebrate Brain. and lateral surface of the parietal lobe; and especially two of these distinguished as the ascending parietal or posterior central and the superior parietal, the other two being commonly known as the supramarginal and angular gyrus. 14. Quadrate, or quadrate gyrus, is a convolution of somewhat square figure appearing on the median surface of the cerebrum between the callosum marginal sulcus in front and the parietooccipital sulcus behind, and continu- ous below with the gyrus fornicatus, also called precuneus. L5. Sigmoid gyrus is the somewhat S-shaped fold which curves about the Lateral end of the cruciate fissure and whose surface includes several constant and well-marked "motor areas." lii. The temporal gyri, a general name of the temporal convolutions. 17. Uncinate gyrus is in the median surface of the cerebrum nearly op- posite the gyrus fornicatus. Is. Gyri operti ("covered gyrus") is the insula. L9. The dentate gyrus is lodged in the hippocampus fissure, and is a long slender roll of gray substance, notched upon its exposed surface. ANATOMY IN A NUTSHELL. 347 LESSON C. Besides the gray matter of the cerebral hemispheres of the cerebellum and the meddulla oblongata, and the ganglia at the base of the brain are: (a) Olfactory bulb which is the anterior enlargement of the olfactory- tract from the which olfactory nerves are sent off. (b) Corpora striata (striped bodies) are large ganglia of the brain, of mixed white and gray substance, situated beneath the anterior horn of each lateral ventricle of the cerebrum. (c) Optic thalamus is a large ganglion of the thalamencephalon, situated upon the crus and separated from the lenticular nucleus by the internal cap- sule; also called thalamus. It gives origin to some of the fibers of the optic nerve. (d) Tubercula quadrigemina are on the dorsal part of the mid-brain. The lobes are paired, right and left, and hence called corpora bigemina in ani- PLATE CLXVII. PINEAL BODY fe CORPRA QUADRIGEMINA CEREBELLUM %, MEDULLA OBLONGATA OLFACTORY DIVERTICULUM THALAMUS A Sagitaal Section of a Vertebrate Brain. mals below mammals. In man they are marked by a cross-furrow so they are called corpora quadrigemina, and constitutute what are called the nates or testes of the brain. The optic nerve arises in part from the optic lobes. (e) Tuber annulare is the annular tuber of the brain, the pons Varolii. The anterior commissure is white and situated directly in front of the an- terior pillars of the fornix. (Plate CLXXX). It connects those parts of the hemispheres not connected by the corpus callosum, viz., in man the temporal lobes and in osmaties the entire rhinencephalon. It forms a curve with the convexity forward and slightly upward and its extremities are spread on! Ian- shaped. Its center forms the anterior boundary of the third ventricle between the anterior pillars of the fornix. It passes beneath or through the bead of the caudate nucleus and the posterior two-thirds of the lenticular nucleus where it is spread out in the substance of the temporal lobe. The A.NTERIOB com- missure is a more primitive commissure than the corpus callosum and de- 348 ANATOMY IN A NUTSHELL. creases in size as the corpus callosum increases. The anterior fibers of the an- terior commissure (pars olfactoria) connect the olfactory bulbs of opposite sides and in man is very small, but in osmatics it is large, being twice as large as the posterior portion or hemispheral bundle of fibers. This anterior portion is large in fishes. The posterior portion of the anterior commissure connects the tem- poral lobes and the amygdalae nucleus of opposite sides. The middle fibers pas through the olfactory bulb of one side to the temporal lobe of the opposite side. Thus we may have a lesion on one temporal lobe producing loss of smell of the opposite side of the nose called crossed anosmia. The middle or soft commissure is gray; it is very delicate, though some- time- it is double. It connects the two optic thalami, which takes place about PLATE CLXVI1I. EPIPHYSIS CORPORA QUAORIGEMINA 5TH VENTRICLE IN SEPTUM LUCIDUM FORAMEN Of MONRO HYPOPHYSIS A Sagittal Section of the Brain. the fifth month of intra-uterine life. It is not really a commissure as no fibers pass from it from one side of the brain to the other. The posterior commissure is white and is situated behind the upper end of the aquedud of Sylvius. It forms part of the posterior boundary of the third ventricle. The pineal gland is just above and slightly posterior to it. Most of the fibers of this commissure are a continuation of the fibres of the fillet, which after decussation, pass through the optic thalamus into the corona radiata of the opposite side. The anterior fibres pass from the root of the pineal gland to the nucleus of the trigonum habenulse on one side and the nucleus of the third nerve of the opposite side. The fornix is composed of Longitudinally arched bundles of fibers. It 1 ANATOMY IN A NUTSHELL. 349 consists of a body and two anterior pillars and two posterior pillars . It is sit- uated just beneath the corpus callosum. its posterior part being attached to the corpus callosum. The body is triangular with the apex in front and base be- hind. It forms one of the boundaries of the roof of the third ventricle and part of the floor of the lateral ventricle. The anterior pillars or columx.e for- NICES, descend from the gray matter of the third ventricle behind the anterior commissure and in front of the foramen of Monro. As they descend they spread out. leaving an interval which is occupied by the septum lucidum. They receive reinforcements from the tsenia semicircularis and the crura of the pineal gland and the septum lucidum. They form loops around the cor- PLATE CLXIX. GREAT LONGITUDINAL FISSURE j&M OLFACTORY TRACT A Coronal Section Through the Anterior Horns of the Lateral Ventricles. jiora albicantia, making the stroma zonale or white portion.- of these bodies. Fibres continue from the corpora albicantia and the optic thalamus called filn rs of Vizq'd'azyr. The posterior pill uts of the fornix descend from the sides of the body of the fornix and between the diverging crura and the splenium of the corpus callosum is the psalterium or lyra consisting of white matter and having on its surface some transverse oblique, and longitudinal line-. From it- fancied '' semblance to the strings of a harp this area is called a lyra. Bach pillar passes around the pulvinar of the optic thalamus and then descends in the descending horn of the lateral ventricle. While there they send libers t<> the hippocampus major ami end in the gyrus hippocampus and the uncinate gyrus. The corpus callosum (callous body) is the great white commissure of the 350 ANATOMY IN A NUTSHELL. hemisphere of the brain: the commissure magna or trabs cerebri. This struc- ture is peculiar to the mammalia; it is first found in a rudimentary state in the implacentals, and increases in size and complexity to the highest mammals, coincidentally with a degree of other special cerebral commissures. It is also called callosum. The corpus callosum connects the frontal, parietal, central and occipital lobes. It is the great transverse commissure of the brain. It is three and one-half inches long on the superior surface and two and one-half inches on the inferior. It extends within one and one-fourth inches of the anterior boundary <>f the brain and within two inches of the posterior boundary of the brain. It PLATE CLXX. BODY Cr LATERAL VENTRICLE. CHOROID PLEXUS- 0F CAUDATE NUCLEUS EXTERNAL CAPSULE OPTIC TRACT HlPPOCAMPAL FISSURE „ur.. uri„ ALBICANTIA A Coronal Section Through Middle Commissure of Brain. is convex above and concave below, thinner in the center of body than at either end. Tin: posteriob end is called the splenium or ped. The anterior end which is between the frontal lobes is called the genu or Knee. The rostrum is the continuation of the genu and joins the lamina cinerea. On the superior surface a groove extends along the median line called the raphe and on each side of tlii- are the stride longitudinales or nerves of Lancisi. These nerves are two distind white bands given off to the termination of the corpus callosum and culled the peduncles of the corpus callosum. They pass across the anterior perforated space to end in the temporal lobes, uniting with the inner root of the olfactory tract. The forceps minor are fibers which go for- ANATOMY IN A NUTSHELL. 351 ward from the anterior and lateral angles into the frontal lobes. The forceps major are fibers which continue backward through the posterior angles into the occipital lobe. LESSON CI. The septum lucidum forms the inner boundary of the lateral ventricle and unites in front with the genu and rostrum of the corpus callosum. Posteriorly and inferiorly it is united with the fornix and its anterior peduncles. (Plate CLXXXIV). It consists of two laminae which enclose the fifth ventricle. It is PLATE CLXXI. LATERAL SINUS A Coronal Section Through the Posterior Horns of Lateral Ventricles. a triangular area of gray matter. This ventricle was originally a part of the great longitudinal fissure but the two hemispheres are united above by the cor- pus callosum and below by the fornix, and the space betwe< ;> them becames a distinct cavity with walls of its own — lamina 1 or septum Lucidum. The Loner layer is gray, middle white, and external one ependymal or ependyml tissue covered by the epithelial layer continuous with that lining the lateral ventricle. Velum interpositum or tela choroidea superior the word tela means a web and is applied to a membrane formed by the position of the pia mater and ependyma when the intervening layer of nerve tissue has disappeared. It is a triangular process of pia mater which is prolonged through the transverse fissure and lies over the third ventricle and upper surface of the op1 ic thalamus. from its under surface it supplies two vascular processes which form the 352 ANATOMY IN A NUTSHELL. choroid plexus of the third ventricle and each, side the choroid plexus of the lateral ventricles are formed. The optic thalami are mostly gray matter but are white exterally and are situated above the tegmentum of the cms. The inner surface of each forms the lateral bounary of the third ventricle and the upper suiface forms part of the floor of the lateral ventricle. The internal capsule (fibres of the crusta or pes) separate the outer sur- face of each optic thalamus from the lenticular nucleus. Each optic thalamus has four surfaces. (1) superior or dorsal (2) inferior or ventral, (3) internal or mesial, and (4) external or lateral. The taenia semicircularis separates the PLATE CLXXI1. POSTERIOR CORNU FORAMEN OF MONRO ANTERIOR CORNU A Cast of the Ventricles of the Brain. superior surface from the caudate nucleus. This surface is divided by the sulcus choroidens into mesial and lateral portions. The lateral portion of this depression is in the floor of the lateral ventricle. Anteriorly it grows into a prominence, the anterior tubercle. The superior surface is separated from the mesial surface by the peduncles of the pineal gland. The posterior surface divides into a large prominence, the pulvinar. The trigonum habenulae is a depressed area of gray matter between the pulvinar and the beginning of the peduncles of the pineal gland. The ganglia of habenulae is anterior to the tri- gonum habenulae. The internal and external geniculate bodies are elevations of gray matter on the posterior and inferior surface of the pulvinar. The internal geniculate body is situated on the inferior and inner side of the pulvinar, between the brachia of the corpora quadrigemina. It is covered" with a layer of white fibers. The external geniculate body is below and external to the internal geniculate. ANATOMY IN A NUTSHELL. 353 It is of a yellowish-gray color. The projection system of fibers which pass through the internal capsule and bundles are the peduncles of the optic thala- mus The pineal gland, also called conarium and epiplysis, is a small reddish body PLATE CLXXIII. ANT COMMUNICATING A CIRCLE OF WILLIS AND ARTERIES OF BRAIN. The Circle of Willis. developed from the hind* r par! of the roof of the first cerebral vesicle, and lying in front of and above the nates. Its substance consists mainly of epithelial follicles and connective tissue; there is no evidence thai it is a nervous struc- ture, and its t'nnction.if it possesses anv.is unknown. It was formerly supposed by some (as the Cartesians) to be the scat of the soul. (Plate CL XXX). 354 ANATOMY IN A NUTSHELL Then' arc numerous peduncles of the brain. Those of the cerebellum are three pairs and are stout bundles of nerve fibres which connect the cerebellum with other chief divisions of the brain. They are distinguished by their posi- tion as superior, middle, and inferior peduncles or crura. The superior pair emerge from the mesial part of the medullary substance of the hemispheres, and run forward upward to reach the nuclei tegmenti of the opposite sides, after decussation under the formatio reticularis. Also called (1) crura ad corpora quadrigemina, (2) crura ad cerebrum, (3) processus cerebelli ad cerebrum, (4) processus-e-cerebello ad testes. (.">) branchia conjunctiva, and (6) branchia con- junctoria). (Plate CLXXXVIII). PLATE CLXXIV. Showing; Blood Supply of the External Surface of the Brain. The middle pair from the ventral transverse fibres of the pons, emerging from the lateral part of the white substance of the hemispheres. (Also called crura or processus ad uiedullani). (Plate CLXXXVIII). LESSON CI I. The fissures of the cerebellum are three in number — two vertical and one horizontal. The great horizontal fissure is a continuous fissure which separates the cerebellum into upper and lower portions. It begins in front at the middle peduncles, and extend- around the outer and posterior border of each hemi- sphere. The vertical ones are : 1. Incisura cerebelli anterior, the anterior median notch of the cerebellum, into which the corpora quadrigemina arc received. 2. Incisura cerebelli posterior, the median notch on the posterior outline of the cerebellum, formed by the projection of the cerebellar hemispheres be- yond the vermis. (Plate CLXXXVIII). ANATOMY IN A NUTSHELL. 255 The vermis is the median lobe of the cerebellum; the vermiform process of the cerebellum is divided into the prevermis and the postvermis. The olivary body is the ganglion of the oblongata lying on either side just lateral of the pyramid, and forming an oval projection on the surface just below the pons. It consists of the nucleus olivaris inferior with a covering and filling of white matter, also called inferior olivary body, or inferior olive, and corpus semiovale. The corpus dentatum is (a) a plicated capsule of gray matter, open an- teriorily, situated within the white substance of each cerebellar hemisphere. Also called ganglion of the cerebellum and nucleus dentatus. (b) A somewhat similar mass of gray matter in each olivary body. Also called corpus ciliare. PLATE CLXXV. FISSURE OF ROLANDO. PERFORATING BRANCHES MIDDLE CEREBRAL A. IN FISSURE. OF SYLVIUS. Showing Distribution of Middle Cerebral Artery. The lateral tract is continuous with the lateral column of the spinal cord, lies behind the olivary body and in front of the restiform. The restiform body is the inferior peduncle of the cerebellum, by which it connects with the oblongata and parts below. It contains the direcl cere- bellar-tract fibres, crossed and uncrossed from the posterior columns of thecord, and fibres from the centra-lateral (lower) olive . The fillet is some special bundle of nerve-fibres; especially, a band of Longi- tudinal fibres lying in the ventral and outer parts of the tegmental region of the brain. Its distribution is not known, bu1 it seems to conned below with the posterior columns of the spinal cord and above with the corpora quadrigemina, optic thalami, lenticular nucleus, and cortex cerebri. It is also called lemniscus. A vesicle is a small, bladder-like structure, cavity cell, or the like, in a body. There are three vesicles in the brain, anterior, middle, and posterior. They are 356 ANATOMY IN A NUTSHELL. I embryonic and so transitory, and have other names when matured They are called anterior, middle, and posterior, corresponding to the fore-brain, mid- braiD ^d hind-brain. They are pmnitive structures and become the ven- tricles of the brain. The three commonly form five by the subdivision of ' Tbe septum lucidum is the median partition of the lateral ventricles of the ,„,„,. ^dosing the camera, pseudocele, or so-called fifth ventricle. Also called ,,, septum pellucidum, (2) septum medium, (3) septum ventnculorum, (4) ventricular septum. (5) septum medullare tnangulare. The fornix is an arch. In the human brain it consists of two Longitudinal bundles of fibres, one on each side, which rise from the corpora albicantia pass up. as the anteriob pillars of the fornix in front of the foramina of Monro PLATE CLXXVI. ARR SUPPl.kD BY M D3LE CEREBRAL ARTERY. Showing Blood Supply on Mesial Surface, (Sagittal Section^f Brain). and behmd the anterior commissure, these somewhat flattened and in apposi- tion to each other, arch backward beneath the corpus callosum and above the velum interpositum, forming the body of the fornix and then diverge toward the back pari of die corpus callosum, to turn down, as the posteriok pillars f the fornix (crura fornices), into the floor of the descending cornua of the lateral ventricles, where their free edges form the fimbriae. The fimbria is a narrow band of white fibres running along the median concave side of the hippocampus major. It is a continuation of the pillars of the fornix. Also called taenia hippocampa and corpus fimbriatum. The taenia semilunaris consists of commissural fibres between the corpus striatum and the optic thalamus. The cerebrum is thai portion of the brain which lies in front of the cere- bellum ami pons Varolii. It comprises aboul seven-eighths of the weight oi the brain. It is the center of intelligence and thought . ANATOMY IX A NUTSHELL. 357 The cerebellum is called the arbor-vita 1 or tree of life. It is the center for the control of muscles. It is between the corpora qnadrigemina in front and the medulla oblongata behind, and forming part of the roof of the fourth ven- tricle. The pons, also called pons Varolii and pons cerebelli, is a great transverse commissure seen at the base of the brain in front of the medulla. Its fibres connect the hemispheres of the cerebellum with each other and the medulla. The medulla oblongata is (a) marrow; (b) the so-called spinal nervous sys- tem; the myelon; more fully called medulla spinalis: (c) the hindmost segment of the brain, continuous with the spinal cord. PLATE CLXXVII. area supplied by middle cerebral artery. Showing Blood Supply at Base of Brain. A ventricle (literally a belly, a stomach) is a small cavity. Those of the brain are a series of connecting cavities, containing fluids, within the brain, continuous with the central cavity of the spinal cord. They are the remains of the original neural canal, formed by a folding over of the epiblast. The optic commissure or chiasma, somewhat quadrilateral in form, rests upon the optic groove of the sphenoid bone, being bounded, above, by the lamina cinerea; behind, by the tuber cinereum; on either side, by the anterior perforated -pace. Within the commissure the optic nerves of the two sides undergo a partial decussation. The fibres which form the inner margin (in- ferior commissure of Gudden) of each trad are continuous across from one to the other side of the brain. These may be regarded as commissural fibres (intercerebral) between the interna] geniculate bodies. Some fibres are con- tinued across the anterior border of the chiasma, and connect the optic uerves of the two sides, having no relation with the optic tracts. They may be re- garded as commissural fibres between the two retinae (inter-retinal fibres'). The outer fibres of each tract are continued into the optic nerve of the -nine side. 358 ANATOMY IN A NUTSHELL. The central fibres of each tract are continued into the optic nerve of the opposite side, decussating in the commissure with similar fibres of the opposite tract. The ventricles arc two lateral, third ventricle, fourth ventricle, FIFTH \ ENTRICLE, and THE VENTRICLE OF THE CORPUS CALLOSUM. The lateral ventricles arc found one in each hemisphere; they communicate with each other and with the third ventricle through the foramen of Monro. PLATE CLXXVIII. NINTH TENTH AND ELEVENTH LIGAMENTMM DENTICULATUM Showing Falx Cerebri, Etc. The third ventricle lie- between the optic thalami. It communicates with the fourth ventricle through the aqueduct of Sylvius. The fourth ventricle/lies between the cerebellum and the pons and medulla. The so-called fifth ven- tricle, (n- pgeudocele, has no connection with the other cerebral ventricles, being of a different nature and simply a small interval between the right and left layers of the septum lucidum. ANATOMY IN A NUTSHELL. 359 LESSON cm. The Medulla Oblongata is about one and one-half inches long and three- fourths of an inch wide and one-half of an inch antero-posteriorily. It extends from the foramen magnum inferiorly to the pons superiority. It is the smallest part of the main divisions of the brain but the largest from a physiological standpoint. It has five main centers in it, viz., (1) Respiratory, (2) Cardio- inhibitory, (3) Vasomotor, (4) Diabetic, and (5) Salivary. (Plate CLXXXV1I). PLATE CLXXIX. OLFACTORY BULB OPTIC NERVE OPTIC COMMISSURE |NT. CAROTID ARTERY THIRD N FOURTH N SIXTH N AUDITORY ARTERY, .AUDITORY AND FACIAL SUPERIOR PETROSAL INFERIOR PETROSAL STRAIGHT SINUS. TORCULAR HEROPHlLl >jPERI0R LONGITUDINAL SINUS. OPHTHALMIC VEIN- CAVERNOUS SINUS. OPHTHALMIC DIVISION OF FIFTH N BASILAR A VERTEBRAL A. ANTERIOR SPINAL A. GLOSSOPHARYNGEAL AND PNEUMOGASTRIC HYPOGLOSSAL SPINAL ACCESSORY OCCIPITAL SINUS RIGHT LATERAL SINUS, Sinuses at the Base of the Brain. It is gray on the outer side and white on the inner. Its posterior SUR- FACE makes the lower part of the anterior boundary or the floor of the fourth ventricle. Its anterior surface rests upon the basilar process of theoccipital bone. In the median line of the anterior surface is the antero-median fissure which is continuous with the antero-median fissure of the cord. On each side of this fissure there is a pyramid. This pyramid has fibres next to the fissure which are derived from the crossed pyramidal tracts after they push the gray matter of the anterior horn of the cord superficially. Next to this it has the fibres of the direct pyramidal tract. External to the pyramid we have the olivary body superiority and the lateral tract infcriorily. This olivary body has 360 ANATOMY IN A NUTSHELL. the inferior olivary nucleus and the dentates nucleus. The olivary nucleus is hollow and gives off, from an opening in its side, little fibres called the ped- uncles of the olivary body. Next to the olivary and lateral tract external we have part of the restiform body. Another name for the restiform body is in- ferior pedicles of the cerebellum. The posterior surface of the medulla has the postero-median fissure and on each side' of it is (1) the funiculus gracilis, (2) funiculus cuneatus, (3) the funiculus Rolando. (4) lateral tract. The upper portion of the posterior surface makes the restiform body or the inferior peduncles of the cerebellum. PLATE CLXXX. POST. COMMISSURE. EPIPHYSIS OR PINEAL GLAND. SPLENIUM OF CORPUS CALLQSUM ANT v COMMISSURE. U "^FORAMEN OF MONRO. OPTIC NERVE. INFUNDIBULUM. HYPOPHYSIS OR PITUITARY BODY. A Sagittal Section of Brain, Showing the Third and Fourth Ventricles The fibres in the cold which travel through the direct cerebellar tract, which is in the lateral column of the cord, pass up into the medulla into the resti- form body, instead of passing straight into the lateral column. The funiculus Rolando is a continuation of the gray matter from the posterior horn of the cord, where it is called substantia gelatinosa Rolando, up into the medulla where it is situated between the funiculus cuneatus and lateral column. Cerebellum (little brain) is about one-tenth of the entire brain. It weighs about five ounces. It is about one-eighth as large as the cerebrum in the adult. In early child] 1 it may he as small as one-twentieth of the cerebrum. It is situated in the posterior fossa at the base of the skull, being separated from the cerebrum by the tentorium cerebelli. It consists of two hemispheres connected by the worm (vermiform process). The medulla is situated in the anterior ANATOMY IN A NUTSHELL. 361 inferior portion in a groove called the vallecula. The falx cerebelli is situated in a groove posterior to the worm between the two hemispheres. The hemi- spheres have fissures like the cerebrum but do not have convolutions like the cerebium but instead have folia. The cerebellum is gray on the outer side and white on the inner side. It forms the roof or posterior boundary of the fourth ventricle. PLATE CLXXXL CORPORA QUADRIGEMINA TRACT SUPERIOR CEREBELLAR PEDUNCLE FOURTH VENTRI CLE — ^?^^^^ x (^^^n; HIDDLE CEREBELLAR % : ^2§f*73 PEDUNCLE -^> ^%l\\ ^ f Ml EIGHTH NERVE NUCLEUS INFERIOR CEREBELLAR PEDUNCLE - A Sagittal Section of Brain Showing Fibers. The worm, commencing with the anterior superior part, and passing backward consists op the following parts: Frenulum (1) Lingular Precentral fissure Fraenulum Ala lobulus centralis (2) Lobulus centralis Ala lobulus centralis Post-central fissure Anterior crescentic-lobule (3) Oilmen monticuli Anterior crescentic lobule Preclival fissure Posterior erescentic lobule (4) Clivus Post-clival fissure Posterior erescentic lobule. Posterior superior lobule (5) Folium cacuminis Posterior superior lobule 3(52 ANATOMY IN A NUTSHELL. The lower worm from before backward consists of the following parts: Flocculus (1) Nodule Flocculus Amygdala (2) Uvula Amygadala BiventraJ (3) Pyramid Biventral Sledner lobe Post-gracile fissure Postero-inf erior lobe (Inferior semilunar) (4) Tuber valvulae Slender lobe Post-gracile fissure Postero-inf erior lobe (Inferior semilunar) There are four sets of gray nuclei in the white matter of each hemisphere called (1) Corpus dentatum. (2) Nucleus emboliformis. (3) Nucleus globosis. I h Nucleus fastigii. (Plate CLNXI). PLATE CLXXXII. A Sagittal Section of Brain, Showing Centers of Smell and Taste. The cerebellum has three sets of peduncles, the superior ones pass from the cerebellum to the corpora quadrigemina (processes-e-cerebelli ad testes) and have efferent fibres in them.* The middle ones connect the middle part of the cerebellum with the pons and have both afferent and efferent fibres. The [NFERIOK ONES connect the cerebrum with the cord and are called the restiform bodies. LESSON CIV. The pons is the connecting link for the other parts of the brain. It is con- nected to the cerebellumby the middle peduncles of the cerebellum. It is con- nected to the cerebrum by the crus cerebri or the peduncles of the cerebrum. It is connected to the medulla by fibres through the pyramidal tract. It is situated on the basilar process of the occipital bone and the posterior part of the sphenoid bone. It is one inch long and one and one-half inches wide. Its ♦There are afferent fibres immediately beneath the superior peduncle in the valve of Vieussens. ANATOMY IX A NUTSHELL. 363 anterior surface is convex from side to side and slightly convex from above downward. Its superior border is longer than the lower border and Is convex, while the lower border Is almost straight. In the median line on the anterior surface there is a groove for the basilar artery. Its posterior surface is concave and forms the upper part of the floor of the fourth ventricle. A coronal section will divide it into an anterior or inferior portion and a posterior or superior portion. The posterior part is called tegmentum. The anterior part consists of three main divisions (1) superficial transverse fibres which pass from the middle peduncles of the cerebrum and give the pons its name., (2) deep transverse fibres which decussate in the pons connecting one side of the cerebellum with the opposite side of the cerebrum. (3) is longitudinal fibres which intermingle with the deep transverse fibres and pass through the medulla into PLATE CLXXXIH. Location of Centers of the Brain. the crust a or pes of the crus. The tegmental portion of the pons, or posteior part, has four main parts. Anteriorly (1) the fillet. (2) formatio reticularis, (3) posterior longitudinal bundle-, and (4) superior olivary nucleus. A hemorrhage in the pons, if it is above the decussation of the seventh nerve will cause paralysis of the opposite side of the face and opposite side of the body but if it is below the decussation of the seventh nerve it will cause paralysis of the same side of the face and opposite side of the body, producing what is known as crossed hemisphlegia. The sixth nerve, seventh nerve, and par' of the eighth nerve have their deep origin in this part of the pons. The crus cerebri or the peduncles of the cerebrum pass upward and outward from the upper margin of the pons into the substance of the cerebrum. They are about three- fourths of an inch long. A cononal section will divide this into an anterior or inferior and a posterior or tegmental portion. The anterior is called crusta 364 ANATOMY IN A NUTSHELL. or pes and has motor fibres in it. The posterior portion is the tegmental por- tion and has sensory fibres in it. The Restiform body or inferior peduncles of the cerebellum receives its fibres from four main sources (1) from the nucleus gracilis et cuneatus of the same side. (2) from nucleus gracilis et cuneatus of opposite side, (3) from the lateral column of the cord through the direct cerebellar tract, (4) from the nucleus of the olivary body of the opposite side. PLATE CLXXXIV. A Sagittal Section ok the Brain. The area where the cranial nerves leave the brain substance is called the Si perficial ORIGIN. The group of cells from which the fibers spring or in which they end is the deep origin. (Plate CLXXXVII). Rule. — The deep origin of all the cranial nerves, except the first and sec- ond ;ind a part of the eleventh, is in the floor of the aqueduct of Sylvius or in the floor of the fourth ventriclk. The third and fourth have their deep origin in the aqueduct of Sylvius. The fifth, sixth, seventh, eighth, ninth, tenth, pari of the eleveth, and twelfth have their deep origin in the floor of the fourth ventricle. • Definition for centre. — (1) Any ganglion or plexus giving off nerves which control function. (2) Any GROUP of ganglion tells which has a stim- ulating or inhibitory office. (3) It is a group of GANGLION CELLS closely con- nected with one another and acting together in the performance of some func- tion, as the cerebral centers, psychical centers; respiratory or vaso-rnotor cen- ter-. The first and second cranial nerves are processes of the brain and therefore have neither superficial nor deep origin. We say there are twelve pairs of cranial nerves; it would be better to say twelve sets for in the first or olfactory nerves there are twenty or thirty nerves. The first nerve is one of special sense, thai of smell. The primary center for smell is in the olfactory lobe. (Plate ANATOMY IN A NUTSHELL. 365 CXCIX) the secondary center in the uncinate gyrus of the temporal lobe on the mesial surface. (Plate CLXXXII). This has been demonstrated by experiments upon animals and by pathological research on the brain of man. In osmatic animals these lobes (gyrus hypoeampus, uncinate, and hippocampus major) where the center of smell is located, are well defined. In anosmatic they aresmall. If the olfactory tract be removed these lobes will atrophy and in case of lesion in these lobes the loss of smell (anosmia) will follow. The ol- factory tracts, which are white, lie almost parallel to one another, extending from the under surface of the frontal lobe. The bulb is reddish-gray in color and lies on the cribriform plate of the ethmoid. From the bottom of these bulbs the olfactory nerves are given off, twenty or thirty in number, to be distributed to the cells of Schultze in the Schneiderian membraxk. The three roots from the tracts are the external, middle, and internal. The external root PLATE CLXXXV. Showing Long and Short Association Fibers of the Brain. is white and extends into the anterior end of the hippocampus gyrus of the tem- poro-sphenoidal lobe. The middle one is gray and ends in the trigonum ol- factorium. The inner one, or mesial hoot, is white and passes backward and inward to end in the anterior extremity of the gyrus fornicatus. The mesial root is continuous with one end of the limbic lobe and the external root with the other. This nerve is made up exclusively of non-medullated fibers. They are deficient in the white substance of S< hwann and consist of axis-cylinders with a distant nucleated sheath in which there are, however, fewer nuclei than in the ordinary non-medullated fibers. 1. Anosmia is the loss of smell. 2. Hyperosmia is increased sensitiveness. 3. Parosmia is perversion of the Function of smell. 4. Kakosmia is a condition where everything smells alike to the patient and the odor is a peculiar or offensive one. 366 ANATOMY IN A NUTSHELL. The arachnoid holds the tracts in position in the sulci. The dura mater covers the nerves and is continuous with the periosteum of the nasal fossa. The pia mater is continuous with the neurilemma. PLATE CLXXXYI. CuHNU OF LE.-T LATERAL VENTRICLE ANTERIOR PILLAR OF FORNIX ROSTRUM OF CORPUS CALLOSUM TENIA SEMICIRCULARIS EXTERNAL CAPSULE CLAUSTRUM PIA MATER IN HIPPOCAMPAL FISSURE OF CORPUS CALLOSUM POSTERIOR CORNU OF LEFT LATERAL VENTRICLE A Horizontal Section (5fthe Brain. The second cranial nerve or optic nerve is a process of the brain like the olfactory. The center for sigh* bin the cuneate lobule of the occipital lobe. The optic aerve extend- forward and outward from the optic commissure or chiasma to the posterior part of the eye-ball,entering a little to the inner side of the cen- ter to spread out into the retina. The chiasma or commissure is rectangular and upon the olivary eminence of the sphenoid bone and on the anterior part ANATOMY IN A NUTSHELL 367 of the diaphragma sella. Above it is the lamina cinerea, behind it is the tuber cinereum. On either side is the anterior perforated space. The optic tracts extend outward and backward from the chiasma to (1) the external gen- iculate body. (2) The posterior or inferior quadiigeminal body. (3) The PLATE CLXXXVII. DESCUSSATION OF PYRAMIDS. Showing Superficial Origin of the Cranial Nerves. internal geniculate body. (4) Under part of the pulvinar of the optic thala- mus. From these four parts the optic radiations extend to the center of sight. Those fibers which do not decussate at the OPTIC COMMISSURE have already decussated in the corpora quadrigemina. This is the reason that a lesion of one center of sight will cause blindness in the opposite eye and vice versa, for both sets of decussating fibers are destroyed. A lesion through the middle of 368 ANATOMY IN A NUTSHELL. the chiasms will produce blindness in the inner half of each eye. A lesion of the left optic nerve will produce blindness in the left eye and vice versa. A lesion of the left optic tract will produce blindness in the left half of each eye and vice versa. As this nerve pass< s from the brain it receives coverings from the dura mater, arachnoid, and pia mater. It passes through the optic foramen with the ophthalmic artery, being above and on the inner side of the artery. The optic, motor oculi, trochlear, trifacial, and the abducent nerves are all concerned with the eye -ball and its apparatus, thus making all the of PLATE CLXXXVIII. INTERNAL GCNICULATE BODY 4TH CRANIAL N SUPERIOR PEDUNCLE MEUDLLART VELUM great horizontal fissure. Tim: Superior View of the Cerebellum. first six cranial nerves, excepting the first. The optic nerve is the nerve of sight. The motor oculi, trochlear, and abducent are th< nerves to the mnscles of the eyeball, and the fifth nerve supplies the ophthalmic, lenticular, or ciliary gang- lion with one of iis roots, from which ganglion nerves pass to the iris. The eyeball is Located in the orbit which consists of seven bones, viz., (1) frontal, (2) ethmoid, (3) sphenoid, (4) lachrymal, (5) superior maxillary, (6) malar, and (7) palate. In the two orbits there arc but eleven bones, the frontal, ethmoid and sphenoid being common to the two. The orbit is somewhat pyramidal in shape with the base forward and apex backward. (Plate CCXXIX The axial lines, if extended, would meei on the sella turcica of the sphenoid. ANATOMY IN A NUTSHELL. 369 The orbit communicates with the cavity of the cranium by (1) the optic fora- men and (2) the sphenoidal fissure. It communicates with four fossa?, (1) with the nasal fossa by the nasal duct. (2) with the temporal fossa, (3) with the zygomatic fossa. (4) and with the spheno-maxillary fossa. These last three by the spheno-maxillary fissure. Each orbit has nine foramina. — (1) supraorbital, (2) infraorbital. (3) an- terior ethmoidal, (4) posterior ethmoidal. (5) optic. (6) sphenoidal fissure, (7) spheno-maxillary fissure. (8) nasal duct, (9) malar foramina. LESSON CV. The floor is formed by three bones, (1) the orbital surface of the superior maxillary; (2) the orbital process of the malar; (3) the orbital process of the PLATE CLXXXIX. CPTIC TRACT 3RD CRANIAL N. EXTERNAL GENICULATE BODY. . MIDDLE PEDUNCLE -OPTIC TRACT. 4TH CRANIAL NERVE. -EXTERNAL GENICULATE BODY. MOTOR RCOT OF bTH N. SENSORY RCOT OF 5TH N. "GREAT HORIZONTAL FISSURE' The Inferioe View of the Cerebellum. palate. The floor is somewhat fiat and has (1) the infraorbital canal; (2) a depression for the Inferior oblique muscle anteriorly; (•">) the infraorbital groove posteriorly; (4) the palato-maxillary suture posteriorly. The root' is formed by the two bones. (1) the orbital plate of the frontal bone anterior- ly; (2) the lesser wing of the sphenoid posteriorly. The ROOF is dome-like. At its outer angle is the lachrymal fossa for the lachyrmal gland. The depr< ssion for theSuperior oblique muscle is at the inner angl< . Tin inner wall is formed by four bom s, (1) the nasal proc< ss of the superior maxillary ; (2) the lachrymal bone; (3) the os planum of the ethmoid; (4) body of the sphenoid. It has,(l) lachrymal crest;(2) groove for lachrymal sac; (3) ethmo-lachry- mal suture; (4) ethmo-sphenoidal foramina. 370 ANATOMY IN A NUTSHELL The outer wall is formed by two bones, the orbital process of the malar and the greater wing of the sphenoid bone. It presents (1) the opening of the malar canal. (2) spheno-malar suture. The four boundaries of the orbit make four angles, viz., the stjperiob external, superior internal, inferior external, and inferior internal. The superior external angle has(l) fronto-malar and PLATE CXC. Showing the Writing Center in the Brain. fronto-sphenoidal articulation, (2) the sphenoidal fissure which transmits the third, fourth, three divisions of the ophthalmic division of the fifth, and sixth nerves, filaments of the sympathetic, processes of the dura mater, orbital branches of the middle meningeal and recurrent lachrymal arteries. PLATE CXCI CONUS MEDULLARS GANGLION ON A POSTERIOR NERVE ROOT ANTERIOR SPINAL ARTERY -THORACIC XII LUMBAR I COCCYGEAL FILUM TERMINALE SURROUNDED BY CANDA EQUINA Antkkiok Yikw of Cauda Equin \. 371 372 ANATOMY IN A NUTSHELL. The superior internal angle has (1) the lachrymo-ethmo-frontal suture, anterior ethmoidal foramen which transmits the anterior ethmoidal vessels, and nasal nerve, (2) the posterior ethmoidal foramen which transmits the posterior ethmoidal vessels and sometimes a branch of the nasal nerve. The inferior ex- ternal angle has the spheno-maxillary fissure which is formed by the greater wing of thf sphenoid bone externally and the superior maxillary bone and palate bone internally. This fissure connects the orbit with (1) the temporal fossa, (2) zygomatic fossa, (3) spheno-maxillary fossa and transmits the infraorbital artery, superior maxillary nerve and its orbital branches and the ascending PLATE CXCII. LIGAMENTUM DENTICULATUM POSTERIOR ROOT LINEA SPLENDNS ANTERIOR ROOT Showing the Dura Mater, Arachnoid, and Piamater. branches of Meckel's ganglion. The inferior internal angle has the ethmo-max- illo-palato-lachryma] suture. At the apex of the orbit is the optic foramen which is between the two roots of tin h sser wing of the sphenoid. It transmits the optic nerve and opthalmic artery, the nerve lying above and inner to the arten-. The ligament of Zinn is attached to the circumference of the optic foramen, deficient at the upper and outer part, and gives a common origin to the four Recti OlUSCleS. The supraorbital notch or foramen is situated at the junction of the inner and middle third of the upper circumference of the orbit. It transmits the supraorbital vessels and nerve. A line drawn from this notch or foramen In the mental foramen passes through the infraorbital foramen. There are EIGHT MUSCLES in the orbit, viz.. the four Recti, the two Oblique, ANATOMY IX A NUTSHELL. 373 Levator palpebrae, and the Tensor tarsi (Horner's muscle). 1. Papillitis is an inflammation of the optic papilla. 2. Xeuroretinitis is inflammation of the optic nerve and retina. 3. Retrobulbar Neuritis is an inflammation behind the eye-ball. PLATE CXCIII. POSTER 0- MEDIAN SlUXUS H r ^C\ A. ATTHELEVEL OF THE6TH CERVIC/-. NERV- fi00rr ANTERIOR FISSURE CENTRAL CANAL B.AT THE MID- DORSAL REGION POSTERIOR ROOTS ANTERIOR ROOTS CAT THE CENTRE OF THE LUMBAR ENLARGEMENT 0. AT THE UPPER PART OF THE CONUc MEDULLARS E. AT THE LEVEL OF THE 5TH SACRAL NERVE ROCTi L AT THE LEVEL OF THE COCCYGEAL NERVE ROOTS Transverse Sections <>k the Cord at Different Li.\ els. 4. Amblyopia is a dimness of vision from imperfect sensation of the re- tina and without an organic lesion of the eye, 5. Amaurosis is blindness, especially blindness occuring without apparent lesion of the eve. from disease of the optic nerve, retina, spine or brain. 374 ANATOMY IN A NUTSHELL. 6. Retinal or oculae hyperesthesia is a condition in which the eye is abnormally sensitive to light. 7. Ny< i ai.< h'Ia is a condition where the patient can see better in dim light. 8. Hemianopsia is half blindness, a condition in which there is blindness of one-half of the visual held. 9. Myopia is short-sightedness, too great refracting power of the eyes so lhat the rays coining from an object beyond a certain distance are fixed in front of the retina. PLATE CXCIV. MARGINAL ZONE OR LISSAUER S TRACT. A Transverse Section of the Cord, Showing Tracts, Diseases, Etc. 10. Hypermetropia or hyperopia is far-sightedness, the focusing of parellel rays behind the retina. 11. Presbyopia is long-sightedness, an impairment of vision due to old age dependenl upon diminution of the power of accommodation from loss of elasticity of the crystalline lens, causing the near-point of distinct vision to be removed farther from the eye. 12. Emmetropia is a normal condition of the eye as respects refraction. 13. Astigmatism is a condition caused by inequality of the curvature of the different meridians of the cornea. Itmaybe caused by(l) imperfections of the lens, (2) unequal contraction of the ciliary muscles, (3) retinal imperfections. PLATE CXCV PARUTiD GUND TEMPORAL 'DISTRIBUTION OF FACIAL NERVE POSTERIOR AURICULAR A. SUBMAXILLARY GLAND EXTERNAL CAROTID SUBCLAVIAN ARTERY VEIN INTERCOSTAL ARTERY NERVE THE SYMPATHETIC GANGLIA COELIAC AXIS $1 *. ' •* fig *J*Sfe) the Inferior oblique. In front of these are the nuclei of the fibers for accommoda- tion and for sphincter pupillae. It is covered with pia mater and arachnoid on leaving the brain. It pierces the dura mater anterior and external to the pos- terior clinoid process after having passed between the superior cerebellar and the posterior cerebral arteries. It then passes through the cavernous sinus 390 ANATOMY IN A NUTSHELL. above the other orbital nerves. In this position it communicates with the ophthalmic division of the fifth and with the cavernous plexus. Before enter- ing the sphenoidal fissure it divides into two branches, a superior and an in- ferior one, with the nasal branch of the fifth nerve between them. (Plate ( CXXIV). All the structures on the Lower border of the sphenoidal fissure are be- tween tlif two heads of the External rectus muscle. The superior branch is the smaller, h passes forward over the optic nerve and supplies the Levator palpebrae and Superior rectus muscles. The inferior branch supplies three muscles; the division which goes to the Internal rectus passes beneath the optic nerve; the second division passes to the Inferior rectus, and the third or lower division passes to the Inferior oblique between the External rectus and the In- ferior rectus. This division to the Inferior oblique sendsa motor branch to the In- ferior rectus. The branches of the third nerve enter their muscles on the orbital surface except the branch to the Inferior oblique which enters on the posterior 1 inn ler. This third nerve may supply the anterior belly of the Occipito-frontalis, PLATE CCV. DUCTS OF LACHRYMAL GLAND. LACHRYAMAL SAC CARUNCLE NASAL .DUCT Nasal Duct, Conjunctiva, and Lachrymal Gland. the Corrugator supercilii, and the Orbicularis palpebrarum. These muscles are generally supplied by the seventh, but they have escaped paralyses in lesions of the nuclei of the seventh nerve. From the nucleus of the third nerve some fibers which descend in the posterior longitudinal bundle join the facial nerve ju.-t before it leaves the pons; these fibers supply the three muscles above men- tinned. Paralyses of the third nerve may be only in part as any fibers to one muscle or it may be the whole nerve. When the whole nerve is paralyzed the following result : (1 ) Prominence of the eye-ball because most of the mus- cles are relaxed. (2) Extern vl strabismus, the eye-ball being drawn outward because the External rectus which is supplied by the sixth is not paralyzed. (3) Ptosis because the Levator palpebrae is paralyzed. (4) Loss of accommoda- tion because the [nternal rectus, the ciliary muscle, and the sphincter pupillse are paralyzed. (5) Dilatation of the pupil because the sphincter fibers of the iris are paralyzed. ANATOMY IN A NUTSHELL. 391 LESSON CX. (Plate CCXIII). The fourth cranial nerve or Pathetic or Trochlear, has its superficial origin in the valve of Vieussens behind the corpora quadrigemina. The two nerves decussate on the upper surface of the valve. Its deep origin is in the floor of the aqueduct of Sylvius. This nerve can be seen on the base of the brain on the outer side of the cms cerebri, just in front of the pons. It is the smallest of all the cranial nerves but has the longest intercranial course. Coming from the upper end of the valve of Vieussens this nerve crosses the superior peduncles of the cerebellum and the crusta of the mid-brain, just beneath the pons, then it pierces the dura mater in the free border of the tentorium, immediately be- hind and external to the posterior clinoid process. From this point it passes forward in the outer wall of the cavernous sinus between the third nerve and the ophthalmic division of the fifth (See Plate CCXXXII) ; it then crosses the PLATE CCVI. TARSAL CARTILAGE The Muscles of the Orbital Region. third nerve and enters the orbit through the sphenoidal fissure (anterior Lacer- ated); in this fissure it is the highest of all the nerves (See Plate CCXXIV) being situated at the upper and inner angle, internal to the frontal nerve. In the orbit it passes inward above the origin of the Levator palpebrae to enter the orbital surface of the Superior oblique. In the cavernous sinus it communi- cates with the ophthalmic division of the fifth, with the ciliary plexus, and semis a recurrent branch backward between the layers of the tentorium as far as the lateral sinus. While in the anterior lacerated fissure it may send a branch to the lachrymal nerve. If the fourth nerve is paralyzed the function of the Superior oblique is lost and one cannot turn the eye-ball now \\\ \ki> \\n out- wai;i>. Should one attempl to do so the eye is twisted inward producing double vision, diplopia. 392 ANATOMY IN A NUTSHELL. The sixth nerve or Abducent has its superficial origin from the lower part of the pons in the groove between the pyramid and the pons or in the constricted part of the pyramid. Its deep origin is in the floor of the fourth ventricle close to the median line and a little lower than that of the motor root of the fifth. This origin is traced to a nucleus under the upper half of the funiculus teres. This nerve enters the cavernous sinus after the dura mater of the basilar process of the sphenoid, running through a notch immediately below the pos terior clinoid process. In the cavernous sinus it lies external to the internal carotid artery. From this sinus it enters the orbit between the two heads of the External rectus to supply this muscle, entering the muscle on the orbital surface. PLATE CCVII. SUP. RECTUS. INTERNAL RECTUS. INf. OBLIQUE. EXTERNAL RECTUS. SUP. -OBLIQUE. INF. RECTUS. 'y Showing the Directions that Muscles of the Eye-Ball Move the Eye. For its position in the sinus (See Plate CCXXXII.) All the structures on the floor of the sphenoidal fissure lie between the two heads of the External rectus. For position of the nerves in the orbit (See Plate CCXV). The fourth nerve lies on the Superior oblique, the frontal nerve on the Levator pal- pebrae, and the lachrymal nerve on the External rectus. The superior division of the third nerve lies along the Superior rectus; the nasal nerve crosses the optic nerve from without inward: the optic nerve is surrounded anteriorly by the ciliary nerves; the lenticular ganglion lies between the optic nerve and the Ex- ternal rectus. The sixth nerve is on the outer surface of the orbit. The in- ferior division of the third nerve is below the lenticular ganglion and this nerve is joined by filaments from the cavernous plexus, carotid plexus, and the ophthal- mic nerve. If the sixth nerve is paralyzed internal or convergent squint follows as the External rectus loses its function. The pupil is contracted to some extent in paralysis of this nerve as some of the sympathetic fibers to the radiating muscle of the iris pass along this nerve. The fifth nerve is the largest of the cranial nerves. It is more like a spinal nerve than any other of the cranial nerves. It is a compound nerve, having ANATOMY IN A NUTSHELL. 393 an anterior or motor, and a posterior or sensory root with a ganglion upon it. It is called the trifacial or trigeminus, lis superficial origin is on the side of the pons, nearer the upper than the lower border. Its motor fibers, which are three or four bundles, are separated from the sensory fibers, which are seventy to one hundred bundles, by a few transverse fibers. The deep origin is in the floor of the fourth ventricle. Its sensory portion is in a nucleus in the pons just below the floor and just beyond the margin of the upper half of the fourth ventricle. The motor portion is a nucleus internal to the sensory and external to the funiculus teres on the upper half of the floor. (Plates CCXIY- CCXV). PLATE CCVTII. 2ND Showing Refraction of Light Through Crystalline Lens. It is the sensory nerve to the head and face, and a motor NERVE to the muscles of mastication. Its roots pass through an oval opening in the dura mater near the apex of the petrous portion of the temporal bone. The senBory root is from the Gasserian ganglion, which is situated in Meckel's cave. This cave is a depression near the apex of the anterior surface of the petrous portion of the temporal bone. The anterior or motor root passes under the Gasserian ganglion and is not joined to it but joins the inferior maxillary division of the fifth after it passes through the foramen ovale, thus making this pari of the nerve a coin- pound nerve; in fact it is the only pari of the fifth nerve which is a compound nerve for the other two divisions are purely sensory. This ganglion gives off from its anterior edge three trunks. (1) Ophthalmic, (2) Superior maxillary, and (3) Inferior maxillary. It sends communicating branches to the carotid plexus, tentitorium. cerebellum, and the dura mater of the middle fossa. 394 ANATOMY IN A NUTSHELL. I. The ophthalmic branch purely sensory, is the smallest and courses along the outer wall of the cavernous sinus below the third and fourth nerves. It divides into three branches which leave the cranium through the anterior lacer- ated or sphenoidal fissure. (For relation of these branches see Plate CCXXIV.) These branches are the frontal, nasal, and lachrymal. The ophthalmic sup- plies the eye-ball, the lachrymal gland, the orbital and nasal mucous membrane and skin of the eyebrow, forehead, and nose. The frontal branch is the largest and is just external to the fourth nerve and the anterior lacerated or sphenoidal fissure and passes forward on the Leva- tor palpebral dividing into two branches. PLATE CCTX. SUPERIOR FORNIX UPPER LID LOWER LID INFERIOR FORNIX Superior Fornix and Inferior Fornix of Conjunctiva. LESSON CXI. (a) The supraorbital which passes through the supraorbital foramen or notch. It gives a branch to the diplce and mucous membrane of the frontal sinus. The outer and inner branches supply twigs to the pericranium and pierce the Frontalis muscle. They communicate with branches from the facial nerve and are distributed to the skin of the scalp in the frontal and parietal regions. The outer branch is the larger and passes backward almost to the lambdoid suture. (b) The supratrochlear nerve is the smaller and passes inward above tin' pulley of the Superior oblique and sends a branch to join the infratrochlear branch of the nasal. It Leaves the orbit between the supraorbital foramen and the pulley and passes upward under cover of the Corrugator supercilii and ( >ccipito-frontalis to supply the skin of the lower part of the forehead near the midline. The lachrymal is the smallest branch. It passes to the under surface of the lachrymal gland where ii joins the orbital of the superior maxillary, form- ing a loop which sends branches into the gland. It passes through the sphenoid- ANATOMY IN A NUTSHELL. 395 al fissure external and below the frontal nerve and passes along the upper bor- der of the External rectus muscle. It then pierces the palpebral fascia and supplies the conjunctiva and integument at the outer canthus of the eye and that over the external angular process. The nasal branch is the third division of the ophthalmic division of the fifth. It passes into the orbit between the two divisions of the third nerve on the floor of the sphenoidal fissure. In the orbit it passes from the outer to the inner side over the optic nerve, below the Superior rectus, then it passes between the Superior oblique and Internal rectus to leave the orbit through the anterior ethmoidal foramen with the anterior ethmoidal vessels into the cranium. In the cranium it passes forward outside of the dura mater, which separates it from the Levator palpebral to pass through the nasal slit into the nasal fossa where it divides into its three terminal branches. PLATE CCX. CILIARY PROCESSES. AND MUSCLE^ SUSPENSORY LIGAMENT. Crystalline Lens. (a) Internal or septal branch, which is distributed to the upper and front of nasal septum, (b) External branch to superior and middle turbinated bones and to the mucous membrane of the outer wall of the nose, (c) Anterior branch runs in the groove on the inner surface of the nasal bone. It pierces the wall of the nose between the nasal bone and the upper lateral cartilage and sup- plies the integument of the lower part of the dorsum of the nose as far as the tip. The nasal nerve gives off the following collateral branches: 1. The long root to the ciliary ganglion which runs forward on the outer side of the optic nerve to the upper and back part of the ciliary, lenticular, or ophthalmic ganglion. 2. Long ciliary branches, two or three in number, pass along the inner side of the optic nerve, join the short ciliary branch from the ganglion, thru pierce the sclerotic coat to be distributed to the ciliary muscle, the iris, and the cornea. 3. Infratrochlear nerve is given off just before the nasal nerve passes between the Superior oblique and Internal rectus. It communicates with the Supratrochlear and is distributed to the skin of the eyelid and side of the nose, conjunctiva, lachrymal sac, and caruncula lachrynialis. This lenticular, ciliary, or ophthalmic ganglion has three roots. 396 ANATOMY IX A NUTSHELL. A MOTOR ROOT from the third nerve, sympathetic root from the cavernous plexus, and a sensory root from the nasal. Its branches are distributed to the iris, ciliary muscle, and cornea. 11. The superior maxillary division of the fifth is intermediate in size and position between the ophthalmic and inferior maxillary division. It, like the ophthalmic branch, is purely sensory. It comes from the anterior part of the Gasseriarj ganglion and passes through the cavernous sinus in the lower and outer part; it then leaves the cranium through the foramen rotundum, entering PLATE CCXI. CANAL OF SCHLEMN CILIARY BODY CILIARY PROCESSES EXTERNAL RECTUS CHOROID COAI POSTERIOR CHAMBER. CANAL OF PETIT NTERNAL RECTUS MUSC1 NERVE SHEATH A Horizontal Section of the Eye-Ball. the Bpheno-maxillary fossa where it is connected with Meckel's ganglion. As it passes forward it is called the infratrochlear nerve and passes in the groove on the floor of the orbit and comes out on the face through the infraorbital foramen. This foramen is beneath the Levator labii superioris and the Levator anguli- oris. The nerve in this position anastomoses with the seventh to form a plexus ANATOMY IX A NUTSHELL. 397 which gives off three branches, (1) palpebral, (2) nasal, and (3) labial. While in the sphenomaxillary fossa it is in relation with the infraorbital artery which accompanies it on its course to the face. The branches of distribution are: (1) those given off in the cranium; (2) those given off in the spheno-maxillarv fossa; (3) those given off in the infraorbital canal: and (4) those given off on the face. Those in the cranium are one or two meningeal branches which unite with the recurrent branch of the inferior maxillary division of the fifth and also with the sympathetic nerve around the meningeal artery which accompanies it to the dura mater. PLATE CCXII. LEVATOR PALPEBRAE RECTUS SUPERIOR; RECTUS INFERIOR RECTUS INTERNUS. INFERIOR OBLIQUE, The Third Cranial or Motor Oculi Nerve. In the spheno-maxillarv fossa are, 1. Orbital or temporo-nialar branch which passes upward and forward to enter the spheno-maxillarv fissure where it divides into temporal and malar branches. The temporal branch passes upward in a groove in the outer wall of the orbit where it receives a branch from the lachrymal before it traverses the Bpheno-malar foramen to enter the temporal fossa. It turns round the anterior border of the temporal fascia, then running forward and outward to pierce its fascia about an inch above the zygoma to anastomose with the seventh and auiiculo-teniporal of the inferior maxillary division of the fifth, and supplies the skin of the anterior part of the temporal region. The malar branch (subcutaneous mala?) supplies the skin on the promi- nence of the cluck after passing along the external inferior angle of the orbit through the foramen in the malar bone where it perforates the Orbicularis palpebrarum muscle. 2. The spheno-palatine branches are two in number and descend to the Bpheno-palatine or Meckel's ganglion but do not end there, for most of the fibers pass into the palatine nerves. 398 ANATOMY IN A NUTSHELL. 3. The third set are (1) the posterior superior dental, usually two in number. They pass downward and outward through the ptery go-maxillary fissure into the zygomatic fossa where they give branches to the mucous mem- brane of the gums and the posterior part of the mouth. They then enter the posterior dental canals on the zygomatic surface of the superior maxillary bone to communicate with the middle dental nerve and branches to the lining mem- brane of the antrum of Highmore (superior maxillary sinus). It also gives off three branches to the molar teeth which enter the foramina at the apices of the fangs to supply the pulp. (b) The middle superior dental and the anterior superior dental are given off in the infraorbital sulcus. The middle supplies the bicuspid teeth and the mucous membrane of the antrum and the gums. After leaving the infraorbital nerve it passes downward and forward in a canal in the superior maxillary. These branches which supply the teeth anastomose with the anter- ior superior and posterior superior dental branches. At the junction of the middle and anterior is the ganglion of Bochdalek; at the junction of the middle and posterior is the ganglion of Valentin. PLATE OCX III. RECURRENT TO SYMPATHETIC- The Trochlear or Fourth Cranial Nerve. LESSON CXII. (c) The anterior superior branch is given off just before the infraorbital nerve enters the infraorbital foramen. It descends to supply the incisor and canine teeth. It gives branches to the gums and mucous membrane of the antrum and the nasal branch which enters the nasal fossa through a small foramen and supplies the mucous membrane of the forepart of the inferior meatus and its floor. It communicates with the nasal branch from Meckel's ganglion. The branches on the face are palpebral, labial, and nasal. The palpebral supplies the skin and mucous membrane of the lower eye- lid. At the outer angle of the orbil it joins with the seventh and malar branch of the orbital. ANATOMY IN A NUTSHELL. 399 The nasal branch passes inward and upward under cover of the Levator labii superioris to supply the skin on the posterior part of the lateral aspect of the nose. It joins with the nasal branch of the ophthalmic. The labial branch descends beneath the Levator labii superioris to be distributed to the integument of the upper lid, also to mucous membrane of mouth and to labial glands. » PLATE CCXIV. TO TENTORIUM CEREBELLI. ... LESTICULARJiANGLION. ,GASSEPIAV JJTRIFAPAL ^ / V ^ ^— & r.auni mil / -- u -■- HATES FROM CARVERNOUS PLEXUS. FROM 3RD. NERVE. MOTOR ROOT GREAT SUPERFICIAL PETROSAL. FROM 7JH NERVE. GREAT DEEP PETROSAL. FROM CAROTID PLEXUS. J C. WITH AURICULOTEMPORAL. AURICULOTEMPORAL TOFACIAL TO TEMPORO-MAXILLARY JOINT. TO MEATUS-AUDITORIUS. MALL SUPERFICIAL PETROSAL FROM THE FACIAL* STMP. ON MIDDLE MENINGEAL. C C 4 . X T0 TENSOR PALATI ^Vr INFERIOR FROM SYMPATHETIC ON FACIAL ARTERY. TO INTERNAL PTERYGOID TO TENSOR TYMPANI. JWT. BELLY OF DIGASTRIC. Showing Branches of the Fifth Cranial Nerve. III. The inferior maxillary division of the fifth, the mandibular branch, is a compound nerve after it passes through the foramen ovale. It is the largesl branch of the fifth nerve. Its sensory portion comes from the Gasseriau gang- lion. This compound nerve, immediately after it leaves the foramen ovale, divides into anterior and posterior branches. The main trunk before it divides has the External pterygoid muscle and optic ganglioD external, and the Tensor palati muscle internal, and in front of it is the posterior border of the Internal pterygoid muscle, and behind is the middle meningeal artery. The branches from the trunk are (1) a recurrent which passes backward with the middle meningeal artery through the foramen spinosum to supply the dura mater. 2. The nerve to the Internal pterygoid muscle. This nerve sends a motor branch to the optic ganglion. The anterior division of the main nerve is small 400 ANATOMY IN A NUTSHELL. ami chiefly motor ami gives off a masseteric branch which accompanies the ter artery through the sigmoid notch of the inferior maxillary bone to be distributed to the Masseter muscle. It gives a twig to the tempcro-mandi- 1 nilar articulation. 3. Deep temporal branches, two or three in number, which lies be- tween the bone and the upper border of the External pterygoid muscle to end in the deep surface of the Temporal muscle. The anterior one is from the Buccal to supply the front of the Temporal muscle. The middle one to supply PLATE CCXV. SUPRATROCHLEAR N, SUPRAORBITAL N PULLEYOF SUPERIOR OBLIQUE M TENDON OF SUP OBLIQUE TAHSAL CARTILAGE OF UPPER EYELID LACHYMAL GLAND .OOP BETWEEN ORBITAL AND LACHRYMAL NERVES LEVATOr, PALPEBRAL M. SUPERIOR RECTUS FRONTAL N. INTERNAL RECTUS M. OPTIC N. SHORT CILIARY NERVES. ASAL N. LENTICULAR GANG LION INFERIOR OBLIQUE M PALFEBRAL BRANCH NASAL BRANCH LABIAL BRANCH ANT. .SUPERIOR DENTAL N. AN D A MIDDLE SUPERIOR DENTAL A AND N GINGIVAL A. INCISIVE BR._ EXTERNAL RECTUS M. INFERIOR RECTUS M. LACHRYMAL N. THIRD N. FOURTH NERVE. SIXTH NERVE. OPHTHALMIC DIV. OF 5TH N SUPERIOR MAXILLARY N GASSERIAN GANGLION. HENO-PALATINEN. IAN N. AURICULOTEMPORAL N INFERIOR MAXILLARY N SMALL MENINGEAL A MIDDLE MENINGEAL A INTERNAL MAXILLARY A. NFERIOR DENTAL A. NFERIOR DENTAL N BUCCAL A. A MYLO-HYOID N MENTAL N MENTAL A CHORDA-TYMPANI N. Showing Distribution of the Fifth Nerve in Reference to Other Structures. the deep part of the Teiu ] >or;il muscle after passing above the External ptery- goid. The posterior one after uniting with the masseter nerve is sent to the posterior pari <<\ the Temporal muscle. PLATE CCXVI. SUPRATROCHLEAR N INFRATROCHLEAR N NASAL N SUPRACLAVICULAR SHOWING THE CUTANEOUS NERVE SUPPLY OF HEAD AND NECK Showing Cutaneous Nerve Supply of Head \\i> \i< k. 101 402 ANATOMY IN A NUTSHELL. 4. The buccal is sensory and comes out between the two heads of the Ex- ternal pterygoid to reach the Buccinator and is often joined to the anterior temporal and external pterygoid nerves. It communicates with the seventh and is distributed to the mucous membrane of the skin of cheek. 5. Branch to the External pterygoid muscle is generally adherent to the long buccal nerve. The posterior branch of the common trunk is larger and is chiefly sensory. It has three main branches, (a) auriculo- temporal, (b) lingual which is purely sensory, but (c) the inferior dental nerve has a few motor fibers in it which pass to the Mylo-hyoid muscle. 6. The auriculotemporal arises by two heads between which is the middle memingeal artery. It then passes under the External pterygoid muscle, over the capsular ligament into the temporo-mandibular joint. From here upward with the temporal artery beneath the parotid gland to the temporal fossa where it becomes cutaneous and lies posterior to the superficial temporal artery. It gives off seven branches: (a) a branch to facial nerve, (b) a branch to the otic ganglion, (c) two anterior auricular branches distributed to tragus and upper and outer part of pinna, (d) superior temporal to integument of the greater part of the temporal region and they anastomose with the seventh, (e) auricular branch to temporo-maxillarv articulation, (f) branches to external auditory meatus, which branches are given off in the parotid gland. They pass between the cartilage and the bone to enter the meatus. These branches supply the upper part of the meatus, tympanic membrane, and occasionally the lobule, (g) branches to the parotid gland. 7. LiNGUAL(gustatory)formerly supposed to be the nerve of taste. so it was called gustatory, but it is a nerve of common sensation and the name gustatory is still used for this nerve. It lies at first internal to the External pterygoid muscle and then it passes downward in front of the inferior dental nerve and is joined at an acute angle by the chorda tympani nerve from the seventh. From here L1 passes downward and forward between the Internal pterygoid and the ramus, over the Superior constrictor of the pharynx on the Hyo-glossus muscle, above the deep part of the submaxillary gland to the sides of the tongue. It has (a) communicating branches to the anterior dental nerve and submaxillary ganglion and the twelfth nerve, and (b) branches of distribution to the tongue. 8. TheiNFERiOR dental is the largest branch and passes downward underthe External pterygoid muscle posterior to the lingual nerve. then to the dental for- amen after passing between the ramus and internal lateral ligament. It passes through the dental canal to emerge at the mental foramen. This nerve has four main sets of branches, (a) Those to the Mylo-hyoid muscle, (b) branches to the molar and bicuspid teeth, (c) branches to mucous membrane and canine teeth, and (d) branches to the integument of chin and lower lip. The Gasserian ganglion is sometimes called the semilunar ganglion. It lies in Meckel's cave near the apex of the petrous portion of the temporal bone. Beneath this ganglion is the motor root of the fifth nerve and the large super- ficial petrosal nerve which is a branch of the seventh. This latter nerve helps to form the vidian nerve. Filaments from the cavernous plexus of the sympa- thetic join this ganglion on its inner side. Branches pass to the tentorium ANATOMY IN A NUTSHELL. 403 cerebelli and the dura mater of the middle fossa from this ganglion. The three great branches of the fifth nerve, viz., the ophthalmic, the superior maxillary, and the inferior maxillary arise from this ganglion. Besides the Gasserian ganglion the fifth nerve has four other ganglia. (1) The Lenticular, ciliary, or ophthalmic ganglion, (Plate CCXIV) is about the size of a pin's head and is reddish gray in color. It is situated between the optic nerve and the External rectus muscle. The ophthalmic artery is generally on its inner side. This ganglion has three roots, (a) the sensory root which PLATE CCXVII. SUPERIOR NASAL NERVES SPHENOPALATINE N. MECKEL S GANGLION NASAL NERVE NASAL BONE OTIC GANGLION SYMPATHETIC ROOT AURICULO-TEMPORAL N. MIDDLE MENINGEAL A. INTERNAL PTERYGOID TENSOR PALATI I NASO-PALATINE N EXT. PALATINE NERVE Meckel's ( Ganglion and the Otic Ganglion. comes from the nasal branch of the ophthalmic and joins the upper angle of the ganglion. This is the long root, (b) The motor root which conies from a branch of the third nerve that passes to the Inferior oblique muscle. This is the short mot and joins the inferior angle of the ganglion, (c) The sw,n-\- thetic root which coin* s from the cavernous plexus of the sympathetic. It usually blends with the long root. This ganglion gives off five or ten short ciliary nerves from the anterior superior and the anterior inferior angles. These nerves pass with the ciliary arteries forward, one set above the optic nerve and 404 ANATOMY IN A NUTSHELL. the other set below it. After being joined by the long ciliary nerves of the nasal branch of the fifth, they pierce the back part of the sclerotic coat of the eye and then pass forward in grooves on the inner surface of the sclerotic coat to supply the ciliary muscle, iris, and cornea. (Plate CCII). LESSON CXIII. (2) Meckel's ganglion is also called spheno-palatine and is situated in the spheno-maxillary fossa. It is reddish gray in color and somewhat triangular in shape. It has three roots, (a) a sensory root which comes from the su- perior maxillary nerve through the spheno-palatine branches. Most of the fibers of these nerves pass in front of Meckel's ganglion but a few of them enter it. (b) Its motor root comes from the facial nerve through the great super- ficial petrosal, (c) Its sympathetic root comes from the great deep petrosal which is a branch of the carotid plexus. This motor root and this sensory root unite to make the vidian nerve which enters the posterior surface of the gang- lion. The great superficial petrosal nerve comes from the geniculate ganglion of the seventh nerve in the aqueductus Fallopii. After passing through the hiatus Fallopii, it runs forward in a groove on the anterior surface of the petrous portion of the temporal bone under the dura mater and the Gasserian ganglion. In the middle lacerated foramen it unites with the large deep petrosal which comes from the carotid plexus and runs through the carotid canal on the outer side of the internal carotid artery. It then enters the middle lacerated foramen where with the large superficial petrosal it forms the vidian. This ganglion gives off the following branches, (a) ascending which are two or three small branches pass to the orbit through the spheno-maxillary fissure and supply its p< riosteum, (b) the anterior palatine, sometimes called large palatine, passes through the posterior palatine canal and the posterior palatine foramen to the hard palate where it runs forward in a groove nearly to the incisor teeth. It supplies tin- gums, mucous membrane, and glands, and communicates with the naso-palatine nerves. The inferior nasal branches come from the anterior palatine and pass through foramina in the palate bone and supply the middle meatus and the middle and inferior turbinated bones. The anterior palatine also give s off a palatine branch after leaving the canal which supplies tin- .-oil palate (c) the middle or external palatine is not always present, but when it is it passes through an accessory palatine canal to supply the uvula, tonsil, and soft palab , (d) the posterior or small palatine passes through the small posterior palatine canal to supply the Levator palati, Azygos uvulae, soft palat . tonsil, and uvula. These last two branches with branches from the glosso-pharyngeaJ n< rve form a plexus around the tonsil. This plexus is called circulus tonsillaris, (e) The superior nasal which arefour or five branches pass through the sph< no-palatine foramen where they supply the mucous membrane on tin superior turbinated processes and the middle turbinated boms and also the mucous membrane of tin posterior ethmoidal cells. It communicates with the anti rior dental by a branch which passes to the inner surface of the anterior wall of the antrum of Highmor< . (f) The naso-palatine passes forward through ANATOMY IN A NUTSHELL. 405 the spheno-palatine foramen and then across the roof of the nose to the septum. and from here it runs downward and forward beneath the mucous membrane to the anterior palatine foramen. The naso-palatine nerve on the left side passes through the anterior of the two foramina of Scarpa, while the one on the right side passes through the posterior one. Here they supply the mucous membrane behind the teeth and join the anterior palatine nerve, (g) The pharyngeal branches, called pterygo-palatine, arise from the back of the gang- lion and pass with the ptery go-palatine artery through the ptery go-palatine canal to supply the mucous membrane of the upper part of the pharynx behind the Eustachian tube, (h) The posterior superior nasal are a few small branches which pass in the sheath of the vidian nerve to supply the mucous membrane at the back part of the roof, septum, and superior meatus in the nose, and also to the mucous membrane covering the end of the Eustachian tube. (3) The otic ganalion, sometimes called Arnold's, is reddish gray in color. It is small and flat and situated under the foramen ovale on the inner surface of the inferior maxillary nerve near the point where the motor and sensory branches join. This ganglion has behind it the middle ni< ningeal artery. On its inner side the cartilaginous portion of the Eustachian tube and the origin of the Tensor palati muscle. This ganglion has three roots which are (a) its PLATE CCX VI 11. x= ■" to sympathetic The Abdtjcens or Sixth Cranial Nerve. motor root which comes from the internal pterygoid branch of the inferior maxillary division of the fifth, (b) its sensory root may come from the same origin as the motor root, (c) its sympathetic root comes from the sympathe- tic fibers from the middle meningeal plexus. (N. B.) Its motor root may come from the facial nerve, and its sensory from the glosso-pharyngeal nerve through the small superficial petrosal nerve and the tympanic plexus. Branches from this ganglion are (a) a filament passes backward on the OUtei side of the Eustachian tube to the Tensor tympani muscle, (1>) a branch passes to the Tensor palati muscle. Both of these branches are derived prin- cipally from the interna] pterygoid nerve, (<•) Small branches pass to the chorda tympani and buccal nerves. (4) The submaxillary ganglion is situated above the deep portion of the submaxillary gland close to the posterior border of the Mylo-hyoid muscle. This ganglion has three roots which are (a) its SYMPATHETIC ROOT is from the plexus on the facial artery, (b) its motor root is from the chorda tympani of the facial and (c) its sensory root is from the fifth nerve. This ganglion gives off the following branches, (a) five or six small branches which supply the 406 ANATOMY IN A NUTSHELL. mucous membrane of the mouth and Whorton's duct and the submaxillary gland, (b) branches pass from the lingual branch through the submaxillary ganglion with the chorda tympani to the sublingual gland and tongue. Thus we sec that each of these four ganglia has three roots, a motor, a sensory and a sympathetic. LESSON CXIV. (Plate CCXIX-CCXX.) The superficial origin of the seventh nerve (Plate CLXXXVII) is in the upper part of the groove between the olivary and restiform bodies of the medulla oblongata. The deep origin is in the pons under the floor of the fourth ven- tricle, anterior and external to that of the sixth nerve. The seventh cranial nerve and the eighth cranial nerve were formerly called the seventh and con- sisted of two parts, portio dura, which is now called the seventh, and the portio mollis, which is now called the eighth. The pars intermedia arises from the medulla between the seventh and eighth cranial nerves and is connected with them at its origin. The seventh nerve or facial nerve is the motor nerve of the facial muscles of expression, of the muscles of the external ear, Platysma myoides, Buccinator, posterior belly of the Digastric, Stylo-hyoid, Lingualis, and Stapedius. This nerve passes with the eighth nerve into the internal aud- itory meatus where they are joined by the pars intermedia. From the internal auditory meatus it runs into the aqueductus Fallopii where it has an enlarge- ment upon it called the geniculate ganglion, which is reddish in color. It now bends backward on the inner wall over the fenestra ovalis and then runs ver- tically downward behind the tympanum to the stylo-mastoid foramen. After it passes out of the stylo-mastoid foramen it runs forward in the parotid gland and crosses the external carotid artery. At the ramus of the jaw it divides into the temporo-facial and cervico-facial branches. These two branches with their sub-divisions form the pes anserinus. The seventh nerve gives off the following branches of communication, (1) in wditory canal, (a) small branches to the auditory nerve, (2) in aqueduct of Fallopius, (a) large superficial petrosalfrom thegeniculate ganglion which with the large deep petrosal forms the vidian nerve. This nerve passes to Meckel's ganglion, (b) Small superficial petrosal passes from the geniculate ganglion to the otic ganglion, (c) external superficial petrosal from the genicu- late ganglion to the sympathetic plexus around the middle meningeal artery, (d) a branch to the auricular branch of the pneumogastric (Arnold's). (3) At tin. exit OF the stylo-mastoid foramen (a) a branch to the great auricular of the cervical plexus, (b) to auriculo-temporal of the fifth, (c) a branch to the pneumogastric, (d) a branch to the glosso-pharyngeal. (4) Behind the ear, a branch of communication to the small occipital. (5) On the face, branches to the three divisions of the fifth nerve. (6) In the neck, branches to the superficial cervical. The seventh nerve has the following branches of distribution (1) I.\ the aqueduct of Fallopius, (a) tympanic branch which arises opposite the pyramid and passes through a small canal in the pyramid to the ANATOMY IX A NUTSHELL. 407 Stapedius, (b) chorda tympani arises a quarter of an inch above the stylo-mas- toid foramen and passes upward and forward and enters the tympanum through the iter chordae posterius on its posterior wall. This opening is between the opening of the mastoid cells and the membrana tympanum. This nerve now passes between the handle of the malleus and the vertical ramus of the incus to the anterior inferior angle of the tympanum where it passes through the iter chordae anterius (canal of Huguier) at the inner end of the Glasserian fissure. PLATE CCXIX. FROM GLOSSO-PHARYNGEAl SUPERFICIAL CERVICAL Branches of Facial Nerve. While in the tympanum this nerve is covered with mucous membrane. It now passes between the Pterygoid muscles and after receiving a t\vi<: from the otic ganglion joins the lingual branch of the fifth nerve and passes with it to the submaxillary ganglion. The sublingual gland may receive a few fillers from this nerve, but most of them pass to the Inferior lingual muscle. Sonic physiologists claim that the chorda tympani nerve supplies the anterior two- thirds of the tongue with taste, others claim thai the ninth nerve passes with this chorda tympani branch to be distributed to the anterior two-thirds of the tongue, in such a case the ninth nerve is the nerve of taste for the entire tongue. 408 ANATOMY IX A NUTSHELL. (2) \i:\i; the stylo-mastoid foramex, (a) posterior auricular arises from the seventh nerve just outside the stylo-mastoid foramen and passes between the external auditory meatus and the mastoid process where it receives a branch of the auricular branch of the vaults. It communicates with the small occipital nerve and the mastoid branch of the great auricular. It now divides into an auricular branch which supplies the Retrahens aurem and an occipital branch which supplies the Occipitalis muscle, (b) the digastric branch may have its origin by common trunk with the stylo-hyoid branch. It supplies the posterior belly of the Digastric and after perforating that muscle joins the glossopharyn- geal nerve, (c) stylo-hyoid branch enters the Stylo-hyoid muscle near its center ami communicates with the sympathetic plexus on the external carotid artery. :;> On the FACE,(a)it has the temporo-facial branch which passes through the parotid gland over the external carotid artery and temporo-maxillary vein, and as it passes over the condyle of the lower jaw it communicates with the auriculo-temporal branch of the fifth nerve, it finally divides into three sets of branches, first, temporal branch which crosses the zygoma of the temporal bone and supplies the Attrahens aurem and Attolens aurem muscles and joins with the temporal branch of the temporo-malar of the fifth ami the auriculo- temporal also of the fifth. It supplies the Orbicularis palpebrarum, Corrugator supercilii, and the Frontalis muscles, and joins the supraorbital and lachrymal blanches of the ophthalmic division of the fifth; second, the malar branches pass to the outer portion of the orbit where a few fibers pass to the Orbicularis pal- pebrarum arid join branches from the lachrymal nerve, and the others supply the lower eye lid and join the malar branch of the superior maxillary; third, the infraorbital passes to the parts between the mouth and the orbit and supplies the superficial facial muscles and the Pyramidalis nasi ami joins with the in- fratrochlear and nasal branches of the ophthalmic at the inner angle of the orbit. Other branches pass under the Zygomatici and the Levator labii superioris, supplying both of these muscles as well as the Levator anguli oris. They form an infraorbital plexus with the infraorbital branch of the superior maxillary and buccal branches of the cervical facial nerves. These branches supply the Leva- tor labii superioris alanine nasi and the muscles of the nose, (b) The cervical facial branch passes forward through the parotid gland across the external carotid artery and receives branches from the great auricular. It divides op- posite the angle of the lower jaw into three sets of branches, first, buccal which crosses the Masseter muscle to supply the Buccinator and the Orbicularis oris. These buccal branches join the infraorbital branches of the temporo-facial and the buccal branches of the inferior maxillary; second, the supramaxillary (man- dibular) branches pas> under the Platysma myoides and Depressor anguli oris to supply the muscle of the chin and lower lip and join the mental branch of the inferior dental of the fifth: third, the inframaxillary (cervical) branches pass under the Platysma myoides and supply it. One branch descends vertically to join the superficial cervical of the cervical plexus. The eighth nerve will be given with the anatomy of the ear. PLATE CCXX. TERMINATIONS OF SUPRATROCH LEAR OF INFRA TROCHLEAR OF INFRA-ORBITAL Showing Facial Nerve \\i» Superfic] \i. Cki;\ ecal Plexuj 109 410 ANATOMY IN A NUTSHELL. LESSON CXV. The ninth cranial nerve called the glosso-pharyngeal passes to the tongue and the pharynx. It supplies the raucous membrane of the pharynx, tonsil, and fauces with ordinary sensation, and the tongue it supplies with a nerve of taste. This nerve is a compound nerve. Its superficial origin is in the groove between the olivary and restiform bodies. (Plate CLXXXVII). Its DEEP ORIGIN is from the lower part of the floor of the fourth ventricle from three main points. (1) from a nucleus of gray matter beneath the inferior fovea, (2) from the funiculus solitarius, (3) from the nucleus ambiguus. The nucleus ambiguus gives motor branches to the glosso-pharyngeal and the tenth nerves and to the bulbar part of the spinal accessory nerve. The sensory fibers of the ninth nerve are in the jugular and petrosal ganglia. Van Gehuchten says that the fasciculus solitarius is the only sensory nucleus of this nerve. The ninth nerve passes from its superficial origin outward to leave the skull through the centra] part of the jugular foramen. It has a sheath of dura mater of its own and is situated external to and in front of the pneumogastric and spinal acces- sory nerves. It descends in front of the internal carotid artery and beneath the styloid process and muscles attached to it to the lower border of the Stylo? pharyngeus muscle. The nerve now passes inward, lying upon the Stylo- pharyngeus and the Middle constrictor of the pharynx. It finally passes be- neath the Hyo-glossus muscle to its destination. This nerve has two ganglia upon it . The jugular ganglion or superior one is in the upper part of the groove in which the nerve is placed while passing through the jugular formen. It is quite smal] and may be regarded as a segmentation of the lower ganglion. The petrous ganglion is the inferior one and is situated in the lower border of the petrous portion of the temporal bone. It is much larger than the superior one. Fibers arise from it to connect this nerve with the tenth and the sympathetic. It sends two filaments to the pneumogastric, one of which passes to the auricu- lar branch of the pneumogastric, and the other to the ganglion of the root of the tenth. The branch which passes to the sympathetic passes to the superior cervical ganglion, and the branch which passes to the facial nerve arises from the nerve below the petrous ganglion and joins the facial just after it leaves the stylo-mastoid foramen. (Plate CCXXII). It- branches of distribution are, (1) tympanic branch, called Jacobson's nerve, comes from the petrous ganglion and passes in a small canal in the lower surface of the petrous portion of the temporal bone. The lower opening of this canal is on a ridge between the carotid canal and the jugular fossa. This nerve now passes to the tympanum and forms the typmanic plexus. This plexus gives off (a I a greater pari of the small superficial petrosal, (b) a branch to the large superficial petrosal, (c) branches to the tympanic cavity, (d) branches to the carotid plexus,(e) to the Eustachian tube, (f) to fenestra ovalis, (g) to fen- estra rotunda. (2) Pharyngeal branches which are three or four in number unite with the pharyngeal branches of the pneumogastric and sympathetic nerves to form ANATOMY IN A NUTSHELL. 411 the pharyngeal plexus. This union takes place opposite the Middle constrictor of the pharynx. Branches from this plexus perforate the muscular coat of the pharynx to supply the muscles and the mucous membrane. (3) Muscular branch which is distributed to the Stylo-pharyngeus mus- cle, receives a communication from the seventh nerve. (4) The tonsillar branches, which are small, arise undercover of the Hyo-glossus muscle. They pass to the tonsil around which they form a plexus, circulus tonsillaris. From this plexus twigs pass to the pillars of the fauces and to the soft palate where they communicate with the palatine nerve. PLATE CCXXI. STEP'. V LOCUS PERFORATES' / POSTICUS . // M'ODLE PEDUNCLE OP THE CEREBELLUM RESTIFORM BODY OLIVARY BODY = •=:•,■ - ANTERIOR SUPERFICIAL ARCUATE FIBERS DECUSSATION OF OPTIC NERVE INFUNDIBULUM TUBER CINEREUM CORPORA VAMMILLARIA 0CUL0-M0T0R III.' TROCHLEAR NERVE IV. WINDING ROUND THE CRUS CEREBRI TRIGEMINAL NERVE V ABDUCENT NERVE VI.) FACIAL NERVE VII. SUPERIOR SEMICIRCULAR CANAL EXTERNAL SEMICIRCULAR CANAL POSTERIOR SEMICIRCULAR CANAL Origin and Distribution of Auditory Nerve. (5) The lingual nerves are two in number, one supplies the circumval- late papillae and mucous membrane of the base of the tongue, and the other sel supplies the mucous membrane and follicular glands and the posterior one-halt of the g tongue and communicates with the Lingua] nerve. LESSON CXVI. The tenth cranial nerve, pneumogastric, or vagus. Pancoasl rails this nerve the auriculo-laiyngo-pharyngo-03sophago-tracheo-pulmono-cardio-gas- tro-hepatic. This is a compound nerve and sends motor and sensory fibers the organs of voice and respiration, and motor fiber* to the pharynx, the oesopha- 412 ANATOMY IN A NUTSHELL. mis. stomach, and heart. It is the longest of all the cranial nerves. Its super- ficial origin is from the groove between the olivary and restiform bodies below that <>f the glosso-pharyngeal nerve by eight or ten fasciculi (Plate CLXXXVII). Its deep origin is in the floor of the fourth ventricle from the nucleus vagi beneath the ala cinerea below ami continuous with the nucleus of origin of the glosso-pharyngeal. The origin of the sensory fibers of the tenth nerve is in the ganglion of the root and the ganglion of the trunk. Van Gehuchten says that the only sensory nucleus of the tenth is in the fasciculus solitarius. The nerve now passes over the flocculus to the middle compartment of the jugular fora- men, passing behind the glosso-pharyngeal in the same sheath with the spinal accessory. After leaving the jugular foramen it is connected with the accessory part of the spinal accessory and has an enlargement called the ganglion of the trunk. The accessory part of the spinal accessory nerve sends most of its branches into the pharyngeal and superior laryngeal branches of the tenth, while some of its fibers join the ganglion of the trunk. The tenth nerve now passes down the neck in the carotid sheath to the root of the neck. This sheath contains the in- terna] jugular vein externally, the common carotid artery internally, and the tenth nerve between them but on a plane posterior. The relations of this SHEATH ARE AS FOLLOWS: Ix Front. — A few filaments descending from the loop of communication between the descendens and communicans hypoglossi. Behind. — (1) The inferior thyroid artery, (2) The recurrent laryngeal nerve. (3) The sympathetic nerve. On the inner side. — (1) Trachea, (2) Thyroid gland, (3) Lower part of the larynx (more prominent in the female). The ganglion of the root is a small gray mass about five millimetres in diameter and is situated in the jugular foramen. It is connected with the superior cervical ganglion of the sympathetic and the spinal accessory nerves. It gives off an auricular branch by which it is connected with the facial and the glosso-pharyngeal nerves. It also gives off a recurrent meningeal branch. The ganglion of the trunk is below the base of the skull and in front of the internal jugular vein and is about seventeen millimetres long. It is connected with the accessory part of the spinal accessory nerve, with the hypoglossal nerve, ami with the superior cervical ganglion of the sympathetic, and with the loop between the firsl and second cervical nerves. The branches it gives off are (1) a pharyngeal, (2) a superior laryngeal, (3) a superior cardiac (Plates CCXXII- ( (XX I II. The right pneuinogastric nerve passes downward between the first part of the subclavian artery and the subclavian vein beside the trachea, behind the righl innominate vein, and behind the root of the right lung. It helps to form the posterior pulmonary plexus. It now passes downward in two cords which run on the oesophagus and communicate with the pneumogastric nerve of the opposite side making the oesophageal plexus. The two divisions of the pneumogastric nerve mute into one trunk behind the (esophagus and passing through the oesophageal opening in the Diaphragm, is distributed to the pos- terior surface ot' the stomach and to the solar plexus and its divisions. PLATE CCXXII. > M**^^ Showing Disthibution of Ninth, Tenth, and Eleventh Cranial Nehves. 413 (Mi'litied from Gray's Flower.) 414 ANATOMY IN A NUTSHELL. The left pneumogastric nerve passes between the subclavian artery and the carotid artery, behind the left innominate vein. At this point the left phrenic nerve crosses it. It now passes in front of the arch of the aorta behind the root of the left lung where it helps to form the posterior pulmonary plexus. It now passes along the anterior surface of the oesophagus through the Diaphragm to be distributed to the anterior surface of the stomach and the liver. It occasion- ally joins the solar plexus. The pneumogastric nerve has the following connections: (1) Thk ganglion of the root is joined to the spinal accessory, (2) to the petrous ganglion of the glosso-pharyngeal, (3) to the sympathetic. The gang- lion of thk trunk is joined (1) to the hypoglossal, (2) to the sympathetic, (3) to a loop between the first and second cervical nerves. The branches of distribution are (1) meningeal branch (recurrent) which is a small filament given off from the ganglion of the root in the jugular foramen. Ii is distributed to the dura mater in the posterior fossa at the base of the skull. (2) The auricular branch (Arnold's) comes from the ganglion of the root in the jugular foramen. A branch from the petrous ganglion of the glosso-pharyn- geal joins it. The nerve now passes through a foramen in the outer wall of the jugular fossa of the petrous portion of the temporal bone and communicates with the facial nerve. It leaves the temporal bone by the stylo-mastoid fora- men as a rule but it may pass through the tympano-mastoid fissure. Behind the pinna it divides into two branches one of which joins the posterior auricu- lar of the facial, while the other supplies the posterior and inferior part of the externa] auditory meatus and the back of the pinna. (3) Pharyngeal p.i; \ \< ihes are t wo or three and join the pharyngeal branch of the glosso-pharyn- geal on the outer surface of the internal carotid artery and after passing with this artery interna] to the external carotid artery, it turns downward and inward to reach the posterior aspect of the pharynx. At this point the two nerves are joined by branches from the superior cervical ganglion of the sympathetic to help form the pharyngeal plexus. This nerve is the principal motor nerve of the pharynx and comes from the upper part of the ganglion of the trunk of the pneumogastric. .Most of its fibers come from the accessory portion of the spinal accessory nerve. (4) The superior laryngeal nerve comes from the ganglion ^^ the Punk and passes behind the internal carotid artery where it divides into the external laryngeal nerve which branch joins the pharyngeal plexus and the sympathetic, and it supplies the Crico-thyroid muscle and In- ferior constrictor muscle and occasionally the thyroid gland; and the internal laryngeal nerve which passes through the thyro-hyoid membrane to be distri- buted to the mucous membrane of the larynx, and it joins a branch from the recurrenl laryngeal, (5) The inferior oe recurrent laryngeal nerve on the right side arises at the root of the nick in front of the first portion of the right subclavian artery. It passes around the artery and runs upward and and slightly inward behind the common carotid artery. It now runs in a groove between the common carotid artery and the (esophagus, having with it branches of the inferior thyroid artery. It passes under the lower border of the Inferior constrictor of the pharynx into the larynx where it breaks up into branches for PLATE CCXXIII. LINGUAL NERVE PHARYNGEAL BR OF PNEUMOGASTRlC <=HB MAXILLARY GANGLION HYPOGLOSSAL NERVE SUPERIOR LARYNGEAL N EXTERNAL LARYNGEAL NERVE PHARYNGEAL PLEXUS MIDDLE CONSTRICTOR INFERIOR CARDIAC PNEUMOGASTRlC LEFT COMMON CAROTID PHRENIC RECURRENT LARYNGEAL NERVE PULMONARY PLEXUS SPINAL ACCESSORY GANGLION OF PNEUMOGASTRlC SUPERIOR CERVICAL GANGLION SECOND CERVICAL NERVE STEfiNO-MASTOID THIRD CERVICAL NERVE MIDDLE CERVICAL GANGLION SPINAL ACCESSORY ^M. SUBCLAVIAN ARTERY BRACHIAL PLEXUS |NFER'"R CERVICAL GANGLION TRAPEZIUS VENAAZYGOS TERTIUS INTEKCOSTAI VEI* ARTERY IERVE NA AZYGOS MINOB Showing Pneumogastric Nerve and Sympathetic Ganglia. 416 ANATOMY IN A NUTSHELL. all the intrinsic muscles of the larynx except the Crico-thyroid muscle and communicates with the superior laryngeal. Near the beginning of this nerve it usually gives off a cardiac branch. Between the (esophagus and the trachea it gives branches to these structures and near its termination it gives some branch) s to the Inferior constrictor muscle. On the left side the recurrent laryn- geal nerve conn s in front of the arch of the aorta and winds round the arch ex- ternal to the obliterated ductus arteriosus and passes up the left side of the trachea. The remainder of its course is similar to that of the right side. This nerve passes through the superior opening of the thorax while the right one does not. (6) The cardiac brahches of the pneumogastric all pass to the deep cardiac plexus except the inferior cervical cardiac on the left side. It gives off three cardiac branches, (a) the superior cervical arises from the pneumogastric from the upper part of the neck and join the corresponding branches from the sympathetic, (b) the inferior cervical cardiac nerve of the left side passes down- war* 1 on the 1( f1 side of the arch of the aorta between this arch and the pleura and joins the superficial cardiac plexus. The phrenic nerve is in front of it and the left superior cardiac of the sympathetic is behind it as it crosses the arch of the aorta. On the right side this branch passes in front or beside the innomi- nate artery on the side of the trachea to join the deep cardiac plexus, (c) Tho- racic cardiac branches arise' near the recurrent laryngeal nerve and the one on the right side' is on a higher level than the one em the left because the recurrent laryng< al n< rve com< s off em a higher level on the right side. They pass inward to the fronl of the lower end of the trachea to end in the deep cardiac plexus. 7 i The anterior pulmonary branches are two or three in number which arise at the upper border at the root of the lung. They join filaments from the sympathetic and form the' anterior pulmonary plexus from which fine branches pass along the branches into the lung. (8) The posterior pulmonary br inches are' larger than the anterior branches anel are joined by filaments from the third and fourth thoracic ganglia of the' sympathetic and form the posterie>r pulmonary plexus from which branche s pass into the- root of the lung. Occasion- ally branches from the first and second thoracic ganglia pass te> this plexus. (9) Oesophageal branches are given off from the- pneumogastric both above and below the pulmonary branches, but the' low* r one s are- larger and more numerous than the' upper ones. These oesophageal branches, with the' corresponding branch* s of the opp< sit< side, form the oesophageal plexus (Gulae plexus). (10) The gastric branches pass through the oesophageal op< ning in the Diaphragm and the 1 < ft one is distributed to the anterior surface of the stomach. Some of the largest branch* - accompany the gastric artery along the lesser curvature of the' stomach, and from these small twigs pass on the' hepatic artery and join the hepatic plexus. The terminal branches of the right pneumogastric are distributed on the posterior surface of the stomach and join the cceliac plexus, splenic plexus, and the 1< ft r< mil plexus. LESSON CXVII. The eleventh cranial ner\e (Plate CLXXXVII) is called the' spinal acccs- SOry and is purely motor. It consists of two main parts. (1) an ACCESSORY or MEDULLARY PORTION, and (2) \ SPINAL PORTION. THE SUPERFICIAL ORIGIN li ANATOMY IN A NUTSHELL. 417 of this nerve is by four or five small filaments from the sides of the medulla just below the superficial origin of the tenth nerve. Its deep origin is in the floor of the fourth ventricle in a gray nucleus at the back of the medulla, dorso- lateral to the hypoglossal nucleus. The superficial ami deep origin just given are those of the accessory portion of the nerve. Tin-: superfk i \i. origin of the spinal portion is from the lateral tract of the cord as low down as the sixth cer- vical nerve. The deep origin of the spinal portion may be traced to the medio-lateral tract of the gray matter of the cord. This spinal portion of the nerve passes upward between tin ligamentum denticulatum ami the posterior roots of the spinal nerves to enter the skull through the foramen magnum. It is then directed outward to the jugular foramen where it passes through the middle compartment of this foramen in a common sheath with the pneumogas- tric but separated from it by a fold of arachnoid. While in the cranium it in- n -changes fibers with the accessory portion. After passing out of the foramen PLATE CCXXIV. SUPERIOR DIVISION OF ,RD. 'W/Ji / NASAL ' INFERIOR DIVISION OF RD. TH. OPHTHALMIC VEIN OPTIC FORAMEN Showing Structurks Passing Through the Sphenoidal Fissure. in.- gnum, it passes downward behind the Digastric and Stylo-hyoid muscles to the upper part of the Sterno-cleido-mastoid. It supplies the Sterno-cleido- oid and crosses the post( rior triangle of the neck to the d< ep surface of the Trapezius. The accessory portion, while in the jugular foramen, is connected to the ganglion of the root of the pn< umogastric, and sonic of its fib< rs become B< parated from the spinal portion and pass to the ganglion of the trunk of the pneumogastric from which they p;>ss to the pharyngeal and superior laryngeal branches of the pneumogastric. It supplies the muscles of the soft palate through the pharyngeal branch. Some of the branches are continue. I below die ganglioD of the trunk of the pn< umogastric into the recurrent laryng< ;i! ami cardiac nerves. This is the nerve that is affect ed in spasmodic torticollis. (Plate CCXXII). LESSON ('Will. The twelfth cranial nerve or hypoglossal is exclusively motor and supplies the intrinsic muscles of the tongue and the Genio-hyoid muscle and all the ex- trinsic muscles of the tongue e\c< pt the PalatO-gloSSUS. 'I'm SUPERFICIAL ORIGIN of this nerve arises by tell or fifteen filaments between the pyramidal and 118 ANATOMY IN A NUTSHELL. olivary bodies of the medulla. (Plate CLXXXVII). Its deep origin is from the trigonum hypoglossi in the floor of the fourth ventricle. The nerve passes in two bundles through the anterior condyloid foramen after which they unite. It now passes downward hot ween the tenth and eleventh nerves and between the internal carotid artery and the internal jugular vein to the lower border of the Digastric muscle. It now curves round the occipital artery crossing the ex- ternal carotid and lingual arteries to pass between the Mylo-hyoid and Hyo- glossus muscle. It now enters the Genio-hyo-glossus muscle and is continued forward to the tip of the tongue. Its branches of communication are (1) with the GANGLION OF the trunk of the pneumogastric, which connection takes place close to the exit of the nerve from the skull. It also communicates with ilu pharyngeal plexus as it winds around the occipital artery. (2) It commu- nicates with Tin; SUPERIOR CERVICAL GANGLION of the sympathetic which communication takes place opposite the atlas. (3) It communicates with TIIK KIKST AND SECOND CERVICAL NERVES. (4) WlTH THE LINGUAL BRANCH OF Tin; fifth which communication takes place near the anterior border of the Hyo-glossus muscle. (Plate CCXXII). 1 1> branches of distribution are (1) meningeal, which are represented by two filaments given off in the anterior condyloid foramen, pass backward into the posterior fossa of the skull te> be distributed to the dura mater. These nerves are' probably derived from the first and second cervical nerves, the sym- pathetic, or the tenth. It was formerly thought they were' derived from the fifth, (2) Descendens hypoglossi is given off from the twelfth nerve as it passes round the occipital artery. From this point. is passes down over the -heath of the' common carotid artery and joins the' conmmnicans hypoglossi from the second and third cervical nerves just above the middle of the Omo- hyoid muscle. This loop between the descendens hypoglossi anel communicans hpyoglossi is called the' ansa hypoglossi. From this ansa branches are given to the Sterno-hyoid, Sterno-thyroid, and the posterior belly of the Orno-hyoid muscles. A filament from this loop descends into the chest to join the cardiac and phrenic nerves. (3) The thyro-hyoid branch passes from the twelfth nerve near the- posterior border of the Hyo-glossus muscle downward to supply the Thyro-hyoid muscle. (4) Muscular branches are distributed to the following muscle's, (a) Stylo-glossus, (b) Hyo-glossus, (c) Genio-hyoid, (d) Genio-hyo-glossus, (e) to the intrinsic muscles of the tongue. Possibly the In- ferior lingual muscle receives the chorda tympani branch of the seventh. Sympathetic System. LESS< >.\ (XIX. ( Plate's ( !XCV-( !X( !VI-( !XCV 1 1-( !XCV I II.) The sympathetic nerve differs from the somatic nerve in four different ways: (1) it has a greal tendency to form plexuses; (2) it has a preponder- ance of Qon-medullated fibres; (3) fibers are' interrupted in nerve cells and (4) its individual nerve fibers are smaller. The sympathetic nerve is the nerve of organic life. If we had nothing but the' sympathetic nerve' it would be in the form of the human body. lis frame work consists of a chain of ganglia extend- ing in fnmt of the- vertebral column, the upper ganglia being on the anterior PLATE CCXXV Showing the Ajbdomin \i. Aim: \-. 419 420 ANATOMY IN A NUTSHELL. communicating artery of the circle of Willis and is called the ganglion of Ribes; the Lower one, the ganglion of impar is in front of the coccyx. This frame work mighl be compared to a chain of beads. The thread upon which tho beads are strung is called the sympathetic nerve and the beads represent the ganglia. In the cervical region there are only three, in the dorsal region eleven or twelve, in the lumbar region four, and in the sacral region five. There ought to be thirty-one of these, one for each spinal nerve, but on account of the coalesecence of several into one, there are only twenty-three. There is only one nervous system but it has three divisions: (1) the cen- tral consisting of the brain and spinal cord; (2) the twelve cranial nerves and the thirty-one spinal nerves is the peripheral system; and (3) the rest is called i lie sympathetic system. The frame work of the sympathetic is connected to the anterior branch of the spinal nerves by rami communicantes. Each gang- Lion giv< -s off a ramus to the anterior branch of the spinal nerve which is graj , and the anterior branches of the spinal nerves in the dorsal and lumbar regions give off rami communicantes, which are white, to the ganglion of the syntpa- th< tic. Gray rami communicantes are indigenous to every part of the spinal cord, while the white are indigenous to the dorsal and lumbar regions. Every branch that leaves a ganglion is called a ramus efferent, and these rami efh ren- tes have special names, for instance, those going to anterior branches of the first four cervical nerves are called rami communicantes and those that leave 1 1 it se ganglia and go to the heart are called cardiac branches. The gray rami communicantes after theypass to the anterior branch of the spinal nerves fol- low these- nerves to their destination. Those that are given off to bone, facia, Ligament, or blood vessels are called gray rami communicantes, for instance, the musculo-cutaneous nerve- of the brachial plexus gives off a branch that goes into the nutrie nt foramen of the- humerus; this is an < xample of the gray rami communicantes. Tin- anterior crural nerve and the obturator nerve give off branches to the femoral artery; these- branches are also examples of gray rami. The nerve- to the popliteus muscle- sends a branch with an artery into the tibia. This is another example of gray rami. The- parietal layer of the peritom inn gets its nerv< supply from the- gray rami. Here we apply Hilton's law — the nerv< which supplies th< integumenl supplies the muscle- beneath the integu- nient and the Lining beneath the muscle, and this nerve- that supplies the lining does it through th< branch's called gray rami. The sympathetic nerve is developed from the ganglia upon tin posterior nerve root of the spina! cord. 0n< -i t of physiologists say ii is d< veloped from the suprarenal capsule-. The sympathetic nerve gets to its destination by following the- somatic nerves or blood v< ssels. The sympathetic nervous system, like the central system, con- sists of nerve <■< lis and nerve fibres which are- either motor, senseuy or com- pound. Tin- trophic cells are- in the veite-bral ganglion of the- sympathetic nerve. The motor cells of the sympathetic originate in the' ganglion of the sympathetic and some observers say thai the sensory fibres of the- sympathetic originate here also, but others say tin sensory are- in the- cells of the- spinal ganglia. In tlii> Latt< r case (which is probably true-) reflex action can not take place within the- sympathetic without involving the spinal nerves. The- super- ANATOMY IN A NUTSHELL. 421 ior cervical ganglion is reddish-gray in color, about an inch and a half Long, situated behind the internal jugular vein and the carotid artery and in front of the Rectus capitis amicus major muscle. It is in front of the transverse pre- ss : the second and third cervical vertebra-, sometimes a little higher and sometimes a little lower, and the branches given off from this superior cervical ganglion are rami efferent* s. LESSON CXX. 1. Four gray rami to the first four spinal nerves. 2. Branches to the twelfth cranial nerve and branch to the trunk of the pneumogastric and nervus jugulaiis which divides, sending one branch to the root of the pneumogastric and another to the petrosal ganglion of the ninth. PLATE CCXXVI. BICUSPIDS MOLARS The Permanent Teeth. 3. Four or five pharyngeal branches which unite with the ninth and tenth cranial nerves making the pharyngeal plexus, and other branches to the superior and external laryngeal nerves. 4. Superior cervical cardiac nerve which is behind the carotid sheath, behind or in front of the inferior thyroid artery, in front of the Longus colli where it joins the cardiac branches of the tenth and middle cervical cardiac branches of the sympathetic and recurrent and external laryngeal nerves. It descends behind or in front of the right subclavian artery, along the innomi- nate artery to the division of the trachea to enter the deep cardiac plexus. The left one is in front of the left commoD carotid and the arch of the aorta, joining the superficial cardiac plexus. 5. The nervi molles are branches to the external carotid artery and its subdivisions. They rive off subdivisions (a) to the internal-carotid artery. 422 ANATOMY IN A NUTSHELL. (b) tn the thyroid gland, (c) to the submaxillary ganglion which comes from the sympathetic around the facial artery, (d) to the geniculate ganglion of the seventh and the otic ganglion of the fifth. (i. Sends branches to ligaments and bonis. 7. Sends branches to the internal carotid artery which divides into two -i ts, those on its inner side are called cavernous plexus, those on the other side carotid plexus. The cavernous plexus sends off (a) branches to the pituitary body, (l>) to the dura mater on the sphenoid bone, (c) to the mucous membrane of the sphenoidal sinus, (d) to the third nerve, and the fourth nerve, and the ophthalmic nerve, (e) to the carotid artery, (f) to the ciliary ganglion. The carotid plexus gives off (a) small deep petrosal to tympanic plexus. (h) greal deep petrosal to Vidian nerve, (c) to the Gasserian ganglion of the tilth nerve and (e) to the sixth n#rve. LESSON CXXI. The middle cervical ganglion is often absent. It is triangular in shape and is made by the coalescence of two ganglia and it sends (a) two gray rami com- municantes to the fifth and sixth spinal nerves, (b) branches to the thyroid gland along the inferior thyroid artery, (c) middle cardiac nerve which is be- hind or in front of the first part of the subclavian artery, joins the upper cardiac nerve, recurrent laryngeal nerve and ends in the dee}) cardiac plexus. On the left side this nerve enters the thorax between the left com- mon carotid and the left subclavian artery. It sends an ascending branch to join the superior cervical ganglion and one inferior to join the inferior cervical ganglion. It also sends a branch in front of the subclavian artery to join this ganglion called ansa Yieussens. The inferior cervical ganglion is irregular. In front is the vertebral artery, behind a space between the transverse process of the last cervical and the first i lorsal. It is very close to the first dorsal ganglia with which it sometimes unites. Its branches are; (a) Two gray rami to the seventh and eighth cervical ganglia. (b) Branches to the vertebral artery which join a branch from the first dorsal to make the vertebral plexus which surrounds the vertebral artery and going about it into the circle of Willis. This plexus joins the roots of the spinal nerves in the neck. ;) To the inferior cervical cardiac which sometimes comes from the first dorsal; it joins the middle cardiac nerve and recurrent laryngeal nerve and descends on the trachea to the d< ep cardiac plexus. On the left side this nerve is occasionally joined to the middle cervical to form a common trunk. LESSON CXX II. The thoracic ganglia are eleven in number; the first one is called stellatum. [1 i- situated on the neck of the first rib. The second to the ninth are situated on the heads of the ribs. The tenth and eleventh are on the vertebras. They receive white rami communicantes from the spinal nerves and give off gray rami. Each of these ganglia give off rami efferentes which divide into external and ANATOMY IN A NUTSHELL. 123 internal branches. The external branches stud (1) branches to the meninges of the cord (2) to the posterior division of the spinal nerves. (3) to the anterior divisions of the spinal nerves. These last two pass to the vessels of the skin. glands of the skin, and the muscles of the hair. The internal branches divide into an upper set and a lower set. The uppeb set, four or five, send branches to the vertebrae and to ligaments and thoracic aorta and to the lungs. The lower set give off the great splanchnic nerves. The great splanchnic nerves come from the fifth to tenth and end in the semilunar ganglion. The LESSER SPLANCHNIC nerve passes from the ninth and tenth and ends in the renal or solar plexus. The least splanchnic comes from the last dorsal ganglion to end in the renal plexus. The secretory fibers to the lower limbs, \ A.SO- constrictor to vessels of the abdomen, pilo-motor to the circular fibers of the rectum, and inhibitory fibers to the longitudinal muscles of the rectum de- scend from the thoracic tothe lumbar region. Besides these there are afferenl fibers (splanchnic sensory) which pass towards the posterior roots of the dor- sal nerve. The lumbar ganglia are four, being set in front of the vertebrae. The right cord of the sympathetic is behind the inferior v< na cava, the left behind the peritoneum. White rami pass to these ganglia and gray rami pass from them. The rami efferentes are first, external divisions and second, internal divisions. The external divisions send gray rami to the lumbar nerves. The internal divisions send (1) branches to the aorta. (2) hypogastric plexus to the vertebra? and ligaments, and additional vaso constrictor fibers to the renal vessels anel secretory fibers to the ve ssels of the lower limbs and i on- BTRICTOR fibers to the vessels of the- lower limbs, pilo-motor and motor fibers for the circular and ixhibitory fibers for the longitudinal muscles of the' rectum, and motor fibers to the uterus and vas deferens and round ligament, and VASO-MOTOR to the penis anel motor fibers to the circular and INHIBITORY fibers for the longitudinal muscles of the bladd< r. LESSON ('Will. The sacral portion of the sympathetic ends in the ganglion of [mpar. It has five ganglia which give off rami efft re nte s, (1) gray rami to the sacral nerves, (2) branches to anastomose with the branch* s of the opposite side. <:!) branches to plexuses on the middle sacral artery, (4) branches to plevic plexuses branches from impar to tin coccyx and its ligament to the coccygeal gland. There are no white rami in this portion of the sympathetic. They descend from the dorsal region. Vaso-constrictor and secretory for the lower limbs, pilo- motor for posterior part of the body com< from this region. "White' rami of sacral region" are' represented by their viscera] branches and ar< called pe Ivic splanchnics. They contain motor fibers to the longitudinal muse the bladder and for the longitudinal and inhibitory of the rectum ami to the uterus and secretory to the' prostate gland and vaso-dilator to the penis. White' rami enter tin c< rvical sympathi tic from tin dorsal ; some term in. mi.' in the superior ganglion, some in the middle ganglion, ami some in the lower ganglion. The distribution of many an unknown. The sympathetic has three great prevertebral plexuses. First, the cardiac, 424 ANATOMY IX A NUTSHELL. which is situated below and behind the arch of the aorta. For convenience it is ■divided into two parts, the superficial and d< ep. It is formed by all the cardiac branches and the cardiac branches of the pneumogastric nerve. The three cardiac branches conic from the three cervical ganglia, the superior from the superior one. and the middle from the middle one. and the inferior one from the inferior cervical ganglion. These unite with the pneumogastric nerve and form the cardiac plexuses. The superficial cardiac plexus is made by the left superior cervical cardiac and the left inferior cervical cardiac from the pneu- mogastric, plus fibers from the deep plexus. The superficial cardiac plexus gives off brandies to the right coronary plexus and the left pulmonary plexus. The deep cardiac plexus consists of left portion and right portion. The left por- PLATE CCXXVII. DENTINF PULP CAVITY m m X I * J ■ ■ y r ■ \ i A Verticle Section of a Canine Tooth. tion gives off branches to the left coronary plexus and the left auricle. The right part gives off branches both to the right and left pulmonary plexuses and tlir righl auricle. Thus we see that the cardiac plexus is made by sympathetic nerves plus somatic uerve, and the somatic nerve is the tenth. LESSON (XXIV. Tin ><>lar plexus has three uames, SOLAR, EPIGASTRIC, ABDOMINAL BRAIN. It i< situated around the coeliac axis. It is formed by the three splanchnic nerves from each side and the semilunar ganglia and the right pneumogastric uerve, and occasionally the left. It gives off branches to the following arteries ami these subdivisions take the nami s of the arteries which they surround. ANATOMY IX A NUTSHELL. 1 2 5 This plexus, like the cardiac plexus, is made up of sympathetic nerves plus somatic nerve, which is the tenth cranial. Phrenic ob Diaphragmatic Plexus. This plexus accompanies the phrenic artery and is larger on the right than on the left side. At its point of junction with the phrenic nerve is the Ganglion diaphragmaticum. This plexus is situated on the under surface of the Dia- phragm near the supra renal capsule. Its branches are distributed to (1) In- ferior vena cava. (2) supra renal capsule, and (3) hepatic plexus. There is no ganglion on the left side. It receives branches from the semilunar ganglia and solar plexus, also from the phrenic nerve. This plexus gives off branches to the Diaphragm and the supra renal capsules. Supra Renal Plexi s. This plexus surrounds the supra renal artery and its branches are of large size. At its junction with the great splanchnic nerve is found a ganglion. It receives branches from the solar plexus and semilunar ganglia, also from the phrenic nerve and the diaphragmatic plexus. It distributes branches to the medullary portion of the suprarenal capsules. Renal Plexus. This plexus surrounds the renal artery and contains groups of ganglion cells. Its brandies of distribution enter the hilum of the kidney. This plexus receives branches from the solar plexus ami semilunar ganglia, also from the aortic plexus and smallest splanchnic nerves. It sends branches of distribu- tion to the substance- of the kidn< y, the sp< rmatic plexus anel the inferior vena cava. Spermatic Plexus. This plexus accompanies the spermatic vessels to the testes. It rec< ives branches from the renal, aeirtic, anel pelvic plexus. It elistributes branches to the spermatic vessels, vas deferens, and the testes. In the female this plexus follows the course of the round ligament to the ovarian plexus and i> distributed to the ovaries and fundus of the uterus. Cosliac Plexus. This plexus is a direct continuation of the solar plexus and surrounds the coeliac axis. It receives branches from the solar plexus, the lesser splanchnic nerves, and the right vagus. It sub-divides into the (1) gastric plexus, (2) hepatic plexus. (3) splenic plexus. The gastric plexus accompanies the gastric artery along the lesser curva- ture of the stomach. It receives branches from the coeliac plexus and from the left vagus nerve. It sends branches of distribution to the stomach and to the pyloric plexus. The hepatic plexus is the largesl offset from the coeliac plexus. It receives branches from the coeliac plexus, the left vagus nerve and the righl phrenic nerve. It distributes branch s to the pyloric plexus, and branches to the gastro- duodenal plexus, which plexus divides into the righl gastro-epiploic plexus and the pancreatico-duodenal plexus. It also sends branches to the cystic plexus. the right hepatic and the left hepal LC plexus. The splenic plexus accompanies the splenic artery, and receives branches 421) ANATOMY IN A NUTSHELL. from the cceliac plexus, the right vagus nerve, and the left semilunar ganglion. It distributes branches to the pancreatic and left gastro-epiploic plexus, also to the substance of the spl< i n. Superior Mesenteric Plexus. This plexus emerges from under cover of the pancreas and surrounds the trunk of the superior ni< seiiti ric artery. A few ganglia which are found around this artery are called ganglia mesenterica. The branches of this plexus are of a large size and are white and firm. It rec< ives branches from the solar plexus. the cceliac plexus, and the right vagus nerve. It gives off branches to the pancreas, all the small intestines, to the ascending and half of the transverse colon, and to the pancreatico-duodenal plexus. PLATE CCXXVIII. ANTERIOR PALATINE FORAMEN ACCESSORY PALATINE FORAMINA Tin: Hard Palate. Branches from this plexus form .a secondary plexus corresponding to the primary and secondary loops of 'he artery and reach the small intestines by spreading ou1 in the m< s< ritery. \< 'Kin- Plexus. This plexus is situated on the sid( s and in fronl of the aorta, between the origins of the superior and inferior mesenteric arteries. It receives branches from th< solar pit xus and semilunar ganglia, also from the lumbar ganglia. It gives off branches of distribution to the spermatic plexus, the inferior mesenteric plexus, tin- hypogastric plexus, and the inferior vena cava. Inferior Mesenteric Plexus. The inferior Mesenteric plexus surrounds the inferior mesenteric artery and divides into a number of secondary plexuses. Upon this artery is a gang- lion called the inferior mesenteric ganglion. This plexus receives branches ANATOMY IN A NUTSHELL. 427 from the aortic plexus. It distributes branches to half of the transverse colon and the descending colon, to the sigmoid plexus, to the superior hemorrhoidal plexus, and to the pelvic plexus. LESSON CX XV. Hypogastric Plexus. This plexus is situated in front of the promontory of the sacrum between the common iliac arteries. It contains no ganglia. It receives branches from the aortic plexus, the lumbar ganglia. It bifurcates below into two lateral halves which form the pelvic plexuses. This plexus is made up exclusively of sympathetic nerves. Pelvic Plexus. This is situated at the side of the rectum and bladder in the male, and in the female it is at the side of the rectum, bladder and vagina. It accompanies the branches of the internal iliac artery and supplies the pelvic viscera. This plexus contains small ganglia. It is formed by the two lateral continuations of hypogastric plexus, branches of the sacral part of the gangliated cord, branches of the second, third and fourth sacral nerves. It sends branches of distribution to the middle hsemorrhoidal plexus, the inferior hemorrhoidal plexus, the vesical plexus, the prostatic plexus, the vaginal plexus, and the uterine plexus. The middle hsemorrhoidal plexus is situated on the sides of the rectum, and is formed by branches from the pelvic plexus. It communicantes above with the superior hsemorrhoidal plexus and below with the inferior hsemorrhoidal plexus. It is distributed to the rectum. The inferior hsemorrhoidal plexus arises from the back part of the pelvic plexus and joins with branches from the superior and middle hsemorrhoidal plexuses. It is distributed to the rectum. The vesical plexus arises from the fore part of the pelvic plexus, and is formed chiefly by fibers from the third and fourth sacral nerves. Tin nerves sent off pass on each side of the bladder. This plexus is divided into two groups, (1) superior group, (2) inferior group. It distributes branches to the bladder, the vesiculse seminales, the vas deferens, the spermatic plexus. The prostatic plexus is a continuation downward of the pelvic plexus and is situated around the prostate gland. Its nerves are of large size. On the sides of the gland are several ganglionic masses from one-fourth to one-half an inch in length (ganglia prostatica of Muller). It is joined by branches of the internal pudic nerve. It distributes branches to the prostate gland, the ves- iculse seminales, small cavernous nerves to the erectile structure of the penis, corpora caveronsa and corpus spongiosum, barge cavernous nerve joins the dorsal branch of the pudic nerve and supplies the corpora cavernosa and corpus spongiosum. The vaginal plexus arises from the lower part of the pelvic plexus and is composed hugely of sacral nerves. It is situated on the sides of the vagina. It gives off branches to the erectile tissue of the vagina, the mucous membrane of the vagina, and a few twigs to the clitoris. The uterine plexus arises from the upper pari of the pelvic plexus and ac- 428 ANATOMY IN A NUTSHELL. companies the uterine artery between the layers of the broad ligament It receives a few twigs from the ovarian plexus. It distributes branches to the cervix and body of the uterus. Other filaments pass separately into the body oJ the Qterus and fche Fallopian tubes. There are ganglionic enlargements found mi these filaments. PLATE CCXXIX. C'JRRUGATOR SUPERCILII ORBICULARIS PALPEBRARUM TENDO OCULI LEVATOR ALBII SUPERIORIS LEVATOR LABII SUPERIORIS ANTERIOR NASAL SPINE LEVATOR ANGULI ORIS INCISIVE FOSSA COMPRESSOR NARIS OEPRFSSOR ALAE NASI LEVATOR MENTI OEPRESSOR LABII INFERIORS £ DEPRESSOR ANGULI ORIS GROOVE FOR FACIAL ARTERY Tin: Bones of the Orbit. LESSON CX XVI. The gray rami coimn unit-antes originate in cells of the vertebral ganglion, ^d in,,,, here pass to their destination byway of the spinal nerves, (1) to ad- J;, "" ! / y: "';f •'• '"' "' the Prevertebral plexus, (3) directly to the viscera and vessels. Ihe.r trophic cells are in these ganglia where they originate. These ANATOMY IN A NUTSHELL. 429 nerves are indigenous in every part of the spinal cord. The branches that pass to the femoral artery from the Anterior Crural and Obturator are gray rami communicantes, and through these branches the non-medullated axis-cylinder processes of the sympathetic ganglion cells reach the vessels, fascia', bones, cartilages, and periosteum of the lower extremity. A gray ramus communicans passes to the tibia from the branch of the in- ternal popliteal nerve which passes to the Popliteus muscle. Each spinal nerve is joined near its origin by a gray ramus communicans from the sympathetic gangliated cord. The superior cervical ganglion gives off four gray rami com- municantes to the first four cervical nerves. These rami may come from the sympathetic nerve below the ganglion. The middle cervical ganglion s< ntds two gray rami to the fifth and sixth cervical nerves. The inferior cervical ganglion sends two gray rami to the seventh and eighth nerves. The first dorsal ganglion (stellatum) of the sympathetic or the last cervical sends a gray ramus to the first dorsal nerve. One ganglion may send gray rami to two nerves, or two gray rami to one nerve. In the lumbar and sacral regions the gray rami are long and pass downward and outwards over the bodies of the vertebrae to reach the an- terior division of the nerve. In the lumbar region they pass under the Psoas magnus muscle. The white rami communicantes originate in the motor roots of the cranial and spinal nerves. Some of these white rami pass through the vertebral gang- lia without interruption, while others arborize with cells in the vertebral gang- lia. The white rami communicantes are indigenous in the thoracic and upper lumbar regions only, while the gray rami are indigenous in all parts of the cord. The white rami may be called the visceral divisions of the spinal nerves. Al- though the white rami are for the most part derived from the ventral or an- terior roots, yet some of them come from the dorsal or posterior roots. The white rami from the hist two lumbar, and peihaps also from the third and fourth lumbar nerves, pass forward by themselves or in company with the gray rami to join the upper pait of the lumbar gangliated cord. The fifth lumbar and in si sacral do not have white rami while the third sacral and possibly tin s ( cond and fourth have both white and gray rami. The fifth sacral and coccygeal nerves hav< no white rami. In Plate CXCVI1 1 we s< e the gray and white rami communicantes. A, B, ( '. and D represent white or n < dullat< d rami, while E, F, G, H, L, M, N, r< pres< nt tlu gray or non-medullated ran i. A passes from the anterior or ventral root to the sympathetic ganglion of its own segmenl through which it passes to the ganglion below. B has a similar origin but ends in the ganglion of its own segment. Chas a similar origin and passes through the sympathetic ganglion of its own segment to a prev< rtebral plexus or directly to visc< ra. 1 ) has a sim- ilar origin and passes through the sympathetic ganglion of its own stum, nt to end in a higher ganglion. F originates in the sympathetic ganglion and passes along the posterior nerve rod to the dura mater of thi mn\. G originates in the sympathetic ganglion and passes along the posterior division of the spinal nerve to its destination. II originates in the sympathetic ganglion ami passes along the anterior division of the spinal nerve t<> iis destination. It passes to PLATE CCXXX. CEREBRAL CORTEX OPTIC THALAMUS CORPORA QUADRIOEWINA CEREBELLAR CORTEX NUCLEUS DENTATUS \ prosencephalon ( [cerebrum) mesencephalon (mid brain) NUCLEUS FASCICULUS CUNEATUS NUCLEUS FASCICULUS GRACILLIS NUCLEI I METENCEPHALON PONTIS /pONSiCEREBELLUM ULBAR V. MYELENCEPHALON NUCLEI ( MEQULLA OBLONGATA SPINAL CORD Showing the Sensory Pathways to the Brain. 330 (Modified from Eckley's Jackson.) ANATOMY IN A NUTSHELL. 431 somatic, vasomotor, pilo motor, and secretory. K originates in the sympa- thetic ganglion and passes along the recurrent branch to the vertebrae, ligaments, spinal vessels, and dura mater of the cord. L originates in the sympathetic ganglion and passes along the gray rami for a short distance then it leaves it to pass to the vertebra?, intercostal and lumbar vessels. M originates in the sym- pathetic ganglion and like all others that originate in this ganglion are called rami efferentes. X originates in the sympathetic ganglion and pass to the gang- lion above it or the ganglion below it. LESSON ( XXV II. "The gross anatomy of the cervical sympathetic gives no idea of its true anatomical relations as revealed by physiological experiments and pathological phenomena. The physiological connections as at present understood mar be summed up as follows: 1. Pupillo-dilator fibers pass by white rami communicantes from the first, second and third thoracic nerves and ascend in the sympathetic cord to the superior cervical ganglion to form arborizations round its cells. Thence gray fibers pass to the Gasserian ganglion and reach the eye-ball by the ophthal- mic division of the fifth and long ciliary nerves. 2. Motor fibers to the involuntary muscles of the orbit and eyelids from the fourth and fifth thoracic nerves follow a similar course. 3. Yaso-motor-fibers to the head, secretory fibers to the submaxillary gland, pilomotor fibres to the head and neck are derived from the upper thor- acic nerves and reach their areas of distribution after a similar interruption in the superior cervical ganglion. 4. The accelerator fibers of the heart are derived from the upper tho- racic spinal nerves, and end similarly in the middle and lower cervical ganglion gray fibers in the cervical cardiac nerv< s completing the connection." — (Gerrish). " A patient with laceration of the cervix goes through five stages: (1) irri- tation; (2) INDKiESTION; (3) .MALNUTRITION! (4) ANEMIA; (5) NEUROSIS. These stages will appear if the patient has a neuropathic constitution or diathesis. "A general summary of the abdominal brain is: that (a) it presides over nutrition; (b) it controls circulation: (c) i1 controls gland secretion; (d) it pre- sides over the organs of g< n< ration; (e) it influences in a dominant, though not an absolute control its peripheral visceral automatic ganglia." — (Byron Rob- inson). LESSON CXXVIII. ( nvi.ii Tim , Paths. (Pint, s CCX X \-( '( 'X X X I-( '( XXXIII). The cortex of each hemisphere of tin brain is in communication with the opposite half of the body by means of fibers conducting impulses to and from it. These fibers maybe divided into two sets, according to the dir< ction of con- duction : centrifugal, or motor, which conduct < xcitations from the cortex to the various muscles of the body: and centripetal, or sensory, which convey excita- PLATE ('( XXXI. CEREBRAL CORTEX prosencephalon (cerebrum) mesencephalon (mid brain) NUCLEUS FASCICU NUCLEUS FASCICU NUCLEI I MESENCEPHALON PONTIS ((PONS « CEREBELLUM^ MYELENCEPHALON MEDULLA OBLONGATA) > SPINAL Showing the Motor Pathways From the Biiain. 432 (Modified from Eckley'a Jackson.) ANATOMY IN A NUTSHELL. 433 tions from the skin, mucous membranes, bones, special sense organs, to the cortex, where are produced in an unknown way what we call sensation. Each half of the body is thus represented in or projected upon the cortex of the opposite hemisphere; hence the name of projection fibers given to those fibers of the brain through which communication is maintained. (Plate CLXXXI). Thev are in many instances collected into distinct bundles; so that we may speak of motor and sensory tracts or paths, meaning thereby definite groups of fibers along which motor or sensory impulses, as the case may be, travel. Moreover these groups of fibers often arise from or terminate hi fairly definite areas of the cortex, which areas are usually called centers. (Plate CLXXXI 1 1). Thus, that from which springs the fibers that conduct impulses to the muscles which produce the movements of the hand may be called the motor center of the hand; that which receives the fibers along which visual impressions travel is the center of sight. Of the many ways in which impulses may travel between the brain and the spinal cord, the following (1), (2), (3), (4), (5), (6), are the most important that have been demonstrated. If these impulses travel through the cerebellum we call the way they pass the indirect route, but if they miss the cerebellum we call the way they travel the direct route. This applies to both motor and sensory impulses. Sensory impulses, which are afferent, (centripetal) take the following routes: (1.) They travel by the way of the tracts of Goll and Burdach (fasciculus gracilis et cuteatus) (Plate CCXXX) to the nuclei gracilis et cuneatus by means of neurones of the first order. By way of explanation we might say that a neurone system consists of a group of nerve fibers and their cells of origin. From nuclei gracilis et cunetus the impulses travel by neurones of the second order through the mesial fillet to the optic thalamus. The mesial fillet crosses to the opposite side and gives off collaterals to (a) the bulbar nuclei, (1)) to the mid-brain. From the optic thalamus the impulses travel to the cerebral cortex by the way of neurones of the third order, however some of those of the second order may pass through the optic thalamus to the cerebral cortex uninterrupted. Thus we see two neurone systems may carry the impulses to the cortex or it may take three. Muscle and joint sensations travel through these i racts. This route is direct because it does not travel through the cerebellum. (2.) After passing through neurones of the first order by the way of col- laterals to the gray matter of the anterior horn, the impulses travel through the AlNTERO-lateral- ground bundle (fasciculi proprii) by neurones oi the second order to the optic thalamus. While in the posterior longitudinal bundle (fas- ciculus longitudinalis medialis) collaterals are given to the bulbar nuclei and mid-brain. From the optic thalamus neurones of the third order pass to the Cortex. This route is direct and conveys cutaneous and painful sensations. (3.) After passing through neurones of the first order by the way of col- laterals to the cells of gray matter of the cord, they travel by the way of the tracts of Gower's (antero-lateral ascending) by neurones of the second order through the dorsal region of the pons and medulla to mid-brain and optic thal- amus. From the optic thalamus neurones of the third order complete the 434 ANATOMY IN A NUTSHELL. course to the cortex. This route is direct and conveys cutaneous and painful sensations. LESSON (XXIX. (Plate CCXXX). (4.) This route is indirect because it passes through the cerebellum. Neu- rones of the first order carry impulses to nuclei gracilis et cuneatus by way of i i; vers ok Goll and Btjrdach just as in the direct route. From here neurones of the second order through the restiform bodies (inferior peduncles of the cere- bellum) of the same or opposite side to the vermis, giving off collaterals to the nuclei in the cerebellum, such as nucleus dentatus. Impulses now pass from PLATECCXXX1I. OPTIC NERVE INTERNAL CAROTID ARTERY I OPHTHALMIC ARTERY \ / ANTERIOR CLINOIO PROCESS TROCHLEAR NERVE \ / / rn „ r \ \ / / TROCHLEAR NERVE. DIAPHRAGMA SELLAE "^^^^^^T^nA ^gSS? ^/W'M/^^M^P^—— LACHRYMAL BRANCH PITUITARY FOSSA. -J|f ^FIW \ ."' (R^^f^/ ft - ' f ^T ■7^Ju\ '" 'f^'fiS. ■":;:•- A-.^^-^p' -^>'-^V^^-l0CUL0-M0T0R NERVE. -SUP. DIVISION ll^^.X 1 /^^^'\ ::: ^-V5^ ~ g ^ 3x// NASAL BRANCH OF OPHTHALMIC NERVE SPHENOIDAL SINUS ^m^^y^My^m^ x - ■" - ■ "---■^S— ^3^y\^^0CUL0-M0T0R NERVE (INF. DIVISION; ADUCENT NERVE^^^^y^ftQ-X^^^^__ "' ^ ABDUCENT NERVE SPHENOID B0NEs£— ^J^^Tp-J^ MAXILLARY DIVISION OF TRIGEMINAL NERVE INTERNAL CAROTID ARTERY/ /(^a r ^y »f'*pT^/^. N \\^^^ H CAVERNOUS SINUS / / / \ \ \ ' / / \ \ FORAMEN OVALE OPHTHALMIC DIVISION OF TRIGEMINAL NERVE / / \ \ / / \ INFERIOR MAXILLARY DIVISION OF TRIGEMINAL NERVE SOP. MAXILLARY DIVISION OF USEMINAL NERVE — ' / \ INF. AXILLARY DIVISION OF TRIGEMINAL NERVE ' MOTOR RO The Cavernous Sinus (Modified from Cunningham.) the vermis to the nucleus dentatus by way of neurones of the third order. From t he nucleus dentatus impulses pass to the red nucleus of the opposite side through the superior peduncles. This is done by means of neurones of the fourth order. From the red nucleus neurones of the fifth order pass to the optic thalamus. From the optic thalamus neurones of the sixth order pass to the cortex. !■">.! These Impulses pass in the direct cerebellar tract (fasciculus spino-cerebellaris dorso-lateralis) then through the inferior peduncles of the cerebellum to the vermis of the same and opposite side by means of neurones of the second order. Collaterals are given off to the nucleus dentatus. From the vermis neurones of the third order pass to the nucleus dentatus and from here by in urones of the fourth order to the red nucleus. From the red nucleus to the optic i hah) inns by n< urones of the fifth order and from the optic thalamus to the cortex by neurones of the sixth order. Neurones of the first order trans- mit impulses to cells in the columns of Clark by the way of collaterals. This route is indirect because it passes through the cerebellum. AX ATOMY IN A NUTSHELL. 435 (6.) In this route impulses pass up (Power's tract (fasciculus spino- cerebellaris ventro-lateralis) by neurones of the second older to the mid-brain. From here they reach the superior worm by the way of the superior peduncles of the cerebellum. The remainder of the route is the same as that in route 4 and 5. Neurones of the first order give collaterals to cells of the gray matter. The indirect route may take six neuroxk SYSTEMS to complete its course while the direct takes only three. This route is indirect because it passes through the cerebellum. LESSON CXXX. (Plate CCXXXI). The motor impulses, which are efferent (centrifugal) take the following routes : (1.) By the way of the pyramidal tract without passing through the cerebellum. This route is direct. Impulses in this route pass from the cortex through the corona radiata. internal capsule, and pyramidal tracts to the lower end of the medulla by neu- rones of the first order. From the lower end of the medulla the fibers pass in the following ways: (a) most of them cross to the opposite side in the decussa- tion of the pyramid to descend in the crossed pyramidal tract (fasciculus cere- bro-spinalis lateralis) to end in the gray matter of the anterior horn. (1>) some of the fibers descend in the direct pyramidal tract (fasciculus cerebro-spinalis ventralis) to end in the gray matte r of the anterior horn, (c) the remaining fibers d< set rid in the crosst d pyramidal tract of the same side to e nd in the gray matter of the anterior horn. From the cells in the gray matter of the anterior horn neu- rones of the second order carry impulses to the muscle. Thus we see that two neurone systems will carry a motor impulse from the cortex to the muscle 1 . (2.) By the way of corpus striatum and mid-brain without passing THROUGH THE CEREBELLUM. This route is direct. These- impulses pass by neurones of the first order to the- corpus striatum. Most of these' come from the frontal region. They now pass by neurones of the se'e-eind order to the' mid-brain. From the' mid-brain impulses pass by neurones of the third order by the' antero-lateral de scending tract to end in the' gray matter of the' 'anterior horn. Neurones of the fourth order now carry the impulse' to the muscles over the' anterior roots of the spinal nerves. (3.) By way of the pyramidal TRACT, NUCLEI PONTIS, CEREBELLUM, BUL- BAR nuclei. This route passes through the cerebellum therefore it is an in- direct route. Impulses pass by the neurones of the first order through the corona radiata, internal capsule, and pyramidal tract to the pons. From the- pontis nuclei impulse's pass by the' middle' peduncle's to the' cortex of the opposite side of the- cerebellum. From here neurones of the third order carry the im- pulses to the' dentate' nucleus. Neurones of the fourth order pass from the dentate' nucleus to the bulbar nuclei. Neurones of the fifth order pass from the bulbar nuclei to end in the gray matte r of the and rior horn and from here neurones of the' sixth order pass to the muscle s. PLATECCXWIII. CEREBRAL CORTEV PROSENCEPHALON ( ERERKUM) MESENCEPHALON i METENCEPHALON PONTIS / /PQNS*CEKEBELLUM| myelencephalon (medulla oblongata) NUCLEUS FASCICULUS CUNEA"r|£ - - NUCLEUS FASCICULUS C-RACILLIS SPINAL COHD Showing Both Sknsoiiy and Motor Pathways. Modified from Eckley- Jackson.) 436 ANATOMY IN A NUTSHELL. 437 Every sensory point of the body is connected to every motor point by a re- flex pathway, and all nerve impulses conform to the reflex type. A reflex impulse may pass over many different paths between any given sensory point and motor point. (Plate CCXXXII) show- both afferent and efferent pathways. The brain is a collection of gray ganglia connected by white commissures. (Xote). The middle commissure is gray, but it is not a commissure in the true sense because it has not fibers hi it. When we can name and define the commissures of the brain and give the boundaries of all the ventricles and describe each structure which helps to make these boundaries, then we understand something of the brain. LESSOX CXXXI. The Transverse Commisures are : 1. Anterior commissure. See page 347 2. Middle commissure. See page 348 3. Posterior commissure. See page 348 4. Optic commissure. See page 366 5. Corpus callosus. See page 350 6. Pons varolii. See page 362 7. Fornix, also longitudinal. Page 348 8. Sup. or ant. medullary velum (valve of Yieussens.) 9. Inf. or post, medullary velum The Longitudinal commissures are: 1. Olfactory tracts. See page 365 2. Tsenia Semicircularis. See page 356 3. Crura cerebri. See page 363 4. Processus-e-cerebello-ad-testes. page 354 5. Peduncles of pineal glad. 6. Fornix. See page 348 7. Gyrus Fornieatus. 8. Lamina cmerea. See page 345 9. Infundibulum. 10. Fasciculus uniformis. See LESSON CXXXII. Third Ventricle. ROOF. 1. Corpus callosum. See page 350 2. Fornix. See page 348 3. Velum interpositum (Tela choroidea superior). See page 351 4. Epithelium. floor. 1. Tegmental portion of the diverg- ing crura cerebri. See page 363 2. Posterior perforated spare 3. Corpora albican i in. See pa.ue 349 4. Tuber cinereum. 5. Infundibulum. 6. Lamina cinerea (anterior wall). WTKRlnR BORDER. 1. Anterior commissure. See page 347 2. Anterior pillars of fornix. Page 349 3. Foramen of Monro. Seepage ".11 P< istkriok BORDER. 1. Posterior commissure. Page 348 2. Aquedud of Sylvius. Page 341 3. Epithelium from pineal body to velum interpositum (tela choroi- dea superior). BIDES. 1 . ( tptic thalamus. See page :, 1 >,S ANATOMY IX A NUTSHELL. PLATE CCXXXIV. BREGMA. TEMPORAL RIDGES. 3» CO O NION. — BONE S — l-FRONTAL. 6-MALAR. 7-LACHRIMAL. 8-SDR MAXILLARY. 9-NASAL. KHNF. MAXILLARY. 2-PARIETAL. 3-0CC1P1TAL. 4-TEMPORAL. 5-SPHENOID. — -SUTURES- CORONAL- FROM PTERION TO PTERION. BETWEEN FRONTAL AND PARIETALS. SAGITTAL- FROM BREGMA TO LAMBDA - BETWEEN THE PARIETALS. LAMBDOID- FROM ASTERION TO ASTERION BETWEEN PARIETAS AND OCCIPITAL. The Sutures of the Skull. LESSON CX XX III. L \ti:i; \i. Ventricle: ROOF - OUTER SIDE. L. Corpus callosum. See page 350 1. Corpus callosum. See page 350 '''•" nK - INNKK SIDE. 1. Caudate nucleus. 1. Corpus callosum. Seepage :r><> 2. Taenia semicircularis. See page 356 2. Fornix. See page 348 :: - Lamina cornea. 3. Septum lucidum. See page 351 4. Choroid plexus. "). optic thalamus. Sec page 352 6. Fornix. See p.-iu<' '■'< 18 ANATOMY IX A NUTSHELL. 439 LESSON CXXX1Y. Fourth Ventricle. The ruof or posterior boundary Is formed by the cerebellum and has the following points for consideration: 1. Superior peduncles of cerebellum. See page 354 2. Valve of Vieussens, anterior or superior medullary velum. 3. White matter of vermiform process of cerebellum. 4. Inferior medullary velum. 5. Epithelial lining of choroid plexus. 6. Tela choroidea inferior. 7. Obex. 8. Ligulse. The floor or anterior boundary is formed by the pons and medulla and has the following points for consideration: 1. Eminentia teres. 2. Fovea superior. 3. Conductor sonorus. 4. Locus caeruleus. 5. Fovea inferior. 6. Ala cinerea (trigonum vagi.) 7. Trigonum hypoglossi. 8. Tuberculum acusticum. LESSON CXXXV. The first cranial nerve is called olfactory. It leaves the cranium through the cribriform plate of the ethmoid. One disease of this nerve is called anosmia. The second cranial nerve is called optic. It leaves the cranium through the optic foramen. One disease of this nerve is optic neuritis. The third cranial nerve is called motor oculi. It leaves the cranium through the anterior lacerated (sphenoidal) fissure. Paralysis of this nerve will canst 1 ptosis. The fourth cranial nerve is called trochlear. It leaves the cranium through the anterior lacerated (sphenoidal) fissure. Paralysis of this nerve will cause diplopia. The fifth cranial nerve is called trifacial. The ophthalmic division Leaves the cranium through the sphenoidal fissure. This division of the nerve is sub- ject to malarial and septic poisons. The superior maxillary division Leaves the cranium through the foramen rotundum. The inferior maxillary division leaves the cranium through the foramen ovale. These last two divisions are subject to rheumatic influences. The fifth nerve is involved in tic-douloureux, neuralgia, and toothache. The sixth cranial nerve is called abducens. It leaves the cranium through the anterior lacerated (sphenoidal) fissure. Paralysis of this nerve will cause convergent squint. The seventh cranial nerve is called facial. It starts to leave the cranium through the internal auditory meatus and after passing through the aqueduc- PLATE CCXXXV. GROOVE FOR SUPERIOR LONGITUDINAL SINUS GROOVE FOR ANTERIOR MENINGEAL ARTERY FORAMEN CAECUM — CRISTA GALLI SLIT FOR NASAL NERVE GROOVE FOR NASAL NERVE ANTERIOR ETHMOIDAL FORAMEN ORIFICES FOR OLFACTORY NERVES POSTERIOR ETHMOIDAL FORAMEN ETHMOIDAL SPINE OLFACTORY GROOVES OPTIC FORAMEN OPTIC GROOVE OLIVARY PROCESS ANTERIOR CLINOID PROCESS MIDDLE CLINOID PROCESS POSTERIOR CLINOID PROCESS GROOVE FOR SIXTH NERVE MIDDLE LACERATED FORAMEN ORIFICE OF CAROTID CANAL DEPRESSION FOR GASSERIAN GANGLION NTERNAL AUDITORY MEATUS SLIT FOR DURA MATER SUPERIOR PETROSAL GROOVE FORAMEN LACERUM POSTERIUS ANTERIOR CONDYLOID FORAMEN AQUAEOUCTUS VESTIBULI _- POSTERIOR CONDYLOID FORAMEN MASTOID FORAMEN - POSTERIOR MENINGEAL GROOVES Showing Foramina at the Base^of the Skull. 440 ANATOMY IX A NUTSHELL. 441 tus Fallopii it passes through the stylomastoid foramen. This nerve may he paralyzed after it leaves the stylo-mastoid foramen, or during its passage through the petrous portion of the temporal hone, or at its origin in the brain. In any of these cases it is called Bell's paralysis. Paralysis of this nerve in the brain is also called bulbar paralysis. The eighth cranial nerve is called auditory. It starts to leave through the internal auditory meatus but stays in the internal ear. One disease of this nerve is deafness. The ninth cranial nerve is called glosso-pharyngeal. It leaves the cranium through the middle compartment of the jugular foramen. Loss of taste is ageusia. The tenth cranial nerve is called pneumogastric. It leaves the cranium through the middle compartment of the jugular foramen. One thing that may happen when this nerve does not preform its function is asthma. The eleventh cranial nerve is called spinal accessory. It leaves the cranium through the middle compartment of the jugular foramen. Paralysis of this nerve causes spasmodic torticollis. The twelfth cranial nerve is called hypoglossal. It leaves the cranium through the anterior condyloid foramen. Paralysis of this nerve causes motor aphasia. The following are the descriptions of those parts of the brain not previously given. (1) Valve of Yieussens is a thin leaf of medullary substance between the superior peduncles of the cerebellum. It is also called anterior or superior medul- lary velum. (2) Posterior or inferior medullary velum is the commissure of the flocculus of the cerebellum. (3) Posterior perforated space is the depression just behind the cor- pora albicantia at the base of the brain. The arteries which pass through this space pass to the optic thalamus. It would be better to call it the posterior perforated substance. (4) Tuber cinereum is a tract of gray matter extending from the optic commissure to the corpora albicantia. and it is one of the structures in the floor of the third ventricle. (5) Lamina cinerea is a connecting layer of gray matter between the cor- pus callosuin and the optic commissure. » (6) Infundibulum is a funnel shaped process of the brain passing from the tuber cinereum to the pituitary body. (7) Corpus striatum consists of the caudate nucleus, the lenticular nucleus. and the internal capsule, and is situated opposite the Assure of Sylvius. (8) Choroid plexuses are vascular plexuses in the ventricles of the brain. (9) Tela choroidea [nferior is the membranous pari of the roof of the fourth ventricle. (10) Peduncles of the pineal gland are delicate white bands passing forward from each side of the pineal gland along the edge of the third ventricle to join the anterior pillars of the fornix. PLATE CCXXXVI. ANTERIOR PALATINE FOSSA _ TRANSMITS LEFT NASO- PALATINE NERVE TRANSMITS ANTERIOR PALATINE VESSEL TRANSMITS RIGHT NASOPALATINE NERVE ACCESSORY PALATINE FORAMINA TENSOR PALATI POSTERIOR NASAL SPINE AZYGOS UVULAE HAMULAR PROCESS SPHENOID PROCESS OF PALATE PTERYGOPALATINE CANAL BASILAR PROCESS TENSOR TYMPANI RECTU! PHARYNGEAL SPINE FOR. SITUATION OF SUPERIOR CONSTRICTOR EUSTACHIAN TUBE AND CANAL FOR TENSOR TYMPANI LEVATOR PALATI — — CANAL FOR JACOBSON S NERVE AQUAEDUCTUS COCHLEAE - FORAMEN LACERUM POSTERIUS CANAL FOR ARNOLDS NERVE ANTERIOR CONDYLOID FORAMEN CONDYLE ARTICULATES WITh ATLAS " — ORAMEN POSTERIOR CONDYLOID FORAMEN LIGAMENTUM NUCHAE lm; Inferior Surfa< e of Base of Skull 442 ANATOMY IN A NUTSHELL. 443 (11) Obex is a band of gray nervous matter at the point of the calamus soriptorius. The calamus scriptorius is the groove on the floor of the fourth ventricle, at the end of which is the Ventricle of Arantius. (12) Ligula is the tongue shaped organ of white matter on the lower part of the roof of the fourth ventricle. (13) Fovea superior is a depression in the floor of the fourth ventricle on the outer side of the eminentia teres. (14) Fovea inferior is a depression with its apex at the striae, which cross the center of the floor of the fourth ventricle, and its base below. (15) Eminentia teres is on each side of the median line on the upper half of the floor of the fourth ventricle. It is produced by an underlying bundle of white fibers (funiculus teres) formed by fibers of the facial nerve. (16) Conductor sonorus is formed by a whitish band of fibers which are connected below with the strke medullaris. (17) Ala cinerea (trigonum vagi) is a d< pr< ssion below the inferior fovea. (18) Trigonum hypoglossi is situated on the inner side of the inferior fovea. (19) Tuberculum acusticum is situated en the outer side of the inferior fovea. (20) Fasciculus unciformis connects the parietal lobe with the temporal lobe, and is situated in the bottom of the fissu'-e of Sylvius. (21) Locus ceruleus is a bluish depression above the fovea superior. LESSON CXXXVI. The relations of the External Carotid Artery. (Plates CXVI- CXVII-CXVIII. In Front. — (1) Skin. (2) Superficial fascia. (3) Platysma and deep fascia. (4) Anterior border of Sterno-mastoid, (•">) Hypoglossal nerve, (6) Lingual vein, (7) Facial vein, (8) Digastric muscle. (9) Stylo-hyoid muscle. (10) Parotid gland with facial nerve and temporo-maxillary vein in its substance. Behind. — (1) Superior laryngeal nerve, (2) Stylo-glossus, (3) Stylo? pharyngeus, (4) Glosso-pharyngeal nerve, (5) Parotid "land. Externally. — Internal carotid artery. [nternally. — (1) Hyoid bone, (2) Pharynx, (3) Superior laryngeal nerve, (4) Parotid gland, (5) Ramus of jaw. The INTERNAL CAROTID ARTERY (PlaKs CXVI-CXVII-CXVIII) which begins at the upp< r border of the thyroid cartilage is divided for convenience into four parts. (1) The cervical portion passes vertically upward in front of the transverse processes of the three upper cervical vertebra? to enter the car- otid canal in the petrous portion of the temporal bone. This portion has no branches. (2) The petrous portion passes in the carotid canal where it runs forward and inward in front of the tympanum and from here ascends to the cavernous sinus. This portion gives off the tympanic branch, which runs through a small foramen in the wall of the carotid canal to enter the tympanum. (3) The cavernous portion passes in the cavernous sinus to the posterior clinoid process and from here along the body of the sphenoid bone and then passes 444 ANATOMY IN A NUTSHELL. upward on the inner side of the anterior clinoid process where it leaves the cav- ernous sinus. This portion gives off (a) the artkri.e receptaculi branches which pass to the pituitary body, Gasserian ganglion, and to the walls of the cavernous sinus and inferior petrosal sinus, (b) anterior meningeal which passes over the lesser wing of the sphenoid to the dura mater in the anterior fossa, ici ophthalmic — this artery has been described od page 383, (4) The cerebral portion \'\ the antero-internal frontal, which passes to the two inferior frontal lobes; ami the middle internal frontal, which passes to the corpus callosum and i" the inner surface of the ascending frontal lobe and first frontal lobe; and it finally gives off the posterior internal frontal which passes to the quadrate lobe, il.) MIDDLE CEREBRAL, (Plates CLXXIII-CLXXV) which runs outward in the fissure of Sylvius and gives off its branches near the central lobe. Its branches ANATOMY IN A NUTSHELL. 445 are anterolateral ganglionic which passes to the corpus striatum, internal cap- sule and optic thalamus; external and inferior frontal which pass to the third frontal convolution; ascending frontal which passes to the ascending frontal convolution; the ascending parietal which passes to the ascending parietal con- volution; and parieto-sphenoidal which passes to the angular convolution and the superior temporo-sphenoidal convolution, (c) The posterior commu- nicating artery, (Plate CLXXIII) which runs backward and joins the pos- terior cerebral artery. It sends postero-mediaD ganglionic branches which pass through the posterior perforated space, the optic thalamus and wall of the third ventricle, (d) Anterior choroid artery which runs backward into the descending horn of the lateral ventricle. (Plate CLXXIII.) The circle of Willis is formed by seven arteries which make an enclosure at the base of the brain just beneath the third ventricle. All the structures in the floor of the third ventricle are in the circle of Willis except the tegmental portion of the cms, and everything in the circle of Willis is in the floor of the third ventricle except the optic commissure. The arteries that make this circl e arc the two posterior cerebral from the basilar; the two anterior cerebral which are branches of the internal carotid; the two posterior communicating and the anterior communicating which is the shortest artery in the body and has upon it ganglion of Ribes. The posterior cerebral which are branches of the basilar artery wind around the cms cerebri to the under surface of the occipital lobe. Here it sends branches (a) TO THE UNCINATE LOBE, (b) TO THE CUNEATE LOBE, (c) TO THK TEMPORAL lobe. Xear its origin it receives the posterior communicating artery. The postero-median ganglionic branches pass from the posterior cerebral through the posterior perforated space to the walls of the third ventricle. A posterior choroid branch conns from the posterior cerebral and passes to the velum in- terpositum and choroid plexus. A postero-Iateral ganglionic branch comes from the posterior cerebral ami passes to the optic thalamus. LESSON CXXXVII The Relations of the Entern kl Carotid Artery. Ix Front. — (1) Skin, (2) Superficial ami deep fascia, (3) Platysma, (4) Sterno-mastoid, (5) Occipital artery, (0) Posterior auricular artery. (7) Hypo- glossal nerve, (8) Parotid gland, (9) Stylo-glossus, (10) Stylo-pharyngetis. (11) Glosso-pharyngeal nerve, (12) Pharyngeal branch of the pneumogastric. Behind. — (1) Rectus capitis amicus major. (2) Sympathetic, (•'>) Super- ior laryngeal nerve. Externally. — (1) Internal jugular vein, (2) Pneumogastric nerve. Internally. — (1) Pharynx, (2) Superior laryngeal nerve. (3) Ascending pharyngeal artery, (4) Tonsil. The Right subclavian artery arises from the innominate opposite the sterno- clavicular articulation and passes upward and outward to the Scalenus anticus muscle on the right side. The left Subclavian artery arises from the end of the arch of the aorta and ascends to the Scalenus anticus muscle. The artery 440 W ATOMY IX A XI TSHELL. now runs outward behind the Scalenus anticus muscle then downward under the clavicle to the lower border of the first rib where it takes the name of axil- lary. 'Hit' Scalenus anticus muscle divides this artery into three portions. The portion internal to the muscle is the first portion, the portion behind it is ;Ik second portion, and the portion < xternal to it is the third portion. 'I'm: Relations of First Portion ok the Right Subclavian Artery. 1\ Front. — (1) Skin. (2) Superficial fascia. (.'!) Platysma and deep fascia, l Clavicular origin of Sterno-mastoid, (5) Sterno-hyoid, (6) Sterno-thyroid, (7) Anterior jugular, (8) Internal jugular, (9) Vertebral veins, (10) Pneu- PLATE CCXXXVIII. METOPIC SUTURE. FRONTAL %% EMINENCE SUPERCILIARY Wk' RIDGE. 0BICULAR1S PALPEBRARUM.' INT. ANGULAR PROC SUPRAORBITAL NOTCH OR FORAMEN. CORRUGATOR SUPERCILII. NASAL SPINE. Extern \i. Surface of Frontal Bone. mogastric nerve, (11) Cardiac nerves, (12) hoop from the sympathetic. Behind. (1) Recurrent laryngeal nerve, (2) Sympathetic, (3) Pleura i 1 1 Apex of lung. Beneath.— (1) Pleura, (2) Recurrent laryngeal nerve. Tin: Relations of First Portion ok Left Subclavian Artery. In Front. (1) Pneumogastric nerve, (2) Cardiac nerves, (3) Phrenie nerve, (4) Left carotid artery. (5) Thoracic duct, ((i) Left internal jugular. (7i Vertebral vein, (8) Innominate vein, (9) Sterno-thyroid. (10) Sterno- hyoid, (11) Sterno-mastoid. Behind. (1) Oesophagus, (2) Thoracic duct. (.'-!) Inferior cervical gang- ANATOMY IN A NUTSHELL. 447 lion of sympathetic, (4) Longus colli. Outer Bide. — (1) Pleura, (2) Left lung. Inner Side. — (1) Trachea. (2) (Esophagus, (3) Thoracic duct. LESSON CXXXVIII. The Relations of Second Portion of Subclavian Artery are the same on each side. In Front. — (1) Skin, (2) Superficial fascia, (3) Platysma and deep cer- vical fascia, (4) Sterno-mastoid, (5) Phrenic nerve, (6) Scalenus auticus. ' 7) Subclavian vein. Behind. — (1) Pleura, (2) Scalenus medius. Aboa t e. — Brachial plexus. Below. — Pleura. The Relations of Third Portion of Subclavian Artery are the same on each side. In Front. — (1) Skin, (2) Superficial fascia, (3) Platysma and deep cer- vical fascia, (4) Descending branches of cervical plexus, (5) Nerve to sub- clavius muscle, (6) Subclavius muscle, (7) Suprascapular artery, (8) Supra- scapular vein, (9) The external jugular vein, (10) Transverse cervical vein. (11) Clavicle. Behind. — (1) Scalenus medius, (2) Lower cord of brachial plexus. Above. — (1) Brachial plexus, (2) Omo-hyoid muscle. Below. — First rib. LESSON CXXXIX. The branches of the subclavian artery are (1) vertebral, which arises at the upper and back part of the artery and passes upward through the foramina in the transverse processes of the upper six cervical vertebrae. After it passes through the foramen in the transverse process of the atlas, it passes behind the articular process of this bone in the sinus atlantis lying superficial to the sub- occipital nerve. 11 now pierces the dura mater and passes through the torn men magnum of the occipital bone to the front of the medulla oblongata. It unites with the opposite vertebral at the low< r border of the pons to form the basilar artery. The branches of the vertebral artery are: (A) the cer- vical branches which send muscular branches to the neck, lateral spinal which pass through the intervertebral foramen and then divides into two branches one of which runs along the nerve roots to the cord and its coverings, the other divides into ascending and descending branches which form with similar branches from above and below loops on the posterior surfaces of the bodies of the vertebrae. (B) cranial branches which send posterior menin- geal branches to the posterior fossa, anterior spina! descends in front of the medulla and unites with its fellow to form a single trunk at the foramen mag- num. This main branch descends in the anterior median fissure of the cord. For description of anterior spinal and posterior spina! see page 337. The pos- terior inferior cerebellar is tin- last branch of this crania] portion and winds around the medulla across the restiform body to the under surface of the cere- bellum. lis ANATOMY IN A NUTSHELL These two vertebral arteries unite to form the basilar artery, which runs in a groove in the middle of the pons to its anterior border where it divides into the posterior cerebral branch. The basilar artery gives off (A) numerous TRANSVERSE BRANCHES to the polls and adjacent parts, (B) THE INTERNA! \i [>n (C) the anterior inferior cerebellar artery which crosses the cms cere- belli to the anterior border of the under surface of the cerebellum, (D) the 51 perior cerebellar which winds abound the crus cerebri on each side near the fourth uerve to reach the upper surface of the cerebellum. PLATE CCXXXIX. ANT. SUP. ANGLE. POST.SUF. ANGLE POST. INF ANCLE. FOR LATERAL SINUS. -GROOVES FOR ODLE MENINGEAL, ARTERY. ANT. INF. ANGLE. [nternal Surface of the Parietal Bone. (2) The internal mammary arises from the first portion of the subclavian artery opposite the thyroid axis and descends on the posterior surfaces of the costal cartilages to the sixth interspace where it divides into the musculo* phrenic and the superior epigastric branches. As it passes down it is about a half an inch fromthe sternal margin. The branches of the internal mammary are (a i COMES \Kuvi phrenici which accompanies the phrenic nerve to the Diaphragm, (b) the mediastinal branch which passes to the anterior med- iastinum, (c) pericardiac which passes to the anterior surface of the pericardium, (d) sternal branches which pass to the posterior surface of the sternum, (e) interior [ntercostal branches which pass to the five or six upper in- terspaces where each branch divides inio two divisions to pass along the mar- \\ \TOMY IX A NUTSHELL. 449 gins of the interspaces, (f) perforating branches which pass through the five or six upper interspaces to the skin and muscles on the chest, and those that pass through the second, third, and fourth spaces go to the mammary gland. Of its terminal branches the musculo-phrenic runs behind the cartilages of the false ribs to pierce the Diaphragm at the eighth or ninth rib and ends at the twelfth rib where it gives off anterior intercostals to the lower intercostal spaces pericardiac branches, and diaphragmatic branches. Its other terminal branch the superior epigastric descends in the interval between the sternal and costal attachments of the Diaphragm to pierce the sheath of the Rectus muscle running on its posterior surface to anastomose with the deep epigastric in the substance of this muscle. LESSON CXL. (3) The thyroid axis arises near the the Scalenus Anticus from the first portion of subclavian artery and gives off inferior thyroid, suprascapular, and trans versalis colli arteries. The inferior thyroid artery ascends behind the middle cervical ganglion of the sympathetic and the sheath of the common carotid artery to the thyroid gland. It crosses the vertebral artery, Longus colli muscle, and the recurrent laryngeal nerve. It may, however, pass under this nerve. Its branches are, (a) tracheal, which pass to the trachea, (b) oesophageal, which pass to the oesophagus, (c) muscular, which pass to the adjacent muscles, (d) inferior laryngeal, which passes to the back of the larynx with the recurrent laryn- geal nerve, (e) ascending cervical, which passes between the Scalenus an- ticus muscle and the Rectus capitis anticus major on the anterior tubercles of the transverse processes. The suprascapular artery crosses the Scalenus anticus muscle behind the clavicle and passes over the transverse ligament of the scapula to the supra- spinous and infraspinous fossa?. This artery goes to the clavicle, scapula, and humerus, as well as to the sterno-clavicular articulation and acromio-clavicu- lar articulation and the shoulder girdle. The transversalis colli is on a higher level than the suprascapular artery and crosses the Scaleni muscles and the brachial plexus to the Trapezius muscle. Here it divides two branches, (a) superficial cervical which ascends under the anterior border of the Trapezius to anastomose with the superficial branch of the arteria princeps cervicis, (b) tiiio posterior SCAPULAR branch, which runs under the Levator anguli scapulae to the superior angle of the scapula and then descends under the Rhomboidei muscles to the inferior angle of the scapula. This artery may arise from the third portion of the subclavian. (4) The superior intercostal comes from the upper and hack pari of the subclavian artery and descends on the neck of the first two ribs to supply the first two intercostal spaces. In the first intercostal space it gives off a branch which is distributed in like manner to the aortic intercostals. The artery in the second intercostal space generally joins one from the highest aortic intercostal. All intercostal arteries give off branches to the posterior 450 ANATOMY IX A NUTSHELL. spinal muscles and a small one which passes to the spinal cord and its mem- brane. The profundus cervicis most always comes from the superior inter- costal, but it may come from the subclavian artery itself. It ascends under the Complexus muscle as far the axis to anastomose with the deep branch of the arteria princeps cervicis. The relation— of the thoracic aorta are given on page 286. and its branches arc (1) pericardiac, which are small arteries and are distributed To the pericardium. (2) the bronchial arteries are nutrient arteries to the lungs. The one on the right side may come (A) from the first aortic intercostal, PLATE CCXL. PARITTAL FORAMEN. TEMPORAL R,DGES - jurtu :^*~ ART , LT'5 Wl SPHENOID. SQUAMOUS PORTION, TEMPORAL MUSCLE. ■^-EMINENCE. MASTOID PORTION- External Surface of the Parietal Bone. (B) IT MAY COME BY A COMMON TRUNK WITH THE LEFT BRONCHIAL which collies from the fronl of the thoracic aorta. There are generally two on the left side. These arteries nourish the bronchial tubes, the cellular tissue of the lungs, the bronchial glands, and the (esophagus, (3) (Esophageal arteries are generally four or five in number,and come from the front of the thoracic aorta and pass ob- liquely to the oesophagus. Above they anastomose with the inferior thyroid arteries, ami below with branches from the phrenic and gastric arteries. (4) The posterior mediastinal arteries are small arteries which supply the glands in the posterior mediastinum. ANATOMY IN A NUTSHELL. 451 LESSON CXLI. (5) The intercostal arteries are eleven in number. Those of the first and second spaces come from the subclavian, and the remaining nine come from the thoracic aorta. The last one, which passes along the lower border of the Last rib, is called the subcostal. The right intercostal arteries are longer than the left ones because the aorta is situated on the left side of the spine. In each intercostal space the artery lies upon the External intercostal muscle and has in front of it the pleura and a thin fascia. From here it passes between the two layers of intercostal muscles and passes to the lower border of the rib above to pass forward in the groove on the lower border of this rib to anastomose with the anterior inter- costals which are branches of the internal mammary. The first intercostal, which comes from the aorta, anastomoses with the superior intercostal, while the last three intercostals which come from the aorta pass between the abdom- inal muscles to anastomose with the epigastric in front and with the phrenic and lumbar arteries behind. In each intercostal space there is a vein, artery, and nerve, and their position from above down is vein, artery, and nerve, ex- cept in the upper intercostal spaces where the nerve is first above the artery. Fibrous arches keep the intercostal muscles from pressing upon the intercostal arteries during respiration. The lower intercostal arteries pass into the ab- dominal wall and into the sheath of the Rectus muscle where they anastomose with the internal mammary and the deep epigastric artery. The branches of the intercostal arteries are (a) the posterior or dorsal branch, which passes backward to the inner side of the anterior costo-transverse ligament where it is distributed to muscles and integument of the back after dividing into an ex- ternal and internal branch, (b) The spinal branch, which passes through the intervertebral foramen to be distributed to the spinal cord and its coverings and the bodies of the vertebrae, (c) The collateral intercostal branch arises from the intercostal artery close to the angle of the rib and then passes downward to the upper border of the rib below, along which it passes to anas- tomose with the anterior intercostals from the internal mammary. The thoracic aorta commences on a level with the fourth dorsal vertebra and descends on the left side of the spine to pass through the abdominal open- ing in the Diaphragm after which it is called abdominal aorta. The abdominal aorta commences at the aortic opening in the Diaphragm extends to the front of the body of the fourth lumbar vertebra where it divides into tiih right and lkft common iliac arteries. (Plate XCI | LESSON CXLI I. The Relations of the Abdominal Aorta. In Front. — (1) Lesser omentum, (2) Stomach. (3) Branches of the cceliac axis, (4) Solar plexus, (5) Splenic vein, ((>) Pancreas, (7) Left renal vein, (8) Transverse duodenum, (9) Mesentery, (10) Aortic plexus. Behind. — (1) Left lumbar veins, (2) Vertebral column. Right Side. — (1) Right cms of Diaphragm, (2) Inferior vena cava, (3) Yena azygos major, (4) Thoracic duct, (5) Right semilunar ganglion. 452 ANATOMY IN A NUTSHELL. Left Side. — (1) Left lumbar veins. (2) Left semilunar ganglion. The branches of the abdominal aorta are (1) parietal branches and under this we have (A) phrenic branches which are two in number and as a rule arise close together on the under surface of the Diaphragm, but they present PLATE CCXLI. A-0CCIP1T0 FRONTALIS. B-TRAPEZIUS. C-STERNO- MASTOID D-SPLENIUS E-COMPLEXU! F-0BL'Q5.SUR G - RECTU S CAPITUS POST. Ml H-NECTUS CAPIT POST.MIN. I - RECTU5- CAP.LAT. J-FEC-CAB/I K-RECCftP.AJfT.MJ. L-SURCONSTRICTO M- POST. CONDYLOID FORAMEN. N- ANT. CONDYLOID FORAMEN. 0- SUP. CURVED OR NUCHAL LINE. P- LINEA SUPREMA. Q- INF. CURVED LINE. R-FOR LIGAMENTUM NUCHAL. ^■% S - INION OR EXT. %a OCCIPITAL ^ .„ PROTUB- ERANCE. T- CREST. U-BAS- & ILAR PROC V- PHAR- YNGEAL SPINE. -TUBERCLES FOR CHECK LIGAMENTS X- JUGULAR PROC. Y- CONDYLES. ART.WITH ATVS. External Surface of Occipital Bone. much variation in their origin since they may come by a common trunk or one may come from the comae axis and the other from the renal artery. The one on the righl side passes across the crura of the Diaphragm to the under surface of that muscle behind the inferior vena cava, while the one on the left side passes behind the oesophagus to the under surface of the Diaphragm. (B) Ltjmbab arteries are five pairs and arise from the back of the aorta to pass outward on the body of the vertebrae beneath the Psoas magnus muscle and the sympathe- tic nerve. The first two pairs pass under the crura of the Diaphragm and the right one also passes under the inferior vena cava. Near the transverse pro- cesses of the vertebrae they divide into an abdominal branch, which passes outward beneath the Quadratus lumborum to end between the muscles of the abdominal wall where they anastomose with the deep epigastric, the internal mammary, the ilio-lumbar, and the circumflex iliac arteries. It is well to say ANATOMY IN A NUTSHELL. 453 that the first pair cross the Quadratus lumborum muscle. The other branch is the dorsal branch which passes with the posterior primary branch of the inter- costal nerve and gives off spinal branches which supply the spinal cord and its coverings. It anastomoses with the intercostal artery. (C) Sacramedia is a small branch given off at the bifurcation of the abdominal aorta and passes over the fifth lumbar vertebra and the sacrum to the coccyx where it anasto- moses with the lateral sacral arteries. (Plate XC.) LESSON CXLIII. (2) The visceral branches and under these we have (A) coeliac axis, which is a short trunk about a half of an inch long, arises between the crura of the Diaphragm just above the Pancreas. It passes horizontally forward and di- vides into three branches. Gastric or coronary artery is the smallest of these three branches and passes upward to the left side behind the lesser' sac of the peritoneum to the cardiac end of the stomach. It also uives branches to the oesophagus, then turns to the right and passes along the lesser curvature of the stomach sending branches to both sides of the stomach. It anastomoses with the pyloric branch of the hepatic artery. Hepatic artery passes forward and upward between the layers of the lesser omentum to the transverse fissure in the liver where it divides into right and left hepatic branches to supply the lobes of the liver. In the fetus this is the largest of the branches of the cceliac axis because it supplies the liver which is such a large organ in the fetus. In the adult this artery is smaller than the splenic artery. The branches of the hepatic artery are Pyloric, which extends along the lesser curvature of the stomach passing from right to left to anastomose with the gastric artery. ( i.\^- tro-duodenalis pass behind the first portion of the duodenum and divides into the folio whig branches. Gastro-epiploiea dextra, which runs along the greater curvature of the stomach from right to left to anastomose with the gastro-epiploiea sinistra which is a branch of the splenic artery. This artery gives branches to both the stomach and the great omentum. Pancreatico- duodenalis superior passes between the second part of the duodenum and the pancreas. After supplying both of these organs, it anastomoses with the pan- creatico-duodenalis inferior which is a branch of the superior mesentery and with the pancreatic branches of the splenic. The right hepatic passes to the righl lobe of the liver ami uives off the cystic artery which supplies the gall bladder. The left HEPATIC passes to the left lobe of the Liver and uives off branches to the Spigelian lobe . The splenic artery is the largest of the three branches of the cceliac axis and is very tortuous in its course. It passes along the upper border of the pancreas, crosses the left kidney to the spleen. It divides into pancreatic^ i'\i;\ e. These pancreatic branches supply the upper border of the pancreas while Tin; PANCREATN \ MAGNA, which is :i single large branch, passes from the left to the right near the posterior surface of the pan- creas accompanying the pancreatic duct. Tun GASTRIC BRANCHES, called vasa BREVIA, are live or >i\ in number and pass to the left extremity of the stomach which it supplies. Gastroepiploic* sinistra is the Largesl o\' the branches of the splenic artery and runs from left bo right along the greater cur- 454 ANATOMY IN A NUTSHELL. vature of the stomach between the layers of the great omentum. It anasto- moses with the gastro-epiploica dextra and supplies both the greater omentum and the stomach. (B) Superior mesentery arises about one-fourth of an inch below the cceliac axis and passes between the pancreas and the third portion of the duodenum which it crosses and passes downward to the right be + ^en the layers of the mesentery. It supplies all of the small intestine, except the first portion of the duodenum. It also supplies the caecum, the ascending PLATE CCXLII. FOR FALX CEREBELLI. FOUFALX CEREBRI TORCULAR HEROPHILI. POST CONDYLOID FORAMEN. LATERAL SINUS ANT GONDYLOID FORAMEN FOR PETROSAL SINUS. JUGULAR FOSSA. GROOVE FOR MEDULLA. BASILAR PROC. Internal Surface of Occipital Bonk. colon, the transverse colon. Its branches are pancreatico-duodenalis in- ferior, which passes from Left to right in the concavity of the duodenum where ii anastomoses with the pancreatico-duodenalis superior. It gives branches to the head of the pancreas and to the transverse and descending portions of the duodenum. Vasa entestini tenuis are twelve or fifteen in number which c • from the left convex side of the superior mesenteric artery to supply the jejunum and ileum. Aboul two inches from their origin each branch divides and joins similar branches from the adjacent artery thus forming arches from ANATOMY IN A NUTSHELL. 455 which numerous branches are given off to supply the mesentery and the small intestine. Four or five sets of arches are given off. The ilio-colic artery is given off from the right side of the superior mesentery artery. It passes be- tween the layers of the mesentery to the right iliac fossa where it divides into two -anehes, ascending and descending. The ascending one passes to the ascending colon and anastomoses with the colica-dextra. The descending one passes to the lower part of the ileum, csecum. appendix, and ileo-csecal valve. The colica-dextra arises from the middle of the superior mesentery artery and passes behind the peritoneum to the ascending ion where it gives off an ascending branch which anastomoses with the colica-media. and a descending branch which anastomoses with the ileo-colic. Colica-media comes from the upper part of the concavity of the superior mesenteric artery and passes for- PLATE CCXLIIL LESSER WING. 1 - ANT.CLINOIO PROCESS 2 - MID. CLINOIO PROC 3 - POSTCLINOID PROC 4 -OPTIC GROOVE 5-- OLIVARY PROC. 6 - SELLA TURCICA. 7 - CAVERNOUS GROOVE 8-LINGULA 9 -SPINOUS PROC. \/\ SUPP0RT5 PTERYGOI GRqOVE FOR OLFACTORY TRACT. C REATER WING 10- FORAMEN OPTICUM. II- GROOVE FOR SIXTH WTRVE. 12 -SPHENOIDAL FISSURE. 13- FORAMEN VESALII. H- FORAMEN OVALE 15- FORAMEN 'X-'l SPINOSUM. 1/ 16- FORAMEN ROruNDUM Posterior View of the Sphenoid Bom:. ward in the transverse meso-colon where it givi s a right branch which anas- tomoses with the colica-dextra, and a left branch which anastomoses with the colica-sinistra. ((') (Plate CLVII.) The inferior mesentery artery arises from the left side of the aorta aboul an inch and a half above the bifurcation. It supplies the descending colon, sigmoid flexure, and the greater part of the rec- tum. It lies a1 hist on the left side of the abdominal aorta, then crosses the Psoas muscle, left common iliac artery, ami un ter, to the back of the rectum. It gives off the following branches. COLU \->i\i>ti; \. which passes behind the peritoneum upward in front of the left kidney to th< descending colon where it divides into an ascending branch, which anastomoses with the colica-media, and a descending branch which anastomoses with the sigmoid artery and the superior hemorrhoidal artery. Tin: sigmoid lrteri passes to the sigmoid flexure and anastomosi s with the colica-sinisl ra and the superior haemorrhoidal. 156 ANATOMY IN A NUTSHELL. The SUPERIOB hemorrhoidal artery is really a continuation of the inferior mesenteric artery and passes behind the rectum to divide into two branches in the meso-rectum. One branch passes od cither side to within about six inches oi the anus where they subdivide to supply the rectum. This artery anasto- moses with the sigmoid, middle and inferior haemorrhoidal arteries. (D) The suprarenal, sometimes called middle capsular, are two in number and come from the abdominal aorta a little below the cceliac axis. They pass obliquely upward and outward over thecrura of the Diaphragm to the suprarenal body. They anastomose with the superior capsular of the phrenic and the inferior capsular of the renal. (E) The renal arteries are two in number which come PLATE CCXLIV. SPHENOIDAL FISSURE, OPTIC FORAMEN ARTIC. WITH PERPEND'R PLATE- ARTIC. WITH MALAR. TEMP'L FOSSA ORB [TAL SURFACE PTERYGOID RIOGE. ZYGOMATIC FOSSA + SPHENODAL TURBINAL BONES W\( puss out the i xternal abdominal ring into the scrotum where it sup- ANATOMY IN A NUTSHELL. 457 plies the testicle. Each artery anastomoses with the artery of the vas deferens and the cremasteric artery. In the female these arteries are called the ovarian. They are shorter than the spermatic and do no1 pass out of the abdominal cav- ity. They rim between the layers of the broad ligament of the uterus to the ovary and the round ligament and Fallopian tubes. Branches are given off which follow the round ligament through the inguinal canal to the integument of the labium and groin. PLATE CCXLV °TERYG0ID FOSSA ,'fl\^ ~ TENSOR PALATI ^ INTERNAL PTERYGOID SUPERIOR CONSTRICTOR The Pterygoid Processes. LESSOX CXLIV. Muscles of the Thorax. External intercostal*. — Description. — Then are eleven of these on each side, extending from the tubercles of the ribs posteriorly to the commencement of the cartilages of the ribs anteriorly. From the ant t rior < xtremity of the mus- cle the anterior intercostal membrane extends forward to the sternum. The fibers of the External intercostals pass downward and forward like tin fib the External oblique muscle of the abdomen. A firm layer of fascia covers the outer surface of the External intercostal aswell asthe inn; r surface of tin In- ternal intercostal muscles. The middle im< rcostal fascia, which is more deli- cate than either of the oth< rs, is placed b< I \v< < n the two set> of muscl< s. The Intercostal fascia' are best shown In twe< n the External intercostal muscles and rn ui n anteriorly and b< tw< en the I nit rnal int< rcostals and the spine pos- teriorly, for in th< m situations tin- muscular fiU rs arc d< fici< at. Origin. — From the lower border of each rib < xtending from the tubercles to the commencemi nt of the cartilag* s. Insertion. — Into the upper bord< r of the rib below extending to the car- tilages in the two lower spaces, but in tin upper two or three not quite so far. Action.— To raise the ribs so as to increase the capacity of the chest. Xki;\ e Supply . Inn rcostal n< rv< s. 458 ANATOMY IX A NUTSHELL. Blood Supply. — Intercostal arteries. Internal intercostal*. — Description. — These are eleven in number. Their tillers pass obliquely downward and backward in the opposite direction to those of the External intercostals. They extend from the sternum anteriorly to the angles of the ribs posteriorly. Origin. — From the inner surface of each rib and the costal cartilage. [NSERTION. Into the upper border of the rib below. Action. — To depress the ribs and diminish the thoracic cavity. At the from of the chest the Internal intercostal muscles help the External intercostal muscles in raising the cartilages. PLATE CCXLVI. MASTOID PORTION MASSETER. CLASERIAN FISSURE CLENOID FOSSA. EXT. AUDITORY MEATUS STYLOID PROCESS - STYLO- GLOSSUS STYLO-HYOID ^'.W^J^ TRACHELOMAST. DIGASTRIC. SPLEVHUS-CAPITIS. STERNOCLEIDOMASTOID- RETRAHENS AURICULAM The External Surface of Temporal Bone. PROCESS. STYLO- PHARYNGEUS. Nerve Si pply. — Intercostal nerves. Blood Supply.— Intercostal arteries. Infracostals, also called Subcostals. — Description. — These muscles vary in their size and number and are placed on the inner surface of the ribs where the Internal intercostals cease. Origin. — From the inner surface of the rib. Insertion. Into the inner surfaci > of the first, second or third rib below. Their direction is like thai of the Internal intercostals. They are more often presenl between the lower ribs than between the upper ribs. Ai i [on. Depress ribs. N u;\ i. Si I'i'i.i . Intercostal uerves. Blood Supply. Intercostal arteries. Triangularis sterni. Des< ription.- This muscle is situated upon the inner wall of the chesl anteriorly and consists of thin muscular and tendinous fibers. ANATOMY IN A NUTSHELL. 459 The attachment of this muscle varies not only in different bodies but on the opposite side of the same body. The superior fibers pass vertically, its middle fibers obliquely outward, and its lower fibers horizontally. Origin. — From the posterior surface of the ensiform cartilage and the posterior surfaces of the sternal end of the costal cartilages of the three or four lower true ribs, and also from the lower one-third of the posterior surface of the sternum. Insertion. — Into the inner surface and lower border of the costal cartil- ages of the second, third, fourth, and fifth ribs. Action. — Muscle of forced expiration. Nerve Supply. — Intercostal nerves. Blood Supply. — Intercostal arteries. PLATE CCXLVII. EMINENCE FOR SUP. SEMI-CIRCULAR CANAL \ SUP. SURF. OF PETROUS PORTld FOR SUP. PETROSAL SINUS SQUAMOUS PORTION. FOR LATER SINUS POST. SURFACE OF PFTROUS PORTION DEPRESSION FOR CASSER1AN GANGLION. CAROTID CANAL ' OPENING FOR SMALLER PETROSAL N. HIATUS FALLOPII INT AUDITORY MEATUS OPENINGFOR PROC.OF DURA-MATCR AQUEDUCTUS VESTIBULI The Petrous Portion of the Temporal Bone. Levatores costarum. — Description. — These muscles are situated between the transverse processes of the seventh cervical vertebra and the eleven upper dorsal vertebrae and the border of the first rib below them. There are twelve on each side of the spine. Origin. — From the ends of the transverse processes of the seventh cervi- cal and the eleven upper dorsal vertebra 1 . Their direction is obliquely down- ward and outward. Insertion. — Into the upper bonier of the firsl rib below between the tubercle and angle. In the lower Levatores costarum muscles there is a second insertion to the second rib below its origin, thus where this is true each rib re- ceives fibers from the transverse processes of the two vertebras. Action. — Muscle of inspiration. Nerve Supply. — Intercostal nerves. Blood Supply. — Intercostal arteries. 460 ANATOMY IN A NUTSHELL. LESSON CXLV. The mediastinum is the -pace in the thorax which contains all the thoracic viscera except the lungs. This word comes from two other words — medius, the mil Idle, ami sto, I stand. The anterior mediastinum is the space between the sternum anteriorly and the pericardium posteriorly. It contains the Tri- angularis sterni muscle, parts of other muscles, lymphatic nodes, and areolar tissue. The middle mediastinum is the space which is nearly the same as the pericardiac cavity. It contains the heart, the ascending aorta, pulmonary artery, and the superior vena cava, i.e., the parts of these which are within the pericardium. It also has the phrenic nerves, the root of each lung, and lym- phatic nodes. The posterior mediastinum is the space between the spine pos- PLATE CCXLVIII. EUSTACHIAN TUBE PROC. COCHLEARIFORMIS. ' PROMONTORY. STAPES CAROTID CANAL/ CANAL FOR FENESTRA ROTUNDA -[■<-•— q TYMPANI. PYRAMID. AQUEDUCTUS FALLOPII ANTRUM ^\ V COCHLEARIFORMIS l^^EUSTACHIAN TUBE C\\ TYMPANUM. CAROTID CANAL. %&Y ANTRUM. \ STYL0I0 PROCESS. MARROW AQUEDUCTUS FALLOPII. CELLS. The Temporal Bone Laid Open. teriorly and the pericardium anteriorly. It contains the descending aorta, the azygos v< ins the thoracic duct, the (esophagus, pneumogastric nerves, and thi splanchnic aerves. The superior mediastinum is the space which has in front the upper pari of the sternum and the spine behind. It is situated above the pericardium and contains all the forty structures which pass through the superior opening in the thorax except the apices of the lungs and the pleura'. For structures which pass through the superior opening in the thorax see page232. Name and classify these forty structures. LESSON CXLVI. Muscles of the Superficial Abdominal Region. Obliquus externus also called Descending oblique. — Description. — This ANATOMY IN A NUTSHELL. 461 muscle is the most superficial and the largesl muscle in the superficial abdominal region. It is situated on the side and front part of the abdomen. The side of the muscle consists of muscular fibers and its anterior part of aponeurotic fibers. The aponeurosis of this muscle is strong but thin, and its fibers pass obliquely downward and inward. At the linea alba, or median line of the ab- domen, it joins the aponeurosis of its fellow. It is connected to the lower border of the Pectoralis major above and below its attachment extends from the anterior superior spine of the ilium to the spine of the os pubes ami theilio- pectineal line, thus forming Poupart's ligament. Okigin. — From the external surface and the lower borders of the eight lower ribs. The attachment of the digitations run downward and backward. The first five of these digitations, which increase in size from above downward. PLATE CCXLIX. CANAL FOR JACOBSON'S NERVE AQUAIDUCTUS COCHLEAR CANAL FOR ARNOLD'S NERVE JUGULAR FOSSA VAGINAL PROCESS. STYLOID PROCESS. STYLO-MASTOID FOR AM E JUGULAR SURFACE. OCCIPITAL GROOVE.^ DIGASTRIC FOSSA. OPENING OF CAROTED GANAL. QUAPLAT'L ROUGH SURFACE TENSOR TYMPANI MUSCLE LEVATOR PALATI CANAL FOR EUSTACHIAN TUBE AND,.TENSOR TYMPANI MUS. STYLO-PHARYNGEUS EMINENTIA ARTICULARIS The Inferior Surface of Petrous Portion of Temporal Bonf. are received between the corresponding processes of the Serratus magnus mus- cle, while the last three digitations which diminish in size from above down- ward interdigitate with processes of the Latissimus dorsi muscle. Insertion. — Into the anterior half of th( out< r lip of the cr< si of I he ilium, and into the aponeurosis of the muscle extending from the prominence of the ninth costal cartilage to the anterior superior spinous process of the ilium. Action. — To compress the viscera. To flex the thorax on the pelvis or to flex the pelvis on the thorax. These muscles of the abdominal wall assisl in micturition, defecation, and parturition. Nerve Supply.— Lower intercostals, BLOOD SUPPLY. — Intercostal and lumbar arteries. Obliquus interims, also called Ascending oblique. Description. This muscle lies bfeneath the External oblique and is smaller and thinner than that muscle. Origin.- From the outer half of Poupart's ligament, from the anterior 462 ANATOMY IN A NUTSHELL. two-thirds of the middle lip of the crest of the ilium, and from the posterior layer of the lumbar fascia. Insertion. — Those fibers which arise from Poupart's ligament arch down- ward and inward over the spermatic cord in the male and the round ligament in the female, and arc inserted with fibers of the Transversalis muscle into the cresl of the os pubes and the pectineal line to the extent of half an inch. The (•unjoined tendon is formed by the joining of the Internal oblique muscle and the Transversalis just spoken of. The part of the muscle which arises from the anterior one-third of the middle lip of the crest of the ilium, passes horizontally and at the linea semilunaris it divides sending the lower one-fourth of its aponeurosis in front of the Rectus muscle to be inserted into the linea alba, while the upper three-fourths sends a layer of fascia in front of the Rectus muscle to be inserted into tbe linea alba and a posterior layer to pass behind the sheath of the Rectus muscle to be inserted into the linea alba also into the seventh, eighth. and ninth ribs. That part of the muscle which passes obliquely upward is inserted in the lower border of the cartilages of the three lower ribs PLATE CCL. SUP. BORDER ^v MEDIAN I' I' BORDER. SI-, .'/ LESSON CXLVIL Transversalis.- Description. — This muscle which is placed beneath the Internal oblique takes its name from the direction of its fibers. Oniiiix. From outer one-third of Poupart's ligament, anterior three- fourths of the inner lip of the crest of the ilium, and inner surface of the car- tilages of the lower six ribs, interdigitating with the Diaphragm. It also comes from the lumbar fascia. Insertion.— This muscle ends in a broad aponeurosis the lower part of which joins the Internal oblique forming the conjoined tendon. The remain- ./ GROOVE ^'^Bfc- ■/ FOR NASAL NERVE. \*.*$&s»^~ A? The Nasal Bone. where it is continuous with the Internal intercostal muscles. The outer layer of the conjoined tendon is called the ligament of Hesselback. while the inner layer is called the ligament of Henle. A.CTION. — Same as External oblique. Nerve Supply.— Lower intercostals. ilio-hypogastric, and sometimes the Uio-inguinal. Blood Supply. — Intercostal and lumbar arteries. ANATOMY IX A NUTSHELL. 463 iiig part of the aponeurosis passes horizontally Towards the linea alba, but at the linea semilunaris it passes behind the Rectus muscle blending with the pos- terior layer of the Internal oblique. Action. — Same as the External oblique. Nerve Supply. — Intercostal, ilio-hypogastric, and sometimes the ilio- inguinal. Blood Supply. — Intercostal and lumbar arteries. Rectus abdominis. — Description. — This muscle extends from the sym- physis pubes to the sternum. It is much broader and thinner above than below and is separated from its fellow by the linea alba. The linea' transversa are tendinous intersections which cross this muscle. There are three such lines. One is situated opposite the umbilicus and one at the extremity of the ensiform cartilage, and a third one between these two. Occasionally one or two additional lines may be seen. These lines are homologues of ribs. The sheath of the Rectus muscle contains the Pyramidalis muscle and the superior epigastric artery, the deep epigastric artery, anel the terminal branches of the lower intercostal and lumbar arteries anel nerves. PLATE CCLI. LACHRYMAL GROOVE \/wSjk HAMULUS The Lachrymal Bone. Origin. — By two heads. (1) the external or Larger head being attached to the crest of the os pubes. (2) the internal one is connected with the ligaments covering the symphysis and interlacing with its fellow of the opposite side. Insertion. — Into the cartilages of the fifth, sixth, and seventh ribs, and occasionally connected with the costo-ziphoid ligaments and side of the ensi- form cartilage. Action. — To compress abdominal viscera, and to flex thorax. Xervk Supply. — Lower intercostals. Blood Supply. — Intercostal, lumbar, deep epigastric and superior epigas- tric arteries. Pyramidalis. — Description. — This muscle is situated in the same sheath with the Rectus abdominis muscle in front of the lower portion of that muscle. It may be absent on one or both sides, or it may be double on one side. Origin. — From front of pubic bone and anterior pubic Ligament. Insertion. — Into the linea alba half way to the umbilicus. Action. — To tense linea alba. Nerve Supply. -Twelfth thoracic and ilio-hypogastric. 464 ANATOMY IN A NUTSHELL. Blood Supply. — By arteries in the sheath of the Rectus. Cremaster. — Description. — This muscle, which consists of thin musular fasciculi which are continuous with those of the Internal oblique and some times with those of the Trans versalis, descends through the external abdominal ring from the front of the spermatic cord. Origin. — From the middle of Poupart's ligament. Insertion. — Into the crest of the os pubis and sheath of the Rectus. Action. — To retract testicle. Nerve Supply. — Genital branch of the genito-crural. Blood Supply. — Spermatic artery. PLATE CCLII. FQRSUP.TURBINAL. RIDGE FORMID.TURBINAL. ANTRUM POST. PALATINE GROOVE. INF MEATUS PALATINE PROC. NASAL PROC MIDDLE MEATUS RIDGE FOR NF.TURBINAL. ART WITH VOMER ANT. NASAL SPINE. -CREST ANT PALATINE £i GROOVE. The Internal Surface of Superior Maxillary Bone. The origin and insertion of this muscle is similar to that of the lower fibers of the Internal oblique. This muscle is found in the male, but a few muscular fibers may be seen on the round ligament of the female which correspond to this muscle. LESSON CXLVIII. Muscles of deep Abdominal Region. (1) Psoas parvus which has been described on page 134. (2) Psoas magnus which lias been described on page 134. (3) Uiacus which has been described on page 135. (4) Quadratus lumboruni. — Description. — This muscle is situated in a sheath formed l>v the anterior and middle layers of the lumbar fascia. On the ANATOMY IN A NUTSHELL. 465 anterior surface of this muscle beneath this fascia are the last dorsal, ilio-hypo- gastric, and ilio-inguinal nerves. The middle layer of the lumbar fascia sep- arates this muscle from the Erector spinae. This muscle as its name implies is quadrilateral, broader below than above. Origin. — From the ilio-lumbar ligament and the crest of the ilium for about two inches. Occasionally a second portion of this muscle is found situ- ated in front of the muscle, and when so found it has its origin from the upper borders of the transverse processes of three or four lower lumbar vertebrae and is inserted into the lower margin of the last rib. Insertion. — Into the apices of the transverse processes of the four upper lumbar vertebrae and into the lower border of the last rib for about half its length. Action. — To draw down the last rib and acts as a muscle of inspiration. Nerve Supply. — Last dorsal, first and occasionally the second lumbar. Blood Supply. — Intercostal and lumbar arteries. LESSON CXLIX The word membrane is used to name any thin expansion of tissue, and has the following classes: (1) Serous membrane, which is the simplest of all forms. These serous membranes derive their name from the fact that they are moist with a fluid like blood-serum. The serous membranes are closed sacs, such as the pericardium, pleura, and peritoneum. However, the peritoneum in the female is an open sac. (2) Synovial membrane which lines the joints. This membrane secrets synovia, which resembles the white of egg. Under synovial membrane we have three classes, (a) articular, which occurs hi joints, (b) vaginal, which is found where the tendons of muscles run over bones, (c) bursal. A synovial bursa is a bag which is lined with synovial membrane and placed between the tendon of a muscle and a bone, or two muscles, or two tendons. (3) Mucous membrane. The mucous membrane lines open cavi- ties. (4) Cutaneous membrane, which is commonly called skin. The peritoneum is a serous membrane with a smooth shining surface. This membrane is transparent, uncolored, strong, and moist. The peritoneum is reflected from the abdominal walls and from pelvic walls over the viscera to invest and at the same time hold them in position. The part which lines the abdominal and pelvic wall is called parietal or external peritoneum, and that which invests the viscera, to agreater or lessextent, is called the visceral or internal peritoneum. If it were possible to separate the entire peritoneum from the body, it would be in the form of a large closed sac with a constric- tion a little above its center, thus forming the greater and lesser sacs of the peritoneum. The passage way between these two sacs is called the foramen OF Winslow. The foramen of Winslowhas above it the caudate lobe of the liver, in front of it the lesser omentum, below it the duodenum, and hepatic vessels, behind it the inferior vena cava. The lesser sac of the peritoneum lies back of and below the stomach and liver, while the greater sac lies in front and below these viscera. 466 ANATOMY IN A NUTSHELL. The peritoneum (literal meaning is stretched around) in the male forms a closed sac. Ln the female it tonus an open sac by means of the two Fallopian tubes. It has an outer or parietal layer and an inner or visceral layer. It lines mos1 of the viscera of the abdominal cavity and in its development forms folds and ligaments. The lesser sac is in the greater omentum but the greater sac is not in the lesser omentum. A fold of peritoneum going from the abdom- inal wall to the small intestine is called the mesentery. A fold of peritoneum going from the lesser curvature of the stomach to the transverse fissure of the liver is called the lesser omentum and a fold of peritoneum going from the greater curvature of the stomach to the transverse colon is called the greater omentum. The greater omentum has four layers in it which cannot be demonstrated in the adult but can be in the fetus. The lesser omentum has two folds in it. A fold of peritoneum passing from the liver to the spleen is called gastro-splenie omentum. All other folds of peritoneum are called ligaments. The following eleven structures are entirely covered with peritoneum: (1) Spleen, (2) liver. (3) stomach, (4) first portion of the duodenum, (5) small intestine, (6) csecum, (7) transverse colon, (8) sigmoid flexure, (9) first portion of the rectum, (10) ovaries, and (11) the uterus. The following six structures are entirely stripped of peritoneum, (1) pan- creas, (2) kidney. (3) suprarenal capsule, (4) third portion of the rectum. (5) anterior portion of the bladder, and (6) lower portion of the vagina. Tracing the greater sac, (Plate CLI.) starting at the umbilicus and de- scending, it covers the anterior abdominal wall, reflected over the symphysis pubis, over the posterior portion of the bladder, overthe uterus and the anterior surface of the rectum, forming a pouch called the pouch of Douglas, up the pos- terior abdominal wall it reaches almost to the pancreas and there it is reflected towards the small intestine forming the posterior layer of the mesentery; sur- rounding the small intestine il passes up to the abdominal wall again, forming the anterior laverof the mesentery and thereit is reflected over to the transverse colon, forming the posterior layer of the transverse meso-colon; from there ii forms the fourth and first layers of the greater omentum, passing up to the stomach ami from there over the anterior border of the stomach and continuing up to the transverse fissure of the liver forming the anterior layer of the lesser omentum. From this fissure ii continues over the anterior portion of the liver, forming the suspensory ligament of the Liver, from there being reflected on the anterior abdominal wall down to the starting point. The lesser sac (Plate CLI) is traced from the posterior surface of the liver, descending and forming the posterior layer of the lesser omentum. being reflected over the posterior surface of the stomach and from there form- ing the second and third Layersof the greater omentum and from there ascend- ing and forming tli<' anterior laverof the transverse meso-colon up to the pos- terior surface of the liver. The peritoneum can be shown as a closed sac best by a transverse section at the umbilicus! (Plate CL.) The functions of the peritoneum are as follows: (1) It secrets serum which Lubricates its adjacent surfaces. (2) it absorbs any excess of its own secretion rOMY IX A XUT>HELL. 4« 17 M well as foreign material which may be introduce! is Ligatory such as the falciform ligament of the liver. (4) it is pilieate.as the plica epigastrica where it makes a fold over the episgastric artery, (5) it is mi which hind organs to the walls of the abdomen and conducts nutrient nerves and vessels to the organs. The transverse meso-colon is an example of this. (6) It is omental. which means it binds one organ to another. An example the gastro-splenic omentum. An omentum may or may not contain nutrient nerves and vessels. Nerve Slpply. — The parietal peritoneum receives its nerve supply from the sympathetic through the gray rami commnnicantes. The visceral, peri- toneum receives its nerve supply from the solar plexus. PLATE CCLIII. POST. DENTAL CANALS P-ARTIC.WITH LACHRYMAL 0- INFRAORBITAL GROOVE. R -MALAR PROC. S -ALVEOLAR PROC. T- INCISIVE TOSSA. U-CANINE FOSSA. V- CANINE FMINENCE. W-OBRITAL SURFACE. X- FACIAL SUREACE. Y ZYGOMATIC SURFACE ^ A Z-TUBEROSUY. A-0RB1CULAR1S- PALPEBRARUM B-TENDO-OCULI. C-LEV.LADU SUP. AL/tQUE-NASI. /:/* D-INF.OBUQUE. E-LEV.LABII- SUPERIORIS F - LEV. ANG. ORIS. G- COMPRESSOR MARIS. H- DEPRESSOR ALAl-fJASl. M I - MASSETER. g J - BUCCIN- ATOR. K- NASAL PROC L -NASAL NOTCH. M-NASAL SPINE. N- NUTRIENT FORAMINA. External Surface i >f Superk »b Maxill \ky B< >ne. Blood Supply. — The parietal peritoneum receive- its blood supply from the intercostals, phrenic, lumbar, circumflex iliac, and deep epigastric arteries. The visceral peritoneum receives its blood supply from the gastric, hepatic splenic, renal, ami mesentery arteries. These latter arteries nourish organs. LESSON CL. The kidney (Plate CCLXVI) belongs to the urinary system, which has but one function, that of elimination, while the alimentary system has two functions, appropriation and elimination. The kidney is bean-shaped ami is situated between the spinous processes <<\ the eleventh dorsal and the third 468 ANATOMY IN A NUTSHELL. lumbar. The right kidney is a little lower than the left one on account of the liver being above the kidney on the right side. The scar, or the point where the vessels enter and leave the kidney is on the inner border, about its middle. Its vessels bear this relation to one another, the renal vein, renal artery, and the ureter, from before backward. The kidney is entirely stripped of peritoneum. It has above and in front of it the suprarenal capsule which has something to do with the pigmentation of the body and is considered by some as belonging to the sympathetic nervous system. The kidney has the following dimensions, four and three-fourths by two and one-half by one and three-fourths inches. It weighs from four to six ounces. Its nerve supply is from the renal plexus which comes from the solar plexus. Its blood supply is the renal, suprarenal, spermatic, and Lumbar. The right renal vein contains the purest blood in the body. The outer portion of the kidney is called cortex, while the interior is called medullary portion. The kidney in the fetus and someof the lower animals looks like a bunch of grapes; it is made up of individual lobes; the point where these lobes coalesce entirely disappears in the adult kidney, giving the appearance of one solid body. The physiolological kidney consists of the uriniferous tubules. These are about one-half million in number and would be fifteen miles in length if placed end to end. This uriniferous tubule consists of (1) a capsule or head, (2) neck, (3) spiral portion, (4) descending portion, (5) loop, (6) ascending portion, (7) distal spiral portion, (8) convoluted portion, (9) irregular portion, (10) arched portion, and (11) a descending portion. (Plate CCLXV.) The capsule, or Malpighian body, takes from the blood the water and lesser salts, while the rest of the tube takes the more important salts from the blood. The medullary portion of the kidney consists of Malpighian pyramids, eighteen or twenty In number, with the apex towards the hilum of the kidney. The apex consists of infundibula, and the infundibula make the calices, the calices form the pelvis and the pelvis opens into the ureter. Between these pyramids is cortex, the same as the cortex of the outer portion of the kidney, but has a special name, called the column op Bertin. That part of the uriniferous tubules consisting of a straight portion and the two spiral portions form what is called the medullary ray, or the pyramids of Ferrein, the base of the pyramid is on the base of the Malpighian pyramid and the apex is towards the periphery. The uriniferous tubules in the cortex form what is called the labi rinth. The relations of the right kidney. Above. — Suprarenal capsule. Ix Front. — (1) Suprarenal capsule, (2) Liver, (3) Duodenum, (4) As- cending colon, (5) Jejuno-ileum. Bihim). (1) The last rib, (2) Diaphragm, (3) Quadratus lumborum, (4) Psoas magnus. (Plate VIII.) The relations of the left kidney. Above. — Suprarenal capsule. In Front. — (1) Suprarenal capsule, (2) Spleen, (3) Stomach, (4) Pan- creas, (5) Splenic flexure, (6) Descending colon, (7) Jejuno-ileum. ANATOMY IN A NUTSHELL. 469 Behind. — (1) The last rib, (2) Diaphragm, (3) Quadratus Lumborum, (4) Psoas magnus. (Plate VIII.) The organs of the urinary system are, (1) the two kidneys, which form the urine from the materials furnished by the blood; (2) the ureters, which con- vey the urine away from the kidneys; (3) the bladder in which the urine is stored until it is discharged, and (4) the urethra, a tube through which the urine passes from the bladder. The kidney is a glandular structure whose function is the purification of the blood by the excretion of the urine. It is held in position by its vessels, the peritoneum and the abundant fatty tissue. This fatty tissue forms the " adipose capsule. ' ' The hilum of the kidney is the place on the median side of the kidney. corresponding to the place of the scar on the bean. It is where the ureter goes out and the vessels and nerves enter. The capsule of the kidney is a smooth fibrous membrane closely investing the kidney and forming its outer coat. Floating kidney is one which has become loose and displaced hi the abdo- men. Surgical kidney is a term somewhat loosely applied to nephritic condi- tions, secondary conditions to mischief farther down in the urinary tract, but especially to suppurative pyelonephritis arising from cystitis. The pelvis or sinus of the kidney is the concavity or re-entrance at the hilum of the kidney. The calices of the kidney are cup-like or infundibuliform be- ginnings of the ureter in the pelvis of the kidney surrounding the apices of the Malpighian pyramids, each usually receiving more than one pyramid. There are from seven to thirteen such calices, converging and uniting in the infundi- bula, which in turn combine to form the pelvis. The infundibula of the kidney are, (a) the calices; (b) the two or three main divisions of the pelvis of the kidney formed by the confluence of the calices. The apices of the Malpighian pyramids, also called mamillae, are the papillse of the kidney. The Malpighian pyramids are pale-reddish conical masses forming the medullary part of the kidney, whose apices project into the calices of the pelvis of the kidney, and are called papillae. The Malpighian corpuscles or bodies are the glomeruli of the kidney surrounded by its capsule. These form the terminations of the branches of the uriniferous tubules, occur in the cortical substance of the kidney, and are about in 1 ,,,, of an inch in dia- meter. They are formed of the expanded end of the tube invaginated by the bunch of blood vessels constituting the glomerulus which thus are embraced in a double epithelial sac, and the blood is separated from the lumen of the tubule by the vascular wall and the epithelium of the inner layer of the capsule. The Malpighian tuft is the glomerulus or vascular network or plexus in a Malpighian body. Marcello Malpighi (1628-94) was an Italian anatomisl and physiologist. The cortical substance of the kidney is the outer part of the kidney sub- stance which contains the glomeruli. The columns of Bertin are named after E. F. Bertin, a French anatomist (1712-81). They are the prolongations in- ward of the cortical substance of the kidney between the pyramids. 470 AX ATOMY IX A NUTSHELL. The tubes of Ferrein make the pyramids of Ferrein. They are in help to the cortical substance and are convoluted. The pyramids ofFerrein are formed by bundles of straight and convoluted renal tubules which constitute the medul- lary rays, so named on account of their radiation from the medulla. The tubes of Bellini are the excretory tubes opening on the papilla. They are straight tubes. The tubes of Henle connect those of Bellini and Ferrein. They are looped tubes. The capsule of Muller is the dilated extremity of a tube of Ferrein invest- ing the Malpighian tuft probably by two layers, similar to the pleural invest- ment of the lung's. PLATE CCLIV. MASSETER Internal Surface of the Malar Bone. The nerve SUPPLY to the kidney is from the renal plexus which is formed by filaments from the solar plexus and the lesser splanchnic nerve. The blood supply is from the renal artery and renal vein, (a) Afferent (vessels carrying to), (1>) efferent vessels (carrying from). The kidney is very vascular. The larger arterial branches run up between the pyramids of Mal- pighi to subdivide a1 their bases into cortico-medullary arches which lie be- tween the cortex and medulla, giving off arterioles in both directions, the cor- tical branches supplying afferent twigs to the glomeruli within the capsules of Bowman. The medullary branches running inwards to form plexuses around the straight and looped tubules of the Malpighian pyramids. The efferent vessels of the Malpighian glomeruli form a capillary plexus around the uriniferous tubule- and terminate in renal veins. The surface of the kidney receives small arteries which pass through the fatty capsule from the suprarenal, spermatic, and lumbar vessels .The super- ficial veins appear in the form of little stellate groups (stars of Yerhayen) which ANATOMY IN A NUTSHELL. 471 communicate with the venous plexus in the adipose capsule and by means of this with the visceral and parietal veins close by. These vein> are very dis- tinct when the organ is congested. The renal lymphatics may be divided into two sets, capsular and parenchy- matous. They terminate in a series of glands lying with the renal vessels in the subperitoneal tissue, and their contents are ultimately conveyed into the receptaculum chyli. LESSON CLI. The ureter (Plate VIII.) is a tube conveying the urine from the kid- ney to the blader in mammals, or into the cloaca in case no bladder exists. The human ureter is a slender tube from fifteen to eighteen inches long running from the pelvis of the kidney to the base of the bladder, at the posterior angle of the trigonum. It is behind the peritoneum and rests upon the Psoas muscle. Its structure includes (1) a fibrous coat. (2) longitudinal and circular muscular fibers, and (3) a lining of mucous membrane with vessels and nerves from various sources. The ureter pierces the wall of the bladder very oblique- ly. It runs for nearly an inch behind the muscular and mucous coats of the bladder. Blood Supply. — (1) The renal, (2) Spermatic. (3) Internal iliac, and \ Inferior vesical. Nerve Supply. — (1) Inferior mesenteric. (2) Spermatic plexus, (3) Pel- vic plexus. The bladder is the reservoir in which the urine is collected from the ureters. It has four coats. (1) the mucous, which is nearest the cavity. (2) the areolar. (3) the muscular, and (-4) the serous. The trigonum is a triangular space or area at the base of the bladder, whose apex is at the beginning of the urethra. and whose other two angles are at the point of entrance of the ureters into the bladder. When the bladder is collapsed its mucous walls fall together in such a way that a sagittal section shows the line between them in the shape of a V with unequal and widely spread arms, the point of the V indicating the opening of the urethra. Its dimensions are three by five inches. It> capacity is about a pint. In the child the bladder is almost an abdominal organ, while in the adult it is in the pelvis. The urachus is a fibrous cord extending from the fundus of the bladder to the umbilicus. It represents in the adult a part of the sac of the allantoic and associate allantoic vessels of the fetus, whose cavities have been obliterated. It is that intra-abdominal section of the navel-string which is constituted by bo much of the allantoic sac and hypogastric arteries a- becomes impervious, the section remaining pervious being the bladder and superior vesical arteries. It sometimes remains pervious, as a malformation, when the child may urinate l)v the navel. 472 ANATOMY IN A. NUTSHELL. The allantois is a fetal appendage of most vertebrates, developing as a sac or diverticulum from the posterior portion of the intestinal cavity. It is one uf the organs of the embryo of all amniotic vertebrates, or those which develop an amnion, but is wanting or is most rudimentary in amphibians and fishes, In birds and reptiles it is large and perforins a respiratory function, and in mammals contributes to form the umbilical cord and placenta. Its exterior primitively consists of mesoblast, its cavity receiving the secretion of the pri- mordial kidneys (Wolffian bodies). So much of the sac as remains pervious within the body of the embryo becomes the urinary bladder, or in some degree a urinary passage. The umbilical arteries and veins course along the elongated stalk of the sac, which becomes the umbilical cord, and that part of these allantoic vessels within the body which does not remain pervious become the urachus and round Ligament of the liver. The expanded extremity of the allantois, in most mammals, unites with the chorion to form the placenta. In those vertebrates, as mammals, in which the umbilical vesicle has but a short period of activity, the allantois chiefly sustains the functions whereby the fetus is nourished by the blood of the mother and has its own blood arterialized. In parturition, so much of the allantois as is outside of the body of the fetus is cast off, the separation taking place at the navel. The uvula vesica? is a slight projection of mucous membrane from the bladder into the cystic orifice of the urethra. The arteries of the bladder are the superior, middle and inferior vesical and in the female the uterine and vaginal also; its veins are radicles of the internal iliac. The Lymphatics accompany the veins and terminate in the internal iliac gland. The nerves are derived partly from the sympathetic system through the hypogastric plexuses, partly from the cerebro-spinal system through the third and fourth sacral nerves. The former supply the mucosa, the latter of the muscularis. The bladder is held in place by ligaments which are divided into true and false. The true ligaments are five in number; the two anterior, two lateral, and the urachus (superior). Tin: false ligaments, also five in number, are formed by folds of the peritoneum. The false are named the two posterior, two Lateral and superior. LESSON CLII, The word urethra (Plates CCLXXII-CCLXXIX) is derived from the Greek which means to urinate. The male and female urethrae differ. It is a modifica- tion of a pari of a uro-genital sinus into a tube ora groove for the discharge of the secretion of the genital <>r urinary organs or both; in most mammals, in- cluding man, a complete tube from the bladder to the exterior, conveying urine and semen in the male sex. urine only in the female: in some birds a penial groove for the conveyance of semen only. The urethra in the male is always a part of the penis, or penial urethra, continuous usually with the urethral part ANATOMY IN A NUTSHELL. 473 of the urogenital sinus; that of the female is only exceptionally a part of the clitoris. In man the urethra extends from the bladder to the end of the penis, usually a distance of eight or nine inches. The male urethra has three portions — the prostatic, the membranous, the spongy — the structures and the rela- tions of which are essentially different. Except during the passage of the urine or semen the urethra is a mere transverse cleft or slit with its upper and under surfaces in contact. At the orifice of the urethra, at the end of the penis. the slit is vertical and in the prostatic portion somewhat arched. The pros- tatic portion is one and one-fourth inches long, the membranous three-fourths of an inch long, and the spongy four and one-half inches long. The first and second portions are not subject to any physiological changes such as character- ize the third. PLATE CCLV. FRONTAL PROC. TEMPOROMALAR CANALS. LEVATOR l.ABU SUP. / ZYGOMATICS 'M1N- 7YC0MATIC PROC. ZYG0MAT1CUS MAJ. External Surface of Malar Bone. The urethra has three coats, mucous, muscular, and erectile. The bulb of the urethra is the posterior enlarged rounded extremity of the corpus spong- iosum of the penis. The crista urethra is the crest of the urethra; a longitudinal fold of mucous membrane and subadjacent tissue on the median line of the floor of the pros- tatic urethra, about three-fourths of an inch in length and one-fourth of an inch in height where it is greatest. On the summit open the ejaculatory duct-. It is also called colliculus seminalis, caput galliaginis, and veruinontanum. The prostatic sinus is a longitudinal groove in the Hoor of the urethra on each side of the crest, into which the prostatic ducts open. The pocularis sinus is a small cul-de-sac, from a quarter to hall' an inch in its greatest diameter, situated at the middle of the highest part of the crest of the urethra. It corresponds with the uterus of the female. Also called prostatic vesicle, utricle, uterus masculinus. The semilunar ducts open on the margins of the sinus pocularis. Cowper's glands (Plate (VLXXIX) are a pair of accessory prostatic or urethral glands of lobulated or follicular structure which pour a mucous secre- 474 ANATOMY IN A NUTSHELL. tion into the urethra In man they arc small. about the size of a pea, Lying be- neath the membranous portion of the urethra, close behind the bulb and empty- ing into the bulbous portion of the tract. Their size, shape, and position vary in different animals, in some of which they are much more highly developed than in man. Tlie tossa navioularis is (a) a recess in the urethra, near the urinary meatus, where the caliber of the tube is enlarged. (1») A depressed space between the posterior commissure of the vulva and the fourchette. The lacuna magna is the Largesl of several orifices of mucous follicles, situated on the roof of the fossa naviculars. The glands of Littre are the crypts along the spongy portion of the urethra. The prostate ("standing in front") is a glandular body situated around the initial portion of the urethra. It develops at puberty, atrophies after castra- tion, and in certain animals increases in size during the breeding season. The female urethra is a tube beginning at the meatus urinarius Lnternus in the bladder and ends at the meatus urinarius externus in the vulva. It is about one ami one-half inches long, imbedded in the anterior all of the vagina. perforating the triangular ligament, and surrounded by the fibers of the Com- pressor urethrse muscle. Its diameter is about one-fourth inch, but it is capable of considerable dilatation, being surrounded by softer structures than those around the male urethra. When dilated far beyond its usual calibre it does not lose its tone. LESSON CLIII. The literal meaning of hernia is branch. It is a tumor formed by the dis- placement and protrusion of a part which has escaped from its natural cavity by some aperture and projects externally. It is sometimes called rupture. We may have hernia of the brain and of the coverings of the cord, of the thorax. or of the abdomen. When we speak of hernia without any qualification, we mean hernia of the abdomen, and this is the most common form, consisting of the protrusion of some part of the viscera through a natural or accidental aperture in the inner wall of the abdomen, the external skin generally remaining unbroken. The following are some of the forms of hernia: 1. Cerebral hernia, which is a protrusion of the brain through an open- ing in tin' cranial walls. 2. Ci;i RAL HERNIA or FEMORAL HERNIA is a hernia descending beside the femoral vessels. '4. Direct inguin \i. hernia is a hernia of the intestine or omentum which descends through the inguinal canal: but uo1 through the internal abdominal ring having broken into the canal below this ring in Hesselbach's triangle. 4. Tin: [NDIRECT or OBLIQUE [NGl [NAL HERNIA is a hernia whose course is thai of the spermatic cord through the ingiunal canal. 5. LUMBAR HERNIA is a hernia in the loins or lumbar region. 6. Phrenic hernia i- a hernia projecting through the Diaphragm into one of the pleural cavities. ANATOMY IN A NUTSHELL. 475 7. Strangulated hernia is a hernia so tightly compressed in some part of the channel through which it has been protruding as not to be reducible by ordinary means, as by the application of pressure and tointerfere with the cir- culation in the protruding part. 8. Umbilical hernia is a henna of the intestine at the navel. It is called exomphalos. The following are the principal causes of hernia: 1. Tight lacing, because it diminishes the abdominal cavity. 2. Crying and fretting, bronchitis, asthma, cough. 3. Deposit of fat in the omentum because it increases the volume and weight of the parts within. 4. Pregnancies because of the stretching of the abdominal walls. 5. Straining in defecation. 6. Phimosis because of the straining to expell the urine. 7. Feats of strength as in lifting heavy weights. 8. Men have larger inguinal rings, women have a larger femoral arch, so sex has something to do with the kind of hernia. 0. Presence of the spermatic cor, I. 10. Deficiency of some of the layers below. 11. Persistence of the original process of the peritoneum. 12. A long mesentery. The inguinal canal is parallel to Poupait's ligament and just aboveit, ex- tending from the internal abdominal ring to the external abdominal ring. It is about an inch and a half long. This is a potential canal, but for a short time in the later months of fetal life it is a real canal. The spermatic cord in the male and the round ligament in the female pass through this canal. Its direction is downward, forward and inward. The relations of the inguinal canal. In Front. — (1) Skin. (2) Superficial fascia. (3) External oblique muscle for all the way, (4) Internal oblique muscle for the outer third of the canal. Below. — The union of the transversalis fascia with Poupart's ligament. Behind. — (1) The conjoined tendon. (2) Transversalis fascia, (3) Triangu- lar fascia, (4) Subperitoneal tissue. (5) Peritoneum. Above. — Arched fibers of the Internal oblique and Transversalis muscles. The COVERINGS OF THE [NDIRECT nii oblique inguinal hernia from within outward ark: 1. Peritoneum, which is the proper hernial sac. 2. Extra-peritoneal fat. This is almost inappreciable. 3. Infundibuliform fascia, which Ls from the internal abdominal ring. 4. Crematseric fascia, which is from the inguinal canal. 5. Intercolumnar fascia, which is from the external abdominal ring. 6. Two layers of superficial fasica. 7. Skin. The coverings of the direct [ngi enal hernia from within outward are: 476 ANATOMY IN A NUTSHELL. 1. Peritoneum. 2. Extra-peritoneal fat. .'■>. Transversalis fascia. 4. Conjoined tendon, which takes the place of cremasteric fascia in the- indirect hernia. 5. Intercolumnar fascia, which takes the place of infnndibnliform in the indirect hernia. 6. Two layers of superficial fascia. 7. Skin. PLATE CCLVI. CORONOID PROC. A-MASSETER. B-BUCCINATOR. C-LEVATOR-MENTI. D-DEPRESSOR-LABU- INF. E-DEPRESSOR-ANGULI-ORIS F-PLATYSMA-MYOIDES. G- MENTAL FORAMEN. MENTAL m/A ' PROC. groove for facial artery. External Surface of Inferior Maxillary Bone. The external abdominal ring (Plate XV) is a potential opening in the apon- eurosis of the External oblique muscle which is made by the divergence of two of its fasciculi. The size of this opening varies on account of the strength of its sides or pillars. It is about an inch long and half an inch wide. It is situ- ated above and to the outer side of the crest of the os pubis. The spermatic cord in the male and the round ligament in the female passes through this opening to pass from the abdomen. The relations of the external abdominal ring. Above. — A series of curved fibers called the intercolumnar. Below. — The crest of the os pubis. On Either Side. — Columns or pillars of the ring. ANATOMY IN A NUTSHELL. 477 The internal abdominal ring (Plate XV) is situated about half way between the anterior superior spine of the ilium and the symphysis pubis. It Is about half an inch above Poupart's ligament and in the transversalis fascia. This is also a potential opening. This is much larger in the male than in the female. The relations of the internal abdominal ring. Above and Externally. — Arched fibers of the Transversalis muscle. Below and Internally. — Deep epigastric vessels. The spermatic cord in the male and the round ligament in the female pass through this opening. Gimbernat's ligament is about a half an inch in length and larger in the male than in the female. In the erect posture it is almost horizontal in direc- tion with its base directed outward, it being triangular in form. It is derived from the External oblique muscle and is reflected downward and outward from the spine of the os pubis to be inseretd into the pectineal line. Its anterior margin is continuous with Poupart's ligament. The triangular ligament of the abdomen is attached by its apex to the pectineal line where it is continuous with Gimbernat's ligament. From there it passes inward beneath the spermatic cord behind the inner pillar of the ex- ternal abdominal ring and in front of the conjoined tendon to the linea alba where it joins its fellow. Poupart's ligament is formed by the fascia of the External oblique muscle of the abdomen and passes from the anterior superior spine of the ilium to the spine of the os pubis. This ligament lies beneath the spermatic cord and is called crural arch. LESSON CLIV. Femoral hernia passes below Poupart's ligament and passes down towards the saphenous opening in the femoral or crural canal. If it passes through this opening it is called complete, if it does not it is called incomplete. The coverings of a femoral hernia from within outward are: 1. Peritoneum. 2. Subserous areolar tissue, called the fascia propria of Cooper. 3. Septum crurale, which is from the femoral ring. 4. Crural sheath, which is from the transversalis fascia. 5. Cribriform fascia, which is from the saphenous opening. 6. Superficial fascia. Its superficial layer. 7. Skin. The femoral sheath is funnel-shaped and has three compartments in it. The outer one is for the femoral artery. THE MIDDLE ONE tor the femora] vein, and the internal one for the femoral canal. (Plate XVI). The femoral canal is about three-fourths of an inch Long and extends from the femoral ring above to the saphenous opening below. The relations of the femoral canal. In Front. — Transversalis fascia. 178 ANATOMY IN A NUTSHELL. Behind. — Iliac fascia. Kvn i;\ \i.ly. — A septum between it and the vein. Internally. — Gimbemat's ligament and the meeting of the iliac fascia and the transversalis fascia. The femoral ring is the upper opening of the femoral canal and is oval shaped about half an inch in diameter. It is larger in women. The relations of the femoral ring. I.\ Front. — Poupart's ligament and the deep crural arch which is a thick- ening of the transversalis fascia. Behind. The Pectineus muscle and the ilio-peetin'eal line. [ntern u.i.y. — Gimbernal 's ligament. Extern u.i.v.- Femoral vein. It is closed by the septum crurale. which is composed of fatty connective tissue and is perforated by lymphatics passing from the superficial to the deep group. There is a small lymphatic gland here. On the upper and outer angle of this ring is the deep epigastric artery. On the upper and inner margin is the obturator artery, when it arises from a common trunk with the deep epi- gastric artery which it does in about thirty per cent of the cases. The coverings of the umbilical hernia are: 1. Peritoneum. 2. Extra-peritoneal fatty tissue. 3. Transversalis fascia. 4. Prolongation of scar tissue of the umbilicus stretched out. 0. Superficial fascia. (i. Skin. Congenital hernia (Plate CCLXXXVIII) is applied to hernia which takes place from birth or during any period of life, if the conditions favorable to its occurrence existed at birth. The vaginal portion of the tunica vaginalis may not close after the descenl of the testicle in the fetus, and in this case when there is a hernia the intestine does not push forward a sac which comes from the parietal layer of the peritoneum, but instead it lies in a sac formed by the tunica vaginalis which is still connected with the peritoneal cavity. These forms of hernia ate called congenital and are always oblique. The following are the different kinds of congenital hernia: 1. Hernia in the tunica \ vginalis testis. In this form of congenital hernia the intestine surrounds the testis and the sac is formed by the tunica vaginalis testis, because the intestine passes through the narrow canal which is present between the cavity of the peritoneum and the tunica vaginalis tes- tis, the original communication between them is not obliterated. 2. Hernia in the funIcular portion of the tunica vaginalis. In this form of congenital henna the sac is formed by the original pouch of the peritoneum which descends with the testicle but is shut off from the tunica vaginalis testis by a thin septum. The canal above this septum being still presenl and communicating with the peritoneal cavity. '.]. Infantile hernia. This form of congenital hernia is rare and is pro- duced by the descent of the hernia through the internal abdominal ring but ANATOMY IN A NUTSHELL. 479 behind this abnormal extension of the tunica vaginalis, in this case there arc three layers of peritoneum in front of the hernia, two of them arc from the tunica vaginalis and the third from the sac around the hernia. In this form of hernia the tunica vaginalis testis may pass up as high as the internal abdominal ring. 4. Encysted hernia. This is the rarest of all forms of congenital hernia and is formed by the hernia pushing the closing septum of the internal abdom- inal ring as a diverticulum into the unclosed tunica vaginalis. PLATE CCLVII. MUSCLES A-EXT. PTERYGOID B-INT. PTERYGOID C-TEMPORAL. D-BUCCINATOR GROOVES LIG'MTS.LTr. J-MANDIBULAR SPINE. K- MANDIBULAR FORAMEN L-SPHENO-MAND'R LIG'MT. M-STYLO-MAND'R LIG'WT E-SUP. CONSTRICTOR. N-GROOVE FOR SUBMAY'Y GLAND. F-MYLO-HYOID. O-GR00VE FOR SUBLING'L GLAND G-GENI0-HYO-GL0SSUS.P-MYLO-HYOID GROOVE H-GENIO-HYOIDEUS. 3-MYLO-HYOID RIDGE. R-CAPSULE. Internal Surface of Inferior Maxillary Bone. LESSON CLV. Veins. Every vessel that Leaves the heart is called an artery, and every vessel thai enters the heart is called a vein. Arteries, as a rule, carry pure blood, while the veins carry impure blood bu1 there are exceptions to each of these cases. The pulmonary arteries carry impure blood while the pulmonary veins carry pure blood. As a general thing veins have valves and arteries do not have valves, but there arc exceptions to tins rule, for the pulmonary artery has a valve and the pulmonary veins do not have valves. Veins, like arteries, have three coats, and the middle coai like that of the artery lias sympathetic fibers around it but not so well developed as in the arteries. 480 ANATOMY IN A NUTSHELL. The veins of the dura mater of the brain are called sinuses, also cavities in bones arc called sinuses. After the blood has left the heart by way of the arteries and nourished the entire body, it comes back to the heart by means of veins. We have a pulmonary venous system and a systemic venous system. The veins of the upper extremity have been described on page 117 and the veins of the lower extremity have been described on page 192. We will now give the remaining veins of the body. Tin: Veins ok the Exterioe of the Head and Face. 1. The frontal vein passes down the middle of the frontal bone to the inner canthus of the eye, after which it is called angular. It lies parallel with its fellow of the opposite side which it joins by a transverse branch just before it reaches the root of the nose. At their beginning the frontal veins communi- cate with the temporal veins. At the inner angle of the orbit they receive the the supraorbital veins. Plate CXV. 2. The supraorbital vein lies on the forehead externally to the frontal vein which it joins to form the angular vein at the inner angle of the orbit. 3. The angular vein passes from the inner canthus of the eye where it is formed by the two veins just mentioned and passes to the base of the nose. Its radicles are (a) supraorbital, (b) frontal, (c) superior palpebral, and (d) nasal, 4. From the base of the nose this vein continues as the facial, which passes under the Zygomatici muscles and over the anterior border of the Masseter muscle in a groove on the inferior maxillary bone. From here it passes into the internal jugular after communicating with the external jugular. Its radi- cles are (a) angular, (b) inferior palpebral, (c) dorsal and lateral nasal, (d) anterior internal maxillary (deep facial), (e) coronary (superior and inferior), (f) buccal, (g) masseteric, (h) labial, (i) submental, (j) ascending palatine, (k) tonsillar, (1) glandular (parotid and submaxillary), (m) part of the temporo- maxillary. 5. Temporal vein is formed. by the anterior temporal and posterior tem- poral which collects the blood from the side and the vertex of the head and after uniting above the zygoma, passesover the zygoma to be situated in front of the ear between the condyle of the jaw and the external auditory meatus. It now passes in tn the substance of the parotid gland where it receives the in- ternal maxillary vein to form the temporo-maxillary vein. The radicles of this vein are (a) anterior temporal, (b) posterior temporal, (c) middle temporal, (d) parotid, (e) anterior auricular, (f) transverse facial. 6. The internal maxillary vein is formed by radicles which correspond to the branches of the internal maxillary artery. These radicles form the pterygoid plexus of veins, and this plexus of veins communicates with the facial vein by the anterior internal maxillary vein or deep facial. 7. The temporo-maxillary vein is formed by the temporal and internal maxillary veins in the substance of the parotid gland. At the angle of the jaw it joins the posterior auricular to form the external jugular. It may however, divide into an anterior branch which joins the facial vein and a posterior branch which joins the posterior auricular to form the external jugular. ANATOMY IN A NUTSHELL. 4S1 S. The posterior auricular vein conies from a plexus on the side of the head and hack of ear. It receives the stylo-mastoid vein and branches from the external ear. It joins the temporo-maxillary to form the external jugular. 9. The occipital vein is formed from a plexus at the hack part of the vertex of the skull. It is placed deeply between muscles of neck. It passes over the suboccipital triangle under theComplexus muscle where it communicates with the vertebral vein. It empties into the internal jugular as a rule, hut occasion- ally into the external jugular. The Veins of the Neck. (Plate CXV.) 1. The external jugular vein collects the blood from the exterior part of the cranium and the deep part of the face. It is formed by the junction of pari of the temporo-maxillary trunk and the posterior auricular veins in the sub- stance of the parotid gland at the angle of the jaw. From this point it passes down beneath the Platysma myoides muscle over the Sterno-cleido-mastoid muscle and ends near the clavicle in the subclavian vein. Sometimes it empties into the internal jugular vein. It has two pairs of valves which do not prevent the regurgitation of blood, as they are not complete valves. The portion of the vein between the two valves is called a sinus. The upper pair of valves is about an inch and a half above the clavicle, while the lower pair is at its temi- nation into the subclavian vein. Its radicles are (a) posterior external jugular, (b) suprascapular, (c) transverse cervical, (d) frequently the anterior jugular. 2. The posterior external jugular vein receives the blood from the integu- ment and muscles in the tipper and back part of the neck and also from the occipital region. It lies between the Splenitis and Trapezius muscles. It empties into the middle of the external jugular vein. 'A. The anterior jugular vein aiises near the hyoid bone and is formed by the superficial veins of the submaxillary region. It collects the blood from the superficial muscles and integument of anterior and middle regions of neck. It joins its fellow just above the sternum. Ii empties into the subclavian or ex- ternal jugular vein. It has no valves. 4. The internal jugular vein collects the blood from the brain and the superficial pint of the face. It is formed by the inferior petrosal sinus and lateral sinus. It passes down the side of the neck in the common carotid sheath on the outer side of the carotid artery. For contents of this sheath see page 282. It joins the subclavian vein near the inner margin of the Scalenus ami- cus muscle. It is provided with a pair of valves which are placed about three- fourths of an inch above its termination. Its radicles are (a) pharyngeal, d>) lingual, and under lingual we have dorsal of tongue and Lingual vena comites and ranine, (c) common facial, (d) superior thyroid, under which we have laryn- geal and ci'ico-t hyroid, (e) middle thyroid, (f) occipital, which may be a radicle of the external jugular. ."). The vertebral vein commences in the occipital region and drains the deep muscles at the upper and back pari of the neck. This is more of :i plexus of veins than one large vein and they run down through the foramina in the 482 ANATOMY IN A NUTSHELL transverse processes of the cervical vertebra?. When they reach the sixth cer- vical vertebra they form two main trunks, one of which passes through the foramen in the transverse process of the sixth cervical vertebra and the other through thai of the seventh. They now unite into a common trunk which empties into the back pari of the innominate vein. One pair of valves guard its mouth. The radicles of the vertebral vein are (a) muscular, (b) dorsi-spinal, (c) meningo-rachidian, (d) ascending cervical, (e) deep cervical, (f) first inter- costal. The deep cervical, also called posterior vertebral, lies between the Com- plcxus and the Semispinalis muscles. It accompanies the profunda cervicis aitery. It empties into the lower end of the vertebral vein. PLATE CCLVIII. INFUNDIBULUM ETHMOIDAL CANALS MIDDLE TURBINATED uncinate process Lateral View of the Ethmoid. LESSON CLVI. The axillary vein commences at the lower border of the axillary space and receives radicles corresponding to the branches of the axillary artery. At the outer border of the first rib it continues as the subclavian vein. Below the Lower border of the tendons of the Teres major and Latissimus dorsi it is called basilic It has a pair of valves opposite the lower border of the Subscapularis muscle. At the termination of the cephalic vein and the subscapularis vein. valves arc also found. The subclavian vein is a continuation of the axillary vein at the outer border of the first rib to the inner end of the clavicle where it joins the internal jugular vein and makes the innominate vein. The external jugular vein empties into this veil] and the anterior jugular may empty into it. The Scalenus anti- cus muscle and the phrenic nerve separate this vein from the subclavian artery. It has valves about an inch from its termination. The right innominate vein, which is about an inch long, is formed behind the inner end of the clavicle by the internal jugular and subclavian veins. It ANATOMY IN A NUTSHELL. 483 passes downward to join the left innominate vein at the inferior border of the first right costal cartilage to make the superior vena cava. Its radicles are. (a) right vertebral, (b) right internal mammary, which are two for each artery but uniting into a common trunk before entering into the innominate vein, (c) right inferior thyroid, which are three or four in number pass from the thy- roid venous plexus into the left innominate vein, (d) right superior intercostal, receives the blood from the second and third intercostal spaces. The right lymphatic duct opens at the angle where the right subclavian vein joins the right internal jugular vein. The left innominate vein, which is about three inches long, is larger than the right. It is formed by the left internal jugular vein and the left subclavian vein at the inner end of the clavicle. It joins the right innominate vein to form the superior vena cava. The innominate veins have no valves. The radicles of the left innominate vein are, (a) left vertebral, (b) left internal mammary, which are two for each artery but unite into a common trunk before entering into the innominate vein, (c) left inferior thyroid, which are three or four in number pass from the thyroid venous plexus into the left innom- inate vein, (d) the left superior intercostal receives the blood from the second and third intercostal spaces. The one on the right side passes down to enter the vena azygos major, while the one on the left side passes across the arch of the aorta to enter the left innominate vein, and receives the left bronchial vein. The highest inter- costal vein, which comes from the first intercostal space, empties into the cor- responding vertebral or innominate vein. The superior vena cava is formed by the two innominate veins behind the junction of the first right costal cartilage with the sternum. It is about three inches long and passes clown into the right auricle opposite the upper border of the third right costal cartilage. This vein has no valves. Its radicles are, (a) pericardiac, (b) mediastinal, (c) vena azygos major. It collects the blood from the upper half. of the body. When the blood is given off from the thoracic aorta into the intercostal arteries, it comes back by the intercostal veins, which would have no place to empty unless there was a special provision made for them. They cannot empty into the heart, and the inferior vena cava has no length above the Diaphragm, and the superior vena cava is too high for most of them, so they empty into veins called azygos veins which connect the superior and inferior vena cava. The azygos veins have no valves, but their tributaries do have valves. The azygos veins are: (Plate CXCV). 1. The vena azygos major, also called right azygos vein. This vein com- mences at the first or second lumbar vertebra by a branch from (a) right lum- bar veins, (b) or by a branch from the righl renal vein, (c) or by a branch from the inferior vena cava. After passing through the aortic opening in the Dia- phragm, it passes to the fourth dorsal vertebra along the right side of the ver- tebral column and ends in the superior ven cava just before it enters the per- icardium. Its radicle.- are. (a) the lower ten intercostal veins on the righl side, 4M ANATOMY IX A NUTSHELL. (in vena azygos minor from the Left side, (c) oesophageal, pericardiac, and medias- tinal veins, (d) the right bronchial vein, (e) the right superior intercostal vein. 2. The vena azygos minor, also called left lower or smaller azygos vein. This vein is formed by a branch from (a) the lumbar veins, (b) or from the left renal vein. After passing through the left cms of the Diaphragm, it passes along the left side of the vertebral column ami at the ninth dorsal vertebra passes to the right behind the thoracic aorta and thoracic duct to end in the vena azygos major. 1 1 > radicles are, (a) four or five lower intercostal veins cf the left side, (b) some (esophageal and mediastinal veins. 3. The left upper azygos vein, also called vena azygos tertius. The radicles of this vein are from the intercostal spaces between the left superior intercostal vein and the highest radicle of the vena azygos minor. These radicles join to form a main trunk, which empties into the vena azygos major or the vena azygos minor. Somtimes this vena azygos tertius is wanting, then the left superior intercostal vein takes its place. The bronchial veins from the right side empty into the vena azygos major; while those of the left side open into the left superior intercostal or vena azygos tertius. For veins of the abdomen see page 186. LESSON CLVII. The Portal System of Ykixs. (Plates CXXXVIII.) The portal system collects the blood from the digestive tract and from the spleen. The veins of this system form the portal vein which enters the liver and breaks up into branches like an artery into the substance of the liver. This system consists of: 1. The inferior mesenteric vein, which drains the blood from the rectum, sigmoid flexure, and the descending colon. This vein empties into the splenic vein after passing behind the transverse pari of the duodenum and the pancreas and over the left kidney. Its hemorrhoidal radicles inosculate with the luemor- rhoidal branches of the internal iliac. 2. The superior mesenteric vein collects the blood from the small intestine, the caecum, the ascending colon, and transverse colon. The radicles of this vein correspond with the branches of the superior mesenteric artery, just as the radicles of the inferior mesenteric correspond to the branches of the in- ferior mesenteric artery. This vein passes in front of the transverse portion of the duodenum and behind the pancreas to join the splenic vein at the upper binder of the pancreas where it forms the portal vein. 3. The splenic vein commences in the hilum of the spleen by five or six branches which unite to form one main funk. It now passes below the splenic artery and behind the upper border of the pancreas in front of the abdominal aorta to join the superior mesenteric vein. I. The gastric vein, also called coronary, is a large vein which passes along the lesser curvature of the stomach to the cardiac end where it receives radicles ANATOMY IX A NUTSHELL. 485 from the oesophagus and then passes behind the lesser sac of the peritoneum into the portal vein. ."). The portal vein is formed by the splenic vein and the superior mesenteric vein behind the neck of the pancreas. It passes behind the first part of the duodenum and then in the lesser omentum to the transverse fissure of the liver. It now divides into right and left branches for the right and left lobes of the liver and also gives ;i branch to the Spigelian lobe. For the further subdivi- sion of the portal vein see page 190. The portal vein most always receives the cystic vein, although it may sometimes end in the right branch of the portal vein. PLATE CCLIX. VERTICAL PLATE INFUNDIBULIIM CRIBRIFORM PLATE Superior View of the Ethmoid. The veins of the heart are: 1. The great cardiac vein (coronary vein) commences at the apex of the heart and passes to the base of the ventricles in the anterior interventricular groove. From here it passes to the left in the auriculo-ventricular groove to the back pari of the heart where it opens into the coronary sinus. Its opening has a pair of valves. Its radicles are. (a) those winch drain the right ventricle, (b) those from the left ventricle, (c) those from the left auricle. These radicles have valves. 2. The posterior cardiac vein (the middle cardiac vein) commence- at the apex of the heart and passes along the posterior interventricular groove to empty into the coronary sinus, where it has a valve. 1 1> radicles are. (a) those from the posterior surface of the left ventricle, (b) those from the posterior surface of the right ventricle. 3. The left cardiac veins collect the blood from the posterior surface of the left ventricle and open into the coronary sinus. There are three or four of these. 186 ANATOMY IN A NUTSHELL. 1. The anterior cardiac veins collect the blood from the anterior surface of the right ventricle and empty into the lower part of the righl auricle. There are three or four of these veins, and the largest one, which is called the vein of Galen passes along the right border of the heart. 5. The right coronary vein (small coronary) empties into the coronary >inus after passing between the righl auricle and the right ventricle. Its rad- icle- are, (a) from the hack part of the right auricle, (h) from the hack part of the right ventricle. 6. Venae Thesesii, also called venae cordis minimse, open by small orifices on the inner surface of the right auricle. These orifices are called foramina Thebesii. 7. The coronary sinus is a dilatation situated in the posterior part of the hit auriculo-ventricular groove. It receives all the veins just mentioned ex- cept the vena 1 Thebesii, and it also receives the oblique vein of Marshall, which is from the back part of the left auricle. This vein empties into the right auricle of the heart between the inferior vena cava and the auriculo-ventricular open- ing. It is guarded by the valve of Thebesii (coronary). All these veins of the heart, which empty into the coronary sinus have valves except the oblique vein of Marshall. Tuk veins of Spinal Column and Cord. The veins of the spinal column and cord are: (Plates CI-CII.) 1 . Dorsi-spinal veins, which collect the blood from the back on either side of the spinous processes. These veins form a great plexus, which join the veins in the spinal canal by branches which perforate theligmenta subflavaand by other branches which pass through the intervertebral foramina. These veins end in the vertebrals in the neck, in the intercostal veins, and in lumbar and sacral veins in their respective regions. 2. Meningo-raehidian veins, which are situated in the spinal canal, form two greal columns, (a) the anterior longitudinal spinal veins which pass from the foramen magnun to the base of the coccyx. There are two of these anterior longitudinal spinal columns, one on each side of the posterior surface of the bodies of the vertebras. The radicles of these veins are venae basis vertebrarum. These veins communicate with the dorsi-spinal veins, vertebral veins, inter- costal veins, Lumbar ami sacral veins, (b) The posterior longitudinal spinal veins are situated along the posterior border of the spinal canal. They com- municate freely with the anterior ones, the dorsi-spinal veins, vertebral veins, intercostal veins, lumbar veins and sacral veins. The meningo-raehidian veins are not of uniform caliber and communicate freely with one another, thus form- ing sort of a plexus. 3. Venae basis vertebrarum pass from the posterior surface of the vertebrae to join the transverse trunk connecting the anterior spinal veins. They collect the blood from the substance of the hone and are similar to the veins of the diplce found in the hones of the cranium. 4. The medulli spinal veins collect the blood from the substance of the cord which forms a venous plexus around the entire surface of the cord between ANATOMY IN A NUTSHELL. IS', the arachnoid and pia mater. In the upper part of the neck these veins empty into the inferior cerebellar veins or the inferior petrosal sinus. Below this they empty into the veins of the spinal canal. None of the spinal veins have valves. LESSON CLVIII. Veins of Diplce. These veins lie between the two plates of the bones of the cranium and can be seen by removing the outer plate of the skull. They are, (1) the frontal, which empties into the supraorbital vein, (2) the anterior temporal which joins the deep temporal vein, (3) posterior temporal which joins the lateral sinus, (4) the occipital which joins the occipital vein or lateral sinus. Emissary veins are small veins which pass through foramina in the bones of the cranium to connect the sinuses with the external veins of the head. The principal ones are as follows: (1) One which passes thorugh the parietal for- amen to connect the veins of the scalp with the superior longitudinal sinus. (2) One which passes through the mastoid foramen to connect the posterior auricular vein or occipital vein with the lateral sinus. (3) One which passes through the anterior condyloid foramen to connect the vertebral vein and deep veins of neck with occipital sinus. (4) One which passes through the posterior condyloid foramen to connect the lateral sinus with the deep veins of the neck. (5) One which passes through the foramen ovale. (6) Two or three which pass through the middle lacerated foramen. (7) One which passes through the foramen of Vesalius. The fifth, sixth, and seventh all connect the cavernous sinus with pterygoid and pharyngeal plexuses. (8) One which passes through the carotid canal to connect the cavernous sinus with the internal jugular vein. Cerebral Veins. The cerebral veins havethin coatsandno muscular coat or valves. They are divided into a superficial set and a deep set. Under the superficial set we have (1) superior cerebral veins, which are lodged in the fissures on the cerebral sur- face and pass forward and inward to the superior Longitudinal sinus, (2) The median cerebral veins which collect the blood from the convolutions of the mesial surface of the hemispheres. These veins empty into the superior veins or into the inferior longitudinal sinus. (3) Inferior cerebral veins collect the blood on the lower pari of the outer and on the under surface of the cerebral hemisphere. Under these veins we have, (a) middle cerebral which runs along the fissure of Sylvius on the under surface of the temporal lobe and empties into the cavernous sinus. (b) the great anastomotic vein of the Trolard runs along the horizontal Limb of the fissure of Sylvius and empties into the anterior part of the cavernous sinus, (c) the other veins on the under surface of the brain empty into the super- ior petrosal sinus and lateral sinus. 488 ANATOMY IN A NUTSHELL. Under the deep set, we have (1.) Venae Galeni, which are two in number. Thrv are formed by the vena corporis striata and vena choroidea. They pass hack and onl of the transverse fissure to enter the straight sinus. These two veins generally unite into one vein, just before the entrance into the straight sinus. (2.) The basilar vein is formed by the junction of the deep Sylvian vein, inferior striate vein, and anterior cerebral veins. It now passes backward over the cms cerebri to enter the vein of Galen just before its junction with the vein of the opposite side. The cerebellar veins. Under these we have, (1) superior qnes, which pass forward and inward to end in the straight sinus and the veins of Galen, but some of them pass outward to the lateral and the superior petrosal sinus, (2) the inferior cerebellar veins end in the lateral sinus, superior petrosal sinus, and occipital sinus. The veins of the medulla oblongata and pons end in the inferior petrosal sinus and lateral sinus. PLATE CCLX. WITH LACHRYMAL WITH SUP. MAXILLARY. 1 ARTICULATES WITH ETHMOID. MAXILLARY PROC. ARTIC. WITH PALATE POSTERIOR END. Inferior Turbinated Bone. WITH LACHRYMAL. LESSON CL1X. The Sinuses of the Dura Mater. (Plates CLXXVIII-CLXXIX.) The sinuses of the dura mater are as follows: 1. The superior longitudinal sinus commences at the foramen caecum and passes along the upper border of the falx cerebri to end in the torcular Her- ophili, where ii receives the occipital sinus and the straight sinus. The blood which passes through the superior longitudinal sinus and the occipital sinus turns to the righl at the torcular Herophili to pass into the right lateral sinus, while the blood from the straight sinus passes into the left lateral sinus. How- ever, this may be vice versa. At the foramen caecum a small vein com- municates with the veins of the nasal fossa' in children. This sinus on cross section is triangular with apex below next to the falx cerebri. The chorda' Willisii arc fibrous glands which constrict this sinus and take the place of valves. Most of the radicle- of this sinus pass into it in such a manner that the blood is received at righl angles to or againsl the current in the sinus. It receives veins from the diploe and the dura mater, the superior cerebral veins, and veins from the pericranium niter passing through the parietal foramina. ANATOMY IN A NUTSHELL. 489 The torcular Herophili is a dilatation at the point on the eight side of the internal occipital protuberance where the superior Longitudinal, occipital and straight sinuses meet. 2. The inferior longitudinal sinus passes along the lower border of the falx cerebri. It receives veins from the falx cerebri and also some from the sagittal surface of the hemispheres. It ends in the straight sinus, ami on cross section is circular. This sinus, as well as the preceding one. increases in size from before backward. 3. The straight sinus connects the inferior longitudinal sinus with the superior longitudinal sinus and is situated at the junction of the falx cerebri with the tentorium cerebelli. The inferior longitudinal sinus, venae Galeni, and superior cerebellar veins empty into it. 4. and 5. The lateral sinuses are two in number and are situated where the tentorium cerebelli joins the bone. The right one, after receiving the blood from the superior longitudinal and occipital sinus, passes to the light as far as the petrous portion of thetemporal bone. It then passes downward and in- ward to the jugular foramen, where it receives the inferior petrosal sinus to make the jugular vein. It also receives the superior petrosal sinus at the base of the petrous portion of the temporal hone. The left lateral sinus has a sim- ilar description but receives the blood from the straight sinus. It occasionally receives the blood from the superior longitudinal and occipital sinus, and then the right lateral sinus receives the blood from the straight sinus. 6. and 7. The occipital sinus which is the smallest of these sinuses, may be double. It is situated where the falx cerebelli joins the hone, ami as said before, it empties into the torcular Herophili. These seven sinuses are situated on the upper and back part of the skull, while the remaining sinuses of the dura mater are situated at the base of the skull. 8. and 9. The cavernous sinuses pass from the sphenoidal fissure to the apex of the pelrous portion of the temporal hone. They are formed by the ophthalmic vein and end by dividing into the superior and inferior petrosal sinuses. In each cavernous sinus the following structures are found; (a) The third cranial nerve, (b) the fourth cranial nerve, (c) the ophthalmic division of the fifth cranial, (e) the sixth cranial, (f) the internal carotid artery. For position of these structures in this sinus see plate CCXXXII. The facial vein communicates with this sinus through the ophthalmic vein. The circular >inm connects the two cavernous sinuses. 10. The circular sinus surrounds the hypophysis. The anterior segment of this circle is larger than the posterior one. One or the other of these seg- ments may be absent. 11. and 12. The superior petrosal sinuses are two in number, one on either side, and they connect the cavernous with the lateral sinus. They are situated along tin' superior border of the petrous portions of the temporal bone. Veins fromtympanic cavity, some cerebellar vein- and inferior cerebral Veins, pass into it . 4'. M) ANATOMY IN A NUTSHELL. 13. and 14. The inferior petrosal sinuses pass from the cavernous sinus to the jugular foramen where they join the lateral sinus to make the internal jugular vein. They arc situated where the posterior border of the petrous por- tion of the temporal bone joins the basilar process of the occipital. 15. The transverse siims (basilar sinus) connects the two inferior petrosal sinuses. It passes over the basilar process of the occipital bone. The Muscles of the [schio-rectal Region. (Plate CCLXXI.) Corrugator cutis ani. — Description. — This muscle radiates from the ori- fice of the anus and is a thin involuntary muscle. < Origin. — From the true skin externally from the anus. Insertion. — Into the submucous tissue internally. A.CTION. — To raise the skin in ridges around the anus. Nerve Supply Sympathetic nerve. Blood Supply. — Inferior hemorrhoidal. External sphincter ani. — Description. — This muscle surrounds the margin of the anus and is elliptical in shape and thin and flat in form. It is about an inch broad opposite tin 1 anus, and from its anterior to its posterior extremity it is about three inches. It consists of two planes of muscular fibers. Origin. — From the tip of coccyx by a narrow tendon and from super- ficial fascia in front of bone. Insertion. — Into the central tendons of perineum where it joins with the Transversus perinaei, Levator ani. and Accelerator urinae. Action. -To close anus. Nerve Supply. — From the anterior division of the fourth sacral and in- ferior lnemorrhoidal branch of the internal pudic nerve. Blood Supply. — Inferior hemorrhoidal from internal pudic. Internal sphincter ani. — Description. — This muscle surrounds the lower part of the rectum for about an inch. It is composed of involuntary muscu- lar fibers. A' HON.- -To close the amis. Nerve Supply. — Hsemorrhoi lal. Blood Supply.— Inferior hemorrhoidal from internal pudic. Levator ani. Description. — This muscle which is thin and broad is sit- uated on the side of the pelvis. It helps to support the viscera in the pelvic cavity. Sometimes the anterior portion of this muscle is separated from the posterior portion by connective tissue, and then it is called the Levator pros- tatas. Origin. From the posterior surface of the body and ramus of the os pubis on the outer side of the symphysis. Also from the inner surface of the spine of the ischium and from the fascia between these points. Insertion. I 1 I The posterior fibers are inserted into the sids of the apex of the coccyx, and those fibers just in front of these mute with those of the opposite side extending between the coccyx and the margin of the anus. (2) The middle fibers, which form the greater portion of the muscle, are inserted ANATOMY IN A NUTSHELL. 491 into the sides of the rectum blending with the fibers of the sphincter muscles. (3) The anterior fibers, which are the longest, descend upon the side of the prostate gland to join beneath it with fibers of the opposite side, and also blend- ing with fibers of the External sphincter and Transversus perinaei a1 the central tendon. Action. — It is a muscle of forced expiration. It also supports the Lower end of the rectum, vagina, and bladder during efforts of expulsion. Nerve Supply. — Branch from the anterior division of the fourth sacral and a branch from fhe pudic nerve which sometimes comes from the perineal or from the inferior hemorrhoidal division. Blood Supply. — Internal pudic. Coccygeus. — Description. — This muscle is situated parallel to the Levator ani but behind it. Its upper border is separated from the lower border of the Pyriformis muscle by the internal pudic vessels and nerves. PLATE CCLXI. ANTERIOR BORDER. GROOVE FOR SEPTAL CARTILAGE ALA. P031. POST. SUP. BORDER. ) Wk I VIEW. Ha GROOVE FOR NASO- PALATINE NERVE The Vomer. ALA. Origin. — From the apex of the spine of the ischium and from the lesser sacro-sciatic ligament. Insertion. — Into the margin of the coccyx and side of lower piece of sacrum. Action. — Raises and supports coccyx. Nerve Supply. — Branch from the fourth and fifth sacral nerves. Blood Supply. — Internal pudic. LESSON CLX. Muscles of the Perineum in the Mali:. (Plate CCLXXI.) Transversus perinsei. — Description. This muscle, which passes across the back part of the perineal space, is a narrow muscular slip. Origin. — From the inner and forepart of the tuberosity of the ischium by a small tendon. Insertion. — Into the central tendon of the perineum. Nerve Supply. — Perineal branch of the internal pudic. Blood Supply. — Internal pudic. 492 ANATOMY IN A NUTSHELL. Accelerator urinae. — ( Bulbo-cavernosus-Ejaculator seminis.) — Descrip- tion. -This muscle is situated in the middle line of the perineum just in front of the anus. It consists of two similar parts united in the middle line by a tendinous raphe. Origin. From the central tendon of the perineum, and from the median raphe in trout. Insertion.— Into the anterior surface of the triangular ligament into the hull) and adjacent parts of the corpus spongiosum, and into the tunica albu- genia of corpora cavernosa. Action.— To empty the urethra and assist the erector penis. Nerve Supply. —Perineal branch of the internal pudic. Blood Supply. — Superficial perineal from internal pudic. Erector penis. — ( [schio-cavernosus.) — Description. — This muscle covers part of the cms penis and is situated on either side of the lateral boundary of the perineum. This muscle is broad in the middle and narrow at the extrem- ities. Origin. — From the inner surface of the tuberosity of the ischium, from the surface of the cms, and from the adjacent portion of the ramus of the ischium. [nsertion. — Into the sides and into the under surface of the crus penis by an aponeurosis. Action". — By compressing the crus penis, it retards the blood through the veins and in this manner keeps the organ erect. Nerve Supply. — Perineal branch of internal pudic. Blood Supply.— Superficial perineal from internal pudic. Compressor urethra'. — (Constrictor urethra'. ) — DESCRIPTION. — This muscle is situated between the two layers of the triangular ligament and surrounds the membranous portion of the urethra. Origin.— From the junction of the rami of the os pubis and ischium, ex- tending to half an inch or more. [nsertion. Each portion of this muscle divides into two fasciculi which surround the urethra from the prostate gland behind to the bulbous portion of the urethra in front. They mute at the upper and lower surfaces of this tube with the muscle of the opposite side. Action. These muscles acting together assist expelling the fluids and compressing the membranous portion of the urethra. Nerve Supply.— Perineal branch of the internal pudic. Blood Supply. — Superficial perineal from internal pudic. LESSON CLXI. Mcs< lesofthe Perineum ixthk Female. ( Plate CCLXXI.) Transversus periiuei. DESCRIPTION. — This is a small muscular slip in the female which passes across the back part of the perineal space. Okioiw From the inner and forepart of the tuberosity of the ischium by a small tendon. ANATOMY IN A NUTSHELL. 41)o Insertion. — Into the central tendon of the perineum. Action. — This muscle with its fellow fixes the central tendon. Nerve Supply.- — Perineal branch of internal pudic. Blood Supply. — Superficial perineal from internal pudic. Sphincter vagina. — Description.— The Sphincter vagina which surrounds the orifice of the vagina is the homologue of the Accelerator mime in the male. Origin. — Posteriorly from the central tendinous part of the perineum where it blends with the External sphincter aid. Insertion. — Into the corpora cavernosa of the clitoris, and a fasciculus passes over the body of the clitoris to compress its dorsal vein. Action. — To diminish the orifice of the vagina. Nerve Supply. — Perineal branch of the internal pudic. Blood Supply. — Superficial perineal from internal pudic. Erector clitoridis. — Description. — This muscle is the homologue of the Erector penis in the male, but is a smaller muscle. Origin. — From the inner surface of the tuberosity of the ischium behind the eras clitoridis, and also from the surface of the eras and the adjacent por- tion of the ramus of the ischium. Insertion. — Into the sides and upper surface of the eras clitoridis. Action. — To maintain the organ erect by pressing on the eras clitoridis and retarding the return of blood through the veins. Nerve Supply. — Perineal branch of the internal pudic. Blood Supply. — Superficial peiineal from internal pudic. Compressor urethra. — (Constrictor urethra). — Origin. — From the margin of the descending ramus of the os pubis. Insertion. — The fibers from the front part of the muscle cross the sub- pubic arch in front of the urethra to blend with its fellow of the opposite side, while fibers from the posterior portion pass inward to blend with the walls of the vagina behind the urethra. Action. — To expell the mine and assist in erection. Nerve Supply. — Perineal branch of the internal pudic. Blood Supply. — Superficial perineal from internal pudic. LESSON CLXII. The Perineum. (Plate CCLXIX.) The word Perineum is \\>n\ in three different senses. ( 1 ) il includes the entire outlet of the pelvis, which extends from the apex of the sub-pubic arch in front to the tip of the coccyx behind, and laterally between the tuberischii. (2) Il is the part of the pelvic outlet in fnint of a line connecting the tuberi- schii. This is called the true perineum, while the pari behind this line is called the anal, ischio-rectal. or false perineum. (3) In the surgical and obstetrical sense of the word the term may include in the female all the deeper par t between the posterior wall of the vagina and the anterior wall of the ledum. Tin- is called the perineal body. 494 ANATOMY IN A NUTSHELL. The ischio-rectal fossae are situated on each side of the lower end of the recutm, having on the outer side of each fossa, the tuberosity of the ischium, The ischio-rectal fossa is in the form of a pyramid with its apex corresponding to the junction of the Levator ani and Obturator muscles. Its base is between the anus and the tuberischii. It is bounded on the inner side by the Sphincter ani. Levator ani. and Coccygeus muscles; and behind by the edge of the Gluteus maximus and the great sacro -sciatic ligament. It is the site of abscesses and is filled with a mass of adipose connective tissue. (Plate CCLXX.) THE FAsei.K OF THE PERINEUM ARE: 1. The superficial layer of the superficial fascia, which is continuous with the sub-cutaneous fascia of the thighs, is thick and loaded with fat. This is the lowest of all the fascia of the perineum. PLATECCLXII. ORBITAL PROCESS ORBITAL SURFACE SPHENOIDAL SURFACE POSTERIOR NASAL SPINE AZYGOS UVULAE The Palate Bone, Posterior View. 2. The deep layer of the superficial fascia is called Colles' fascia. It is not thick, but very strong. It is attached posteriorly to the perineal ledge. anteriorly it becomes continuous with the external fascial investment of the scrotum ami the fascial covering of the penis. It extends laterally to the rami of the pubis ami ischium. Some anatomists call this fascia the anterior LEAFLET OF THE TRIANGULAR LIGAMENT. 3. Tin' anterior Layer of the deep perineal fascia is triangular in shape like Colles' fascia,being bounded on either side by the ramus of the pubis and ischium and extending in from from the pubic arch and sub-pubic ligament to the per- ineal Ledge p0Steri6rly. Some anatomists call this THE MIDDLE LEAFLET OF 'IH1-; TRIANGUL \l< LIG V.MENT. 4. The posterior layer of the deep perineal fascia is called by some anato- mists THE POSTERIOR LEAFLET OF THE TRIANGULAR LIGAMENT and has the same attachments as the middle leaflet of the triangular ligament. ANATOMY IX A XUTSHELL. 495 The "white line," or arcus tenmbtEus, extends from the inner aspect of the spine of the ischium to the back of the os pubis, external to the symphysis, and is formed by a thickening of the obturator fascia where the fascia of Leva- tor ani muscle meets the obturator fascia. This line, of course, is Dot straigb.1 because it comforms to the curve of the pelvic wall. Buck's fascia is a continuation of Colles' fascia which extends forward upon the penis, which it invests completely, as far as the gland.-. The triangular ligament of the urethra. One set of anatomists describe the anterior layer of the deep perixeai. fasci \ as the triangular ligament, while another set include the posterior layer of the deep perineal fasci \. thus making two layers of the triangular ligament. Still a third set of anat- omists include Colles' fascia in the triangular ligament, thus making three leaflets in the triangular ligament. Where these three triangular leaflets meet posteriorly is called the perineal ledge, and as they pass forward towards the symphysis pubis there are two spaces between these three leaflets. The one between the first two leaflets is called the superficial perineal inter- space, and contains the following structures: 1. The crura of the corpora cavernosa. 2. The bulb of the corpus spongiosum. 3. Scattered fibers of the Superficial transverse periinei muscle. 4. Arteiies of the corpora cavernosum and dorsal vessels of the penis. 5. Dorsal nerves of the penis. 6. Superficial perineal vessels and nerves. The space between the second and third leaflets of the triangular ligament is called the deep perineal interspace and contains: 1. The membranous urethra. 2. C'owper's glands. 3. Internal pudic arteries. 4. Pudic veins. 5. The pudic lymphatics. 6. Dorsal nerves of the penis. 7. The deep Transverse peiinaei and Compressor urethra muscles. The central tendon of the perineum is about half an inch in front of the amis, in the middle of the perineal ledge, and is the place where the External sphincter ani and Accelerator mime and Transverse perinaei muscles meet. Alcock's canal is about two inches in length and is formed by a delamina- tion of the obturator fascia. It is situated on the outer wall of the ischio- rectal fossa, extending from the lesser sacro-sciatic foramen to the lower border of the triangular ligament. The internal pudic vessels and nerve pass through this canal. (Plate CCLXX.) The pelvic fascia lines the cavity of the pelvis and at the white line it divides into (1 ) rk< Tn-\ ESU \\. FASCIA, which is called visceral layer of the pelvic fascia. This layer descends from the white line over the Levator ani muscle, over the prostate gland. rentum, vesiculae seminales and the bladder. It forms the true ligaments of the bladder. (2) The obturator fascia, which is called the mm; anatomy in a nutshell. parietal layer of the pelvic fascia. This layer passes from the white line on the pelvis tn cover the Obturator interims muscle, and above Alcock's canal gives off the anal fascia (ischio-rectal) over the lower surface of the Levator ani mus- cle. This fascia with the corresponding fascia of the opposite side forms the deep superior layer of the triangular ligament. LESSON CLXIII. Lymphatic System. (Plates CCLXXXIX-CCXC.) "niphatic system consists of lymphatic vessels, and lymphatic nodes. The lymphatic vessels of the small intestine are called lacteals or chyliferous vessels because during the process of digestion they contain chyle which they carry into the blood through the thoracic duct. The lymphatic vessels are present in all the pari of the body except the hair, nails, cuticle, and cartilage. The lymphatic system is in the form of the human body. It commences in microscopic space- which join one another to make larger spaces until they finally form the two lymphatic ducts, the righl and the left. The left one is called the thoracic duct because it passes through the thorax. It collects lymph from all the body except the right half of the head, the right half of the thorax. and the upper surface of the liver, and the right arm. The lymph in these structures just named pass into the right lymphatic duct. This right lympha- tic duct is about half an inch long and empties into the tight subclavian vein. The lefi lymphatic or thoracic duct is about eighteen inches long and passes upon the vertebral column behindthe archof the aorta, ii finallyends in the left subclavian vein. This duct may be double for part of its way or throughits en- ure course, and it may empty into the vena azygos major. It has constric- tions through its entire course and a double valve at its termination. Every cell in the body is surrounded by lymph and is therefore an aquatic animal. These cells receive their food from the lymph into which they also throw their waste products. The lymphatic vessels in the body are in two sets, superficial and deep. The superficial lymphatics pass just under the skin with the superficial veins and they pierce the deep fascia to join the deep lymphatic vessels. The deep lymphatics although not so numerous as the superficial ones are larger and accompany the deep blood vessels. The lymphatic, absorbent, or conglobate nodes are small bodies of adenoid tissue which the lymphatic vessels pass through on their way to the thoracic and lymphatic duct-. These nodes vary in size from very small ones which are microscopic, to large one- which are aboui the si/.e of a small bean. Their color is pinkish-gray, but those in the bronchial region are a darker color. The lymphatics, like veins, have three coats, but the smallest lymphatic vessels have one coat which is composed of epithelial cells. Those vessels which have three coat.- have the following arrangement, (1) an inner coat of epithelium and a -mull amount of yellow fibrous tissue: (2) \ MIDDLE COAT composed of muscular tissue and yellow fibrous tissue: (3) AX OUTER COAT which consists of white fibrous tissue and a little of the yellow fibrous tissue. All three of these coat- pu1 together are transparent. Valves are present in ANATOMY IX A NUTSHELL. 497 lymphatic vessels to prevent the backward how of the lymph. They are formed by folds of the lining membrane and their position is marked by a circular con- striction. The thoracic duct has three coats, (1) an internal or endothelial, (2) a middle of white connective tissue, (3) an external of areolar tissue. There are numerous valves in the thoracic duct especially at its upper end, and there is a pair at its termination to prevent blood from entering the duct. The kelations of the thoracic duct are: .Behind. — (1) The body of the second lumbar vertebra, (2) Bodies of the seven lower thoracic vertebra 1 , (3) Anterior common ligament, (4) Lower right intercostal arteries. (.1) Vena azygos minor, ((>) Vena azygos tertius, (7) Upper thoracic vertebrae. Ox Right Side. — (1) Right cms of the Diaphragm, (2) Vena azygos major, (3) Right pleura, (4) (Esophagus. In Front. — (1) Aorta and right cms of the Diaphragm, (2) Pericardium, (3) (Esophagus, (4) Arch of the aorta, (5) First portion of subclavian artery. On Left Side. — (1) Aorta, (2) Left pleura, (3) Vena azygos minor. (4) Vena azygos tertius. PLATE CCLXIII. ORBITAL PROCESS ETHMOIDAL SURFACE SUPERIOR MEATUS SPHENO-PALATINE FORAMEN^ SPHENOIDAL PROCESS 'J ; MEA /o\V < v ORBITAL SURFACE MAXILLARY SURFACE (MC -* TUS c, *|fc-MAXILURY PROCESS INF. TURBINATED ft, .' s /^ _j .x j\\ INFERIOR / = MEATUS A ARTICULATES WITH " / ffWm HORIZONTAL i PLATE ARTICULATES WITH VOMER AND OPPOSITE HONE The Lateral View of the Palate Bone. The receptaculum chyll is the beginning of the thoracic duct. It isan irregu- lar, sacculated and fusiform sac. It has no valves in it. and its dimensions are one and a half by three-quarters of an inch. It is situated in fronl of tin" sec- ond hunbai' vertebra. A lymphatic node consists of an outer pari called a capsule, which is made of white fibrous tissue and a small amount of smooth muscular tissue. From the inner surface of t his capsule trabecular pass towards the center of the node. 498 ANATOMY IN A NUTSHELL. These trabecule arc broad at the attachment of the capsule but small in the central portion. The outer portion of the node is called cortex and the inner portion is called medulla. These trabeculse form numerous divisions in the node, and these divisions are partly filled with pulp The space between the pulp and the division wall is called the lymph sinus and is crossed by a net- work of adenoid reticular tissue. This pulp is a mass of leucocytes. The hilum is a notch where the arteries enter and the veins and efferent vessels Leave the node. These nodes make white blood corpuscles. There are aboul seven hundred lymphatic nodes in the body andtheyare all situated beneath the deep fascia except the superficial inguinal nodes. LESSON CLXIV. The superficial lymphatic vessels of the upper extremity pass from the tips of the fingers towards the shoulder with the superficial veins. Those on the inner side of the arm run with the ulnar veins towards the elbow then with the basilic vein to the axillary glands and deep vessels. Those on the outer side of the arm run with the radial veins to the elbow, and at this point some join the basilic group, while others run with the cephalic vein to the axillary nodes. A few i^ this last set pass between the Deltoid muscle and the Pectoralis major to the subclavian nodes. The deep lymphatic vessels of the upper extremity pass with the deep blood vessels. They accompany the following arteries in the forearm: (t) radial, (2) ULNAK. (3) ANTERIOR INTEROSSEOUS, (4) POSTERIOR INTEROSSEOUS. They communicate with the superficial lymphatic vessels at intervals. They ac- company the brachial artery from the elbow and pass through the axillary and subclavian nodes to the thoracic duct on the left side, while those on the right side pass to the right lymphatic duct. The superficial lymphatic nodes of the upper extremity are not numerous. In the cubital fossa there are two or three and above the internal condyle near the basilic vein there is one or two. The deep lymphatic nodes of the upper exremity are found along the radial and ulnar vessels. A few small ones are found along the inner side of the brachial artery, and one or two just above the inner condyle. There arc ten ortwelve around the axillary vessels which drain the front of the chest and the skin of the back. The subclavian nodes are two or three which are connected with the axillary nodes and deep cervical nodes. They lie under the clavicle. The superficial lymphatic vessels of the lower extremity lie in the supei- ficial fascia. They are divided into two groups, (1) a large internal group which follows the internal saphenous vein to the vertical set of the superficial inguinal nodes. From these superficial inguinal nodes some efferent vessels pass through the cribriform fascia and femoral sheath to a node in the femoral canal by which it communicates with the vessels of the trunk, and others pass through the fascia lata to the deep inguinal nodes. (2) An external group, which is smaller and is situated on the outer side of the foot, sends one set of vessels across the tibia just below the knee to join the internal group, while the ANATOMY IN A NUTSHELL. 499 other set passes with the external saphenous vein to join the popliteal nodes. The deep lymphatic vessels of the lower extremity accompany the following arteries: (1) anterior tibial, (2) posteriok tibial, (3) perineal, to the popliteal nodes. From the popliteal nodes they pass with the femoral vein to the deep inguinal nodes, and then under Poupart's ligamenl to the nodes around the external iliac vessels. The lymphatic vessels in the gluteal region pass to the "luteal nodes in the great sacro-sciatic foramen. The lymphatic vessels of the ischiatic region have a similar course. The superficial lymphatic nodes of the lower extremity are, (1 ) eighl or ten superficial inguinal nodes which lie just under the skin. They consisl of two sets, (a) the upper oblique along Poupart's ligament, which drains the scrotum, penis, abdominal wall, perineal and gluteal regions, and urethral mucous membrane, (b) The vertical set which surrounds the saphenous open- ing and receive the superficial vessels of the lower extremity. The deep lymphatic nodes of the lower extremity are, (1) one or two anter- ior tibial, which are placed beside the anterior tibial artery on the upper part of the interosseous membrane, (2) four or five popliteal, which are placed around the popliteal vessels, (3) the deep inguinal, which are placed under the deep fascia around the femoral vessels. These communicate with the superficial inguinal nodes through the saphenous opening. (4) The gltjte \i.. which follow their corresponding vessels into the great sacro-sciatic foramen above the P) r riformis muscle. (5) Ischiatic which follow their corresponding vessels into the sacro-sciatic foramen below the Pyriformis muscle. LESSON CLXV. The superficial lymphatic vessels of the pelvic and abdominal walls pass with the superficial blood vessels. (1) Those below the umbilicus pass with the superficial epigastric vessels to the oblique set of the superficial inguinal nodes. (2) A DEEPER SET passes with the deep epigastric vessels to the ex- ternal iliac nodes which form a chain around the external iliac blood vessels. Three of these nodes are found just behind the crural arch which communicates with the lumbar nodes above and with the inguinal nodes below. (3) Those FROM THE SIDES OF THE LUMBAB PART OF THE ABDOMINAL WALL pass with the superficial iliac blood vessels to the oblique set of the superficial inguinal node-. lmt most of them pass with the ilio-lumbar and lumbar blood vessels to the lateral lumbar nodes. (4) Those of the gluteal region pass around the outer side of the nates to end in the superficial inguinal nodes. (">) THOSE of the scrotum A\D perineum pass with the external pudic vessels to end in the superficial inguinal nodes. (6) Those of tin: penis end in the superficial inguinal nodes. (7) Those which drain the mucous membrane of the labia, NYMPH.E, and clitoris in the female end in the oblique set of the super- ficial nodes. The deep lymphatic vessels of the pelvic and abdominal walls pass with the chief biood vessels and are, (1) those which accompany the gluteal ves- BELS, (2) THOSE WHICH ACCOMPANY THE [SCHIATIC VESSELS, (•')) THOSE WHICH 500 ANATOMY IX A NUTSHELL accompany the obturator vessels. All these pass with the internal iliac artery to join the Lumbar mules. (4) Those ok tin: penis pass with the internal pudic vessels to join the internal iliac nodes. The lymphatic vessels of the bladder pass through its mules mi the pos- terior surface ami join the lymphatic vessels from the prostate gland ami seminal vesicles pass into the internal iliac nodes which surround the internal iliac blood vessels. These nodes receive radicles corresponding to the branches of the internal iliac artery and they communicate with the lumbar nodes. The lymphatic vessels of the rectum pass through nodes on its outer wall and in the meso-rectum. They empty into the sacral nodes which occupy the sides and t'roiii of the sacrum in the meso-rectal fold. PLATE CCLXIV SUPERIOR TURBINATED INFERIOR TURBINATED The Meatuses. Tin' lymphatic vessels of the uterus are. (1) SUPERFICIAL ONES which are situated under the peiitoneum and (2) deep ones situated in the substance of the uterus. Those from the vagina and from the cervix pass into the sacral nodes and internal iliac nodes, while those from the body and fundus pass into the -broad ligamenl to join those from the ovaries, broad ligaments, and Fallo- pian tubes to pa-- with the ovarian vessels to the lumbar nodes. These lum- bar nodes are situated around the common iliac vessels, the aorta, and inferior vena cava on the front of the lumbal- vertebrae. They receive vessels from the lower extremities, pelvis, testes, ami some of the abdominal viscera. They unite with the lacteal- to help form the thoracic duct. The lateral lumbar nodes are situated between the transverse processes of the vertebra? behind the ANATOMY IN A NUTSHELL. 501 Psoas magnus muscle and help to drain the spinal canal, posterior and lateral abdominal walls. The lymphatic vessels of the testicle are. (1) superficial which arc from the surface of the tunica vaginalis, and (2) deep ones which are from the epididymis and body of the testis. They empty into the lumbar nodes. The lymphatic vessels of the kidney are, (1) superficial and ('_') deep. These two vessels mute at the hilum to join the vessels from the ureter and suprarenal capsule. They end in the lumbar nodes. The lymphatic vessels of the stomach are two set>. (1) SUPERFICIAL ONES in the subserous coat and (2) deep ones in the submucous coal. The ves- sels which drain both surfaces of the stomach pass alongthe lesser curvature to end in nodes at the pyloric end of the stomach. Those which drain the fundus pass to the splenic nodes and those which pass along the greater curvature of the stomach join lacteals at the root of the mesentery. The lymphatic nodes of the stomach lie within the lesser omentum and around the cardiac and pyloric orifices along the curvatures of the stomach. The lymphatic vessels of the spleen are. (1) superficial which lie under its peritoneum, and (2) deep which lie in its substance. They end in the thoracic duet after receiving the pancreatic lymphatic vessels. The nodes of the spleen are situated in its hilum. The lymphatic vessels of the small intestine are called lacteals and are, (1) superficial which are placed between the layers of the muscular coat, or between the nmscnlar and peritoneal coats. They run longitudinally. (2) Deep which are situated in the submucous tissue and run transversely with the mesenteric vessels. These empty into the thoracic duct. The lymphatic nodes of the small intestine, called mesentery node-, lie between the layers of the mesentery, and they are about one hundred and fifty in number. They vary in size from that of a pea to that of a small almond, and the largest ones are situated near the duodenum and the ilio-csecal valve. In these positions they are also more numerous. The lymphatic vessels of the large intestine are in two sets. (1) THOSE of the csecum, ascending colon, and transverse colon which pass to the mesenteric nodes, and (2) those of the descending colon, sigmoid flexure, and rectum which pass to the lumbar nodes. The lymphatic nodes of the large intestine are not so numerous as those of the small intestine and are very few along the transverse colon. They are -it- uated upon the intestine itself or along the vascular arches of the arteries. LESSON CLXVI. The lymphatic vessels of the liver are in two sets. (1) THE SUPERFICIAL SET which lie in the subperitoneal areolar tissue, and on the convex surface of the liver. Those vessels on the convex surface of the liver are divided into the following groups, (a) those branches which rnn forward ami then upward in the broad ligamenl pass through the Diaphragm to the anterior mediastinal node-.. These anterior mediastinal nodes are situated on the Diaphragm in front of the 502 ANATOMY IN A NUTSHELL. pericardium and around the greai vessels at the base of the heart. The vessels from the liver jus; mentioned which pass through those mediastinal nodes pass into the right lymphatic duct, (b) Those vessels winch run around the anterior margin to the under surface of the liver pass to nude- in the lesser omentum. Those branches which pass outward to the right lateral ligament pass either through the Diaphragm to the anterior mediastinal nodes or across the cms of the Diaphragm to the anterior mediastinal nodes or across the cms of the Diaphragm into the thoracic duct, (d) Those branches which run outward from the left lobe to the left lateral ligament and then through the Diaphragm to the anterior mediastinal nodes. Those superficial lymphatic vessels which are on the under surface of the liver form the following groups, (a) those branches which arise to the right of the "'all bladder pass to the lumbar nodes, (b) those branches surrounding the gall bladder pass to the nodes in the lesser omentum, and (c) those branches arising to the left of the gall bladder pass either to the oesophageal nodes or to nodes along the lesser curvature of the stomach. Tin: DEEP lymphatic VESSELS of the livee pass with the branches of the portal vein, hepatic artery, and hepatic duct into the substance of the liver. They puss from the liver at the transverse fissure to enter nodes which are placed along the lesser curvature of the stomach and behind the pancreas. Or they may join a lacteal before entering the thoracic duct. The superficial lymphatic vessels of the thoracic wall pass across the Trape- zius and Latissimus dorsi muscle.- behind and the Pectoralis major muscle in front to end in the axillary nodes. Most of those from the mammary gland pass to small nodes which are situated along the lower border of the Pectoralis major muscle in the axilla, however, a few from the inner side of mammary gland pass through the intercostal spaces to the anterior mediastinal node-. The deep lymphatic vessels of the thoracic Avail are. (1) intercostal \ es- SELS which drain the Intercostal muscles and pleura. These join vessels from the buck of the thorax and spinal canal which entering the intercostal nodes descend on the spine to the thoracic duct. The intercostal nodes which are small, lie on each side of the spine near the costo-vertebral articulation, and some of those lying between the Intercostal muscles. (2) The internal mammary which begin on the abdominal muscles above the umbilicus where they communicate with the epigastric. They pass upward through the Diaphrgam where they are joined by the intercostal lymphatic vessels to empty into the right lymphatic duct on the right side, while those on the left side empty into thoracic duct. (3) The lymphatic \ essels of the Diaphragm empty into the anterior mediastinal and internal mammary nodes anteriorly, and into the in- tercostal and posterior mediastinal nodes posteriorly. The internal mammary nodes lie at the anterior end of each intercostal -pan- near the internal mammary vessels. The posterior mediastinal nodes lie along the aorta and oesophagus, and communicate with the intercostal nodes, lumbar nodes, and deep cervical nodes. The superficial lymphatic vessels of the lung form a minute plexus which covers the outer surface Of the lung under the pleura, while the deep lymphatic ANATOMY IX A NUTSHELL. 503 vessels run with the blood vessels along the bronchi. The lymphatics of the Lung empty into the bronchial nodes, which lie around the bifurcation of the trachea and the root of the lung. Several efferenl vessels pass from these nodes to the tracheal nodes and oesophageal nodes at the root of the neck, and those on the right side empty into the right lymphatic duct, while those on the left side empty into the thoracic duct. The superficial cardiac lymphatic vessels lie on the surface of the heart in the subserous or areolar tissue, while the deep cardiac lymphatic vessels lie in the deeper tissues. These vessels accompany the coronary vessels. Those of the right side uniting at the root of the aorta from which place they pass upward over the arch of the aorta along the trachea to the right lymphatic duct. Those of the left side unite at the base of the heart and pass along the pulmonary artery to nodes at the root of the arota. and after ascending along the trachea pass into the thoracic duct. The thymic vessels pass into the internal jugular veins from the under sur- face of the thymus gland. The lymphatics of the oesophagus, after communicating with the posterior mediastinal nodes, end in tin 1 thoracic duct. LESSON CLXVII. The superficial lymphatic vessels of the scalp are as follows: (1) Pos- terior or OCCIPITAL vessels which follow the course of the superficial veins PLATE CCLXV. Tiii'; Urixiferous Turtles. downward over the occipital bone to the occipital nodes. These node- are also called suboccipital and are situated just below the superior line curved of the occipital bone. Their radicles are from the back of the bead, and the vessels from these nodes empty into the superficial Lymphatic nodes of the neck. In secondary syphilis these nodes arc enlarged. (2) POSTERIOR AURICULAR (pos- tero-lateral) vessels pass downward behind the ear toend in the postero-auricu- lar nodes, also called Sterno -mastoid. These nodes are situated over the in- sertion of the Stemo -cleido-mastoid muscle. The vessels which Leave these nodes empty into the superficial cervical. (•"») Temporal lymphatic vessels, also called antero-lateral, pass with the superficial temporal veinand end in the parotid lymphatic nodes. These nodes are situated over the parotid gland 504 ANATOMY IX A NUTSHELL. and sonic of them are in the substance of the parotid gland. Their radicles drain part ofthe temple, externa] pails of the eye lid. and the posterior pari of die cheek. The vessels which leave these nodes empty into (a) sub- maxillary nodes, (b) some of them in the superficial cervical nodes. (4) An anterior or frontal set pass over the frontal hone and empty into the buccal ami submaxillary nodes. The buccal Lymphatic nodes are situated mi the surface of the Buccinator muscle. The superficial lymphatic vessels of the face end in the submaxillary lym- phatic nodes. These nodes are situated beneath the body of the lower jaw in the submaxillary triangle of the neck. There are eight to twelve of these nodes. Their radicles are, (1) FROM THE UPPER AND LOWER LIPS \\D SIDE OF NOSE, (2) FROM THE FLOOR OF THE MOUTH, (3) FROM FRONT PART OF TONGUE, (4) FROM SUBLINGC \l. Wl> SI BM VXILI.ARY SALIVARY GLANDS, and (")) FROM THE ANTERIOR PART OF THE CAROTID LYMPHATIC NODES. The vessels that leave these nodes empty into the deep cervical lymphatic nodes and also into the superficial lym- phatic nodes. The suprahyoid lymphatic nodes are two or three in number and are sit- uated in the median line between the anterior bellies of the Digastric muscles. The superficial lymphatic vessels of the neck join the superfical lymphatic vess< Ls of the seal]) and face and upper part of the thorax. They empty into the superficial cervical lymphatic nodes. These nodes are situated between the Platysma myoides muscle and the deep fascia along the course of the ex- ternal jugular vein. Small lymphatic nodes are found anterior to these between the hyoid bone and the sternum, also posteriorly over the Trapezius muscle. The radicle- of these superficial cervical nodes are, (1) thosk from the occipital NODES, (2) THOSE FROM THE POSTERIOR AURICULAR NODES, (3) SOME FROM THE PAROTID \\D SUBMAXILLARY NODES, ,(4) FROM THE INTEGUMENT OF THE NECK AND external ear. The vessels passing from these nodes end in the deep cervical lymphatic nodes. LESSOX CLXVIII. The deep lymphatic vessels of the head and neck follow the course of the deep arteries and end in the deep cervical chain of lymphatic nodes. They an- a- follows: (1) meningeal i.vMPHATic vessels which pass with the menin- geal arteries through foramina at the base of the skull to end in dee]) cervical nodes. (2) CEREBRAL LYMPHATICS, which pass with the internal carotid artery, bral artery, and internal jugular vein through foramina at the base of the skull to join the deep lymphatic nodes. (3) lymphatic VESSELS of the ORBIT follow the inferior orbital vein into the spheno -maxillary fossa ami fromhere they follow the internal maxillary vein and empty into the internal maxillary nodes and deep carotid nodes, (4) THE LYMPHATIC VESSELS FROM THE TEMPORAL FOSSA wi> ZYGOMATK i i »SS \ pass through the internal maxillary nodes to join the deep cervical nodes, (5) lymphatn \ essels from the inferior of the nose end in the lymphatics of the pharynx and into the deep cervical nodes. They communicate with the subdural lymph space and the subarachnoid lymph ANATOMY IX A NUTSHELL. 505 space by means of the lymph spaces which surround the olfactory nerves. (6) Lymphatic vessels of the mouth and tongue. Those from the floor of the mouth pass into the submaxillary lymphatic nodes after passing through the Mylo-hyoid muscle. Those from the lips pass into both the submaxillary and into the deep cervical nodes. Those deeply situated hi the check and in roof of mouth join the internal maxillary lymphatic nodes. Those on the tongue pass with the ranine vein and empty into the deep cervical nodes, after passing through small lingual nodes in the Hyo-glossus muscle. Lymphatic vessels of the front part of the tongue pass into the submaxillary nodes after passing through the Mylo-hyoid muscle. (7) The lymphatic vessels i >f the pharynx empty into the deep cervical nodes, but those from the upper pari of the pharynx first pass through the post-pharyngeal node. Lymphatic vessels of the tonsil empty into the submaxillary nodes. (8) The lymphatics of the larynx empty into the deep cervical nodes. (9) The lymphatics vessels of the upper part OF the CESOPHAGUS axd trachea open into the deep cervical nodes. (10) The lymphatics of the thyroid gland open into the dee]» cervical nodes. The deep lymphatic nodes of the head are, (1) the lingual, which are sit- uated on the outer surface of the Hyo-glossus and Genio -hyo-glossus muscles. There are two to four in number and collect the lymph from the upper surface and posterior part of the substance of the tongue. The vessels from these nodes empty into the superior nodes of the deep cervical nodes. (2) The [nternal maxillary or deep facial nodes are situated behind the Buccinator muscle and are three to six in number. Their radicles arefrom (a) the orbit, (b) the nose, (c) the temporal and spheno-maxillary fossaB, (d) the upper jaw. (e) the palate, (f) the pharynx. The vessels from these nodes empty into the superior nodes of the deep cervical nodes. (3) The post-pharyngeal node is situated near the base of the skull on the Rectus capitis anitcus major muscle. Its radicles are from (a) the pharynx, do nose, (c) the deep prevertebral muscles. The deep lymphatic nodes of the neck are, (1) an upper ski which passes along the internal jugular vein as far as the thyroid cartilage. This set of nodes receives radicles from the (a) inferior of the cranium. (In from the deep muscle- of the upper part of the neck, (c) from the internal maxillary glands, (d) from the posterior half of the tongue, (e) from the middle portion of the pharynx, (f) the upper part of the larynx, (g) the upper part of the thyroid gland, (h) and some of the vessels from the submaxillary nodes. Vessels from these nodes pass downward to the lower deep cervical nodes. (2) A lower set which follows the internal jugular vein fr the thyroid cartilage to near it- termination. These receive radicles from (a) the lower pari of the neck, (b) the upper set of lymphatic node-, (c)the Lower part of the larynx, (d) lower pari of thyroid gland, (e) the upper part of the oesophagus and trachea, (f) from the superficial cervical nodes. The vessels which leave these node- end in the jugular lymphatic trunk which mute- with the subclavian lymphatic trunk to form the right lymphatic trunk on the right side and the thoracic duct on the left side. 506 ANATOMY IN A NUTSHELL LESSON CLXIX. Frontal Bone. (Plates GCXXXVII-CCXXXVIII.) The frontal bone consists of two main parts, a vertical or frontal por- noN which forms the forehead, and a horizontal or orbito-nasal portion which forms the roofs of the orbits and nasal fossae. The external surface of the vertical portion lias the following points for consideration : 1. Tin. metopic suture (presenl in the young) is situated in the middle of the fn.nial bone. (Plate CCXXXVIII.) 2. The frontal eminence is just below the center of the bOne externally from the mid-lino. PLATE CCLXVL ?- J^BERT.INT^J^g CAV1TY RENAL ARTERY ! NFUNDIBUIU^ Sagittal Section of the Kidney. 3. The arched superciliary ridge is below the frontal eminence and separated from it by a groove. This ridge, which is produced by the frontal sinus, is more disl bid internally. 4. The glabella or nasal eminence is between the superciliary ridges and - continuous with them. 5. Tin si praorbital ^rch is the upper margin of the orbit and separates the vertical and horizontal portions of the frontal bone. 6. The si praorbital mi >t< ii or foramen is at the junction of the inner and middle thirds <>f this arch. It transmits the supraorbital vessels and nerve ANATOMY IN A NUTSHELL. 507 and at this point a small vein from the diplce passes into tin' supraorbital vein. 7. The external angular process is the end of the supraorbital arch and is well marked. It articulates with the malar bone. 8. The internal angular process is the other end of the supraorbital arch and is not so well marked as the external angular process. It articulates with the lachrymal hone 9. The temporal ridges run upward and backward from the external angular process. The lower ridge gives attachment to the Temporal muscle, and the upper one gives attachment to the temporal fascia. 10. The anterior part of the temporal fossa is below these ridges and gives origin to part of the Temporal muscle. 11. The nasal notch is between the internal angular processes and artic- ulates with the two nasal bones mesially and with the nasal process and the superior maxillary bone ext< rnally. | [ P 12. The nas\l process passes from this notch under the nasal bones and the nasal processes of the superior maxillary bones. 13. The nasal spine arises from the under surface of the nasal process and joins the nasal bones in front and the perpendicular plate of the ethmoid behind to form part of the septum. The internal surface of the vertical portion has the following points for consideration : 1. A vertical groove which passes along the middle line for the superior longitudinal sinus, and the edges of this groove give attachment to the falx cerebri. 2. The frontal crest is formed by the edges of this groove muting an- teriorly. 3. The foramen cecum is formed by a notch in the lower end of the frontal crest by its articulation with the ethmoid. This foramen lodges a pro- cess of the falx cerebri, and when open a vein from the nose passes through it to the superior longitudinal sinus. 4. Eminences and depressions are found on this surface of the frontal bone external to the median line for the cerebral convolutions. 5. Furrows which are for branches of the anterior meningeal arteries. 6. Depressions for the Pacchionian bodies are near the vertical groove. The frontal sinuses are two spaces at the anterior inferior part of the bone between its layers. They are lined with mucous membrane and open into the middle meatus of the nose by the ini'undibula. The inferior surface of the horizontal portion has the following point- for consideration: 1. The ETHMOID NOTCH separates two thin plates which forms the vaull of each orbit. This notch is filled by the cribriform plate of the ethmoid, and edges of this notch present half cells which with half cells of the ethmoid make the ethmoidal cells. 2. The lachrymal fossa, which is for the lachrymal gland, is near the external angular process. 3. A depression or tubercle for the fibrous pulley "\ the Superior oblique muscle is at the nasal margin of this surface. 508 ANATOMY IX A NUTSHELL. 4. A.NTERIOB ETHMOIDAL FORAMEN is for the anterior ethmoidal vessels and nasal branch of the ophthalmic nerve. POSTERIOB ETHMOIDAL FORAMEN is for the posterior ethmoidal vessels. The superior surface of the horizontal portion is convex and has depressions and eminences for the frontal convolutions, also grooves for branches of the anterior and middle meningeal arteries. * Ossification. This hone has two centers of ossification, one for each half. Ajrticulation. It articulates with the following hones: (1) the two parietal, (2) the sphenoid. (3) the ethmoid. (4) two nasal. (5) two superior maxillary, (6) two Lachrymal, (7) two malar, thus making twelve bones. Attachment of Muscles. — It has three pairs of muscles attached to it. l Corrugator supercilii, (2) Orbicularis palpebrarum, (3) Temporal. Blood Supply.- The middle and small meningeal arteries on the cerebral surface and the frontal and supraorbital on the outer surface. The ethmoidal arteries and other branches of the ophthalmic artery pass to the horizontal plate Corrugator supercilii. — Description. — This muscle, which is situated be- neath the Occipito- frontalis and Orbicularis palpebrarum at the inner end of the superciliary ridge, is small and pyramidal. Origin. — From inner end of the superciliary ridge of temporal bone. [nsertion. — Into the deep surface of the skin opposite the middle of the supraorbital arch. A.CTION. To draw the eye brow downward and inward, which produces the vertical wrinkles in the forehead. Nerve Supply. — Temporal branch of the facial nerve, or by fibers of the third nerve which join this nerve. Blood Supply. — Supra-orbital and frontal from ophthalmic artery. Orbicularis palpebrarum. -Description. — This muscle, which surrounds the circumference of the orbil and eye lids, consists of an orbicular portion and a palpebral portion. Origin of Orbicular Portion. — (1) From internal angular process of the frontal bone, (2) nasal process of superior maxillary bone. (3) borders and anterior surface of the tendo oculi. [NSERTION. Into the skin of the eye lids, forehead, temple, and cheek. ii- upper fibers blending with the Occipito-frontalis and the Corrugator super- cilii. Origin <>v Palpebral Portion. - From the bifurcation of the tendo oculi. This portion is thinner and paler than the other portion. INSERTION. Into ; i raphe on the outer side of the eye lids, the external tarsal ligament, and malar bone. Ai TION. To close the eye lids. \u:\ i. Supply. Temporal branch of facial nerve or by fibers of the third nerve which join this nerve. Blood Supply. Supra-orbital, frontal from ophthalmic, and branches from the temporal. Temporal. Description. -This is a large and radiating muscle situated in the temporal fossa. ANATOMY IX A NUTSHELL. 509 Origin. — (1) From temporal ridge, (2) temporal fascia, (3) greater part of the temporal fossa. Insertion. — Into the inner surface, apex and anterior border of the cor- onoid process of the inferior maxillary bone. Action. — To bring the incisor teeth together. It is called the biting muscle. PLATE CCLXVII. v X A xx ^ \N A\V \ x) Ull W&: ''I 11 ' WJ-): ?'''«■: . i '■r'i *"/;'/'/'/.,' I,.',:. ''/.////.'»/, ,.' l ! ;.,'|M l ir''//'/' J GLANSCLITORIOIS FRENULUM CLITORIDlS . ORIFICIUM v \v - URETHR/e EXTERNUM LABIUM MAdU&X x - , '.'.' ' '• x" Av \V^^ LABIUM MINUS V_V POST. COMMISSURE :.\\H...\\- <■ : " ■>''• •. > ,_.,..- v ' ' ANUS The Female External Organs of Generation. Nerve Supply. — Temporal branches of the inferior maxillary division of the fifth nerve. Blood Supply. — .Muscular branches from the second portion of the internal maxillary artery. LESSON CL XX. The Parietal Bone. (Plates CCXXXIX-CCXL.) The parietal bone has two surfaces, fouh borders, and four angles for consideration. 510 ANATOMY IN A NUTSHELL. The external surface of the parietal bone has the following points: 1. Parietal emineni e near the center of the bone where ossification com- mences. 2. TWO SEMICIRCULAR TEMPORAL RIDGES which are about two-fifths of an inch apart ami arc continuous with the ridges on the frontal bone, and like those on the frontal bone give attachment to the Temporal muscle and to the temporal fascia. :!. The surface below these ridges gives attachment to part of the Temporal muscle. 4. The parietal foramen is near the superior border and transmits a vein to the superior longitudinal sinus. Occasionally a branch of the occipital artery passes through this foramen. This foramen is inconstant. The internal surface of the parietal hone is concave 1 and has the following points: 1. Eminences and depressions for the cerebral convolutions. 2. Furrows for the middle meningeal artery. 3. A oi;oo\ i.. which with its fellow. Lodges the superior longitudinal sinus. There i- also a groove for the lateral sinus at the posterior inferior angle. The superior border is dentated and with its fellow forms a sagittal suture, which is a synarthrosis joint. This border is the longest and thickest of the four borders. The anterior border joins the frontal bone and helps to form the coronal suture. Tin-; POSTERIOR BORDER joins the occipital bone and helps to form the Lambdoid suture. Tin: [NFERIOR BORDER is divided into the following parts, (a) the anterior. which is overlaped by the tip of the greater wing of the sphenoid, (b) the middle part which i> overlaped by the squamous portion of the temporal bone, and (c) the posterior pari which articulates with the mastoid process of the temporal bone. Tin. INTERIOR SUPERIOR ANGLE is the point where the two parietal bones meel the frontal hone. This is the location of the anterior fontanelle which is called the -oft spol in the baby's head. Tin-: posterior superior axoi.k is the point where the two parietal bones ami the occipital hone meet-. This is the location of the posterior fontanelle. Tin. posterior [NFERIOR vngle joins the mastoid process of the temporal hone. 'I'm. INTERIOR [NFERIOR ANGLE joins the frontal hone and greater wing of the sphenoid hone. OSSIFICATION. — This bone ossifies from one center. Artn i lation. It articulates with. (1) the opposite parietal bone. (2) the occipital bone. (3) the frontal. (4) the temporal, and (5) the sphenoid, thus making five bone-. Attachment of Mi s< les. This bone has but one muscle attached to it, the Temporal. See page 508 Blood Supply. Middle meningeal, occipital, supraorbital arteries. ANATOMY IN A NUTSHELL. 511 LESSON CLXXI. The Occipital Bone. (Plates CCXLI-CCXLIL) The occipital bone is situated at the posterior and inferior region of the cranium and is trapezoidal in form. This bone is curved upon itself. The external surface is convex and has the following points for consideration : 1. The external occipital protuberance is situated midway between the superior point of the hone and the foramen magnum. It gives attachment to the ligamentum nuchse. 2. The external occipital crest is a vertical ridge extending from the external occipital protuberance to the foramen magnum. Tins also gives at- tachment to the ligamentum nucha?. 3. The superior curved line extend- outward on each side from the external occipital protuberance. This line gives attachment to the Trapezius muscle internally and the Occipito-frontalis and Sterno-mastoid muscles ex- ternally. 4. The highest curved lixe (linea suprema) is above the superior curved line and gives attachment to epicranial aponeurosis. 5. The inferior curved lixe, which passes outward from the middle of the external occipital crest together with a depression below it. gives attach- ment to the Rectus capitis posticus major and Rectus capitis posticus minor. 6. The depression between the superior and inferior curved lines gives attachment to the Complexus muscle internally. Splenitis capitis and Superior oblique externally. 7. The foramen magnum is a large oval opening near the inferior angle. Its greatest diameter is antero-posteriorly. It transmits the following struc- tures: (a) the medulla and its membranes, (b) the spinal accessory nerve, (c) the occipi to-axial ligaments, (d) vertebral arteries, (e) anterior and posterior spinal arteries. 8. The condyles are situated on each side of the anterior pail of the foramen magnum. They are convex and reniform in shape. They look back- ward and outward to articulate with the atlas. 9. The tubercles are situated on the inner border of each condyle and give attachment to the check ligaments. 10. The jugulab processes (transverse) are situated externally to the condyles, and help to form the posterior lacerated foramen. 1 1 . The jugular foramen is on the anterior border of i lie jugular process. 12. A quadrilateral facet is on the externa] surface of the jugular pro- cess for its articulation with the petrous portion of the temporal bone. 13. A deep <;k<><>\ e is on the upper surface of the jugular process for the lateral sinus. 14. Ax eminence (paramastoid in animals), which may extend to the transverse process of the atlas, gives attachmenl to the Rectus capitis lateralis muscle and the lateral occipito-atlantal ligament. 1"). Anterior condyloid foramen is on the outer side of each condyle. It 5 1 2 ANATOMY IN A NTTSHELL. transmits the hypoglossal nerve and some meningeal branches. This foramen may lie double. Hi. Posterior condyloid foramen, which is behind the condyle, trans- mit.- a vein in the lateral sinus. It is at the bottom of the posterior condyloid fossa and is often absenl . The basilar process of the occipital hone is situated anterior to the foramen magnum and is quadrilateral in shape. The pharyngeal spine (sagittal ridge) is on its under surface and uives attachment to the tendinous raphe and the Superior constrictor muscle. There is a depression on each side of this spine PLATE CCLXVIII. SUB-PUOIC LIGAMENT WITH APERTURE FOR DORSAL VEIN OF THE PENIS APERTURES FOR DORSAL ARTERY AND NERVE OF PENIS APERTURE FOR AhTERY OF CORPUS CAVERNOSUM CRUS PENIS SUPERFICIAL TRIANGULAR LIGAMENT ISCHIO-CAVERNOSUS. OR ERECTOR PENIS. APERTURE FOR ARTERY TO BULB URETHRAL APERTURE APERTURE FOR COWPER S DUCT POSITION OF BULB APERTURES FOR SUPERFICIAL PERINAEAL VESSELS AND NERVE DORSAL NERVE ANTERIOR LAYER OF TRIANGULAR LIGAMENT DORSAL ARTERY OF PENIS 'ERY OF CORPUS CAVERNOSUM DEEP TRIANGULAR LIGAMENT ARTERY TO BULB PUDIC VEINS DORSAL NERVE. POSITION OF COWPER S GLAND INTERNAL PUDIC ARTERY FASCIA OF COLLES TURNED BACKWARDS POSTERIOR BORDER OF PERINEAL LEDGE JUNCTION OF TRIANGULAR LIGAMENTS WITH FASCIA OF COLLES. Colles' Fascia \.nd the Triangular Ligaments of Perineum. for the attachmenl of the Rectus capitis anticus major ami Rectus capitis anti- CUS minor. The Internal or cerebral surface of the occipital hone is deeply concave ami has the following points for consideration: 1. I'm i; FOSSAE ate foimed by a crucial ridge. The inferior of these fossa' ;iic for tie' cerebellum and the superior ones are for the cerebrum. 2. Till. INTERNAL OCCIPITAL PROTUBERANCE lies at the junction of the divisions of the ridges. It is the point where the six cranial sinuses meet to form the torcular Herophili. '■'•. Crucial ridge has a vertical portion which is for the falx cerebri (above) and the falx cerebelli (below); and a transverse portion for the tentorium cere- l.elli. 4. (d;<)<)\ ES ai'c presenl between the attachment of the dura mater for the sinuses. ANATOMY IN A NUTSHELL. 513 5. The internal openings for the anterior condyloid foramina and pos- terior condyloid foramina are seen on each side of the foramen magnum. The basilar process of the occipital hone on its inner surface has a median groove for the medulla and the pons, and on each side of this groove there is a narrow groove which joins another groove from the petrous portion of the temporal bone to receive the inferior petrosal sinus. The superior ancle is a point where the occipital hone meet- the two parietal bones. This is the position of the posterior fontanelle. Each lateral angle is the point where the occipital hone meets the posterior inferior angle of the parietal bone and the mastoid pail of the tem- poral bone. The inferior angle (basilar process) joins the body of the sphenoid hone. The superior border passes from one lateral angle to the superior angle and helps to form the lambdoid suture. The inferior border passes from the lateral angle to the inferior angle. The upper part of this border joins the mastoid bone and the lower part joins the petrous portion of the temporal bone. LESSON CLXXII. Ossification. — It has from four to eleven centers of ossification. Articulation. — It articulates with the two parietal, two temporal, sphe- noid, and atlas, thus making six bones. Attachment of Muscles. — It has twelve pairs of muscles attached to it, (1) those to the superior curved line are Occipitofrontal is of the frontal region, Trapezius of the first layer of the back, and Stemo-cleido-mastoid of the superficial cervical region. 2. To the space between the curved lines are the Complexus of the fourth layer of the back, Splenius capitis of the third layer of the hack, and Superior oblique of the fifth layer of the back. 3. Those attached to the lnferiok curved line and the space re- twekn it and the foramen macnum are the Rectus capitis posticus major, and Rectus capitis posticus minor of the fifth layer of the back. 4. That attached to the transverse process is the Rectus capitis lateralis of the anterior vertebral region. 5. Those attached to the basilar process are the Rectus capitis anticus major, and Rectus capitis anticus minor of the anterior vertebral region, and the Superior constrictor of the pharynx of the pharyngeal region. Blood Supply.— Occipital, posterior auricular, middle meningeal, verte- bral, and ascending pharyngeal arteries. Occipito-frontalis. Description.— This muscle consists of an anterior portion called frontal, and a posterior portion called occipital, ami a third por- tion which is between these two which is called the tendinous aponeurosis. Origin. The occipital portion arises from the outer two-thirds or one- half of the superior curved line of th 'cipital hone ami the mastoid process of the temporal hone. The frontal portion arises from the I 'yramidalis nasi. 5] i AXATOMY IX A NUTSHELL. Corrugator supercilii, and Orbicularis palpebrarum muscles. A few fibers of this muscle may be attached to the nasal hone and the frontal bone. Ixsi i; i [ON. Into the tendinous aponeurosis of the vertex of the skull. ACTION.— The frontal portion draws the scalp forward and raises the eye brows and skin over the root of the nose. The occipital portion draws the scalp backward. The Occipito-frontalis muscle is chiefly a muscle of facial ex- -!OH. \ i i;\ i; Supply.— The frontal portion receives the facial nerve or branches of the third nerve which join this nerve. The occipital portion receives the pos- terior auricular branch of the facial and sometimes the occipitalis minor. Blood Supply. -The frontal portion receives the supraorbital, frontal, and anterior temporal arteries. The occipital portion receives the occipital and posterior auricular arteries. Trapezius muscle. For description of this muscle see page 4."). Sterno-cleido-mastoid. For description of this muscle see page 40. Complexus. For description of this muscle see page 27."). Splenius capitis. For description of this muscle see page 272. Superior oblique. For description of this muscle see page 278. Rectus capitis posticus major. For description of this muscle see page 278. Rectus capitis posticus minor. For description of this muscle see page 278. Rectus capitis lateralis. — Description. — This muscle belongs to the an- terior vertebral region. Origin.— From the upper surface of the transverse process of the atlas. Insertion. — Into the under surface of the jugular process of the occipital bone. A fellow. INSERTION. Into the basilar process of the occipital bone. ACTION. To flex and rotate the head, and to restore it to its natural posi- tion after being drawn backward. Nerve Si pply. Firsl cervical and a loop between it and the second cer- vical nerve. Blood Supply. Prevertebral branches of ascending pharyngeal. Rectus capitis anticus minor. DESCRIPTION. — This muscle, which is short, lies immediately behind the Rectus capitis anticus major and in front of the occipito-atlantal articulation. Its course is obliquely upward and inward. ANATOMY IN A NUTSHELL. .") 1 5 Origin. — From the anterior surface of the lateral mass of the at la-, and from the root of Its transverse process. Insertion. — Into the basilar process immediately behind the Rectus cap*- it is anticus major. Action. — Same as the Rectus capitis anticus major. Nerve Supply.— Same as Rectus capitis amicus major. Blood Supply. — Prevertebral branches of the ascending pharyngeal. Superior constrictor. — Description. — This muscle, which is situated at the upper part of the pharynx. i> of a quadrilateral shape ami thinner ami paler PLATE CCLXIX. CRANSVERSALIS FASCIA ILIAC FASCIA PELVIU PERITONEUM EXTRA- PERITONEAL TISSUE RECTOVESICAL FASCIA ABDOMINAL MUSCLES ILIAC CREST BORDER OF ACETABULUM ■■•- 'I - '.£ ISCHIORECTAL FASCIA SPHINCTERAL ~. " & :\A 'ikr^T> APEX OF ISCHIORECTAL FOSSA hf^ 'J' i, ="",y, HI . m0 GLUTEUS MAXIMUS OBTURATOR FASCIA OBTURATOR INTERN ALCOCK'S CANAL WITH PUDIC VESSELS The White Link and [schio-Rectal Fossa. than the other Constrictor muscles. Its superior fibers pa-- beneath the Leva- tor palati muscle ami the Eustachian tube. Between the upper border of this JBouscle ami the basilar process this muscle is deficient in fibers ami closed by the pharyngeal aponeurosis. This interval is known as the sinus of Morgagni. Origin. — (1) From the lower one-third of the posterior margin of the internal pterygoid plate, (2) its hamular process, ■'■'<> the contiguous portion of the palate bone. (4i the reflected tendon of the Tensor palati muscle, the pterygo-maxillary ligament, (6) the aveolar process above the posterior extremity of the mylo-hyoid ridge, i?i a few fiber- from the side of the tongue. .510 ANATOMY IN A NUTSHELL. Insertion. — Into the median raphe of the pharynx and to the pharyngeal spine of the basilar process of the occipital bone by fibrous aponeurosis. Action. — To constrict the pharynx. Nerve Supply. — Branches from the pharyngeal plexus. Blood Supply. — It receives its blood supply from the blood supply to the pharynx which is (1) superior thyroid, (2) ascending pharyngeal from the external carotid, and (3) the pterygo-palatine and (4) descending palatine from the internal maxillary. LESSON CLXXIII. Temporal Bone. (Plates CCLXVI-CCLXVII-CCLXVIII-CCLXIX.) The temporal bone lies at the inferior lateral portion of the skull and con- sists of a squamous, mastoid, and petrous portion. It contains the organs of hearing. The squamous portion (scale-like) forms the anterior superior part of the hone. The external surface of the squamous portion is convex and has grooves on its posterior part for the deep temporal arteries. It has attached to it the Temporal muscle, and forms part of the temporal fossa. A part of the tem- poral ridge is situated between this portion of the bone and the mastoid portion. The zygomatic process arises by three roots and extends forward to artic- ulate with the malar bone. Its anterior root, which runs inward and ends in the eminentia articularis, is short and broad. Its middle root, also called post* glenoid process, passes between the auditory process and the mandibular por- tion of the glenoid fossa. The posterior root passes upward and backward from the upper border of the zygoma and forms part of the temporal ridge (here called supramastoid crest.) To THE (JPPEB BORDER of the ZYGOMA is attached the temporal fascia. and to the lower border and concave inner surface is attached the Masseter muscle. The external lateral ligamenl of the lower jaw is attached to a tubercle at the anterior root of the zygoma. Between the anterior and middle roots of the zygoma is the glenoid fossa, the anterior or mandibular portion of which is for the articulation of the condyle of the lower jaw and is covered with car- tilage, while its posterior part lodges the parotid "land. This posterior portion i- formed chiefly by the tympanic plate which forms the antero-inferior wall of the externa] auditory meatus and ends externally in the auditory process. Tin-: Glaserian fissure divides the glenoid fossa and transmits the tympanic branch of the internal maxillary artery and lodges the processus gracilis malleus. The opening of the canal of Eugieb is situated in the angle between the squamous portion and petrous portion of the temporal bone. It transmits the chorda tympana nerve. The internal surface of the squamous portion is concave and has eminences and depressions for the cerebral convolutions, also grooves for the middle meningeal artery. ANATOMY IX A NUTSHELL. oil The superior bordeb of the squamous portion is thin and overlaps the parietal bone. The antebo-infebiob border is thick and articulates with the greater wing of the sphenoid bone. The mastoid portion of the temporal bone projects like a nipple from the inferior portion of the bone posteriorly. The outer surface of the mastoid process has attached to it the Occipito- frontalis muscle near the Retrahens aurem. The mastoid foramen may be on this part of the bone but is often on the occipital bone. It transmits a vein to the lateral sinus and a meningeal branch of the occipital artery. There are numerous small foramina on this surface. The inner surface of the mastoid process has a deep curved fossa for the lateral sinus. This process gives attachment to the following muscles. (1) Sterno-cleido-mastoid. (2) Splenitis capitis. (3) Trachelo-mastoid, (4) Digastric, (5) Retrahens aurem, (6) Occipito -frontalis. The digastric fossa is on the inner side of the mastoid process. The occipital groove, which is for the occipital artery, lies parallel to the digastric fossa in- ternally to it. The mastoid cells are situated in the mastoid process and open into the tympanum. They are lined with mucous membrane. The upper ones are large, while the lower ones are small. The superior border of the mastoid portion articulates with the pos- terior angle of the parietal. The posterior border articulates with the occipital bone between it- jugular process and lateral angle. The petrous portion of the temporal bone is of a pyramidal form and i- situated between the sphenoid bone and the occipital bone. This portion of the bone is very dense and hard. It contains the internal and middle ear and passes forward and inward. It has a base, an apex, three surface.-, and three borders. The base is situated against the squamous and mastoid portions, the lower half of this base can be seen between the divergence of the squamous and mas- toid portions, but the upper half is concealed by them. The base presents the following points: The meatus auditobius extebnus, which is the external opening of the ear. This opening lies in front of the mastoid process between the posterior root and middle root of the zygoma. The upper margin of this opening is smooth and belongs to the squamous portion of the temporal bone. but the rest of it belongs to the petrous portion of the temporal bone and forms the second point for consideration at the base of the petrous portion, namely, the m di- TORY process which is for the attachment of the cartilage of the ear. The apex, which lies internally at the base of the skull, is received betw< the greater wing of the sphenoid and the basilar process of the occipital bone. thus forming the outer boundary of foramen lacerum medium, and contain- the internal carotid canal. The anterior surface of the petrous portion of the temporal bone form- the back part of the middle fossa of the skull and i> united with the squamous .18 ANATOMY IN A NUTSHELL. portion by the temporal or petro-squamous suture. It has six points for con- sideration. (Plate CCXLVII.) 1. Opening of the carotid can \i., which is for tin 1 interna] carotid artery and plexus, is situated near the apex. 2. A depression for the ( I:iss< ■' i:t n ganglion of the fifth nerve above the carotid canal. o. Hiatus Fallopi] is ;i groove which runs outward ami backward. This i- for the »rcai petrosal nerve and branches of the middle meningeal artery. 4. Foramen for the small petrosal nerve. PLATE CCLXX. ••4 . IANGULAR 4.IGAMEN. • . PERIGNEAL VESS. TUBEROSITY OF ISCHIUM NFERIOR /HEMORRHOIDAL VESS GREAT SACRO-SCIATIC LIGAMENT. INFERIOR PUDENTAL NERVE SUPERFICIAL PERINEAL NERVE INFERIOR HAEMORRHOIDAL NERVE CUTANEOUS BRANCH OF FOURTH SACRAL SUPERFICIAL TRANSVERS'JS PERINAEI Showing the Muscles of the Perineum. .■>. Eminence over the superior semicircular canal which is near the center of this surface. <>. A depression external to the eminence over the tympanum. The posterior surface of the petrous portion of the temporal hone forms the anterior pari of the posterior fossa of the base of ihe skull and has the following points for consideration: (Plate CCXLVII.) 1. Meatus ^UDITORIUS [NTERNUS, which is a short canal at the end of which is the lamina cribrosa. This lamina is perforated by branches of the seventh and eighth nerves, which puss into this opening. 2. Opening of the \<>i eductus vestibuli which is behind the meatus ANATOMY IN A NUTSHELL. 519 auditorius interims. It transmits a small artery and vein and Lodges a process of the dura mater. 3. An angulah depression, which transmits a vein to the cancellous tissue ami lodges a process of the dura mater, is between and above these other openings. LESSON CLXXIV. The inferior surface of the petrous portion of the temporal hone forms pai I of the hase of the skull and from its apex to its base it has the following points for consideration: (Plate CCXLIX.) 1. A rough quadrilateral surface for the origin of the Levator palati and Tensor tympani muscles. 2. Opening <>f the carotid canal which ascends vertically into the hone and then turning runs horizontally forward and inward. It transmits the interna] carotid artery and carotid plexus. 3. Aqueductus cochleae, which transmits an artery and vein to and from the cochlea. 4. Jugular fossa is a depression for the sinus of the internal jugular vein, and with the occipital hone forms the foramen lacerum posterius, which trans- mits the internal jugular vein and the ninth, tenth, and eleventh cranial nerves. 5. Foramen foe Jacobson's nerve (tympanic branch of the glossopharyn- geal) is in the ridge between the jugular fossa and the carotid canal. 6. Foramen for Arnold's nerve (auricular branch of the pneumogastric) is in the outer wall of the jugular fossa. 7. The jugular surface is a smooth quadrilateral facet which articulates with the jugular process of the occipital bone. 8. Vaginal process ensheaths the rool of the styloid process and gives attachment to the Tensor palati muscle. !). Styloid prockss, which is about an inch long and runs downward, for- ward, and inward, and gives attachment to the stylo-hyoid, stylo-maxillary ligaments, and to the Stylo-pharyngeus, Stylo-hyoid, and Stylo-glossus muscles. 10. STYLO-MASTOID FORAMEN is between the styloid process and the mas- toid process. It is the end of the aqueductus Fallopii and transmits the facial nerve, and the stylo-mastoid artery enters it. 11. THE AURICULAE FISSURE, which is between the auditory and mastoid processes, is for the exit of Arnold's nerve. Till-: SUPERIOR BORDER of the pet nuts portion of the temporal hone i> the longest and is grooved for the superior longitudinal sinus. It gives attachment to the tentorium cerebelli and has a notch :it its inner end lor the fifth nerve. It separates the middle fossa of the base of the skull from the posterior fossa. The posterior border of the petrous portion of the temporal bone has on its inner half a groove, which with n similar groove on the occipital bone l< ihe inferior petrosal sinus. On the outer half of this border is ;i notch which forms part of the jugular foramen. Tut': anterior border of the petrous portion of the temporal bone is the 520 ANATOMY IN A NUTSHELL shortest and has an inner portion which articulates with the sphenoid hone, and an outer portion which joins with the squamous portion. The processus cochleariformis is a thin plate of hone which separates two canals at the petro-squamous angle. The upper of these canals is for the Tensor tynipani muscle, and the lower one for the Eustachian tube. They lead into the middle ear. Ossification. — This hone ossifies from ten centers. ARTICULATION. It articulates with five hones; (1) the occipital. (2) parie- tal. (3) sphenoid. (4) inferior maxillary. (5) malar. Attachment <>k Muscles.— It has fifteen muscles attached to it: 1. T<> the SQI VMOUS PORTION of the temporal hone, the Temporal muscle of the tempero-maxillary region. 2. To the zygoma, the Masseter muscle of the temporo-maxillary region. 3. To Tin-: mastoid portion, (a) the Occipito-frontalis of the cranial region, (b) Sterno-cleido-mastoid of the superficial cervical region, (c) Splenius capitis of the third layer of the hack, (d) Traehelo-mastoid of the fourth layer of the hack. ie) Digastric of the supra-hyoid region, (f) Retrahens aurem of the auricu- lar region. 4. Tothe styloid process, (a) Stylo-pharyngeus of the pharyngeal region. (b) Stylo-hyoid of the supra-hyoid region, (c) Stylo-glosstts of the lingual region. .">. To the petrous portion, (a) Levator palati of the soft palate, (b) Tensor tynipani of the tympanic region, (c) Stapedius of the tympanic region. I'.i. > Supply. — The stylo-mastoid artery from the posterior auricular. It enters the stylo-mastoid foramen. The tympanic artery from the internal maxillary . It passes through the Glaserian fissure. Petrosal artery from the middle meningeal. It passes by the hiatus Fallopii. Tympanic from the interna] carotid artery, while in the carotid canal. Auditory from the basilar, which enter- the internal auditory meatus and is distributed to the cochlea and vestibule. LESSON CLXXV. Origin and Insertion <»f the Muscles Attached to Temporal Boxe. 1. Temporal muscle which has been described on page 508. 2. Masseter muscle. -Description. — There is a strong layer of fascia which is derived from the deep cervical fascia which covers this muscle and is connected with it. This fascia i- attached to the lower border of the zygoma, and posteriorly it covers the parotid gland, making the parotid fascia. The Masseter muscle consists of two portions, a superficial and a deep portion. The deep portion is smaller and more muscular than the superficial portion. These two portions are united ;it their insertion. The parotid gland overlaps it- posterior margin, while it- anterior margin overlaps the Buccinator muscle. The facial vein crosses it- lower anterior angle. Origin. The origin of the superficial portion is from the malar process of the superior maxillary hone, and the anterior two-thirds of the lower border of the zygomatic arch. The origin of the deep portion is from the posterior ANATOMY IN A NUTSHELL. 521 one-third of the lower border of the zygomatic arch and all of its inner surface. Insertion. — The insertion of the superficial portion is into the angle and Lower half of the outer surface of ramus of the jaw. The insertion of the deep portion is in the upper half of the ramus and outer surface of the coronoid pro- cess of the lower jaw. Action. — It is a muscle of mastication. It raises the back part of the lower jaw. Nerve Supply. — Masseteric branch of inferior maxillary division of the fifth nerve. Blood Supply. — Facial artery, transverse facial artery, and the masseteric branch of the inferior maxillary artery. PLATECCLXXI. CAVITY OF CERVIX WITH AReOR VITA EXTERNAL CS The Uterus, Horizontal Section. 3. Occipito-frontalis muscle, which has been described on page ">13. 4. Sterno-cleido-mastoid, which has been described on page 40. 5. Splenitis capitis, which has been described on page 272. 6. Traehelo-masfoid, which lias been described on page '-'7 1. 7. Digastric— Description. This muscle, which pierces the Stylo-hyoid muscle near its insertion on the hyoid hone, consists of two fleshy bellies and ;i rounded tendon between them. From this tendon of the Digastric a broad aponeurosis is given off which is attached to the body and greater cornu of the hyoid bone. This aponeurosis is called the supra-hyoid aponeurosis. 522 ANATOMY IN A NUTSHELL. Origin. — The origin of the posterior belly is from the digastric groove of the mastoid process of the temporal bone. The origin of the anterior holly is from the fossa on the inner surface of the inferior maxillary bone near the symphysis. Insertion.- Into its central tendon, which is held to the body of the hyoid bone by the supra-hyoid aponeurosis. Action. — To raise the hyoid bone and tongue, to depress the lower jaw and assist in opening the mouth. Nerve Supply. — The posterior belly receives the facial nerve, while the anterior belly receives the mylo-hyoid branch of the inferior dental nerve. Blood Supply. — Facial artery, occipital artery, and posterior auricular artery. 8. Retrahens aurem, — Origin.- From the mastoid process of the temporal hone. 1 nsertk in.- Into concha of ear. and Lower part of cranial surface. Action. To km rad the pinna. Nerve Supply.— Posterior auricular branch of die facial nerve. Blood Supply. — Branches from posterior auricular. 9. Stylo-pharyngeus. — Description. — This muscle, which extends from the styloid process of the temporal hone to die pharynx, is a long slender mus- cle, rounded above and broad and thin below. The stylo-pharyngeus nerve in passing to the tongue lies on die outer side of this muscle. Origin.- From the inner side and base of styloid process. Insertion.- Into the Consl ictor muscles, Palato-pharyngeus muscle, and the posterior border of die thyroid cartilage. Action. - To elevate and widen die pharynx. Nerve Si pply. Glosso-pharyngeal. Blood Supply, ts same as die blood supply to die pharynx, which is found mi page 315. K). Stylo-hyoid. — Description. — This muscle is perforated near its in- sertion by the tendon of die Digastric muscle. It is situated in front of and above die posterior belly of die Digastric. Origin.- From the styloid process of the temporal hone near its base. Insertion, tnto the body of die hyoid b ■. Action. Ii elevates and retracts the hyoid hone. Nerve Supply.- facial. Blood Si pply. Same a- Digastric muscle. 11. Stylo-glossus. Im -i ription.- This is the shortesl and smallest of the Styloid muscles. Origin, from the anterior and external surface of the styloid process near its apex, and from the stylo-hyoid ligament by a thin aponeurosis. Insertion, into the sides of the tongue, and entering the dorsum of the tongue blends with the Lingualis muscle in front of the Hyo-glossus muscle, and its oblique portion passes over the Hyo-glossus muscle and decussates with its fibers. ANATOMY IX A NUTSHELL. 523 Action. — To elevate and retract the tongue. Nerve Supply. — Hypoglossal. Blood Supply. — Facial, lingual and ascending pharyngeal. 12. Levator palati.— Description. — This muscle, which is long, thick, and rounded, is situated on the outer side of the posterior nares. Origin. — From the under surface of the apex of the petrous portioD of the temporal bone, and from the inner surface of the cartilaginous portion of the Eustachian tube. [nsertiOn. — Into the posterior surface of the sofl palate where ii blends with the muscle of the opposite side. Action. — It elevates the soft palate. Nerve Supply. — The spinal accessory through the pharyngeal plexus possibly from the facial through the petrosal branch of the vidian nerve. Blood Supply. — Ascending palatine, ascending pharyngeal, descending- palatine, lingual. 13. Tensor tympani. — Description. — This muscle is situated above the osseous portion of the Eustachian tube in a bony canal. It is separated from the Eustachian tube by the processus cochleariformis. Origin. — From the canal it is situated in. under surface of the petrous portion of the temporal bone, and the cartilaginous portion of the Eustachian tube. Ixskrtion. — Into the handle of the malleus near its root. Action. — To tense the tympanic membrane. Nerve Supply. — From the otic ganglion of the fifth nerve. Blood Supply. — Tympanic branch of ascending pharyngeal. 14. Stapedius. — Description. — This is the smallest muscle in the body. Origin. — From the sides of the cavity in the tympanum. Its tendon pusses through the foramen in the apex of the pyramid. Insertion. — Into the neck of the stapes. Action. — To draw the head of the stapes backward and thus rotating it> base inward towards the vestibule, and probably compressing the contents of the vestibule. Nerve Supply. — Tympanic branch from the seventh. Blood Supply. — Tympanic branch of internal maxillary. If). Tensor palati.- Description.- This is a broad triangular muscle with its base upward, and lies at the outer side of the Levator palati. Origin.— From scaphoid fossa :it the base of the internal pterygoid plate, spine of sphenoid bone, vaginal process of temporal bone, cartilaginous portion of the Eustachian tube, and hamular process. Insertion.- Into the anterior surface of the sofl palate, and the trans- verse ridge on the horizontal portion of the palate bone. Action.— 11 tenses the soft palate, and opens Eustachian tube during deglutition. Nerve Supply. Otic ganglion of the fifth nerve. Blood Supply. Ascending palatine, ascending pharyngeal, descending palatine, lingual. 524 ANATOMY IN A NUTSHELL. LESSON CLXXVI. Ethmoid Bone. (Plates CCLVIII-CCLIX. The ethmoid bone which consists of a horizontal plate a perpendicular plate and two lateral masses is situated at the base of the cranium between the orbits. It is a lighl spongy bone and cubical in form. Its body has the following POI NTS FOR < onsideration: PLATE CCLXXII. ca T 0Rls — A Sagittal Section of the Female Organs of Generation. 1. Cribriform plate (horizontal) forms pan of the anterior fossa of the skull as it is situated in the ethmoidal notch of the frontal bone and between it^ orbital plates. ANATOMY IN A NUTSHELL. 525 2. Crista galli is situated in the median line of the cribriform plate an- teriorly. It is thick and triangular. The long border of this triangle, which is the posterior one. gives attachment to the falx cerebri. The anterior border of this triangle, by its articulation with the frontal bone completes the foramen caecum. Between the two laminae of this triangle, there may be a shuts. 3. Grooves are on this plate on each side of the crista galli for the olfactory bulbs. 4. Foramina perforate this horizontal plate for the passage of the olfactory nerves. These foramina are in three rows, (a) an inner row, which leads to the nasal septum, (b) a middle row which leads to the roof of the nose, and (c) an outer row which leads to the superior turbinated bone. 5. Nasal slit is on the side of the crista galli anteriorly and is for the passage of the nasal nerve, which is a branch of the fifth nerve. 6. Triangular notch is at the back of the cribriform plate for the ethmoid spine of the sphenoid. 7. The perpendicular plate descends from the under surface of the cribriform plate and assists to form the nasal septum. Its sides are grooved for filaments of the olfactory nerves. The nasal spine of the frontal and crests of the nasal bones articulate with its anterior border. The ethmoidal crest of sphenoid articulates with the upper half of its posterior border, while the vomer articulates with the lower half of this border. The triangular cartilage is at- tached to its inferior border. The lateral masses of the ethmoid bone consist of a number of cellular cavities, and each lateral half presents the following points for consideration: 1. The ethmoidal cells have thin walls and are situated between two plates which form its sides. 2. Os planum or orbital plate forms the outer surface of these cells and also forms the inner wall of the orbit. It articulates with the orbital plateof the frontal bone above, and forms the anteriorand posterior ethmoidal foramina by their notched borders coming together with the superior maxillary bone below, with the Lachrymal bone in front, and with the sphenoid and orbital process of the palate bone behind. 3. The middle turbinated process, which is concave outward andforms part of the middle meatus, is the end of a thin plate of bone which descends from the cribriform plate, and forms part of the outer wall of the nasal fossa. 4. The superior turbinated process curves downward and outward. 5. The UNCIFORM PROCESS passes downward to articulate with the in- ferior turbinated bone and forms part of the inner wall of the antrum of High- more. OSSIFICATION. It ossifies from three centers. One center for the body and one for each lateral mass. Articulation. It articulates with thirteen bones, namely, the sphenoid and frontal of the cranium, and all the bones of the face excepl the two malar and the inferior maxillary. The bones of the face it articulates with are: the two nasal, two superior maxillary, two lachrymal, two palate, two inferior tur- 526 ANATOMY IX A NUTSHELL. binated, and the vomer. The ethmoid bone with its articulations form the nasal fossa. The two sphenoidal turbinated bones articulate with the ethmoid also. bu1 as they are processes of the sphenoid we do not name them in the articulations of the ethmoid, since the sphenoid itself has been named. A i i \< hment of Muscles. — There are no muscles attached to this hone. Blood Supply. Aaiterior ethmoidal artery, posterior ethmoidal artery, ami nasal or spheno-palatine branch of internal maxillary artery. LESSON CLXXVII. Sphenoid Bone. (Plates CCXLIII-CCXLIV). 'The sphenoid bone forms most of the middle fossa at the base of the skull. It touches all the hones of the cranium, the vomer, two palate and two malar f the face. Occasionally its external pterygoid plate articulates with the superior maxillary hone. It presents the following points for consideration: 1. A body, which is a hollow cuboid structure with six surfaces. The superior surface has in front THE kthmoidal SPINE which articulates with the cribriform plate of the ethmoid. It then has a smooth surface with a slight longitudinal eminence in the mid-line and on each side of this eminence is a groove for the olfactory tract. The next point is the optic groove, which lodges the optic commissure and ends on each side in thk optic FORAMEN which is for the passage of the optic nerve and the ophthalmic artery. Thk olivary process is immediately behind the optic groove. Thk sklla Turcica (pit- uitary fossa), which is for the pituitary body (hypophysis) of the brain, is just behind the olivary process. Thk middle clinoid processes bound the sella Turcica in front. Thk dorsum skll.k (dorsum ephippii) bounds the sella Turcica behind, and is grooved on each side for the sixth nerve. Thk pos- terior clinoid processes are a1 each upper angle of the dorsum sella?. Grooves are situated laterally on the body for the cavernous sinus and the internal carotid artery. They ate curved like the Italic letter f. Thk lingula is a ridge along the outer margin of this groove posteriori}-. Thk clivus is a shallow depression which lodges the pons and slopes backward from the dorsum sella' to be continuous with the basilar groove of the occipital bone. The posterior surface joins the basilar process of the occipital bone. This ce is quadrilateral in shape and there is a layer of cartilage between it and the occipital bone until about the twentieth year. The anterior surface has in the median line thk ETHMOIDAL CREST. This cresl articulates with the perpendicular plate of the ethmoid. Sphenoidal i ELLS or sinuses are on each side of this ethmoidal crest. Thk SPHENOIDAL Ti RBINATED BONE partly closes these cells or sinuses in front and below, but they communicate with the nose and sometimes with the posterior ethmoidal cell.-. This surface articulates with the orbital process of the frontal bone above, and with the orbital process of the palate bone below, and with the os plannum of the ethmoid LATERALLY. The inferior surface has in its mid-line Tin: ROSTRUM, which articulates with the upper edge of the vomer. Thk vaginal processes are on each side, and articulate with the alae of the vomer. This inferior surface helps to form \ \ \TiiMV IN A NUTSHELL. 527 the nasal fossa. Grooves, which articulate with the sphenoidal processes of the palate bone, form the pterygo-palatine canals which are for the trans- mission of the pterygo-palatine vessels and nerves. 2. The greater wings of the sphenoid arise from the sides of the body and curve upward, outward, and backward. Each greal wing has the following points for consideration: (a) foramen rotundum for the superior maxillary division of the fifth nerve, (b) foramen ovale or the inferior maxillary division of the fifth nerve, the small petrosal nerve, small meningeal artery, (c) foramen Vesalii transmits a small vein, tins foramen is often absent, (d) foramen spinosum transmits the noddle meningeal artery, veins, and sympa- thetic filaments from the cavernous plexus. This foramen is often double. PLATE CCLXXIII. ANASTOMOSIS OF UTERINE AND OVARIAN ARTERIES. HELICINE BRANCHES UTERO-OVARIAN LIGAMENT FIMBRIATED EXTRFMITY OF TUBE MBRIA OVARICA OVARIAN ARTERY. ILIAC INTERNAL VAGINAL BRANCHES OS EXTERNUM The Uterus With Vagina Laid Open. The external surface of the greater wing is convex and is divided by the transverse pterygoid ridge into an upper portion, and a lower portion. The upper portion is larger and forms pari of the temporal fossa, and the lower portion forms part of the zygomatic fossa. This lower surface ends posteriorly in the spinous process, or spine, of the sphenoid. This process gives attach- ment to the Tensor palati and internal lateral ligament of the lower jaw. The anterior or orbital surface of the greater wing of the sphenoid forms pari of the outer wall of the orbit, and is quadrilateral in shape. The upper border of this surface articulates with the frontal bone, the outer border with the malar hone, and the lower border, which is rounded, helps to form the pterygo-maxillary fissure, while the inner, which is sharp, forms the lower border of the sphenoidal fissure (anterior lacerated). This surface has a notch 528 ANATOMY IN A NUTSHELL. at its upper pari for a branch of the lachrymal artery, and a spine at its center which gives origin to one head of the External rectus muscle. 'I'lic circumference of the greater wing of the sphenoid articulates with the temporal and frontal hones. Tart of its inner portion forms the lower boundary of the sphenoidal fissure and helps to form the foramen lacerum medium. 3. The lesser wings ni the sphenoid hone (processes of Incrassias) project outward from the upper and lateral part of the body to end in a sharp point. Each wing has two roots; the upper is thin and flat, and the lower is thicker and has near the body a small tubercle to which is attached the ligament of Zinn. Tin; OPTIC FORAMEN which transmits the optic nerve and the ophthalmic artery is between these roots. The anterior border of each wing articulates with the frontal hone, while the posterior border lies in the fissure of Sylvius, and ends in THE INTERIOR CLINOID process internally. Its upper surface is smooth and flat and is situated in the anterior fossa at the base of the skull. The lower surface forms the upper border of the sphenoidal fissure and the hack of the roof of the orbit. Tin-: sphenoidal fissure (anterior lacerated) is hounded above by the lesser wing of the sphenoid, internally by the body of the sphe- noid, and below by the inner margin of the orbital surface of the greater wing of the sphenoid. The following strictures pass through the sphenoidal fissure: the third nerve, fourth nerve, three divisions of the ophthalmic division of the fifth the sixth nerve, filaments from the cavernous plexus of the sympa- thetic, orbital hranches of the middle meningeal artery, the ophthalmic vein, and recurrent branch of the lachrymal artery. 4. The pterygoid processes of the sphenoid bone descend on either side from the junction of the body witli the greater wing. Each process consists of two plates, external pterygoid plate and internal pterygoid plate, and a pterygoid fossa. Tin: external pterygoid plate forms part of the inner wall of the zygomatic fossa and gives attachment to the External pterygoid muscle, and its inner surface gives attachment to the Internal pterygoid muscle. Tin: internal pterygoid plate is longer and narrower than the external one and has on its extremity the hamular process around which the tendon of the Tensor palati muscle turns. The scaphoid fossa is at the base of the in- ternal pterygoid plate and gives origin to the Tensor palati muscle. The vidian canal is at the loot of the pterygoid process for the vidian nerve and vessels. A triangi lap notch is at the rool of the hamular process to articu- late with the pterygoid process of the palate hone. 5. The sphenoidal turbinated hones (spongy) articulate in front with the ethmoid ami with the palate externally. They are irregular bones, wide an- teriorly, and tapering posteriorly. Ossifn vtion. This bone ossifies from fourteen centers. Articulation. It articulates with twelve hones which are. the two malar, the two palate, and the vomer of the lace, and with all the hones of the cranium which are. frontal, ethmoid, two parietal, two temporal, and the occipital. Attachment of Mi scles. It has twelve pairs of muscles attached to it. TheTemporal of thetemporo-maxillary region, the External pterygoid and the ANATOMY IX A NUTSHELL. 529 Internal pterygoid of the pterygo-maxillary region, the Superior constrictor of the pharynx, the Tensor palati of the soft palate the Levator palpebral of the orbital region, the Superior oblique of the orbital region, the Superior rectus. Inferior rectus. External rectus, and Internal rectus of the orbital region, and the Laxator tympani. Blood Supply. — Middle and small meningeal, anterior deep temporal, vidian, pterygopalatine and spheno-palatine, and twigs from the interna] carotid. LESSON CLXXVIII. 1. Temporal muscle which has been described on page 508. 2. External pterygoid. — Description. — This muscle, which passes almost horizontally between the zygomatic fossa and the condyle of the jaw. is a thick, short muscle, conical in form. Origin. — It arises by two heads between which pass the buccal nerve and the internal maxillary artery. The upper head comes from the pterygoid arch and the inferior surface of the greater wing of the sphenoid, while the lower head comes from the outer surface of the external pterygoid plate, and from the tuberosities of the palate and superior maxillary bone. Insertion. — Into a depression in front of the condyle of the lower jaw. and the inter-articular fibro-cartilage. Action. — To draw the condyle and interarticular fibro-cartilage forward and inward. Nerve Supply. — Pterygoid branch of the inferior maxillary division of the fifth. Blood Supply. — External pterygoid branches of the internal maxillary artery. 3. Internal pterygoid. — Description. — This muscle is a thick and quad- rilateral. Origin. — From the inner surface of the external pterygoid plate and from the tuberosity of the palate bone, and the adjacent pari of the superior maxil- lary. Insertion. — Into the internal surface of the ramus of the jaw as high as the mandibular foramen and mylo-hyoid groove. Action.— To close the mouth and to draw the lower jaw forward and inward. Nerve Supply. — Inferior maxillary division of the fifth nerve. Blood Supply. Branches from the second division of the internal maxil- lary artery. 4. Superior constrictor muscle which has been described on pa^ 5. Tensor palati muscle which ha- been described on page 6. Levator palpebrae (superioris). Description. This muscle is tri- angular in shape and is narrow ami tendinous at ii- origin, bu1 broad and Meshy in its center and ends in a wide aponeurosis which passes between the fibers of the Orbicularis to it > insertion. Origin. — From the under surface of the lesser wing of the sphenoid bone above and in front of the optic foramen. 530 ANATOMY IX A NUTSHELL [nsertion. — Into the aponeurosis of the upper t:\rsal cartilage, skin of lid, and conjunctiva. Action. — Lifts the upper lid and antagonizes the Orbicularis palpebrarum. Nerve Supply. — A branch of the third nerve which pierces the su- perior rectus muscle. Blood Supply'. — Muscular branches from the ophthalmic artery. 7. Superior oblique. -Description. — This muscle belongs to the orbital region and receives the fourth nerve. Orsgin. — From above the inner margin of optic foramen. Its tendon passes through a pulley near the internal angular process of the frontal bone, then beneath the Superior rectus muscle. Insertion. Into the sclerotic coat between the Superior rectus and Ex- ternal rectus muscle at right angles to these muscles. PLATE CCLXXIV. SUPERFICIAL DORSAL VEIN DEEP DORSAL VEIN DORSAL ARTERY CORPUS DARTOS ■ AREOLAR TISSUE ANTERIOR BRANCH - BULBO-CAVERNOUS ARTERY CORPUS SPONGIOSIS A Transverse Section oe the Penis. Action. — it rotates the eye-ball on its antero-posterior axis, drawing the cornea downward and outward. Nerve Supply*. — Fourth cranial nerve. Blood Supply. Muscular branches from the ophthalmic artery. 8. Superior rectus. — Description. — This is the thinnest and narrowest o f the Recti muscles. ORIGIN. From the upper margin of the optic foramen, and fibrous sheath of the optic nerve. Insertion.- Into the sclerotic coat three or lour lines from the sclero- corneal junction. Action. Elevates and abducts and rotates the cornea inward. Nerve Supply. — Third cranial nerve. Blood Si pply. — Muscular branches of the ophthalmic artery. U. Inferior rectus. Origin. From the ligamenl of Zinn with the Internal rectus. ANATOMY EN A NUTSHELL. 531 Insertion. — Into the sclerotic coat three of tour lines from the sclero- corneal junction. Action. — Abducts the cornea. Nerve Supply. — Thin I nerve. Blood*Supply. — Muscular branches of the ophthalmic artery. 10. External rectus. — Description. — This is the largesl of the Recti muscles. Origin. — From two heads. The outer head from the outer margin of the optic foramen. The lower head from the ligament of Zinn and the lower margin of the sphenoidal fissure. Insertion. — Into the sclerotic coat. Action. — It abducts the cornea. Nerve Supply. — The sixth nerve. Blood Supply. — Muscular branches from the ophthalmic artery. All the structures on the floor of the sphenoidal fissure are between the two heads of the External rectus muscle, namely, ophthalmic vein, sixth. two divisions of the third, and the nasal branch of the fifth nerves. 11. Internal rectus. — Description. — This is the broadest of the meet muscles. Origin. — From the ligament of Zinn. Insertion. — Into the sclerotic coat. Action. — It adducts the cornea. Nerve Supply. — From the inferior division of the third cranial nerve. Blood Supply. — Muscular branches of the ophthalmic artery. 12. Laxator tympani, so-called by Sommeriny, is now called the anterior ligament of the malleus. It is attached tuthe neck of the malleus and to the anterior wall of the tympanum, with some of its fibers passing through Glas- erian fissure to the spine of the sphenoid bone. LESSON CLXXIX. Nasal Bone. (Plate CCL). The nasal bone, which with its fellow forms the bridge of the nose, is a bone with two surfaces and four borders. It is situated at the upper part of the face. The outer surface is convex transversely, but concave from above down- wark. It has many small furrows for arteries, and at its center a foramen for a vein. This foramen may be double. The inner surface is jus! the reverse of the ohter surface, which makes it concave transversely and convex from above downward. There i- a longi- tudinal groove on this surface for a branch of the nasal nerve. The superior border articulates with the nasal notch of the frontal bone. It is serrated, thick, ami narrow. The inferior border is thinner and broader than the superior border, ami gives attachment to the lateral cartilage. There is a notch at its middle for the branch of the nasal nerve. The external border articulate- with the nasal process of the superior maxillary bone. ANATOMY IN A NUTSHELL. The internal border articulates with its fellow, and with the nasal spine of the frontal bone above and the perpendicular plate of the ethmoid below. Ossification. — It ossifies from one center. Articulation. — It articulates with four bones. The frontal and ethmoid of the cranium, and its fellow and the superior maxillary of the fare. An \< iiMi.vr of Muscles. — A few fibers of the Occipito-frontalis of the cranial region may he attached to this hone Blood Supply. Nasal branch of the ophthalmic artery, frontal, the angular and the anterior tehmoidal arteries. For ORIGIN and ensertion of the Occipito-frontalis muscle see page Lachrymal Bonk. (Plate CCLI.) The lachrymal bone lies on the anterior part of the inner wall of the orbit. It resembles a finger nail, and has the following points for consideration: The external surface has upon it a vertical ridge called the lachrymal cresl which passes in its mid-line and ends below in the hamular process. This process is sometimes separated from the bone and then is called the lesser lachrymal bone. It helps to form the lachrymal groove above by articula- ble with the lachrymal tubercle of tin' superior maxillary bone. The portion of this surface behind the lachrymal crest helps to form the inner wall of the orbit, while the part in front of the lachrymal crest forms part of the lachrymal groove. The internal surface, or nasal surface, forms part of the middle meatus by its anterior portion, while its posterior portion by its articulation with the ethmoid bone completes the anterior ethmoidal canals. This surface has a furrow upon it corresponding to the position of the crest of the external surface. The anterior border articulates with tin 1 nasal process of the superior maxillary bone and is the longest. The posterior border articulates with the os planum of the ethmoid. The superior border, which is the shortest and thickest, articulates with the internal angular process of the frontal bone. The inferior border articulates with the lachrymal process of the inferior turbinated bone, and posteriorly with the orbital plate of the superior maxil- lary bone These two portions of this border are separated by thecrest. Ossification. — It ossifies from one center. Articulation. It articulates with four bones. The frontal and ethmoid of the cranium, and the superior maxillary and inferior turbinated of the face. Attachment of Muscles. — It has one muscle attached to it. namely, the Tensor tarsi i f the palpebral region. Blood Supplj . Inferior orbital, nasal branch of ophthalmic, and anterior ethmoii lal artei ies. Tensor tarsi. Descr iption.— This muscle is the deep part of the Orbi- cularis palpebral urn. Origin. — It arises from the crest of the lachrymal bone and passes across the lachrymal sac and divides into two portions. Insertion. Into the upper and lower tarsal cartilages. ANATOMY IN A NUTSHELL. Action. — To compress the puncta lachrymals againsl the globe of the eye, and to compress the lachrymal sac into a position mosl favorable for re- ceiving the tears. Nerve Supply. — Facial, and perhaps the third nerve. Blood Supply. — Branches from the facial artery. PLATE CCLXXV. ORIFICES OF URETERS PLICA URETERICA TRIGONE WTERNAL URINARY MEATUS PROSTATE GLAND IFICES Or PROSTATIC DUCTS SINUS POCULARIS COWPEIVS GLAND MEMBRANOUS URETHRA CRUS PENIS ORIFICE OF DUCT OF COWPER'S GLAND PECTINIFORM SEPTUM RPUS SPONGIOSUM PORA CAVERNOSA rOSSA NAVICULARS GCANS NAL URINAY MLATUS A Horizontal Section op the Penis. LESSON CLXXX. Malab Bone. (Plates CCLIV-CCLT The malar bone, or check bone, is situated at the outerand upper part- of the face. It forms part of the outer wall and the floor of the orbit, and part of the temporal and zygomatic fossae. ;,.U ANATOMY IN A NUTSHELL. The external surface of the malar hone is convex and gives attachment to the Zygomaticus major and the Zygomaticus minor. It has a malar fora- men tor malar branch of temporo-malar nerve and vessels. lt> inner surface is concave and has a triangular rough surface for its artic- ulation with the superior maxillary. It has a smooth concave surface ex- ternally which forms part of the temporal fossa above and part of the zygo- matic fossa below. This surface gives origin to the Masseter muscle. The orbital border, or antero-superior, forms part of the circumference of the oribt. The maxillary border, or antero-inferior, articultaes with the superior maxillary hone. The Levator labii superioris propius muscle is attached to this border. The temporal border, or post em-superior, is a curved border. The tem- poral fascia is attached to this border which is continuous with the temporal ridge above and with the upper border of the zygomatic arch below. The zygomatic border, or postero-inferior, is continuous with the lower border of the zygomatic arch and gives origin to the Masseter muscle. The maxillary process articulates with the superior maxillary bone. It is rough ami triangular. The zygomatic process articulates with the zygomatic process of the tem- poral hone. The frontal process articulates with the external angular process of the frontal hone. The orbital process passes backward forming part of the floor and outer wall of the orbit. It also forms part of the temporal fossa and bounds the spheno-maxillary fissure anteriorly. It presents the inner opening of the tem- poro-malar canals. Ossification.— From two or three centers. Articulation. — It articulates with four bones. The frontal, sphenoid, and temporal of the cranium, ami the superior maxillary of the face. An \< iimi.vi of Muscles.— It has five muscles attached to it. Levator labii superioris propius of the superior maxillary region, Zygomatic major and Zygomatic minor of the superior maxillary region, the Masseter of the temporo- maxillary region, Temporal of the temporo-maxillary region. Blood Supply. Interim' orbital, lachrymal branches of the ophthalmic, transverse facial, and deep temporal arteries. Levator labii superioris proprius. — Origin.- From the superior maxillary bone above the infraorbital foramen, al.-o from the lower border of the maxillary process of the malar bone. Insertion. Into the facial part of the Orbicularis oris. \> i [ON. To elevate ami protrude the lip. \'l.l;\ l. Si PPL1 . facial nerve. Blood Supply. Branchesfrom the facial artery. The infraorbital plexus, which is formed by the fifth and seventh nerves and the anastomosis of the infraorbital and facial arteries, are beneath this muscle. ANATOMY IN A NUTSHELL. 535 Zygomaticus major. — Origin. — From the malar bone on its posterior asped of external border. Insertion. — Into the angle of the mouth. Action. — It raises the lip outward. Nerve Supply. — Facial. Blood Supply. — Branches from the facial artery. Zygomaticus minor. — Stenson's dud the facial artery and vein pass under this muscle. Origin. — From the anterior aspect of the external surface of the malar bone. Insertion. — Into the angle of the mouth, where it blends with the Levator labii superioris. Action. — To raise the lip outward. Nerve Supply. — Facial. Blood Supply. — Branches from the facial artery. Masseter muscle which has been given on page 520. Temporal muscle which has been given on page 508. LESSON CLXXXI. Superior Maxillary Bone. (Plates CCLII-CCLIII). The superior maxillary bones are two in number and form the upper jaw. There is only one bone of the face larger than the superior maxillary and that is the inferior maxillary. This bone forms parts of the roof of the mouth, of the floor and outer wall of the nose, of the Moor of the orbit; and parts of the zygomatic and spheno-maxillary fossae, spheno- and pterygo-maxillary fissures. The body of the superior maxillary bom 1 is a hollow cube. This hollow is called the antrum of Highmore. The external surface, or facial surface of the body, looks forward and out- ward. On this surface we have the following points for consideration: The incisive fossa is just above the incisor teeth and gives origin for the Depressor alse nasi muscle. Just below this fossa a portion of the Orbicularis oris is at- tached to the aveolar border. External to this fossa is the origin of the Com- pressor alse nasi. The canine fossa, which skives origin to the Levator anguli oris, is separated from the incisive fossa by the canine eminence. Tins emi- nence is a vertical ridge produced by the canine tooth. The infraorbital fora- men, which is for the infraorbital vessels and nerve, is above the canine fossa. The margin of the orbit gives attachment to the Levatorlabii superioris propus muscle. The posterior, or zygomatic surface is convex and forms pari of the zygo- matic fossa. ()n this surface we have the following points for consideration: Near its center are the openings of the posterior dental canals for the posterior dental vessels ami nerve. The tuberosity, which is at the lower pan of this surface, gives origin to the Internal pterygoid muscle. This tuberosity artic- ulates with the tuberosity of the palate bone and some time- with the external pterygoid plate of the sphenoid. A groove just above this tuberosity i- con- 536 ANATOMY IX A XUTSHELL. verted into the posterior dental canal by its articulation with the palate bone. The superior surface, or orbital surface, forms part of the floor of the orbit. Its inner border articulates with the orbital process of the palate bone behind, and with the os planum of the ethmoid in the middle, and with the lachrymal bone in front. Its outer border helps in form the spheno-maxillary fissure and sometimes articulates with the orbital plate of the sphenoid bone. Its anterior border helps to form the circumference of the orbit and is continuous PLATE CCLXXVI. SPERMATIC ARTERY PAMPINIFORM PLEXUS HEAD Of EPIOIDYMUS GLOBUS MAJOR — HYATID MORGAGNI ARTERY OF VAS DEFERENS. TAIL OF EPIDIOYMUS GLOBUS MINOR — PARIETAL PORTION OF TUNICA VAGINALIS.' Testicle \\i> Spermatic Cord. with the nasal process internally and the malar process externally. The in- fraorbital groove, which is for the infraorbital vessels and nerve, runs forward in the mid-line to end in the infraorbital canal and foramen. This canal also opens into a small canal which runs in the anterior wall of the antrum for the passage of the anterior dental vessels ami nerve. There may also be a sec- ond dental canal for the middle dental nerve which passes to the bicuspid teeth. The Inferior oblique muscle of the orbital region arises from a depression just external to the lachrymal groove. ANATOMY IX A NUTSHELL. 537 The internal surface is divided into two partsby the palate process. The part above the palate process forms part of the outer wall of the nasal fossa and has the large opening of the antrum of Highmore. The part below the palate process forms part of the roof of the mouth and is concave. Above the opening of the antrum of Highmore are half cells which are completed by artic- ulation with the ethmoid and lachrymal hones, while below the opening of the antrum of Highmore is a smooth surface which forms part of the inferior meatus. Behind this opening is a rough surface which articulates with the perpendicular plate of the ethmoid. This surface is crossed obliquely by a groove which is converted into the posterior palatine canal by its articulations with the palate bone. The lachrymal groove is in front of the antrum of Highmore and lodges the lachrymal duct. It is converted into a canal by its articulation with the lachrymal and inferior turbinated hones. The inferior turbinated crest, which articulates with the inferior turbinated hone, is anterior to the lachrymal groove. The middle meatus is the concavity above this crest, while the part below it is the inferior meatus. The antrum of Highmore (maxillary sinus) (Plate CCLXIV) is a pyramidal cavity in the body of the superior maxillary bone. The apex of this cavity is formed by the malar process and its walls are the orbital, facial, and zygomatic surfaces of the body of the sphenoid bone. The outer wall of the nose forms its base in which there is the opening. This opening is partly closed by the ethmoid bone above, by the inferior turbinated below, by the palate bone behind. The posterior dental canals, which are for the posterior dental vessels and nerve, are on the posterior wall of this antrum. Processeson the floor of the antrum are produced by first and second molar teeth. The malar process, which is triangular and rough, is situated between the facial surface and the zygomatic surface and articulates with the malar bone. This process gives partial origin to the Masseter muscle. The nasal process, which passes upward, inward and backward by the side of the nose is triangular and thick. The Levator labii superioris alaeque nasi. Orbicularis palpebrarum, and Tendo oculiare attached to its external surface. Its interna] surface makes part of the outer wall of the nose. The upper part of this surface articulates with the ethmoid hone completing the anterior ethmoidal cells, while below this is the superior turbinated cresl which artic- ulates with the middle turbinated bone. The middle meatus is immediately below, and below the middle meatus is the inferior turbinated crest. The upper border of the nasal process articulates with the frontal bone. The anterior border of this process articulates with the nasal bone. The posterior border of this process has the lachrymal groove for the nasal duct, and the inner margin of this groove articulates ith the lachrymal bone. while the outer margin of this groove forms pari of the circumference of the Orbit. Where it joins with the orbital surface is the lachrymal tubercle. The lachrymal groove is made into a canal by the lachrymal bone and the lachrymal process of the inferior turbinated bone. This canal which opens into the inferior meatus, runs downward, outward, and backward. (Plate CCLII.) 538 ANATOMY IN A NUTSHELL. Areolar process lias eighl cavities in it for the teeth. This process is broad- est behind and is the most spongy part of the superior maxillary bone. Its outer surface behind the first molar tooth gives origin to the Buccinator muscle. The palate process, which passes inward from the inner surface of the body, forms part of the floor of the nasal cavity and the roof of the mouth. On its. lnferior surface is a longitudinal groove or canal for the posterior palatine vessels and the anterior and external palatine nerves. It articulates with the vomer, the palate, and with its fellow process of the opposite side. At the point where the two palate processes meet anteriorly is the anteriok palatine canal or fossa. There are four openings in the bottom of this fossa, the two lateral openings are called foramina of Stenson, and transmit anterior branches of the descending palatine arteries. The anterior and pos- terior foramina are called the foramina of Scarpa, and transmit the naso-pala- tine nerves. The left nerve passing through the anterior one and the right nerve through the posterior one. Sometimes a suture passes from this fossa on each side to the interval between the canine and incisor teeth, thus making a bone called the intermaxillary or incisive hone. See plate CCXXVIII. The SUPERIOR SURFACE is concave transversely and forms part of the floor of the nose, and has the upper openings of the canal of Scarpa and the canal of Stenson. The anterior part of the inner border of this surface is called the nasal crest, which articulates with its fellow thus making a groove to receive the vomer. The anterior extremity of the nasal crest is the anteriok nasal SPINE. OSSIFICATION. — This bone ossifies from seven centers. Articulation. — it articulates with nine bones. The frontal and ethmoid of the cranium, and the nasal, malar, lachrymal, inferior turbinated, palate, and vomer of the face, and with its fellow of the opposite side. Sometimes it articulates with the external pterygoid plate of the sphenoid and also with the orbital plate of the sphenoid. Attachment of Muscles. — It has twelve muscles attached to it. The Orbicularis palpebrarum of the palpebral region, the Inferior oblique of the orbital region, Levator labii superioris aleque nasi of the nasal region, Levator anguli oris of the superior maxillary region, the Compressor nasi. Depressor alse nasi, Dilator nares posterior of the nasal region, Masseter of the temporo- maxillary region, Buccinator of the inter-maxillary region. Internal ptery- goid of the pterygo-maxillary region, Orbicularis oris of the intermaxillary region, Levator labii superioris propius of the superior maxillary region. lb. odd Supply. Infraorbital, alveolar, descending palatine, ethmoidal, frontal, nasal, and facial arteries. LESSON CLXXXII. I 1 i Orbicularis palpebrarum muscle has been described on page 508. (2) Inferior oblique. Origin. It arises fr the orbital plate of the superior maxillary bone. ANATOMY IN A NUTSHELL. ")o'.l Insertion. — Into the sclerotic coat below the insertion of the External rectus. Action. — It turns the eye-ball on its antero-posterior axis outward and upward. Nerve Supply. — Third cranial. Blood Supply. — Muscular branches of the ophthalmic artery. (3) Levator labii snperioris ala^que nasi.— Origin. — From the nasal process of the superior maxillary hone. Insertion. — Into the cartilage of the ala of the nose and into the facial part of the Orbicularis oris. Action. — Elevates the upper lip and dilates the nostrils. Nerve Supply. — Facial. Blood Supply. — Angular artery from the facial. PLATE CCLXXVII. TUNICA ALBUGINEA RECEIVING ATTACHMENT OF TRABECULAE CONI VASCULOSI &m$l& COLLECTING TUBE rvv^- t jsgp VAS DEFERENS VAS ABERRANS 'MINOR' RETE TESTIS IN MEDIASTINUM TESTIS The Testicle. (4) Levator anguli oris. — Origin. — From the canine fossa of the superior maxillary bone. Insertion. — Into the facial part of the Orbicularis oris. Action. — To lift the angle of the mouth. Nerve Supply. — Facial. Blood Supply. — Facial artery. (5) Compressor nasi. — Origin. — From the superior maxillary bone above the incisive fossa. Insertion. — Into the fibro-cartilage of the nose, joining here its fellow of the opposite side and the Pyramidalis nasi. Action. — It dilates the nostril. Nerve Supply. — Facial. Blood Supply. — Lateralis nasi of the facial artery. (6) Depressor alse nasi. — Origin. — From the incisive fossa of the superior maxillary bone. Insertion. — Into the septum and alar cartilage of the nose. 540 ANATOMY IN A NUTSHELL. Action. To contract the nostrils. Nerve Supply. — Facial. Blood Supply.— Branches of the facial. 7 Dilator nares posterior. — Origin.— It arises from the margin of the nasal notch and sesamoid car- tilages. Insertion. — Into the skin at the margin of the nostril. Action. — To dilate the nostril. \ki;\ e Supply. — Facial. Blood Supply. — Branches from the facial artery. (8) Massetef muscle which has been described on page 520. (0) Buccinator. — Description. The upper and lower fibers of the Bucci- nator muscle meet at the angle of the month where they decussate to he con- tinuous with the fibers of the Orbicularis oris, however, the highest and the lowest of these fibers do not decussate. This muscle, which is united with the Superior constrictor of the pharynx by the pterygo-maxillary ligament, forma a muscular wall for the mouth, while the Superior constrictor forms a mus- cular wall for the pharynx. Origin. — From the posterior areolar processes of both the maxillary bonea and the pterygo-maxillary ligament. Insertion.— Into the Orbicularis oris in a manner which has been del scribed in the description of the muscle. Action.- To compress the cheeks. Xia;\ e Supply. — Facial, and buccal branch of the inferior maxillary division of the fifth nerve. Blood Supply. — Facial artery. (10) Internal pterygoid which has been described on page 529. (11) Orbicularis oris. — Description. — The fibers of this muscle are de- rived from the other facial muscles which are inserted into the lips, and it has fibers which belong to the lip itself. The fibers which belong to the lips pass in an oblique direction from the under surface of the skin through the thickness of the lip to the mucous membrane. Besides these two sets of fibers just men- tioned, it has a third set of fibers wheh connect it with the superior maxillary bone :tnd the septum of the nose. Origin. By accessory fibers of nasal septum and the facial muscles sur- rounding the mouth. Insertion. Into the Buccinator and other muscles surrounding the mouth. This muscle is not a sphincter muscle. ACTION.-— To pucker and close 1 the mouth. Nerve Supply.— Buccal and supramaxillary divisions of the cervico- facial division of the seventh nerve. Blood Supply. — Superior and inferior coronary, and inferior labial. (12) Levator labil superioris proprius. — DESCRIPTION. — This muscle covers the origin of the Compressor nasi and Levator anguli oris muscles, and the in- fraorbital vessels and nerve as they pass from the infraorbital foramen. ( )i;i<;i\. from the superior maxillary bone above the infraorbital foramen. ANATOMY IN A NUTSHELL. 541 Insertion. — Into the upper lip blending with the Orbicularis oris. Action. — To elevate the lip. Nerve Supply. — Infraorbital branch of the facial. Blood Supply. — Facial. LESSON CLXXXIII. Inferior Maxillary Honk. (Plates CCLVI-CCLVII). The inferior maxillary bone consists of a body shaped something like a hi nvs shoe with the ends spread, and two vertical rami which meet the body at nearly a right angle. The body has the following points for consideration: The external surface of the body is convex from side to side. bu1 concave from above downward. The symphysis is a vertical ridge in the middle line marking the junction of the two lateral portions of the bone. The mental pro- cess is a prominent triangular eminence which forms the chin. The incisive fossa is situated on each side of the symphysis just below the incisor teeth, ami jives origin to the Levator menti muscle. The Orbicularis oris has an origin just externally from this fossa. The mental foramen is jusl below the interval between the bicuspid teeth and is for the passage of the mental vessels and nerve. The external oblique line passes outward from the base of the mental process for a short distance, then passes upward and finally become- continu- ous with the anterior border of the ramus. This line gives origin to the De- pressor labii inferioris and the Depressor anguli oris muscles, while just below it is attached the Platysma myoides. There is a groove near the anterior inferior border of the Masseter muscle for the facial artery. The internal surface of the body is concave from side to side and convex from above downward, just the reverse of the external surface. It has the following points for consideration: A depression in the mid-line corresponding to the symphysis. The genial tubercles or mental spin-'- are in two pairs and are situated just below the center of this depression on either side. The upper pair give attachment to the Eenio-hyo-glossi, and the lower pair give attachment to the Genio-hyoidei. The sublingual fossa, which is for the sublingual gland, is external to these tubercles on either side. Beneath this sublingual fossa at the lower margin of the bone is the digastric fossa, which gives attachment to the Digastric muscle. The mylo-hyoid ridge passes obliquely upward and outward and gives attach- ment to the Mylo-hyoid muscle. The posterior extremity of this ridge gives attachment to the Superior constrictor muscle and the pterygo-maxillary liga- ment. The submaxillary fossa, which b for the submaxillary gland, is below the mylo-hyoid ridge. These oblique line- mi the external surface and the in- ternal surface divide the body into an upper and a lower portion. The superior border of the body, or aveolar border. i> thick behind and has on each side eighl cavities for the teeth, h gives attachment to the Buccinator muscle on its external surface behind the first molar tooth. The inferior border is longer than the superior border and is thicker an- teriorly which is just the reverse of the superior border. A groove for the 542 ANATOMY IN A NUTSHELL. facial artery is od this border at the function of the body with the ramus. This groove i- also partly od the external surface. The rami of the inferior maxillary bone are the perpendicular portions. They arc quadrilateral in shape and each one has two surfaces, four borders! PLATE CCLXXVIII. GREAT OMENTUM LEFT COMMON ILIAC VEIN A Sagittal Section of the Male Organs op Generation. and two processes. The external surface of the ramus gives attachment to the Masseter muscle. The internal surface of the ramus lias near its center the inferior dental foramen, which open- behind the spine. The mylo-hyoid groove runs obliquely downward from the dental foramen and Indues the mylo- ANATOMY IN A NUTSHELL. 5 !•'• hyoid vessels and nerve. The Internal pterygoid muscle is attached to a rough surface behind this groove. The lingula is a sharp spine at the anterior margin of the mental foramen and gives attachment to the internal lateral ligamenl of the jaw. The anterior border of the ramus is a continuation of the external oblique line. The superior border of the ramus has the coronoid process anteriorly, the deep sigmoid notch in the center, and the condyle of the lower jaw pos- teriorly. The deep sigmoid notch is crossed by the masseteric vessels and nerve. The posterior border, which is thick and rounded, is saddled by the parotid gland. The inferior border is continuous with the body. The angle of the jaw is the junction of the posterior border and the in- ferior border. On the lower part of the posterior border between the Masseter muscle externally and the Internal pterygoid muscle internally is the attach- ment of the stylo-maxillary ligament. The inferior dental canal, which is for the inferior dental vessels and nerve, passesfrom thedental foramen in the ramusof the bone downward and forward. It now turns forward to pas- underthe alveoli in the body of thebone as far as the incisor teeth. It gives off a branch to the mental foramen. This canal lies near the internal surface of the bone for its first two-thirds, and near the external surface 'for its anterior one-third. The coronoid process, which is at the anterior margin of the upper border of the ramus, is thin. flat, and triangular. It gives attachment to the Tem- poral muscle on both its external and interna] surface-. The condyloid process is situated at the posterior margin of the superior border of the ramus. Its condyle, winch has its long axis transversely and its outer end higher and more anterior than the inner, articulates with the glenoid fossa of the temporal bone. The neck of the condyloid process receives the insertion of the External pterygoid muscle internally. There is a tubercle on its external margin for the capsular and external lateral ligamenl of the lower jaw. Ossification. — This bone ossifies from twelve centers; six for each lateral half. Articulation. — It articulates with the glenoid fossa' of the two temporal bone-. Attachment of Muscles. Thee are fifteen pairs of muscles attached to this hone. To the kames. the Masseter of the teniporo-niaxillarv region, the Internal pterygoid and External pterygoid of the pterygo-maxillary region, and Temporal of the temporo-maxillary region; to internal surfaci ok 'nil-: body, the Genio-hyo-glossus and Genio-hyoideus of the lingual region, Mylo-hyoid of the supra-hyoid region, Digastric of the supra-hyoid region, and Superior constrictor of the pharynx : ro the extern ^l surfaci of the body, Depressor lahii Lnferioris and Depressor anguli oris of the inferior maxillary region, Levator menti of the inferior maxillarv region. Orbicularis oris of the .",44 ANATOMY IX A XUTSHELL. intermaxillary region, Platysma myoides of the superficial cervical region, and Buccinator of the intermaxillary region. Blood Supply. — Branches from the internal maxillary. LESSON CLXXXIV. 1. Masseter muscle which has been described on page o'20. 2. Internal pterygoid which has been described on page 529. .!. External pterygoid which has been described on pane 529. 4. Temporal muscle which has been described on page 508. ."). Genio-hyo-glossus. — Description. — This muscle is fan-shaped and placed vertically on either side of the middle line of the jaw. The apex of this muscle is at its point of attachment to the lower jaw and its base is its insertion into the tongue and the hyoid hone. This muscle is more or less blended with its fellow in front but separated from it behind. Origin. — From the superior genial tubercle on the inner side of the sym- physis of the jaw. 1 NSERTK in. Into the upper part of the body of the hyoid bone and median line of the tongue, the side of the pharynx, and the entire length of the under surface of the tongue. Action.— To retract and protrude the tongue. Xki;\ e Supply. — Hypoglossal. Blood Si pply. — Lingual. (>. Genio-hyoideus. — Description. — This muscle increases in breadth as it pa>ses towards its insertion and lies close to its fellow. It is situated be- neath the inner border of the Mylo-hyoid. Origin.— From the inferior genial tubercle of the lower jaw. Insertion. — Into the anterior surface of the body of the hyoid bone. A' tion. To lift and draw forward the hyoid bone. Nerve Supply. — Hypoglossal. Blood Supply. — Lingual. 7. Mylo-hyoid. — Origin. — From the mylo-hyoid ridge of the lower jaw. Insertion. Into the body of the hyoid bone and a median fibrous raphe running in mid-line of the hyoid bone to the chin. V ii"\. Lift- the hyoid and draws it forward. N i i:\ i. Si pply.- -Mylo-hyoid branch of the inferior dental of the fifth. Blood Supply. Submental and mylo-hyoid arteries. 8. Digastric muscle which has been described on page 521. 9. Superior constrictor which has been described on page 515. in. Depressor labii int'erioris, also called Quadratus menti. Origin. From the external oblique line of the inferior maxillary bone below and internal to the mental foramen. Insertion. — Into the lower lip (facial pari of the Orbicularis oris). Action. To draw the lower lip down. Nerve Si pply. Supramaxillary branch of facial nerve. ANATOMY IX A NUTSHELL. 545 Blood Supply. — Branches from the facial artery. 11. Depressor anguli oris (also called Triangularis nienti). Origin. — From the external oblique line of the inferior maxillary bone between the attachments of the Depressor iabii inferioris and Platysma myoides. Insertion. — Into the angle of the mouth. Action. — To draw down the angle of the mouth. Xerve Supply. — Supramaxillarv division of the facial. Blood Supply. — Branches of the facial artery. PLATE CCLXXIX. AMPULLA OF DUCT ACINI OF (HAND ADIPOSE LOCULUS MAMMILLA AREOLA GLAND LOCULUS The Mammary ( }land. 12. Levator labii inferioris, also called Levator menti. Origin. — From the incisive fossa of the inferior maxillary bone. Insertion. — Into the facial pari of the Orbicularis oris and internment of chin. Action.- To raise the lower lip. Nerve Supply. — Supramaxillarv branch of the seventh. Blood Supply. Branches of the facial artery. 13. Orbicularis oris which has been described on page 540. 14. Platysma inyoides. Description. The Platysma myoides, which i^ a broad thin layer of muscle, lies in the superficial fascia. Ork;ix. — From the dee]) fascia which covers the Deltoid and Pectoralis 546 ANATOMY IN A NUTSHELL. major muscles, as it passes over the clavicle a few fibers may be attached to it. Insertion. — Into the fascia extending from the angle of the mouth to the angle of the jaw, also into the inferior maxillary bone below the mental foramen. A.CTION. Helps to depress the lower jaw. Nerve Supply. — The inframaxillary division of the seventh. Blood Supply. — Branches of the external carotid artery. 15. Buccinator which has been described on page 540. LESSON CLXXXV. [nferioe Turbinated Bone. (Plates CCLX-CCLXIV.) The inferior turbinated bone, which is situated in the nasal fossa along its outer wall, is curved upon itself. It has two surfaces, two borders, two ex- tremities, and three processes. The external surface of the inferior turbinated bone is concave, ami helps to form the inferior meatus. The internal surface of the inferior turbinated bone is convex. The extremities of this bone are narrow and pointed. The inferior border (free border) passes to within half an inch of the floor of the nose. The superior border articulates with the inferior turbinated crest of the superior maxillary bone anteriorly, and with the inferior turbinated crest of the palate bone posteriorly. The lachrymal process is on the superior border at the junction of the anterior one-fourth with the posterior three-fourths. It articulates with the inferior angle of the lachrymal bone and also with the nasal process of the superior maxillary bone, thus helping to form the nasal duct. The ethmoidal process is on the superior border about half way between the lachrymal process and the posterior extremity of the bone. It articulates with the unciform process of the ethmoid. The maxillary process, which is immediately below the ethmoidal process but on the external surface of the bone, articulates with the lower edge of the aperature of the antrum of Eighmore, and also helps to close this opening. Ossification.- It ossifies from one center. Articulation. — It articulates with four bones. The ethmoid of the cranium, superior maxillary, lachrymal, and palate of the face. Attachment of Muscles. — It has no muscles attached to it. Bl< m >i> Si pply. — Vomer Bone. (Plate CCLXI). The vomer (ploughshare) forms the postero-inferior part of the nasal septum and is a single bone. It has the following points for consideration: The oaso-palatine grooves or canals are situated on each side of this hone r unnin g downward and forward to the intermaxillary suture. They are for the naso-palatine nerves. The posterior border of the vomer is concave and free. Its lower portion is thin, while its upper portion is divided. ANATOMY IX A NUTSHELL. 547 The inferior border, which is the longest, articulates with the nasal cresl of the superior maxillary and palate bone. The anterior border is short and articulates with the incisor crests of the superior maxillary bone. The antero-superior border receives the Lower margin of the triangular cartilage below and the vertical plate of the ethmoid above. The postero-superior border is the thickest and has a median groove which receives the rostrum of the sphenoid bone. This border is bounded on either side by the ala, which fits in the vaginal process of the sphenoid. This joint is a schindylesis. OSSIFICATION. — This bone ossifies from one center. Articulation. — It articulates with six bones. The sphenoid and ethmoid of the cranium, the two superior maxillary, the two palate of the face. It also articulates with the cartilage of the septum. Attachment of Muscles. — It has no muscles attached to it. Blood Supply. — Anterior and posterior ethmoidal, and nasopalatine through Stenson's canal. LESSON CLXXXVI. Palate Bone. (Plates CCLXII-CCLXIII-CCXXVIII-CCXXIX). The palate bones are two in number and situated between the superior maxillary bones and the pterygoid processes of the sphenoid bone at the back of the nasal fossae. Each bone helps to form the roof, floor, and outer wall of the nose, and the floor of the orbit. They also help to form the spheno-max- illary fissure, spheno-maxillary fossa, and the pterygoid fossa, and the zygo- matic fossae. Each one has the following points for consideration: The horizontal plate, which is thick, has two surfaces and four borders. The superior surface is concave transversely and forms the back part of the floor of the nose. The inferior surface is also concave and forms the back pail of the hard palate, and has upon it a transverse ridge for the attachment of the Tensor tympani aponeurosis. A groove is situated at the outer end of this transverse ridge which with the tuberosity of the superior maxillary bone forms the pos terior palatine canal. Posterior to this groove are foramina of the accessory posterior palatine canals. The anterior border is serrated ami articulates with the palate process of the superior maxillary bone. The internal border is thick and articulate- with the internal border of it- fellow, thus forming a groove on the upper surface for the reception of the vomer. On the posterior extremity of this border is a posterior nasal -pine which is for the origin of the Azygos uvula- muscle. The external border joins the verl Leal plate of the palate bone at righl angle. The posterior border is free and concave, and gives attachment to the soft palate. 548 ANATOMY IN A NUTSHELL. The vertical plate is broad and thick and is directed upward and slightly inward. This plate has two surfaces and four borders. The external surface articulates with the superior maxillary bone for most of its extent. This pari of the hone is rough. The front part of this surface is smooth and covers the orifice of the antrum of Highmore. The upper and back part of this surface helps to form the spheno-maxillary fossa and is also smooth. On the posterior part of this surface is a deep groove which with the superior maxillary hone forms the posterior palatine canal for the descending palatine vessels and the descending palatine nerve. The internal surface forms part of the inferior meatus which is below the inferior turbinated crest.* The superior turbinated crest articulates with the middle turbinated hone, and above this crest is the superior meatus, while between this crest and the inferior turbinated crest is the middle meatus. The inferior border joins the horizontal plate at right angles. PLATE CCLXXX. The Outee Surface of the Pinna. The superior border has a notch separating the sphenoidal process from i he orbital process, and this notch is converted into the spheno-palatine foramen by the sphenoidal turbinated bone. The spheno-palatine vessels and the superior nasal and naso-palatine oerves pass through this foramen. It was stated above that this notch was converted into a foramen by the sphenoidal turbinated bone, but it may be convened into a foramen by the two processes meet ing. The anterior border has the maxillary process at the anterior extremity of tlw inferior turbinated crest. This process closes the antrum of Highmore posteriorly and inferiorly. This border articulates with the superior maxillary I MlllC. The posterior border has a deep groove and articulates with the pterygoid process of the sphenoid bone. The Internal pterygoid muscle has part of its origin from a median groove on the lower pari of this border which forms part of the pterygoid process. The orbital process is triangular in shape and is directed upward and out- ANATOMY IX A NUTSHELL. 549 ward. It has three articular surfaces and two free surfaces. The articular surface- are the anteriob or maxillary, which articulates with the superior maxillary bone. — internal or ethmoidal surface, which articulates with the ethmoid hone. — and posterior or sphenoidal surface, winch articulate.- with the sphenoidal turbinated bone. The free surfaces are the orbital, which forms part of the Moor of the orbit. — ami Tin: external or zygomatic surface, which forms part of the zygomatic fossa. This process has a rounded border which forms part of the spheno-maxillary fissure. The sphenoidal process is -mailer than the orbital process and articulates .superiorly with the body of the sphenoid, and externally with the pterygoid process of the sphenoid. It has three surfaces and two borders. Tin: internal surface, which is concave, forms part of the outer wall of the nasal fossa— the superior surface, which articulates with sphenoidal turbi- nated bone, is converted into the pterygo-palatine canal, — Tin: external surface articulates with the inner surface of the pterygoid process of the sphenoid bone, and also help.- to form the spheno-maxillary fossa. Its ANTER- IOR border forms the back part of the spheno-palatine foramen. Its pos- terior border articulates with the inner surface of the pterygoid process. Ossification. — This bone ossifies from one center. Articulation. — It articulates with six bones. The sphenoid, ethmoid, superior maxillary, inferior turbinated, vomer, and its fellow. Attachment of Muscles. — This bone has four muscles attached to it. The Tensor palati of the soft palate. Azygos uvulae of the soft palate. Internal pterygoid of the pterygo-maxillary region, and Superior constrictor of the pharynx. Blood Supply. — Descending palatine, spheno-palatine, and pterygo- palatine. 1. Tensor palati, which has been described on page 522. 2. Internal pterygoid muscle, which has been described on page 529. 3. Azygos uvulae. — Description. — There is a pair of these muscles although from the name we might think there is but one. There is one on each side of the median line of the soft palate. Origin. — From the nasal spine of the palate bone and the adjacent apo- eurosis of the soft palate. I nsertk i\. Into the uvula. Action. — To shorten the uvula. Nerve Supply.— Internal branch of spinal accessory, through the pharyn- geal plexus. Bloob Supply. — Palatine arteries from internal maxillary. 4. Superior constrictor, which has been described on page 515 LESSON CLXXXVII. Hyoid Bone. (Plate XIX). The hyoid bone, which is situated a1 the base of the tongue consists body, two greater cornua, two lesser cornua, making it horse-shoe in shape. It is called the lingual bone. The anterior surface of tin- body is convex and 550 . AX ATOMY IX A XUTSHELL. has a ventral ridge in its center. There is a small tubercle on the upper end of this ridge. This surface has attached to it the following muscles: Genio- hyoid. Genio-hyo-glossus, Hyo-glossus, Mylo-hyoid, Stylo-hyoid, the aponeu- rosis of the Digastric muscle. The posterior surface of the hotly is concave. The lateral surfaces articulate with the greater cornua. The superior surface gives attachment to the Genio-hyo-glossus, and ( Jhondro-glossus. The inferior border gives attachment to the Sterno-hyoid, Omo-hyoid, and Thyro-hyoid muscles. All muscles attached to this hone are in pairs. The greater cornu projects backward and outward from the lateral sur- face of the body. The thyro-hyoid ligament is attached to the end of the greater cornu. The Hyo-glossus muscle is attached to its outer surface, the Middle consl rictor to its upper border, and the Thyro-hyoid to its lower border. The lesser cornu is situated at the angle where the greater cornu joins the hotly. The stylo-hyoid ligament is attached to its apex. This articulation may he ankylosed hut is generally free. Ossification. — From five centers. Articulation. — It articulates with no bone. A it \i hment of Muscles. — This bone has twelve pairs of muscles attached to it, as well as the thyro-hyoid membrane and the stylo-hyoid, thyro-hyoid, and hyo-epiglottic ligaments. Blood Supply. — Superior thyroid and lingual of the external carotid artery. 1. Sterno-hyoid muscle, which has been described on page 40. 2. Thyro-hyoid. — Origix. — From the oblique line on the thyroid cartilage. Insertion.- Into the body and the greater cornu of the hyoid bone. Action. — To depress the larynx and the hyoid hone. Nerve Supply. — Hypoglossal nerve. Blood Supply. — Superior thyroid artery. '■'•. Omo-hyoid muscle, which has been described on page 59. 4. Digastric muscle, which has been described on page 521. 5. Stylo-hyoid, which has been described 522. 6. Mylo-hyoid, which has been described on page 544. 7. Genio-hyoid, which has been described on page 544. 8. Genio-hyo-glossus, which has been described on page 544. o. Chondro-glossus.- Description.— This muscle is sometimes described as pari of the Hyo-glossus. Origin. From the body and lesser cornu of the hyoid bone. Insertion. Ento the intrinsic muscles of the tongue between the Hyo- glossus ami the Genio-hyo-glossus. Action. To draw down tin- side of the tongue. \i.i;\ e Supplj .- -Hypoglossal. I'.i.t k >n Si ppl"5 . Lingua] artery. Hi. Byo-glossus. ANATOMY IN" A NUTSHELL. 551 Origin. — From the whole length of the greater cornu and from the body of the hyoid bone. [nsertion. — Into the side of the tongue. Action. — To draw down the side of the tongue. Nerve Supply. — Hypoglossal. Blood Supply. — Lingual artery. ] 1 . Middle constrictor. — Origin. — From the greater cornu of the hyoid Ik die and the stylo-hyoid ligament. Insertion. — Into the middle line of the pharynx by the fibrous raphe. Action. — To constrict the pharynx antero-posteriorly. Nerve Supply. — Pharyngeal plexus. PLATE CCLXXXI. DUCTUS ENDOLYMPHATIC!.)"; TYMPANIC CAVITY SACCULE EUSTACHIAN TUBE'! 1/1 4 MEMRRANA TYMPANI EXT AUDITORY MEATUS Diagrammatic View of the Organs of Eearing. (Modified prom Cunningham.) Blood Supply. — Same as the blood supply to the pharynx, which is given on page 315. ^'2. Inferior Ungualis, — This muscle runs along the under edge of the tongue in its whole length, h makes the dorsum convex and shortens the tongue. LESSON CLXXXVIII. There auk three Pairs of Meati ses i\ the Nose. (Plate CCLXIV). The superior meatus, which is the smallest of the three, is situated be- 552 ANATOMY IN A NUTSHELL. tweeD the superior turbinated bone and middle turbinated bone at the upper and back pari of tin- nasal fossa. This meatus occupies the posterior one-third of the outer wall of the nasal fossa. The spheno-palatine foramen opens into it at the back part of its miter wall, while the posterior ethmoidal cells open into it at the anterior part of the outer wall. The spheno-ethmoidal recess is be- hind the superior turbinated bone at the superior and posterior part of the nasal fossa and opens into the sphenoidal sinus. The middle meatus occupies the posterior two-thirds of the outer wall of the nasal fossa and is situated between the middle turbinated bone and the inferior turbinated bone. This meatus communicates anteriorly with the anterior ethmoidal cells by means of the infundibulum and through these cells with the frontal sinus. The opening of the antrum of Highmore is near the center of this meatus. The inferior meatus, which is the largest of the meatuses, is situated be- tween the inferior turbinated bone and the floor of the nasal fossa. It will be noticed that the superior meatus occupied the posterior one-third of the outer wall and the midlle meatus occupied the posterior two-thirds of the outer wall, while the inferior meatus occupiesthe entire length of the outerwall of the nasal fossa. The canal for the nasal duct opens at the anterior extremity of this meatus. The nasal fossae extend from the base of the cranium to the roof of the mouth, and are situated on each side of the middle line of the face. They are two large cavities which are separated from each other by a thin septum. The anterior nares open on the front of the face from the nasal fossa' while the pos- terior nares open into the pharynx. The frontal sinus communicates with the nasal fossa above, the sphenoidal sinus communicates with the nasal fossa posteriorly, and the antrum of Highmore and the ethmoidal sinus communi- cate with it externally. The orbit is joined to the nasal fossa by the lachry- mal groove. The mouth communicates with the nasal fossa by the anterior palatine canal. The cranium communicates with the nasal fossa by the ol- factory foramina, and the spheno-maxillary fossa communicates with the nasal fossa by the spheno-palatine foramen. Sometimes the nasal fossae communi- cate with each other by an opening in the septum. There are fourteen bones in the nasal fossae. They include all the bones of the face except the two malar and the inferior maxillary, and in place of these three it has the frontal, eth- moid and sphenoid of the crainum. The ethmoid bone with all its articu- lation- make the nasal fossa-. The frontal, ethmoid, and sphenoid are com- mon to the nasal fossa, cranium and the orbits. There are numerous foramina at the base of the skull extending from the foramen csecum to the foramen magnum. There are also three large fossae at the base of the skull, namely, the anterior fossa, middle fossa, ami the posterior fossa. (Plate CCXXXV.) Till. WTI.imu; FOSSA HAS THE FOLLOWING FORAMINA: 1. Foramen caecum through which a vein passes to the superior longitu- dinal sinus, sometimes one from the frontal sinus. This is a single foramen, while the others in this fossa arc in pair-. ANATOMY IN A NUTSHELL. 553 2. The ethmoidal fissure through which passes the nasal nerve and the anterior ethmoidal vessels. 3. Olfactory foramina for the olfactory nerves and nasal branches of the ethmoidal arteries. 4. Anterior ethmoidal foramen for anterior ethmoidal vessels and nasal nerve. 5. Posterior ethmoidal foramen for posterior ethmoidal vessels and a branch of the nasal nerve. 6. Optic foramen for the opticnerve and the ophthalmic artery. Thisfor- amen is sometimes given as belonging to the middle fossa since it is <>n the boundary line between the anterior and middle fossa. Thus we can see that there are eleven sets of foramina in the anterior fossa ; five pairs and a single one. LESSON CLXXX1X. The middle fossa is on a lower level than the interior fossa wn HAS THE FOLLOWING FORAMINA ALL OF WHICH ARE IN PAIRS: 1. Sphenoidal fissure (anterior lacerated foramen) winch transmits the third nerve, the fourth nerve, and three divisions of the ophthalmic division of the fifth nerve, and the sixth nerve, also filaments from the cavernous plexus. ophthalmic vein, recurrent branch from the lachrymal artery, orbital branch of the middle meningeal artery, and a process of the dura mater. 2. Foramen rotundum through which passes the superior maxillary divi- sion of the fifth nerve. 3. Foramen Vesalii which is for a small vein. 4. Foramen ovale through which passes the inferior maxillary division of the fifth nerve, small petrosal nerve, and the small meningeal artery. 5. Foramen spinosum through which passes the middle meningeal artery, meningeal veins, and filaments from the cavernous plexus. 6. Foramen laeerum medium through which passes the vidian nerve, a branch from the ascending pharyngeal artery, carotid artery, and carotid plexus. 7. Hiatus Fallopii through which passes the petrosal branch of the vidian nerve and the petrosal branch of the middle meningeal artery. 8. A small foramen through which passes the lesser petrosal nerve. Thus we see there are sixteen sets of foramina in the middle fossa. The posterior FOSSA is ox a deeper level than either of the other FOSSAE AND CONTAINS THE CEREBELLUM AND THE MIDDLE FOSSA CONTAINS TEMPORO-SPHENOIDAL LOBES OF THECEREBRUM AND THE INTERIOR FOSSA CON- TAINS THE FRONTAL LOBES OF THE CEREBRUM. THIS FOSSA HAS THE FOLLOW- ING foramina: 1. The meatus auditorius interims for the facial and auditory nerves and the auditory artery. 2. The aqueductus vestibuli is for a small artery and vein and pri the dura mater. 3. The jugular foramen (foramen laeerum posterius) in which there are three compartments, through the anterior one of which passes the inferior 554 ANATOMY IN A NUTSHELL. petrosal sinus, through the middle one passes the glosso-pharyngeal, pneumo- gastric, and spinal accessory nerves, through the posterior one the lateral sinus, and meningeal branches of the occipital, and ascending pharyngeal arteries. 4. Mastoid foramen (often absent) is for a small vein and sometimes the mastoid artery. .">. The anterior condyloid foramen which is for the hypoglossal nerve, and meningeal branches of the ascending pharyngeal artery. (i. The posterior condyloid foramen (often absent) for posterior condyloid vein. 7. Foramen magnum which transmits the medulla oblongata and its membranes, spinal accessory nerves, vertebral arteries, anterior and posterior spinal arteries, and the occipito-axial ligaments. This foramen is a single one PLATE CCLXXXII. HELIX ANTI- HELIX A\ \\\ | u ATTOLLENS AURICULAI ma fa ml ';'// f& fk \\ | ' / ///' / ATTRAHENS AURICULAM OBLIOUUS AURICULAM EXTERNAL AUDITORY MEATUS - ^ARTIUGINEUS Posterior View of the Ear With Auricular Muscles. and the others are in pairs. Thus we see there are thirteen foramina in the posterior fossa. The eleven in the anterior fossa, and sixteen in the middle fossa, and the thirteen in the posterior fossa make the forty foramina at the base of the -hull. lesson cxc. The temporal fossa (Plate CCXXXIV) is hounded anteriorly by the ex- ternal angular process of the frontal bone, superiorly by the temporal ridges, posteriorly by the temporal ridges, inferiorly by the zygomatic arch. This fossa is separated from the zygomatic fossa by tin 1 pterygoid ridge which is on the outer surface of the greater wing of the sphenoid hone. The temporal fossa is formed by five hone-, ill pari of the frontal hone, (2) greater wing of the sphenoid hone. (3) pari of the parietal hone. (4) squamous portion of the temporal, (5) malar bone. It has the following sutures: (1) a part of the trans- verse facial -uture. ("_M spheno-malar suture, (3) coronal suture, (4) spheno-pari- ANATOMY IN A NUTSHELL. ■>•>•> etal suture, (5) squamo-parietal suture, (6) squamo-sphenoidal suture. The stephanion is the point where the coronal suture meets the temporal ridge. The pterion is the point where the parietal, frontal, squamous portion of the temporal, and the greater wing of the sphenoid meet. The temporal fossa is deep and concave anteriorly, but convex posteriorly. It is marked by grooves which lodge branches of the deep temporal arteries. The Temporal muscle fills this fossa. The zygomatic fossa is bounded anteriorlyby the tuberosity of thesuperior maxillary bone, posteriorly by the eminentia articularis and the posterior bor- der of the external pterygoid process, superiorly by the pterygoid ridge which is on the outer surface of the greater wing of the sphenoid hone and separates this fossa from the temporal fossa, interiorly by the alveolar border of the super- ior maxillary bone, externally by the zygomatic arch and the ramus of the lower jaw, internally by the external pterygoid plate. The internal maxillary artery, the inferior maxillary nerve ami its branches, the External pterygoid muscle. the Internal pterygoid muscle, and the lower pan of the Temporal muscle are situated in this fossa. The spheno-maxillary fissure ami the pterygo-maxillary fissure are at the superior and internal part of this fossa. The spheno-maxillary fissure, which opens into the outer and back part of the orbit, is horizontal in direction and is formed by the lower border of the orbital surface of the greater wing of the sphenoid superiorly, by the external border of the orbital surface of the superior maxillary bone and a small pari of the palate bone inferiorly; by a small part of the malar bone externally; and it joins the pterygo-maxillary fissure at right angles internally. By means of this fissure the orbit communicates with the temporal fossa, zygomatic fossa, and the spheno-maxillary fossa. The superior maxillary nerve and it > orbital branch, the inferior orbital vessels, and the ascending branches from Meckel's ganglion (spheno-palatine) are transmitted by this fissure. The pterygo-maxillary fissure passes at light angles from the inner ex- tremity of the spheno-maxillary fissure and is therefore vertical in direction. It is formed by the separation of the superior maxillary bone from the pterygoid process of the sphenoid bone and is shaped like the letter \ . It transmits the branches of the internal maxillary artery and connects the spheno- maxillary fossa with the zygomatic fossa. The spheno-maxillary fossa is situated beneath the apex of the orbit where the spheno-maxillary fissure joins the pterygo-maxillary fissure. It is bounded by the under surface of the body of the sphenoid bone and orbital process of the palate bone superiorly, by the superior maxillary bone anteriorly, by the anterior surface of the base of the pterygoid process and lower part of the anter- ior surface of the greater wing of the sphenoid bone posteriorly, by the vertical plate of the palate internally. The sphenoidal fissure, the spheno-maxillary fissure, and pterygo-maxillary fissure open into it. The orbital fossa, nasal fossa, and the zygomatic fossa, and the cavity of the cranium communicate with this fossa. The foramen rotundum superiorly, the vidian foramen belo^ and internal to the foramen rotundum, and the pterygopalatine foramen open on 556 ANATOMY IN A NUTSHELL. its posterior wall. The spheno-palatine foramen and the foramen of the pos- terior palatine canal open on its inner wall. .Meckel's ganglion, the superior maxillary nerve, and the termination of the internal maxillary artery are in this fossa. LESSON CXCI. Female Organs of Generation. (Plates CCLXXI-CCLXXII-CCLXXIII). The internal female organs of generation are, (1 ) the vagina, (2) the uterus (3) i lie Fallopian tubes, (4) the ovaries, while the external female organs of generation are known by the term vulva or pudendum. The vagina is the sexual canal of the female which extends upward and slightly backward from the vulva to the uterus. Its upper extremity embraces the cervix uteri, the posterior wall reaching the cervix higher up than does the anterior wall. The anterior wall is two ami three-fourths inches long, while the posterior wall is three and three-fourths inches long. These walls are in contact. There is a longitudinal ridge (carina) of the mucous membrane on the lower half of the anterior wall, while on the posterior wall there are two ridges called cohnnme rugarum. From all three of these ridges transverse rugae pass. In all the higher mammalia the vagina is the terminal section of a Mnllerian dud or oviduct united with its fellow, while in the lower mammalia the vagina is double, wholely or in part there being two more or less complete vagina, the right and the left. In some oviparvus animals, as birds, the termi- nation of the oviduct beyond the uterine part receives the name of vagina. The hymen is a erescentric or circular mucous fold which constricts the vagina at its entrance. When the hymen is ruptured warty eminences mark its -iic. These are called carunculae myrtiformes. The hymen has the fol- lowing forms: 1. Hymen bifenestratus (biforijB)is one in which there are two openings side by side and a broad septum between them. 2. HYMEN CRIBRIFORMIS is one in which the opening is filled by membrane pierced by many small openings. 3. HYMEN DENTICULAR is one in which the opening has serrate edges. 4. Hymen imperforate is one which completely closes the vaginal orifice. In this condition a surgical operation, after commencement ofthe menstrual period, is necessary. 5. Hy.mkn si i i. i'ii i;i.i> is one having an irregularly curved edge as if carved ou1 of thickened tissue. 6. Hymi nsepti sis s in which the opening is divided by a narrow septum. 7. 1 1 "i m EN SUBSEPT1 3 is one in which the opening is partly filled by a septum growing ou1 of one wall bnt not reaching the other. Although the hymen is most always ruptured by sexual congress it may remain unbroken until parturition. The vagina is smallest below and largest where it surrounds the os uteri, where it is very dilatable. The vagina has in FRONT ok it the urethra and the posterior wall of the bladder, BEHIND it the anterior wall of the rectum and the pouch of Douglas. AXATOMV IX A NUTSHELL. .-).)< ox each side of it are the Levator aid muscles and the recto-vesical fascia. The vagina has three coats: 1. Outer or fibro-elastic. 2. Middle or muscular. 3. Mucous or internal. The circular fibers near the entrance constitute the Sphincter vagina mus- cle which has been described on page 493. The mucous lining of the vagina is covered with squamous laminated epithelium, it has no "lands but is furnished with crypts and follicles, there- fore the fluid which moisten- it is the nature of a transudation rather than that of a secretion. Nerve Supply. — Hypogastric plexus, the fourth sacral, and the pudic ei ve. PLATE CCLXXXIII. TERMINATION OF SEMICIRCULAR CANALS CONNECTION OF MODIOLUS WITH CUPOLA APEX OF MODIOLUS FIRST WINDING OF COCHLEA SECOND WINDING OF COCHLEA SCALA TYMPANI INFERIOR THIRD HALF WINDING OF COCHLEA BASE OF COCHLEA The Boxy Cochlea. Blood Supply. — A branch of the internal iliac artery, on either side. passing to the vagina and base of the bladder. This artery corresponds to the inferior vesical artery in the male. It also receives branches of the uterine artery. Lymphatics of the vagina end in the pelvic inguinal nodes. LESSON CXCII. The uterus is that pari of the female sexual passage to which a ripe ovum is conveyed from the ovary ami in which it is detained in gestation until the fetus is matured and expelled in parturition. The non-pregnan1 human uterus is a pear-shaped organ about three inches long: with a broad flattened part above called the body and a narrow, more cylindrical pari below called the cer- vix. Within is a cavity which passes out in the Fallopian tube on each side above ami below opens into the vagina. The cavity narrows as it passes into the cervix at the internal os and continues downward to the cervical canal to terminate at the external os uteri or OS tinea'. The uterus i> supported by the broad ligament which is a transverse fold of peritoneum ami embraces it on each side. It has accessory ligaments, such as the round ligament, vesico- uterine ligament, and lecto-uterine ligament. It consists of :i serous or peri- ANATOMY IN A NUTSHELL. toneal coat, a middle coat of smooth muscular fibers forming most of its thick- ness, and an epithelial lining. The dimensions of the uterus are as follows: about three inches in length. aboul two inches in breadth, and about an inch in thickness. The walls of the uterus are about three-eighths of an inch in thickness. In women who have borne children these dimensions are increased. It weighs from seven to twelve drachm.-. The direction of the uterus is towards the umbilicus, slightly to the right ant I forms an angle with the vagina close to ninety degrees, and as a rule the left superior angle is a little further forward than the right. The position of the uterus is changed when the bladder is full or when the rectum is full. In dis- eased conditions it may be axtkflexed (an abnormal forward curvature); a form of displacement in which the upper part of the organ is bent forward, or we may have ax ANTEVERSION (a forward tipping or tilting of the organ); a displacement in which the organ is tipped forward but not bent at an angle as anteflexion). It may be retroplexed (bent backward), or there may be a retroversion (the tipping of the entired organ backward). The fundus of the uterus is broad and convex and is covered with peri- toneum. The body is flat anteriorly, convex posteriorly, and concave laterally. It is joined to the bladder by its lower anterior fourth. The posterior surface of the body is entirely covered with peritoneum, while in front the peritoneum covers its upper three-fourths. The cervix is the lower constricted portion and is embraced by the upper extremity of the vagina. The cavity of the body is triangular and flattened from before backward. This cavity has too lateral cornua above, and a constricted opening (internal ■ its lower angle. The cavity of the cervix is spindle-shaped ami has on its anterior and pos- terior walls longitudinal folds called arbor vitse. The external os is a transverse orifice at the lower end of the cavity of the cervix and opens into the vagina. It has an anterior lip and a posterior lip. 'I'm. LIGAMENTS OF THE UTERUS ARE EIGHT IX NUMBER. 1. The anterior ligament (vesico-uterine) is a reflexion of the peritoneum from the front of the uterus on to the bladder. 2. The posterior ligament (recto-uterine) passes from the posterior wall of the uterus and over the upper one-fourth of the vagina and then to the rectum and sacrum, thus forming the pouch of Douglas which is behind the upper portion of the vagina. '■'> and 1. The two lateral or broad ligaments are folds of peritoneum which pass From the sides of the uterus to the lateral wall.- of the pelvis, and thus form :i septum across the pelvic cavity. The broad ligaments contain the Fallopian tubes, the round ligaments, the ovaries, the parovaria (organs of Rosenmuller). blood vessels and nerves, as well as connective tissue and unstriped muscle fibers. 5 and 6. The two sacro-uterine ligaments are folds of peritoneum which ANATOMY IN A NUTSHELL. *>">*» pass from the sides of the uterus to the sides of therectum first, then to the sacrum. 7 and 8. The two round ligaments arc about five inches Long and extend from the lateral aspect of the fundus of the uterus through the inguinal canals to the labia majora. They are composed of muscular tissue, areolar tissue, and fibrous tissue, as well as vessels and nerves. The canal of Xuck is a tubule of peritoneum in the young female descending from the uterus into the inguinal canal. It is usually obliterated in the adult. Blood Supply. — (1) The uterine, which is a branch of the anterior division of the internal iliac artery. (2) funicular from the superior vesical, (3) the ovarian from the abdominal aorta. Nerve Supply. — From the inferior hypogastric and ovarian plexus of the sympathetic, and the third and fourth sacral nerves. The lymphatics of the cervix end in the pelvic nodes, while those from the body end in the lumbar node.-. The coats of the uterus are three, (1) a serous, (2) a muscular, and (3) a mucous. The serous coat is the peritoneum which invests the uterus, except at its lower anterior one-fourth. The muscular coat, which is composed of smooth muscular fiber inter- mingled with the areolar tissue, blood vessels and nerves, forms the chief bulk of the uterus. The circular muscular fibers are most numerous in the cervix, while the longitudinal are most numerous in the body of the uterus. The mucous coat is very thick (one-eighth of an inch) is closely adherent to the internal muscular layer. It is pale and smooth, and has the openings of numerous glands upon its surface and is covered with ciliated columnar epithelium. The ovula of Naboth are glandules or follicles within the os uteri and cervical canal which are often distended with mucus, which mucus Naboth mistook for human ova. hence their name. A laceration of the cervix in a diathesis or neuropathic constitution is followed (1) by irritation. (2) indigestion, (3) malnutrition. (4) anemia. (5) neurosis. LESSON CXCIII. The Fallopian tubes (oviducts) which serve to convey the ovum from the ovary to the uterine cavity, are two in number. Each one is aboul four inches long and one eighth of an inch in diameter and they are situated in the free or upper margin of the broad ligament, extending from the superior angles of the uterus to the superior or outer extremity of the ovary. One end of the Fallopian tube opens into the uterus at its superior external point . and the other end opens into the peritoneal cavity. Each tube is lined with ciliated columnar epithe- lium and its mucous lining is continuous with the uterine mucous membrane at one extremity and with the peritoneum at the other extremity. The meso- salpinx is the mesentery of the fallopian tube and it is that part of the broad ligament between the tube and the ovary. Each tube increase- in size from within outward and consists of the following parts: 560 ANATOMY IN A NUTSHELL. 1. The isthmus is the inner constricted third of the tube which is hard, cylindrical, and nearly horizontal. It is about an inch and a half long and one-eighth of an inch in diameter. 2. The ampulla (receptaculum seminis) is the outer dilated portion curving over the ovary and extends from the isthmus to the fimbriated extremity. Its diameter is about twice that of the isthmus and its walls are thinner and softer. The isthmus and the ampulla make the body of the tube. 3. The Iniundibulum is the expanded outer end. the opening of which is the ostium abdominale. 4. The fimbriae are fringe-like processes which are arranged in two or three concentric circles. The frimbria ovarica is larger than its fellows and is at- tached to the superior extremity of the ovary. 5. The hydatid of Morgagni is the cyst like remnant of the Mullerian duct attached to the oviduct by a long stalk of peritoneum. PLATE CCLXXXIV. TERMINATION OF SEMICIRCULAR CANALb CONNECTION OF MODIOLUS WITH CUPOLA CUPOLA. ^ APEX OF MODIOLUS CALA VESTIBULI c/^^J^S5^---^ FIRST WINDING OF COCHLEA SECOND WINDING OF COCHLEA ,B0NY SPIRAL LAMINA — THIRD HALF SUP WINDING OF COCHLEA " SCALA TYMPANI INFERIOR CENTRAI CANAL OF MODIOLUS BASE OF MOOIOLUS The Boxy Cochlea Cut Through. \eu\ e Supply.— The nerves are derived from a plexus around the uterine and ovarian arteries. Blood Supply. — The external tubular from the ovarian ami the internal tubular from the uterine. [/j \irn V.TICS, after joining with those of the uterus, empty into the lumbar lioile-. The ovaries, which are the essential female organs of generation, are two grayish pink bodies situated in the broad ligament behind ami below the Fallo- pian tube. The position of the ovary is indicated on the body by the mid- point of a line drawn from the anterior superior spinous process of the ilium to symphysis pubis. The dimensions of the ovary arc one and a half, by three-fourths, by one- third of an inch. They are not so dense as the ^esticle and in old age atrophiy. T LIG \ Ml. NTS ok 'nil-: OVARY ARE: 1. The utero-ovarian, which is over an inch in length, connects the inferior extremity of the ovary with the superior angle of the uterus. This ligament ANATOMY IN A NUTSHELL. 561 has iii it fibrous tissue, plain muscular tissue which Ls derived from the super- ficial muscular layer of the uterus. 2. The tubo-ovarian (fimbria ovarica) joins the superior extremity of the ovary with the fimbriated extremity of the Fallopian tube. 3. The suspensory (lumbo-ovarian) is the upper part of the external border of the broad ligament. In the normal position of the ovary, if their axes were continued, they would meet in front of the uterus, but the position of the ovary varies because the ligaments are attached to movable points. For instance, if the uterus turns to the right the ovary of that side is vertical and the ovary of the opposite side is nearlv horizontal. LESSON CXCIV. The ovary consists of a vascular stroma which contains the Graafian foll- icles. The stroma is composed of connective tissue which has hi it cells, white fibrous tissue, yellow elastic tissue, plain muscular fibers, blood vessels and nerves. From the hilum a core, called medullary substance, passes into the center of the ovary. It is composed of stroma and has passing from it numerous trabecular to the cortex of the ovary, thus leaving spaces in which are situated Graafian follicles. The tunica albuginea is a condensed layer of the stroma which covers the ovary. The epithelial covering which surrounds the tunica albuginea is the remains of the germinal epithelium. The Graafian follicles are the ova sacs which contain the ova. The ma- jority of these Graafian follicles are microscopic, but when matured they lie- come much larger. The smallest ones vary from g i to i of an inch in diameter and the largest ones from i to * of an inch in diameter. The tunica fibrosa encloses the blood trunks and lymphatic spaces of the follicle. This is the outer layer of the follicle. The tunica propria is a vascular layer composed of connective tissue cells and capillar}' plexuses. This is the inner layer of the follicle. The membrana granulosa is the cell layer which lines the inner surface of the Graafian follicle. The discus proligenis is that part of the membrana granulosa in which the Ovum is imbeded. The membrana propria (vitalline membrane) is between the membrana granulosa and the tunica propria. The corpus luteum is the yellow spot in the substance of the ovary and is caused by the rupture of the Graafian follicle, but it disappears when impreg- nation has not occurred. When impregnation has occurred it may undergo remarkable development . The true corpus luteum (corpus luteum of pregnancy) is usually regarded as absolute proof of previous impregnation. The false corpus luteum (corpus luteum of menstruation) attains its greatesl development in less than a week and begins to shrink in less than three weeks and completely disappears in a 562 ANATOMY IN A NUTSHELL. few weeks. The true corpus luteum continues to grow for two or three months and may be as large as one-third of the entire ovar}\ It continues till toward the end of gestation and then shrinks to a small white scar which may not en- birely disappear until a month after labor. While this is the general rule it does not always hold good for bodies which are identical with the true cor- i'oi;\ i.itka have been found in the virgin ovaries. The ovary in its descent may pass into the inguinal canal and out the ex- ternal abdominal ring and become an external organ like the testicle. This is a very rare occurrance. At the third month of intra-uterine life the ovaries are situated in the lumbar region in front of the Psoas magnus near the kidney and by the ninth month they have descended to the brim of the pelvis. This is caused by the lumbar region growing away from the ovary. Nerve Supply. — The nerves are from the ovarian plexus of the sympa- thetic and branches of the third and fourth sacral nerves. Blood Supply. — Ovarian from the abdominal aorta which corresponds to the spermatic in the male. The blood from the left ovary passes through its veins into the left renal vein, while the blood from the right ovary passes into the inferior vena cava. Lymphatics from the ovary pass into the lumbar nodes. LESSON CXCV. The external female organs of generation are known by the term vulva or pudendum and includes (1) the mons veneris, (2) the labia majora, (3) labia minora, (4) clitoris, (5) the orifice of the vagina. The mons veneris (mount of Venus) is a round prominence at the symphysis pubes in the female, which is cushioned with fat and covered with hair. The labia majora are hairy folds of the skin on either side of the slit of the vulva extending from the mons veneris to the perineum. Where they meei anteriorly they form the anterior commissure, and where they meet below they form the posterior commissure (fourchette) which is about an inch in front of the anus at the anterior boundary of the perineum. The fossa navicularis is between the posterior commissure and the hymen. The nerve supply of the labia majora is the superficial perineal from the pudic and the inferior pudendal from the small sciatic. The labia minora (nymphae) are folds of mucous membrane within the labia majora. They extend from the prepuce of the clitoris to the inner surface of the labia majora. They are not well developed until the age of puberty and air largesl during pregnancy. The vestibule is the space between these lips and the orifice of the vagina. The clitoris, which i> situated at the anterior angle of the vulva is a small elongated erectile body of the female of most mammals. These mammals include the human species and numerous birds, as the ostrich. It differs from the penis of the male in that it is smaller and as a rule not perforated by a ure- thra, although it is in some animals, as lemurs. In the human female it is usually concealed in the normal state of the parts, but in the spider-monkey ANATOMY IN A NUTSHELL. 563 it is quite large and it is difficult to distinguish it from the penis. It con- sists of the corpora cavernosa and the glans clitoridis. The stalk hydatid of Morgagni, when present in the female, is situated in the broad ligament at the outer extremity of the ovary. Ii is a small peduncu- lated sac, being a remnant of the pronephros. lis homologue in the male is the stalk hydatid of Morgagni, for which see, Plate CCLXXVI. The preputium clitoridis is a fold, formed by the Labia minora, covering the clitoris. The duct of Gartner (a relic of the Wolffian duct) is a straight canal ex- tending from the parovarium through the broad ligament to the vagina. Bulbus vestibuli is a mass of erectile tissue situated on each side of the ves- tibule beneath the mucous membrane. It is homologous to the bulb of the cor- pus spongiosum in the male, while the pars intermedialis which is a continua- tion of the bulbus vestibuli anteriorly is homologous to the corpus spongiosum itself. PLATE CCLXXXV. COMMON TERMINATION OF SUPERIOR ANO AUDITORY NERVE VESTIBULAR NERVE COCHLEAR NERVE POSTERIOR SEMICIRCULAR CANALS CUPOLA EXTERNAL ' SACCULARIS R10"R SEMICIRCULAR CANAL BORDER OF SPIRAL PLATE AMPULLA SUPERIOR The Interior of the Labyrinth with Distribution of Auihtoky Nehye. The paroophoron (parovarium) (organ of Etosenmuller) is a relic in the broad ligament of the urinary portion of the Wolffian body. Ii is a tubular body homologous to the organ ofGiraldes (Paradidymis) in the male. It is present only in childhood and cannot always be recognized. The long tube of the parovarium is homologous to the tubeof the epididymis. The short tubules of the parovarium are homologous to therete testis and the coni vasculosi in the male. Bartholin's glands are the vulvo-vaginal glands which are situated on each side of the vagina posteriorly to the bulbi vestibuli. They are small racemose glands about one-third of an inch Long and each opens with a due! near the nymphse. Cowper's glands are the homologues of Bartholin's glands. Sec page 473, For description of the female urethra see page 17 1. The Mammahv Gland. I Plate CCLXXIX). The mammary glands are named is zoology, from their position, axillary, 564 ANATOMY IN A NUTSHELL. pectoral, ventral or abdominal, and inguinal. Sometimes they are quite high on the sides of the animal but are never dorsal. The mamma of the cow is situated in the median line, being formed from the coalescence of as many mammae as there arc teats. These glands are paired as arule and common to both sexes, but remain rudimentary and functionless in the male as a general thing. The male mammas have been known to secrete milk. The mammary gland of the human female is situated between the third and sixth rib on each side between the sternum and the axilla. The nipple is situated between the fourth and fifth rib about four and one-half inches from the middle line of the sternum ; but. of course, this position varies . The base of each nipple is surrounded by a zone of colored skin called the areola, and this areola has numerous small whittish tubercles which contain the openings of the sebaceous glands. The nipple is highly vascular and its skin is sensitive and contains retiform tissue and unstriped muscular fibers. There are about twenty orifices in the summit of the nipple which are the ends of the milk ducts. This gland is racemose and consists of from fifteen to twenty lobes, which are independent of one another. Each of these lobes is made up of lobules, and these are formed by the aggregation of alveoli in which the milk is secreted. Blood Supply. — The anterior intercostals, the external mammary (long thoracic), and acromio-thoracic arteries. Nerve Supply. — Anterior and lateral cutaneous branches of the inter- costal nerves. Lymphatics of the mammary gland pass into the axillary nodes. The Wolffian body is the mesonephros or primitive kidney, the excretory organ of the embryo. It consists of a long tube in the lower part of the body- cavity, running parallel with the spinal axis and joined at right angles by a row of twisting tubes given off from the Malpighian body, and forming a struc- ture resembling a comet. The Wolffian body develops into the head of the epididymis, vas deferens, and ejaculatory duct in the male. LESSON CXCVI The Male Organs of Generation. (Plates CCLXXIV-CCLXXV-CCLXXVI- CCLXXVII-CCLXXVIII). The prostate gland is shaped like a chestnut and is about one and one-half inches in itsl ransverse diameter while it is one and one-fourth inches from base to apex. Its weight is aboul the same as the testicle, (six drachms). The \i'i.\ of this gland is a1 the triagular ligament, [ts base is at the neck of the bladder. Its posterior surface is joined to the rectum by areolar tissue. It - dense firm capsule which is derived from the recto-vesical fascia and the posterior layer of the trangular ligament. It consists of a median lobe and two lateral lobes. It is c posed of glandular matter, and muscular fibers which encircle the urethra. ANATOMY IN A NUTSHELL. 565 The penis is composed of a mass of erectile tissue enclosed in three rod-like segments which are firmly united together by a sheath composed of integu- ment, dartos, and fascia. These segments arc the two corpora cavernosa, and the corpus spongiosum. The root of the penis is attached to the symphysis and pudic arch. The body, which is triangular on cross section, forms the greater part of the free portion of the organ. The glans forms the expanded distal extremity of the organ and is more developed on the dorsal than on the ventral aspect, and the urethral opening is at its distal extremity. The glans is separated from the body by a constriction called the neck. The corpora cavernosa, which lie side by side, form the upper and lateral parts of the penis. (Plate CCLXXIV). The crura are formed by the posterior one-fourth of the corpora cavernosa, Plate CCLXXV, and are attached to the tuberosities of the ischia and the descending rami of the ischia. The groove above the corpora cavernosa are for the dorsal vessels and dorsal nerves, while the groove below that is for the corpus spongiosum. The suspensory ligament of the penis Is a fibrous membrane which connects the root of the organ to the symphysis pubes. The fibrous septum between the two corpora cavernosa, only present between its posterior two-thirds, is called septum pectiniform. The corpus spongiosum lies in the groove between the corpora cavernosa inferiorly. This has no erectile tissue in it like the corpora cavernosa. It con- sists of glans, a body, and a bulb. The clans is somewhat heart-shaped and at its base is a ridgecalled corona glandis, behind which is the neck of the penis. The external urinary meatus is a vertical fissure about one-third of an inch in length at the apex of the glans. It is the outlet of the urethra. The body of the corpus spongiosum has passing through its whole length the urethra. For description of the urethra see page 472, and for Plate page 533. The bulb of the corpus spongiosum is surrounded by the Accelerator mime mus- cle. It passes posteriorly to within an inch of the anus. The prepuce is a continuation of the integument of the penis which more or less completely conceals the glans. The fr.enum pr.eputium is a fold of mucous membrane which connects the prepuce with the glans along the raphe. Phimosis (muz- zling or closure) is the tightness of the foreskin such that it cannot be drawn back from over the glans. Paraphimosis is a retraction of a narrow or in- flamed foreskin which cannol be replaced. Epispadias is a congenital defed in which the urethra opens on the dorsum of the penis. In female epispadias there is a fissure of the upper wall of the female urethra. Bypospadias i- :i congenital opening of the urethra on the under side of the penis. In the female hypospadias there Is an opening of the urethra in the vagina. The dartos is the reddish, cellular, contractile tissue beneath the skin of the penis and continuous with the dartos tissue of the scrotum. The female dartos is a layer of unstriped muscular fibers immediately under the skin o\ the labia majora. The dartos enter- into the formation of the prepuce, and some authorities claim, forms a kind of a sphincter around the preputial ori- fice. The areolar tissue of the penis, which contains the superficial vessels and nerves, is just beneath the dartos. (Plate CCLXXIV). The deep fascia of the penis is beneath the areolar tissue. It is joined to the skin and the corpus 566 ANATOMY IN A NUTSHELL. spongiosum. This fascia and the dartos aided by the Bulbo cavernosi and the [schio-cavernosi muscles compress the veins of the penis in the action of erec- tion. Blood Supply.— The arteries to the penis are branches of the internal pudic. (a) The artery of the bulb, which goes to the bulb of the corpus spon- giosum, (hi the arteries of the corpora cavernosa, (c) the dorsal artery of the penis. The envelops of the penis are supplied by the external pudic, the superficial perineal, and the dorsal artery. The veins of the penis are in two sets, (a) superficial veins, which pass between the dartos and fascial sheath end in the long saphenous and femoral veins, (b) the deep veins, which drain the corpora cavernosa, corpus spongiosum, end in the deep dorsal vein and in the internal pudic vein. Lymphatics of the penis are divided into two sets, (a) superficial ones which pass to the inguinal nodes, and (b) deep ones which empty into the pelvic and Lumbar nodes as well as in the inguinal nodes. Nerve Supply. — The genital branch of the genito-crural and the super- ficial perineal branches of the pudic supply the covering of the penis, while the dorsal nerve of the penis, and superficial perineal, and hypogastric plexus sup- ply the erectile bodies. PLATE CCLXXXVI. SEMICIRCULAR CANAL 5CALA TYMPANI INFERIOR Interior of Bony Labyrinth. The spermatic cord is about four inches long and extends from the internal abdominal ring to the globus minor of the epididymis. It passes through the inguinal canal. It is composed of the following structures held together by areolar tissue and invested by layers broughl down by the descent of the testicle. 1. The vas deferens, which is the excretory duct of the testicle passing from the testis to the ejaculatory dud. It is recognizable by its cord-like resistance to pressure. _'. The artery of the vas deferens, which is a branch of the superior vesical artery. It arises from this artery near the place where the vas deferens crosses the obliterated hypogastric artery, and it divides into an ascending branch which follows the vas deferens through the inguinal canal, and a descending- branch which passes n> the dilated poll ion of the vas deferens and the vesicula seminalis. :!. The cremasteric artery, which is a branch of the dee]) epigastric, passes ANATOMY IN A NUTSHELL. 567 through the inguinal canal with the vas deferens andsupplies the Cremasteric muscle. 4. The spermatic artery, which is a branch of the abdominal aorta, passes over the Psoas muscle to the internal abdominal ring, then through the inguinal canal into the scrotum to the testicle. It gives off the following branches, (a) ureteral branchesto theureter, (b) cremasteric branches to the Cremasteric muscle, (c) epididymal to the epididymis, (d) testicular branches to the bpdy of the testis. 5. The spermatic veins, or pampiniform plexus, surrounds the artery. (i. Spermatic plexus of nerves (sympathetic) accompanying the artery. 7. The vas aberrans is a blind tube connected with the epididymis or vas deferens. Its homologue is the duct of Gartner in the female. 8. The lymphatics which pass with the veins. 9. The Internal cremasteric muscle, which is composed of smooth muscu- lar fibers. 10. The obliterated processes vaginalis of the peritoneum, which is a relic of the tube between the tunica vaginalis and the peritoneum. 11. A branch of the ilio-inguinal nerve. 12. A branch of the ffenito-crural nerve. LESSON CXCVII. The infundibuliform fascia which is from the transversalis fascia, the cremasteric fascia which is from tin 1 Internal oblique muscle, the intercolumnar fascia which is from the external spermatic fascia, the superficial fascia and the skin of the scrotum, all these are coverings of the spermatic cord from within outward. The vesicula? seminales are two lobulated membranous pouches between the base of the bladder and the rectum, and they serve as reservoirs for the semen, as well as secrete the fluid which is added to the semen. They have three coats, an external or fibrous coat, a middle 1 or muscular coat, and an in- ternal or mucous coat. The ejacnlatory duct is about an inch long and is formed by the union of the vas deferens and the vesicula seminalis. Its diameter is aboul one-eighth of an inch above, but where it opens it is about one-fill ieth of an inch. 1 1 opens on the verti montanum on either side of the opening of the sinus pocularis. The testicles are two in number and aresuspended by the spermatic cords. They weigh less than an ounce and are about an inch and a half long, and inch and a quarter deep, and about an inch in thickness. They secrete the seminal fluid. They have the following coverings from within outward. 1. The tunica vaginalis, which is ;i serous covering formed by ;i portion of the peritoneum which descended with the testicle and afterwards forms a closed pouch investing it. This tunica consists of two layers, a visceral ami :i parietal layer. Beneath the tunica vaginalis is the tunica albuginea which i^ ; i strong fibrous coat (Plate CCLXXVII) ; and beneath this coat, the tunica vasculosa (pia mater testis) which is composed chiefly of blood vessels held together by 568 ANATOMY IX A NUTSHELL. areolar tissue. This coat lines the tunica albuginea and the various septa within the testicle. 2. The infundibuliform fascia (internal spermatic) is the fascia propria and is a continuation downward of the transversalis fascia. :;. The cremasteric fascia (middle spermatic fascia) is composed of mus- cular fibers (the ('remaster muscle) which are derived from the lower border of the Internal oblique muscle. 4. The intercolunmar fascia (external spermatic) which is closely adherent to the dartos. 5. The scrotum consists of two layers, (a) the integument which is more or less pigmented and covered in the adult with scattered hair. A raphe is present in the median line from which pass transverse wrinkles, (b) The dartos which is a reddish, cellular, contractile tissue beneath the skin of the scrotum. 1. The epididymis (upon the testis) lies at the posterior and superior part of the testicle and consists of the globus minor which contains the efferent duct, and the globus major composed of vasa efferentia and coni vasculosa. If the epididymis were unraveled it would be a tube twenty feet long. The lobules of the testicle are contained in the spaces formed by the tra- becular which divide the testicle into divisions. These lobules consist of the tubuli seminiferi which consist of a basement membrane lined with a layer of cuboidal cells in which are developed the spermatoza. The tubuli at the apices of the lobules become straight and join the vasa reta which join the rete testes in the mediastinum, the rete testes end in the vasa efferentia which per- forate the tunica albuginea and form the coni vasculosa. Gubernaculum testis is a fetal cord attached to the lower end of the epidi- dymis and to the bottom of the scrotum. It governs the descent of the testicle. Its homologue is the round ligament of the female. The paradidymis (organ of Giraldes) is on the spermatic cord above the epididymis. It represents the remains of the posterior part of the Wolffian body, h is a closed tube. Its homologue is the paroophoron in the female. The duct of Kathke is a part of the duct of Muller which persists hi post- natal life and remains patulous. The oviduct is the homologue of the dud of Rathke. The sessile hydatid of Morgagni is the upper part of the duct of Muller, which persists and is attached to the upper aspect of the testicle. The fimbria of the oviduct is the homologue of the sessile hydatid of Morgagni. LESSON CXCVIII. The Organs oi Hearing. (Plates CCLXXX-CCLXXX VII, inclusive). These organs consist of three portions. 1. The external ear, which consists of (a) pinna or auricle which is not of much importance physiologically, and (b) the meatus auditorius externus, which is ;i canal leading inward to the tympanic membrane. 2. The middle ear, which is composed of (a) the tympanum (an air chamber) containing the malleus, incus, and stapes (the auditory ossicles ) and com- ANATOMY IN A NUTSHELL. 569 municates with the naso-pharynx by means of the Eustachian tube, (b) the mastoid antrum, (c) the mastoid cells, (b) and (c) are accessory air chambers to the tympanum. 3. The internal ear or labyrinth, contains the membranous labyrinth which is a cast of the bony structures. The membranous labyrinth contains the endolymph, and within it are the specialized neuro-epithelial cells and the terminations of the auditory nerve. The perilymph is on the outside of the membranous labyrinth. The External Ear. The pinna is the projecting part of the ear lying outside of the head, and is attached to the malar and temporal bones by ligaments. It consists of a layer of yellow fibro-cartilage covered with integument. It has the following parts. PLATE CCLXXXVII. FOSSA FOR INCUS ARTICULAR SURFACE FOR MALLEUS LEFT MALLEUS SHORT PROCESS ANTERIOR CRU3 BASE- POSTERIOR CRUS HEAD OF MALLtUS SHORT PROCESS — SLENDER PROCESS HANDLE OR MANUBRIUM BASE OF STAPES Malleus, [ncus and Stapes. 1. The helix is the outer curved edge of the pinna which passes upward from the rim of the pinna and ends behind in the lobule. 2. The lobule is the lowest portion of the auricle and consists of fatty and areolar tissue. 3. The fossa of the helix (scaphoid ibssa) is a depression internal to the helix. 4. The antihelix is a range which begins above the Lobule .-u the anti- tragus and passing upward bifurcates to enclose a triangular depression called the fossa of the antihelix. 570 ANATOMY IN A NUTSHELL. 5. The concha is the deep hollow in the center of the pinna which leads into the auditory canal. 6. The tragus is a conical eminence in front of the concha projecting back- ward over the orifice of the external auditory meatus. It is usually covered with hair along its inferior border. 7. The antitragus is a small projection posterior to the tragus from which it is separated by a deep fissure called the incisura intertragica. The muscles of the external ear are divided into two sets, the extkixsk ami the entrinsh . The extrinsic aie. the Attrahens aurem, Retrahens aurem, and Attollens aurem. These muscles have been described on page 522 and in the table of muscles in the back of the book. The [ntrinsic muscles are: 1. Tragicus, which lies vertically on the outer surface of the tragus. L'. Antitragicus lies on the posterior wall of the auditory canal. It arise- from the outer part of the antitragus and passes upward to be inserted into the posterior extremity of the helix. 3. Helicis minor is often absent, but when present is attached to the com- mencemenl of the helix and extends into the concha. 4. Helicis major is situated on the anterior margin of the helix. ">. Transversus aurem is situated on the posterior surface of the auricle in the depression between the helix and the convexity of the concha. 6. Obllquus aurem is on the posterior surface of the auricle passing upward from the convexity of the concha. Nerve Supply. — From the auriculo-temporai, auricularis magnus, occipi- lalis minor, and Arnold's nerve from the tenth. The intrinsic muscles receive the seventh nerve. Action of the Intrinsic muscles is to retard the passage of sound to the meatus. These muscles are rudimentary and unimportant. Blood Supply. — The pinna receives the posterior auricular, the occipital. and superficial temporal arteries. Lymphatics of the pinna empty into the preauricular nodes, and into the nodes upon the insertion of the Sterno-cleido-mastoid muscle. Tin' external auditory canal is a little over an inch long, extending from the concha to the membrana tympani. This canal is curved with its convexity upward. This canal is lined with integument which contains sebaceous and ceruminous glands and also numerous hair follicles. The outer one-third of this canal is cartilaginous, and the inner portion osseous. The Annulus tympanicus isthe osseous portions of this canal at birth, at which time it is an incomplete bony ring. Blood Supply.- From branches of the internal maxillary, posterior auri- cular, and superficial temporal. Nerve Supply. Auriculo-temporai, auricularis magnus. and Arnold's nerve. Tin LYMPHATICS of the external auditory meatus end in the parotid and the posterior auricular nodes. ANATOMY IN A NUTSHELL. 571 The membrana tympani, which is attached to a grooved ridge of bone at the bottom of the external auditory meatus, is an oval, clastic semi-trans- parent membrane about 7 ,] of an inch in thickness, aboul ,-'•., of an inch in its antero-posterior diameter and slightly less in its vertical diameter. This membrane is situated obliquely, its outer surface being directed outward, downward, and forward, so as to form almost a continuation of the posterior wall of the external auditory meatus. In infancy this membrane is al >t horizontal. The membrana tympani is composed of three Layers; an outer or cutaneous layer, a middle or fibrous layer, and an inner or mucous layer. It has the following points for consideration: 1. The umbo (naval) is the dark depressed center of the membrane. 2. The cone of light is a triangular area, the apex of which i> attached to the tip of the handle of the malleus, and at its base extends toward the circum- ference of the membrane. This is of value hi diagnosis of diseases of the tym- panum and membrana tympani. 3. The tubercle which is at the upper border is formed by theshorl pro- cess of the malleus. 4. The stripe which runs down from the tubercle to the umbo and is formei 1 by the handle of the malleus. 5. Sharpnell's membrane (membrana fiaccida) is situated at the upper part of the membrane below the notch of Rivini. This notch is formed where the bony ring to which the tympanic membrane is attached is incomplete. 6. Rivinian foramen is a minute opening which exists in Sharpnell's mem- brane. 7. Membrana tensa is all the tympanic membrane except the membrana fiaccida. This membrane is concave externally. Blood Supply. — From tympanic branches of the internal maxillary and carotid arteries. Nerve Supply. — The external surface receives the auriculo-temporal from the fifth nerve and Arnolds' nerve from the tenth. The internal surface receives branches from the tympanic plexus. LESSON CXCIX. The Middle Ear. The tympanum (drum) is an irregular cavity situated within the petrous portion of the temporal bone, and lined with mucous membrane. It lies be- tween the external auditory meatus and the internal ear. lis antero-posterior length is about half of an inch, vertically a lil tie more I ban half an inch, and its width is about one sixth of an inch. It consists of two main parts, (a) attic or recessus epitympaniticus which is situated in the highesl portion of the tym- panic cavity and contains the head of themalleus and the greaterparl of the incus. This attic leads into the mastoid antrum, do Atrium (tympanic. cav- ity proper) is situated opposite the tympanic membrane. The roof of the tympanum is a thin plate of bone (tegmen tympani) which separates the tympanum from the middle fossa :it the base of the skull. PLATE CCLXXXVII] ENCYSrtO HERNIA INFANTILE HERNIA HERNIA. 'NTC THE TUNICA VAGINALIS HERNIA INTO THE FUNICULAR PROCESS Forms of Congenital Hernia (After Deaver.) 572 ANATOMY IN A NUTSHELL. 573 The floor of the tympanum is formed by the thin plate of bone which sepa- rates the tympanum from the jugular fossa. The anterior Avail of the tympanum is deficient above where the Eustachian tube opens into it. This wall separates the tympanum from the carotid canal and has opening of canal for Tensor tympani muscle above, and below the open- ing of the Eustachian tube. These canals are separated from one another by the processus cochleariformis. The posterior wall of the tympanum separates the tympanum from the mas- toid cells and communicates wtih the mastoid antrum by one large and several small openings. The outer wall of the tympanum is formed by the membrana tympani and by the squamous portion of the temporal bone above. It has the following points for consideration: 1. The iter chordae postertus, which is close to the posterior edge of the drum head. The chorda tympani nerve which is a branch of the seventh cranial nerve enters the tympanum through this opening. 2. The iter chordae anterius, which is just above the drum head, is the opening by which the chorda tympani nerves leaves the tympanum. 3. The Glaseriax fissure, which opens above and in front of the head, lodges the long process of the malleus, the Laxator tympani muscle. and the tympanic branch of the internal maxillary artery. The inner wall of the tympanum is the outer wall of the labyrinth and presents several points for consideration. 1. The fenestra ovalis leads to the vestibule and is closed by a mem- brane which is attached to the base of the stapes. 2. The fenestra rotunda is below the fenestra ovalis and leads into the scala tympani of the cochlea. It is closed by the membrana tympani secund- daria . 3. The promontary is an elevation formed by the first turn of the cochlea. It is covered by the tympanic plexus and is located between the two fenestras and in front of them. -i. The pyramid is behind the fenestra ovalis and from its summit passes the tendon of the Stapedius muscle, and a branch of the seventh nerve pierces the pyramid to supply the Stapedius. 5. The ridge of the aqueductus Eallopii. which is above the fenestra ovalis and covers the seventh nerve in its passage through the tympanum. Blood Supply. — Tympanic branch of the internal maxillary artery, tym- panic branch of internal carotid artery, stylo-mastoid branch of the posterior auricular artery, petrosal branch of the middle meningeal artery, a branch of ascending pharyngeal artery which enters through the Eustachian tube, tym- panic branch of vidian artery. The veins of the middle ear follow the corres- ponding arteries and empty into the temporo-maxillary vein, the superior petros- al sinus, the lateral sinus, the internal jugular vein and pharyngeal veins. The lymphatics of the middle ear end in the posterior auricular and caro- tid nodes. Nerve Supply. — Tympanic plexus which supplies the mucous membrane .J74 ANATOMY IN A NUTSHELL of the tympanum and is formed by the following nerves: (1) Jacob-son's nerve, (2) great superficial petrosal nerve, (3) small superficial petrosal nerve, I I small deep petrosal. The middle ear or tympanum is filled with air and contains the malleus, incus and stapes. These form a chain of bones which transmits the impulses of sound waves between the tympanic membrane and the parilymphand endo- lymph of the internal ear. The malleus (hammer) consists of the following parts, (1) a head, (2) a neck, (3) :i shorl process, (4) long process (process gracilis) (5) handle (manubrim). The handle is connected with the middle layer of the drum head and is situated between this middle and mucous layer. The short process (process brevis) is attached to the Tensor tympani muscle. The long process is received into the Glaseriarj fissure. The head, which is situated in the attic, is connected with the roof of the attic by the superior ligament of the malleus and it articu- lates with the body of the incus. The Incus (anvil) has the following parts, (1) a body (head), (2) a long process, (3) a short process. The body articulates with the head of the malleus. This joint is covered by a capsular ligament and lined by synovial membrane. 'I Tie shorl process articulates with the fossa incudis in the attic to which it is connected by fibrous tissue. The long process articulates with the head of the -tapes. The end of this process is called os orbiculare. This os orbiculare is the smallest bone in the body. In adult life it forms part of the incus. The stapes (stirrup) has the following parts, (1) a head, (2) a neck, (3) a base (foot piece), (4) two crura (branches). The head articulates with the os orbiculare of the incus. This is a ball-and-socket joint. The base fits on the membrane closing the fenestra ovalis. The neck re- ceives the tendon of the Stapedius. The Ligaments of the malleus, incus, and stapes are five besides the capsular ligaments of their articulations. 1. The superior ligament of the MALLEUsisa fibrous band passing from the head of the malleus to the outer part of the roof of the attic. •_'. Tin: interior ligament of the malleus is attached to the anterior wall of the tympanum and to the anterior part of the head and neck of the malleus. It is sometimes described as the Laxator tympani muscle. :;. Tiii': external ligament of the malleus is attached to the neck of the malleus by its apex and to the margin of notch of Rivini by its base. 1. The [NTERNAL ligament of the malleus extends from the tip of the processus cochleariformis to the insertion of the Tensor tympani tendon. 5. The ligament of the incus is attached to the short process of the incus and to the posterior wall of the attic near the orifice of the mastoid ant urn. Besides these five ligaments just named we have capsular ligaments around the joints between the malleus and incus, and between the incus and stapes. The muscles of the tympanum have been described on page 523. The mastoid antrum is situated posterior to the tympanum and is lined with mucous membrane. It opens in the attic of the tympanum and into the mastoid cells. PLATE CCLXXXIX. The Lymph ltic Max. 575 576 ANATOMY IX A NUTSHELL. The mastoid cells are no1 present at birth but at the age of puberty there are a few and they occupy the greater portion of the mastoid process. They are secondary organs of hearing. The Eustachian tube is a passage from the uaso-pharynx to the tympanum. It passes inward, downward, and forward from the tympanum. It is between an inch and a half and two inches long and from one-twelfth to one-fifth of an inch in diameter. It is made up of a bony part which is smaller than the car- tilaginous portion and situated in the temporal bone, and of a cartilaginous portion which is somewhat trumpet-shaped ending hi the pharynx. Its pur- pose is to equalize the air pressure within the tympanum with that of the ex- ternal car. At the point where the bony portion joins the cartilaginous portion i« the isthmus tuba-. The opening of the Eustachian tube into the tympanum PLATE CCXC. A Lymphatic Node (After Gerrish.) is on the anterior wall, while its pharyngeal opening is on the lateral wall of the naso-pharynx behind the posterior nares. This tube is closed except dur ing swallowing, when it is opened by the following muscles: Tensor palati Levator palati. Salpingo-pharyngeus, and pari of the Palato-pharyngeus. lessox re. The Internal Lai;. (Labyrinth). This car consists of a bony labyrinth within which is the membranous labyrinth. Tin' bony labyrinth is made up of the vestibule, the cochlea, and the SEMK li;< i LAB CAN ^LS. The membranous labyrinth is smaller than the bony labyrinth of which it is a casl and the space between the two is lined with endothelium which con- tain- parilymph. The parts which make the membranous labyrinth are, the rjTRK i.i which is a membranous sac in the vestibule, saccule which is also a membranous sac in the vestibule, membranous semicirculab canals which are in 'he osseous canals, and the membranous cochlea which is aspiral tube inclosed in the osseous cochlea. ANATOMY IN A NUTSHELL. 577 The eighth nerve (auditory) which is the portio mollis of the seventh nerve. This nerve has no neurilemma. The organ of Corti is the terminal auditory apparatus in the membranous cochlea. The internal auditory meatus is the opening into the internal oar from the cranial cavity for the seventh ami eighth nerve and stylo-mastoid artery. The vestibule is an oval cavity at the entrance to the cochlea within the internal car. Vertically it is about one-fifth of an inch, laterally about one- tenth of an inch. It contains a fluid called perilymph and the utricle and saccule, and membranous labyrinth. It is situated between the cochlea and the semicircular canals internal to the tympanum. It has the following points for consideration: 1. The fenestra ovalis is on its outer or lateral wall and communicantes with the tympanum. It is closed by the base of the stapes and its annular ligament which is from the periosteal lining of the vestibule. 2. The fovea hemispherica is a small circular depression at the inner portion of the inner or median wall at the bottom of which are numerous mall openings for the vestibular branch of the auditory nerve. - 3. The crista vestibuli is posterior to the fovea hemispherica. It is a vertical crest. The fovea cochlearis is a small depression which is perforated for the passage of the filaments of the auditory nerve. 5. The aqueductus vestibuli is on the posterior portion of the inner wall. It transmits a small vein and lodges the ductus endolymphaticus which con- nects the membranous labyrinth with the general cerebral lymph spaces. 6. The fovea he.mielliptica is an oval fossa on the roof. In the posterior portion of the vestibule are the five openings of the semi- circular canals, while at the anterior portion of the vestibule is an opening leading into the scala vestibuli of the cochlea. The semicircular canals are three C-shaped bony tubes aboul one-twentieth of an inch in diameter which are situated above and behind the vestibule. 1. The superior SEMICIRCULAR canal is nearly an inch long and lies in a saggital plane of the body. 2. The external semicircular canal is abut one-fifth of an inch long and lies horizontally. 3. The posterior semicircular canal is nearly an inch long and lie- in a coronal plane. From this we can see that the three semicircular canal- are at right angles to one another and each forms more than a semicircle. The ampulla is about one-tenth of an inch in diameter. The cochlea is a bony tube about one and a half inch long situated anteriorly to the vestibule. It resembles a snail shell and coils around a central axis two and three-fourths times. It has the following points for consideration : 1. The modiolus (central axis) around which is wound a spiral tube. This axis has numerous canals in it for branches of the auditory nerve and artery, the largest one of these canals is canalis centralis modioli. 2. The base of the cochlea is two-fifths of an inch in diameter and i- 578 ANATOMY IN A NUTSHELL. perforated by numerous foramina for branches of the auditory nerve. It is directed toward the meatus auditorius interims. 3. The spiral canal (canalis spiralis modioli) is the space between the modiolus and the outer wall of the cochlea. It diminishes in diameter as it approaches the apex of the cochlea and ends in a closed extremity (cupola) after making two and three-fourths turns. 4. The lamina spiralis is a thin osseous plate projecting into the spiral canal from the modiolus reaching half way across the spiral canal. It winds around the modiolus and ends near the apex in a hook-like process (the ham- ulus). Helicotrema is the deficiency in the last half turn of the cochlea. The membrana basilaris and the membrana Reissner are two membranes which extend from the free border of the lamina spiralis and are connected with the outer wall of the cochlea. Between them is the scala media (cochlear duct). The scala media divides the spiral canal into three parts, the scala tympani below and the scala vestibuli above, and between these two the scala media. The scala tympani opens into the tympanum at the fenestra rotunda, however, this opening is closed by the membrana secundaria. The scala vestibuli opens into the vestibule. Where these two scalse communicate with each other at the summit of the cochlea is called the helicotrema. The membranous labyrinth is situated within the bony labyrinth from which ii is separated by the perilymph. The utricle lies partly in the fovea hemielliptica and is a flattened, oblong sac. h is filled with endolymph and communicates with the saccule through a small tube in the aqueductus vestibuli. The membranous semicircular canals open into the utricle by five orifices. 1. Macula acustica utricularis is a thickened portion of the walls of the utricle which contain calcareous masses (otoliths) in which are distributed filaments of the vestibular branch of the auditory nerve. 2. DUCTUS ENDOLYMPHATICUS which has been previously described. The saccule, which is smaller than the utricle, receives branches of the auditory nerve through the openings in the fovea hemispheriea, and these branches end in the thicked part of the wall which is covered with otoliths. The membranous semicircular canals are the same shape as the osseous semicircular canals and are about one-fourth the diameter of the osseous canals. Their enlarged extremities are called ampulla. The membranous cochlea (cochlear duct) (scala media) is a spiral tube enclosed in the spiral canal of the osseous cochlea between the scala vestibuli and the scala tympani. It is filled with endolymph and contains the organ ol Cortl which is a complex arrangement of modified epithelial cells including the rods of Corti and the auditory cells. Blood Supply.— From the auditory artery which enters the internal auditory meati - and divides into branches for the cochlea and vestibule. The veins empty into the internal jugular and into the superior petrosal sinus. Nerve Supply.- The auditory ne ve which is the nerve of special sense of hearing. ANATOMY IN A NUTSHELL. 579 Lymphatics of the internal ear end in the tympanic and intracranial lymphatic vessels. The superficial mesial origin of the auditory nerve is from the groove be- tween the olivary and restiform bodies at the lower border of the pons. The deep mesial origin is in the dorsal auditory nucleus, which is on the outer side of the inferior fovea on the floor of the fourth ventricle The superficial lateral origin of the auditory nerve is from the auditory striae, and after winding around the upper end of the restiform body joins the mesial root in the groove between the olivary and restiform bodies. The deep lateral origin is from (1) a ganglion of the lateral root, which is situated in this root as it winds around the restiform body, (2) the auditory striae, (3) the trapezium of the pons, (4) the ventral auditory nucleus. This last nucleus lies in front of the restiform body between the two roots. The main trunk of the auditory nerve now passes into the internal auditory meatus with the facial nerve and the auditory artery. At the bottom of this meatus it comes to the lamina cribrosa, where it divides into the cochlear branch and the vestibular branch. (Plate CCXXI). The cochlear branch sends branches to the saccule, to the ampulla of the posterior semicircular canal, and to the hair cells of the organ of Corti in the membranous cochlea. The vestibular branch has upon it the ganglion of Scarpa,while in the internal auditory meatus it sends branches to the utricle, to the ampulla of the external semicircular canal, to the ampulla of the posterior semicircular canal. The principal salivary glands are the parotid, submaxillary, and sublingual. The parotid gland takes its name from its position which is near the ear. It is about the size of the pinna (auricle) of the external ear, and weighs almost an ounce. It extends from the mastoid process and the angle of the jaw BE- LOW to the zygoma above, being immediately in front of the external meatus. This gland is saddled over the ramus of the lower jaw, and lias upon its outer surface a few lymphatic nodes, while its inner surface has two processes upon it. One of which extends behind the styloid process of the temporal bone and beneath the mastoid process of the same bone, while the other is in front of the styloid process. The following structures pass through the parotid gland: (1) the external carotid artery which gives off the temporal branch above, the posterior auricular behind, and the internal maxillary internally, also the trans- verse facial artery which is a Iranch of the temporal passes through the upper part of the "land, (2) the common trunk formed by the temporal and internal maxillary veins, (3) a branch connecting this trunk with the internal jugular rein, (4) the facial nerve and its branches. (.">) branches of the greal auricular nerve. The upper anterior portion of the gland is called socia parotidis. This portion is often detached from the rest of the gland. The duct of this gland is about two and one-half inches long. It is called Stenson's or Steno's duct. After crossing the Masseter muscle and passing into tin 1 substance of the Buccinator muscle this duct opens upon the inner sur- 580 ANATOMY IN A NUTSHELL. face of the cheek by a small opening opposite the second malar tooth of the upper jaw. This duct is about the size of a crow-quill. It has an external or fibrous coat, which contains contractile fibers, and an internal or mucous coat, which is lined with short columnar epithelium. Blood Supply. — From branches of the external carotid artery. Nerve Supply. — (1) sympathetic from the carotid artery, (2) the fifth nerve (auriculo-temporal), (3) the seventh nerve, (4) the great auricular (cer- vical plexus). The submaxillary gland which weighs about two drachms is situated in the anterior part of the submaxillary triangle of the neck below the mylo- hyoid ridge of the inferior maxillary bone. The stylo-maxillary ligament sep- arates this gland from the parotid gland, and the Mylo-hyoid muscle separates it from the sublingual gland. TIh' duct of this gland (Whadon's) is about two inches long ami opens at the side of the frsenum linguae. Blood Supply. — From the facial and lingual arteries. Nerve Supply. — (1) sympathetic, (2) the fifth nerve (submaxillary), (3) the seventh nerve (chorda tympani). The sublingual gland weighs about a drachm and is situated at the side of the frsenum lingua? in a fossa above the mylo-hyoid ridge of the lower jaw close to the symphysis. The duct of this gland is called the Bartholin or Rivinus. This duct opens into the duct of the submaxillary gland near its termi nation. Blood Supply. — From the sublingual and submental arteries. Nerve Supply. — (1) Sympathetic, (2) the fifth (gustatory). ANATOMY IN A NUTSHELL. " s l ATABLE OF MUSCLES WITH Nerve Supply and Page of Description. Cranial Region. Occipito-frontalis. — Facial, or branches of third cranial nerve, the occipital part sometimes receives the occipitalis minor nerve Page 513 Auricular Region. Attollens aurem. — Origin. — From the Occipito-frontalis aponeurosis. Insertion. — Into the pinna of ear above. (Plate XIV.) Action. — It raises the pinna. Nerve Supply. — Facial. Blood Supply. — Temporal arteries. Attrahens aurem. — Origin. — From the cranial aponeurosis. Insertion. — Into the helix of the ear anteriorly. Action. — It draws the pinna forward. Nerve Supply.— Facial. Blood Supply. — Branches from the temporal. Retrahens aurem. — Posterior auricular of facial nerve Page 522 Palpebral Region. Orbicularis palpebrarum. — Temporal branch of facial or fibers of third cranial nerve Page 508 Corrugator supercilii. — Temporal branch of facial or fibers of third cranial nerve Page 508 Tensor tarsi. — Facial and perhaps third cranial nerve Page 532 Orbital Region. Levator palpebr^e. — Third cranial nerve Page 529 Rectus superior. — Third cranial nerve Page 530 Rectus inferior. — Third cranial nerve Page 530 Rectus internus. — Third cranial nerve Page 53 1 Rectus externus. — Sixth cranial nerve Page ■">:'> 1 Obliquus superior. — Fourth cranial nerve Page ■">•"■•> Obliques inferior. — Third cranial nerve Page 538 Muscles of Tympanum. Stapedius. — Tympanic branch from seventh cranial nerve Page 523 Tensoi; tymi'wi. From the otic ganglion Page 523 Laxator tympani Page 531 Nasal Region. Ptramidalis nasi. — ANATOMY IN A NUTSHELL. Origin. — From the Occipito-frontalis. [nsertion. — Into the fibro-cartilage of the ala of the nose with the Com- ■ 'i- nasi. Action. Depresses the eye brows and makes the transverse wrinkles on the bridge of the nose. N u;\ i. Supply.— Facial. I '.ij ><>i> Supply.— Facial. Levator labij buperioris al^bque nasi. — Facial Page 539 Dilatob naris posterior. — Facial Page 540 DlLATOB NARIS ANTERIOR. — Origin.— From the alar cartilage. Insertion. — Into the skin near the margin of the nose. Action.— To dilate the nostril. \'i.k\ i: Supply.— Facial. Blood Supply. — Facial. Compressor nasi. — Facial Page 539 Compressor narium .minor. — Origin.— From the fibro-cartilage of the nose. Insertion. — Into the skin at the end of nose. Action. - To dilate the nostril. Nerve Supply. — Facial. Blood Supply. — Facial. Depressor al.k nasi. — Facial Page 539 Superior Maxillary Region. Levator labii superioris. — Facial Page 534 Levator anguli oris. — Facial Page 539 Zygom \th is major. — Facial Page 535 Zygomaticus minor. — Facial Page 535 Inferior Maxillary Region. I.i.\ vim; LABI) tNFERiORis. — Facial Page 545 Depressor labii inferioris.. — Facial Page 544 Depressor anguli oris. — Facial Page 545 Intermaxillary Region. l'.i (i [NATOR. Facial and buccal branch of inferior maxillary division of fifth crania] aerve Page 540 Risorius. — < >i;h,i \. From the masseter fasica. Insertion. Into the angle of the mouth. Action.— To draw the angle of the mouth backward. N i.i;\ i. Si pply. Facial. Blood Supply. Facial. Orbicularis oris.- Facial through its buccal and supramaxillary di- visions Page 540 Temporo-Maxillary Region. TEMPORAL.- Inferior maxillary division of the fifth nerve Page 508 Masseter. Inferior maxillary division of the fifth nerve Page 520 ANATOMY IN A NUTSHELL. 583 Pterygo-Maxillary Region. Pterygoideus externus.— Pterygoid branch of the Inferior maxillary division of the fifth nerve Page 529 Pterygoideus internus. — Pterygoid branch of the Inferior maxillary division of the fifth nerve Page 529 Superficial Cervical Region. Platysma myoides. — Facial Page 5 15 Sterno-cleido-mastoid. — Spinal accessory, second and third (?) cervi- cal nerves Page l" Infra-Hyoid Region. (Depressors of the Os hyoides and the Larynx). Sterno-hyoid. — Branches from the loop of communication between the cervical plexus and twelfth cranial nerve Page 40 Sterno-thyroid. — Branches from the loop of communication between the cervical plexus and twelfth cranial nerve Page 41 Thyro-hyoid. — Hypoglossal nerve Page 550 Omo-hyoid. — Tenth, twelfth, and cervical plexus Page 59 Supra-Hyoid Region. (Elevators of the Os hyoides and the larynx.) Digastric. — Posterior belly gets the facial, and the anterior belly gets mylo-hyoid branch of inferior dental nerve Page 521 Stylo-hyoid. — Facial Page 522 Mylo-hyoid. — Mylo-hyoid branch of inferior dental of fifth nerve Page 5 I 1 Geniohyoid. — Hypoglossal nerve Page 5 1 1 Lingual Region. (Muscles of the Tongue.) Genio-hyo-glossus. — Hypoglossal nerve Page 5 I I Hyo-glossus. — Hypoglossal nerve Page 551 Stylo-GLOSSUS. — Hypoglossal nerve Page 522 Chondro-glossus. — Hypoglossal nerve Page 550 Inferior lingualis. — Hypoglossal nerve Page 551 Superior lingualis lies near the upper surface of the tongue passing from base to apex. Its action is to shorten the tongue and make ii concave longitudinally. Nerve Supply.— Hypoglossal. Blood Supply. — Same as tongue. Transverse lingualis runs from the median raphe of the tongue to the dorsum and margin. Its action is to increase the length of the tongue, at the same time make it narrow. X kkye Sui'i'M . I lypoglossal. Blood Supply.- Same as tongue. Vertical lingualis consists of fasciculi which pass from the dorsum ol the tongue to its under surface. Its action is to make the tongue Ik'it and broad. Nerve Supply.— Hypoglossal. Blood Supply. — Same as tongue. 584 anatomy in a nutshell. Palatoglossus. — Origin. — From the median line of the soft palate and from its fellow of the opposite side. Insertion. — Into the side and dorsum of the tongue. Action.— It constricts the fauces and elevates the tongue, also pulls down the velum. Nerve Supply. — Internal branch of spinal accessory through the pharyn- geal plexus. Blood Supply. — Muscles of the Pharynx. Constrictor inferior. — Origin. — From the cricoid and thyroid cartilages. Insertion.— Into the fibrous raphe of the pharynx. Action. — It compresses the pharynx and lifts it upward and backward. Nerve Supply. — Pharyngeal plexus and inferior laryngeal. Blood Supply. — Same as pharynx which is given on page 315. Constrictor medius. — Pharyngeal plexus Page 551 Constrictor superior. — Branches from the pharyngeal plexus. .Page 515 Stylo-pharyngeus. — Glosso-pharyngeal Page 522 Palato-pharyngeus. — Origin. — From the soft palate by two heads near the median line. Insertion. — Into the side of the pharynx and posterior border of thyroid cartilage. It joins the Stylo-pharyngeus muscle. Action. — Constricts the fauces and elevates the larynx and tongue, and closes the posterior nares. Nerve Supply.- — Internal branch of spinal accessory through the pharyn- geal plexus. Blood Supply. — Same as pharynx. Page 315. Muscles of the Soft Palate. Levator palati. — Spinal accessory through pharyngeal plexus, possibly facial through petrosal branch of the vidian nerve Page 523. Tensor palati. — From the otic ganglion Page 523 Azygos uvuljE. — Spinal accessory through pharyngeal plexus. .Page 549 Palato-glossus, which has been described with the muscles of the tongue in the lingual region. Palato-pharyngeus, which has been described with the muscles of the pharynx. Muscles of the Anterior Vertebral Region. Rectus capitis anticus major. — First cervical and loop between it and second cervical nerve Page 514 Rectus capitis antic is minor. — First cervical and loop between it and second cervical nerve Page 514 Rectus CAPITIS lateralis. — First cervical and a loop between it and second cervical nerve Page 514 Longus colli. — Description. — This muscle consists of three portions, ANATOMY IX A NUTSHELL. 585 (a) a longitudinal portion, (b) a superior oblique portion, (c) inferior oblique portion. Origin of the longitudinal portion is from the bodies of the first, second, and third dorsal, and of the sixth and seventh cervical vertebra?. Insertion of this portion into the body of the second, third, and fourth cervical vertebra?. Origin of superior oblique portion is from the anterior tubercle of the trans- verse processes of the third, fourth, and fifth cervical vertebra?. Insertion of this portion into the anterior tubercle of atlas. Origin of inferior oblique portion is from the bodies of the first, second, and third thoracic vertebra?. Insertion of this portion is into the anterior tubercle of the transverse processes of the fifth and sixth cervical vertebra?. Action. — To flex the cervical portion of the spinal column, and rotates it. Nerve Supply. — Anterior branches of the lower cervical before the}' go into the brachial plexus Blood Supply. — Muscles of the Lateral Vertebral Region. Scalenus anttcus. — Origin. — From the anterior tubercles of the transverse processes of the third, fourth, fifth, and sixth cervical vertebrae. Insertion. — Into the tubercle on the inner and upper surface of the first rib in front of the subclavian artery. Action. — It flexes the neck and elevates the first rib. Xerve Supply. — Anterior primary branches of the fourth, fifth, and sixth cervical nerves. Blood Supply. — Scalenus medius. — Description. — Is the largest of the Scaleni muscles and passing through its substance is the posterior thoracic or long thoracic nerve. Origin. — From the posterior tubercles of the transverse processes of the lower six cervical vertebrae. Insertion. — Into the upper surface of the first rib behind the groove for the subclavian artery. Action. — It flexes the cervical portion of the spinal column and elevates the first rib. Xerve Supply. — From the posterior primary branches of the cervical nerves. Blood Supply. — Scalenus posticus. — Description. — Tlii< is the smallest and deepest of the Scaleni muscles and sometimes blends with the Scalenus medius. Origin. — From the posterior tubercle of the transverse processes of the lower two or three cervical vertebra'. Insertion. — Into the outer surface of the second rib behind the origin of the Serratus magnus. Action. — It flexes the cervical vertebrae laterally and raises the Brs1 rib. 586 ANATOMY IN A NUTSHELL. Nerve Supply. — From the lower three cervical nerves. Blood Supply. — Muscles of the Larynx. Crico-thyroid. — Externa] laryngeal from the superior laryngeal Page 251 Crico-arytenoideus posticus. — Recurrent laryngeal branch from pneu- ni( igast ric nerve Page 251 Crico-arytenoideus lateralis. — Recurrent laryngeal branch from pneu- mogastric uerve Page 251 Arytenoideus.— -Recurrent laryngeal branch from pneumogastric and superior laryngeal nerve Page 252 Thyro-artenoideus. — Recurrent laryngeal branch from pneumogastric nerve Page 252 Thyro-epiglottideus. — Recurrent laryngeal branch from pneumogastric nerve Page 252 Aryteno-epiglottideus superior. — Recurrent laryngeal nerve Page 252 ArytEno-epiglottideus inferior. — Recurrent laryngeal nerve Page 252 Muscles of the Back. First layer. Trapezius.— Spinal accessory, third and fourth cervical nerves. .Page 45 LATISSIMUS DORSI. — Middle or long subscapular Page 52 Second layer. Levatob ANGULI suapul.e. — Third and fourth, sometimes the fifth Page r>o Rhomboideus .major. — Fifth cervical nerve Page 55 Rhomboideus minor. — Fifth cervical nerve Page 55 Third layer. Serratus posticus superior. — All the muscles of the third layer Page 271 Serratus posticus inferior — of the back receive the external Page 272 Splenius capitis. — divisions of the posterior branches Page 272 Splenius colli. — of spinal nerves in their respective regions. . . .Page 272 Fourth layer. SACB \l. \M> LUMBAR REGIONS. Exectok SPiNiE.- External division of posterior branches of spinal nerves Page 272 I tarsal region. Ilio-Costalis. Kxternal division of posterior branches of spinal nerves Page 273 Musci i.i s \< i ejssorius ad ilio-costalem.— External division of posterior branches of spinal nerves Page 274 Longissimus dorsi. -External division of posterior branches of spinal nerves Page 274 Spinalis dorsi. [nternal division of posterior branches of spinal nerves Page 274 < tervical region. Cervn ojs \>< endens. External division of posterior branches of spinal nerve- Page 274 ANATOMY IN A NUTSHELL. 587 Transveksalis colli. — External division of posterior branches of spinal nerves Pag Trachelo-mastoid. — Internal divisions of posterior branches, also sub- occipital and great oeeipitial nerves Pag 27 ; Complexus. — Internal divisions of posterior branches, also suboccipital and great occipital nerves 1 ' : , g< 271 BrvENTEK cervicis. — External division of posterior branches of spinal nerves Pag< 27f Spinalis colli. — Internal division of posterior branches of spinal nei Page 275 Fifth layer. Semispinalis dorsi. — Internal divisions of the posterior branches of spinal nerves Pagi 276 Semispinalis colli. — Internal division- of the posterior branches of spinal nerves Page J 7 < , Multifidtjs spin.e. — Internal divisions of posterior branches of spinal nerves Page 276 Rotatores -pix.e. — Internal divisions of the posterior branches of spinal nerves Page 276 Supraspinales. — Internal divisions of posterior branches of spinal ne Page 276 Interspinales. — Internal divisions of posterior branches of spinal nerves Page 278 Extensor coccyges. — Internal division- of posterior branches of spinal nerves Page 278 Intertransversales. — Internal division.- of posterior branches of spinal nerves Page 278 Rectus capitis posticus major. — Suboccipital nerve Page -7 s Rectus capitis posticus minor. — Suboccipital nerve Page -7 s Obliquus capitis superior. — Suboccipital nerve Page -7 s Obliqtjus capitis inferior. — Suboccipital and greal occipital nerves ' Page 280 Thoracic Region. Inter* ostales externi. — fntercostal nerves Page l>, Intercostales interni. — Entercostal nerves Page 158 Infra* ostales. — Intercostal nerves Page 458 Triangularis sterni.- Intercostal nerves Page l> s Levatores costarum. — Intercostal nerves Page 159 Diaphragmatic Region. Diaphragm.— Phrenic plexus, intercostal, and phrenic nerves .. Page 233 Superficial Abdominal Region. Obliquus externus. — Lower intercostal nerves Page 160 Obliquus internus. — Lower intercostals, ilio-hypogastric, - etiraes iUo-inguinal nerve ''•''-' "'' 588 ANATOMY IN A NUTSHELL. Transversalis. — Lower intercostuls, ilio-hypogastric, sometimes ilio- inguinal nerve Page 462 Re( ii S abdominis. — Lower intercostal nerves Page 463 Pyramidalis. — Twelfth thoracic and ili< (-hypogastric nerves. ..Page 463 Cremaster.— Genital branch of genito-crural nerve Page 464 Deep Abdominal Region. Psoas parvus. — Anterior branch of first lumbar nerve Page 134 Psoas magnus.- Anterior branches of second and third lumbar Page 134 Iliactjs. — Anterior branches of second and third lumbar through the anterior crural nerve Page 135 Qu \in; \ti rs lumborum. — Lower intercostal nerves Page 464 Ischio-Rectal Region and Perineum. Corrug viok cutis ani. — Sympathetic nerves Page 490 External sphincter ani. — Anterior division of fourth sacral and in- ferior haemorrhoidal branch of internal pudic nerve Page 490 I xtkkxal sphincter ani. — Hemorrhoidal Page 490 Levator ani. — Branches from anterior division of fourth sacral and branches from pudic nerve Page 490 Coccygeus. — Branches from fourth and fifth sacral nerves Page 491 In the male. Transversus perin^ei. — Perineal branch of internal pudic nervePage 491 Accelerator rnix.E. — Superficial perineal from internal pudic. Page 492 Kkkctoh pexik. Perinea] branch of internal pudic nerve Page 492 Compressor urethr.e. — Perineal branch of internal pudic nerve Page 492 In the female. Ti; lnsversus p Hi !ix. Ei. — Perineal branch of internal pudic nerve Page 492 Sphincter vagix.e. — Perineal branch of internal pudic nerve.. Page 493 Erector clitoridis. — Perineal branch of internal pudic nerve Page 493 Compressor urethra. — Perineal branch of internal pudic nerve Page 493 Anterior Thoracic Region. Pectoralis major. — External and internal anterior thoracic nerves Page 41 Pectoralis minor. — Internal anterior thoracic nerve Page 50 Subclavitjs. — Fifth and sixth cervical nerves Page 42 Lateral Thoracic Region. Serratus MAGNUS. — Posterior thoracic from the fifth and sixth and .seventh cervical nerves Page 54 Acromial Region. Deltoid. — Circumflex nerve Page 43 Anterior Scapular Region. Subscapulars. Upper and lower subscapular nerves Page 56 Posterior Scapular Region. Supraspinatus. Fifth and sixth cervical through suprascapular. Page 56 Infraspinatus. — Fifth and sixth cervical through suprascapular. Page 55 Teres minor.- Fifth cervical through circumflex Page 56 ANATOMY IN A NUTSHELL. 589 Teres major. — Fifth and sixth cervical through the lower subscapular Page 56 Anterior Humeral Region. Coraco-brachtalis. — Musculo-cutaneous nerve Page 58 Biceps. — Musculo-cutaneous nerve Page 58 Brachialis axticus. — Musculo-cutaneous and musculo-spiral . . . .Page 79 Posterior Humeral Region. Triceps. — Seventh and eighth cervical through musculo-spiral. . I'air<- 50 Subaxcoxeus. — Musculo-spiral nerve Page 79 Anterior Radio-Ulnar Region. Proxator radii teres. — Median nerve Page 79 Flexor carpi radialis. — Median nerve Page 81 Palmaris loxgus. — Median-nerve Page 81 Flexor carpi ulnaris. — Ulnar nerve Page 81 Flexor sublimis digitorum. — Median nerve Page 82 Flexor profundus digitorum. — Ulnar and anterior interosseous. Page 82 Flexor loxgus pollicis. — Anterior interosseous Page 84 Proxator quadratus. — Anterior interosseous Page 84 Radial Region. Supinator loxgus. — Musculo-spiral nerve Page 84 Extensor carpi radialis loxgior. — Musculo-spiral nerve Page 85 Extexsor carpi radialis brevior. — Posterior interosseous. . . .Page s "> Posterior Radio-Ulnar Region. Extexsor communis digitorum. — Posterior interosseous Page 85 Extexsor miximi digiti. — Posterior interosseous Page 87 Extexsor carpi ulnaris. — Origix. (1) From the outer condyle of thehumerus bythe common tendon, adjacent intermuscular septa, and deep fascia. (2) from the middle third of the posterior surface of the ulna, (3) from the posterior border of the ulna with the Flexor carpi ulnaris and Flexor profundus digitorum. Insertion. — Into the ulnar side of the base of the fifth metacarpal hone. Action. — To extend the carpus. Nerve Supply. — Posterior interosseous. Blood Supply. — Ulnar artery. Anconeus. — Musculo-spiral nerve Page s 7 Supixator brevis. — Posterior interosseous nerve Pag< ss Extensor ossis metacarpi pollicis. — Posterior interosseous nerve P ss Extensor brevis pollicis. — Posterior interosseous aerve Page ss Extensor longus pollicis. — Posterior interosseous nerve .... Page 91 Extensor indicis. — Posterior interosseous nerve Page 91 Radial Region of the Hand. Abductor pollicis. — Median nerve Page ! 1 1 Flexor ossis metacarpi pollicis.- Median nerve Page 1 12 Flexor brevis pollicis. — Median and ulnar nerves Page 1 12 Adductor obliquus pollicis. — Ulnar nerve Page 1 L2 590 ANATOMY IN A NUTSHELL. Adductor transversus pollicis. — Ulnar nerve Page 112 Ulnar Region. Palmaris brevis. — Ulnar nerve Page 113 Abductor minimi digiti. — Ulnar nerve Page 113 Flexor brevis minimi digiti. — Ulnar nerve Page 113 Flexor ossis metacarpi minimi digiti. — Ulnar nerve Page 113 Palmer Region. Lumbricales. — Two outer ones get the median; two inner get the ulnar nerve Page 113 The three palmar interossei. — Ulnar nerve Page 114 The four dorsal interossei. — Ulnar nerve Page 114 Iliac Region. Psoas magnus. — Anterior branches of second and third lumbar. .Page 134 Psoas parvus. — Anterior branch of the first lumbar Page 134 Iliacus. — Anterior branches of second, and third lumbar through the anterior crural nerve Page 135 Anterior Femoral Region. Tensor vaginae femoris. — Fourth and fifth lumbar and first sacral through (lie superior gluteal nerve Page 135 Sartorius. — Anterior crural Page 135 Rectus. — Anterior crural Page 136 Vastus externus. — Anterior crural Page 137 Vastus internus. — Anterior crural Page 137 Crureus. — Anterior crural Page 138 Subcrureus. — Anterior crural Page 138 Internal Femoral Region. ( rRACiLis. — Third and fourth lumbar through the obturator nerve. Page 138 PectinetjS. — Anterior crural, obturator accessory and occasionally branch from the obturator nerve Page 138 Adductor longus. — Obturator nerve Page 140 Adductor brevis. — Obturator nerve Page 140 Adductor magnus. — Obturator and great sciatic nerves Page 140 Gluteal Region. Gluteus maximus. — Inferior gluteal and small sciatic nerve. . . .Page 141 Gluteus medius. — Superior gluteal Page 141 Gluteus minimis. — Superior gluteal Page 143 Ia riformis.- First and second sacral nerves Page 143 Gemellus superior. — Fifth lumbar, first and second sacral nerves Page 144 Obturatob [nternus. — Fifth lumbar, first and second sacral nerves Page 143 Gemellus inferior.— Fourth and fifth lumbar, and first sacral. .Page 144 Obturator externus. ( >bturator nerve Page 144 Quadratis fi.mokis. Last lumbar and first sacral nerves Page 144 Posterior Femoral Region. Biceps. — Great sciatic nerve Page 14C> SEMITENDINOSUS.- ( iieat sciatic nerve Page 146 ANATOMY IN A NUTSHELL. 591 Semimembranosus. — Great sciatic nerve Page 147 Anterior Tibio-Fibular Region. Tibialis anticus. — Anterior tibial nerve Page 152 Extensor longus digitorum. — Anterior tibial nerve Pago 152 Extensor propius halluces. — Anterior tibial nerve Pane 152 Peroneus tertius. — Anterior tibial nerve Page loo Posterior Tibio-Fibular Region. Gastrocnemius.— Internal popliteal from great sciatic nerve. . . . Page 153 Plantaris. — Internal popliteal from great sciatic nerve Page 154 Soleus. — Internal popliteal and posterior tibial. Page 1 53 Popliteus. — Internal popliteal nerve Page 154 Flexor longus hallucis. — Fifth lumbar, first and second sacral through posterior tibial nerve : Page 1 54 Flexor longus digitorum. — Posterior tibial nerve Page 156 Tibialis posticus. — Posterior tibial nerve Page 1 "fi Fibular Region. Peroneus longus. — Alusculo-cutaneous, a branch of external popliteal nerves Page 15ii Peroneus brevis. — Alusculo-cutaneous, a branch of external popliteal narves Page 157 Dorsal Region of the Foot. Extensor brevis digitorum. — Anterior tibial nerve Page 157 Plantar Region of the Foot. Abductor hallucis. — Internal plantar nerve Page 158 Flexor brevis digitorum. — Internal plantar nerve Page 158 Abductor minimi digiti. — External plantar nerve Page 158 Flexor accessories. — External plantar nerve Page 161 Lumbricales. — The two inner ones get the internal plantar nerve, the two outer ones get the external plantar nerve Page 162 Flexor brevis hallucis. — Internal plantar nerve Page 162 Adductor obliquus hallucis. — External plantar nerve Page 158 Flexor brevis minimi digiti. — Origin. — From the base of the fifth metatarsal bone and from the sheath of the tendon of the Peroneus longus. Insertion. — Into the base of the first phalanx of little toe and fifth meta- tarsal. Action. — To flex the little toe. Nerve Supply. — External plant; . Blood Supply. — External plantar. Adductoe transversus hallucis (pedis). External plantar nerve Page mo The four dorsal lnterossei. External plantar nerve. The firsl and second also receive extra filaments from the anterior tibial nerve Page 160 The three plantar enterossei. External plantar nerve Page L60 INDEX. 593 INDEX Abdoinen, 307 contents of, 307-309 regions of, 307 superficial muscles of, 460 deep muscles of 464 veins of, 186 lymphatics of, 499 Abdominal ring external, 476 ring internal, 477 brain function of. 431 aorta. 4.51-172 aorta relations of, 451 aorta branches of. 452 anterior trunk, 172 Abducens nerve, 439-392 Abductor hallucis muscle, 158 pollicifi muscle, 111 minimi digiti muscle, 113 Accelerator urinse muscle, 492 fibers to heart, 431 Accessoriu^ muscle, 274 Acetabulum, 131 Acromial thoracic artery, 63 Acromio-clavicular articulation, 38 clavicular articulation ligaments, 38 clai icular articulation blood and nerve supply, 38 Adductor transversus hallucis muscle, 160 obliquus hallucis muscle, 158 magnus muscle, 140 brevis muscle, 140 longus muscle. 140 transversa pollicis muscle, 112 Adductor obliquus pollicis muscle, 112 Adenology definition of, 17 Adult circulation, 39 Ala cinerea of brain, 443 Alar thoracic artery, 64 Alcock's canal, 495-214 Alimentary canal, 309 Allantois, 172 Amaurosis, 373 Amblyopia, 373 Amphiarthrosis, divisions of, 26 Anatomy definition of, 17 divisions of, 17 Anastomotica magna artery leu. 178 magna artery (arm), 69 Anconeus muscle, 87 Angular vein, 180 Angle of jaw. 543 Angular processes, 507 gyrus, 345 artery, 292 Angiology definition of, 17 Ankle joint. 21)1-202 Ankle joint blood and nerve supply, 204 joint ligaments of 203 Annec'ent gyrus, 345 Annulu* ovalis, 240 Anosmia, 365 Anterior annular ligament, 221-110 Condyloid foramen. 554 cerebral artery, 114 communicating artery, 444 commissure of brain, 437-347 cardiac \ cm. 486 commissure, '■'• 17 crual nerve. _'ln carpal artery, 96-92 circumflex artery, 65 el hmoidal arterj . 385 intercostal arteries, 148 ethmoidal foramen. 553 interosseous artery, 95 jugular vein, IM Antero-lateral ground bundle tract, 433 lateral ascending tract. 433 Anterior ligament. 61 meningeal artery, 444 mediastinum 460 nerve roots. 333 Spinal arteries. 337 tibial nerve. 218 tibial vein 192 tibial artery, 1N4-1S0 tibial recurrent arterj . 182 tibial artery branches of, 182 thoracic artery. 64 ulna recurrent artery, 95 Antrum of Highmore, 537 Ant ihelix of ear, 569 Antitragicus muscle, 570 Aorta, 284 Aortic opening of diaphragm, 234 plexus, 126 Aponeurosis description of, 17 Aqueduct of Syh ius, 3 1 1 Aqueduct u~ \ est ibuli, Aqueous humor, 376 Arachnoid of brain. 341 Arachnoid of cord, 332 \nii- tendinous, 195 Arch aorta, 285 Arm cutaneous nen es of, 1 19 veins of, 117 questions on, 120 lymphatics of, 198 muscles • . cent ralis ret ina ! princeps cen ici receptaculi artery, ill A Rvstem description of, 594 Arteries, abdominal aorta, 452-172 acromial thoracic, 63 alar thoracic, li 1 anastomotica magna, (leg), 178 anastomotica magna (arm), 69 anterior circumflex, 65. carpal, 92-96 cerebral, 444 communicating, 444 ethmoidal, 385 interosseous, 95 intercostal, 448 meningeal, 444 spinal, 337 thoracic, 64 tibial, 182-180 ulna; recurrent, 95 aorta, 284 articular of knee, 182 ascending cervical 449 pharyngeal, 294 palatine, 291 angular, 292 auricular, 293-294 axillary, 62 basilar, 448 bladder of, 472 brachial, 66 bronchial, 450 calcanean. 186 carotids. 286 cerebellar, 448 circle of Willis. 445 ciliary, 385 coats of, 30 coeliac axis, 453 common interosseous, 95 colica dextra, 455 media, 455 sinistra, 455 coronary, 244-292 cremasteric, 560-176 crico-thyroid, 290 cutaneous of leg, 182 cystic, 453 deep palmar arch, 93 ulnar, 90 circumflex iliac, 176-178 epigastric, 175-178 descending palatine, 298 digital, 186 dorsalis pollicis, 92 indicia, 93 pedis, IM hallucis, IM lingua', 291 external carotid, 1 i:i-288 Artery external iliac, 175 mammary, 6 1 malleolar, 18 I plantar, 186 tarsal, 1st facial, 291 femoral, 170 INDEX. Arjery, frontal, 385 gastro-epiploica dextra, 453 epiploica sinistra, 453 gastro-duodenalis, 453 gastric, 453-327 gluteal, 172 hand of, 106 hepatic, 453 hyoid, 288 hypogastric, 33 ileo-colic, 455 ilio-lumbar, 172 inferior profunda, 66 mesentery, 455 thyroid, 449 laryngeal, 449 vesical, 172 dental, 297 labial, 292 innominate, 286 intercostal, 450 internal auditory, 448 carotid, 443 iliac, 172 maxillary, 295 malleolar, 182 mammary, 448 palpebral, 385 pudic, 173 tarsal. 184 lachrymal, 383 lingual, 290 long thoracic, 64 lumbar, 452 lateral sacral, 172 mediastinal, 448 meningeal, 293 mesenteric, 326 metatarsal, 184 metacarpal, 92 middle cerebral, 444 meningeal, 296 hemorrhoidal, 172 vesical, 173 musculo-phrenic, 449 nasal, 385 nutrient rule of, 19 obturator, 172 occipital, 293 oesophageal, 450- ophthalmic, 383-444-308 ovarian, 457 palmar recurrent, 95 interossei, 94 pancreatica? parvse and magna, 453 pericardiac, 450-448 peroneal, 186 phrenic, 44N-452 plantar digital, 184 pterygoid, 297 posterior carpal, 92-96 cerebral, 445 circumflex, 65 communicating, 445 INDEX. 595 Artery, ethmoidal, 384 interosseous, 95 mediastinal, 450 perforating, 186 scapular, 449 spinal. 337 tibial. 180-185 tibial recurrent. 182 ulnar recurrent, 95 popliteal. 176 princeps pollicis. 93 profunda, 176 pterygo-palatine, 298 pudic. 176 pulmonary. 284 pyloric. 4.53 radial. 91 radial recurrent . 92 radialis indicia, 94 ranine. 291 renal. 456 rule of, 32 sciatic. 174 sigmoid, 455 spheno-rnaxillary. 297 palatine. 298 splenic. 453-327 spermatic. 456-567 sternal, 448 subclavian, 445 sublingual, 291 submaxillary. 291 subscapular, 65 submental. 292 superficial cervical, 449 suprascapular. 449 suprarenal. 456 supraorbital, 384 superficial external pudic. 17S circumflex iliac. 178 epigastric. 178 femoral, 176 palmar arch, 96 superficialis volas, 92 superfieial descending. 288 superior intercostal. 449 epigastric, 449 mesentery. 454 hemorrhoidal. 456 vesical, 172 fibular. 182 profunda. 66 perforating. 94 thoracic. 62 laryngeal. 288 thyroid, 288 sural. 182 temporal, 294 thoracic- aorta, 451 thyroid a\i~. 449 transver>alis, colli, 449 tonsillar, 291 tracheal. 449 tympanic, 295 Artery, ulnar, 95 umbilical. 472 uterine. 174 vasa aberrantia. 69 brevia. 453 intestini tenuis, 451 vas deferens of, 566 vertebral. 447 wrist of, 92 articular of knee. 182 Articular process of vertebra Articulation, acromio-clavicular. 38 ethmoid bone of, 525 elbow joint, til femur. 150 frontal bone of, 508 hip-joint. 194 humerus; of, 61 ilium of. 128 inferior radioulnar, 79 maxillary bone of, 543 turbinated bone of, 546 knee, 198 lachrymal bone of. 532 metatarsal bone of, 164 metatarsophalangeal. 164 metacarpophalangeal. 110 middle radioulnar, 78 nasal bone of. 532 occipital bone of, 513 palate bone of, 549 parietal bone of. 510 pudic bones of, 128 sacrum. 133 sacro-vertebral 280 iliac, 133 coccygeal. 134 sphenoidal hone of, 528 sternoclavicular. 38 superior radio-ulnar. 78 temporal bone of, 520 Aryteno-epiglottideus muscle. 252 Arytenoideus muscle. 252 Ascending cervical artery. 449 gyrus, 245 palatine artery. 291 pharyngeal artery, 294 fibers of cord. 433 Astigmatisn A~t ragalus bone, 162 muscles attached, 162 Atla- hone. 260 muscles attached, 260 ligaments of, 262 Atlantoaxial ligament Auerbach's plexus Auditory ner> «-. 8), 441 meatus, 517 nerve superficial origin, 579 deep origin cochlear branch. 579 vestibular branch. 579 canal external. 570 Auriculotemporal nerve, 102 596 INDEX. Auricles of heart, 240-242 Auricular appendix, 240 Auricular artery, 293-295 Axilla, the 119 boundaries of, 1 19 \ \illary artery. (12-98 vein, 118-482 \\i- bone, 26 l Axis bone muscles attached, 264 ligaments of, 265 Azygos veins, 483-484 uvukr muscle, 549 Hack -km o/, 280 muscles of, '270 Basilar artery, 1 18 vein, 488 process, ."Hi" Bartholin's glands, 563 duct, 315 Bicepa muscle, 146-58 Bicuspid valve, 242 Big four. 319 Hi venter cervicis muscle, 274 Bladder, 471 urachus of, 471 arteries of, 472 ligaments of, 472 lymphatics, 500 Blood penis vessels of, 566 vessels description of, 28 Bone as1 ragalus, 162 atlas, 260 axis, 264 cavities of, 22 els ■ Lcle, 35 :cj \. I". 1 cranium of, 525-20 cuboid, 162 definition of, 23 eai of, 574 eminences of, _'_' Bones, externa] cuneiform, 164 ethmoid, •">-' 1 tare. 2 flat, 20 femur, 1 17 Bbula. I7(i forearm of, 69 frontal, 506 gladiolus, 236 hand of, 106 humerus, ti() In oid, 5 19 ilium. I 25 incus, ">7 1 internal eimifonn 163 inferior maxillary. ."> 1 1 turbinated, 546 innominate, 128 irregular, 2(1 ischium, 127-129 Bones, labyrinth of ear, 576 lachrymal, 532 long, 19 malar, 333 malleus, 574 manubrium, 236 metacarpal, 106 metatarsus, 164 middle cuneiform, 164 middle cuneiform, 164 nasal, 531 non-articular cavities of, 22 navicular. 163 occipital, 511 orbit of, 368 os calcis, 162 palate, 547 parietal, 509 pelvis, 131 phalanges, 164 processes definition of, 19 prominences of, 22 pubic. 127 pubis, 128 radius, 69 rib, 268 sacrum, 132 scapuhe, 45 sesamoid, 20-168 short, 20 sphenoid, 526 stapes, 574 sternum, 236 superior maxillary, 535 temporal, 516 tibia. 166 turbinated, 528 ulna, 69 vertebra, 258 vomer, 546 Wormian, 2 Brain, 339 ala cinerea, 443 anterior commissures of, 437-347 choroid plexuses of, 441 conductor sonorous of, 443 cortex of. 340 corpus callosum of, 350-437 striatum of, 441 coverings of, 341 crura cerebri of, 363-437 divisions of, 341 definition of, i:>7 eminentia teres, 443 fasciculus unciformis, 443 fissures of. 342-343 fornix. 348-437 fourth ventricle, 439 fovea superior, 443 inferior. 443 ganglia of. 343 gyri of, 345 inferior medullary velum, 441 infundibulum, 441 INDEX. 597 Brain lateral ventricle, 438 lamina cinerea, 441 ligula. 443 lobes of. 344-342 longitudinal commissures. 340-437 locus cseruleus. 443 middle commissure. 348-437 obex, 443 Brain, olfactory tract. 365-437 optic commissure. 437-366 peduncles of. 354 pineal gland 441 pons varolii, 362-437 posterior commissure. 437-348 perforated space. 441 ta?nia semicircularii, 356-437 tela choroidia inferior. 441 third ventricle. 437 transverse commissures. 339-437 trigonum hypoglossi. 443 tuber cinereum. 441 tuberculum acusticum. 443 ventricles. 340-358 valve of Yieussens 441 Brachial plexus. 96 communicating branches, 98 artery. 66 relations of, 66 Brachialis amicus muscle. 79 Bronchus, 254 Bronchial veins. 4^4 arteries. 450 Brunner's glands, 321 Bryant's triangle. 196 Buccal nerve. 40_> Buccinator muscle. 540 Buck's fascia. 495 Bulbus vestibuli. 563 Cseeum. 320 Calcarine fissure. 344 Calcaneo-cuboid ligamei.- - - Calloso-marginal fissure. 343 Call"--al gyrus, 34.5 Canal of Nuck. 559 Cardiac nerves. 416 plexus, 424 veins. 244 Cardio-inhibitory center, 359 Carotid arteries. 286 relations of, 2>-7 artery external, 443 internal, 443 Carotid sheath, 282 triangle, superior, 280 inferior. 282 Carotid plexu-. 422 Capillarir-s. description of, 30 Capsular ligament. 48 of knee. : Capsule of Muller, 47" of Tenon Cauda equina, 331 Cavernou- sinus -. 189 plexu-. 422 Cell- of Sehultz Center definition for. 364 Centers in medulla. 359 Center for smell, Central canal of cord, 333 Central lobe of brain, 344 -ystem. 339 tendon perineum. 495 Centrifugal nerves, 431 Centripetal nerves, 431 Cerebrum location of. 356 Cerebellum fi— tires of. 354 Cerebrum lobe- of. 344 exterior of. 342 Cerebellar vein-. Cerebral veil hernia. 474 Cerebellar artery. 448 Cerebellum description of, 357-360 nuclei of, 361 peduncles of, 360-362 Cervicalis ascendens muscle. 27 5 Cervical nerves. 298 plexus. 304 branches of 305 communicating branche-. 98 Cervical nerves second, 301 third. 303 pleura. 256 vertebrae. 264 Cervix, laceration of. 431 Chiasma, 366-357 Chondro-glossus muscle, 550 Chopart's amputation, 194 Choroid plexuses of brain, 441 Choroid coat of eye, 381-376 Chord* tendinea 1 , 241-243 Ciliary ganglion. 395-403 Ciliary body, 386 arteries. - Circle of Willis. 44.'. Circular sinus Circumvallate papillse, 311 Circumflex nerve, 99 Circumpatellar anaston Clavicle articular blood supi 1] articulatioi liean . muscles attached, I" Cliton- 134 muscles attached, 1 3 1 _-.-u- muscle, 191 2 1 *> • 598 INDEX. Cceliac axis, 153 plexus, l-'"> Colles's fascia, 494 Colica-dextra artery, 455 media artery, 455 Colica sinistra artery, 455 ( lolon ascending, 320 descending, 320 Colon, transverse, 320 Columns of Bertin, 468 Of Clarke, 333 Columns carneae, 24 1-2 13 ( !omes nervi phrenici, 307 Common carotid arteries, 288 intero us artery, 95 Commissures of brain, 339 Communicans hypoglossi nerve, 306 Compressor urethra' muscle, 492-493 nasi muscle, 539 Complete fissure, 342 Complexus muscle, 274 t lonarium, 353 Concha of car, 570 Conducting paths of brain, 431 Conductor sonorous, 443 Condyles, 22-61 ( londyloid foramen, 51 1 Congenital hernia, 478 Imi nia kind- of, 478 Conus arteriosus, 241 medullaris, 331 Coraco brachialis muscle, 58 Conjunctiva, 388 Cord membranes of, 332 tracts ,,f, 433 I !oi tex centers of, 433 Coi pus Arantii, 242 callosus, 350-437 call. .Mini, 319-350 dent at um, 361 Cor] hi- striatum, 441 Corpora cavernosa penis, 565 Corpus lutetim of ovary, 561 Coi pora triata, 347 ( !oi nea of eye, 378 -t met tire of, USD I Hi.. nary sinus. 486-240-244 arteries, 211-292 valve, 240 Corrugator cutis ani muscle, 490 supercili) muscle, 508 "** Cortical substance of kidney, 469 Cortes of brain coi meet ion of, 431 Of I. lam. 340 <',,-.,, clavicular ligament, 38 Costal pleura, 256 Cotyloid ligament, 196 Cowper'e (.'land, 137 195 Cranial ner\ es 139 nen e second, 366 nerves description of, 364-27 nerve- rule of origin, 364 nerves table of, 27 Cremastei muscle Hit Cremasteric artery, 566-176 fascia, 567-568 Cribriform plate, 524 fascia, 218 Crico-aryt enoideus lateralis muscle, 251 muscle, 251 thyroid artery, 290 thyroid muscle, 251 Crista galli, 525 vestibuli of ear, 577 Crista urethra, 473 Crural hernia, 474 Crucial anastomosis, 174 ligaments, knee, 200 atlas, 264 Crura cerebri, 363-437 Crureus muscle, 138 Crus cerebri, 363 Crusta petrosa, 31 1 Crystalline humor of eye, 376 Cuboid bone, 162 articulation of, 162 muscles attached, 162 Cutaneous arteries of leg, 182 nerves. 214 membrane description of, 465 Cuneate gyrus, 345 Cystic artery, 453 vein, 485 goitre, 246 Dartos of penis, 565 Deep lymphatic vessels, 498 cervical vein, 482 Dental canal inferior, 543 Depressor alee nasi muscle, 539 Deciduous teeth, 309 Deep circumflex iliac artery, 176 epigastric artery, 175 fascia of arm, 115 ulnar artery branch, 96 palmar arch, 93 Definition of center, 364 Degeneration of cord, 334 Deltoid muscle. 43 Dental nerves, 398 Dentate gyrus, 346 fissure, 342 Dentine of teeth, 311 Depressor labii inferioris muscle, 544 anguli oris muscle, 545 Dermatology definition of, 17 Descending fibers of cord, 335 palatine artery, 298 Diabetic center, 359 Diaphragm muscle, 233 crus of, 234 openings in, 234 Diaphragmatic pleura, 256 plexus, Diarthrosis divisions of, 26 Diastole of heart. 245 [NDEX. Digastric muscle, 521 triangle, 282 Digital arteries, 186 Dilator nares posterior muscle, 540 Diplce veins of, 486 Direct cerebellar tracts, 434 inguinal hernia, 474 coverings of 475 Dorsi-spinal veins, 486 Discus proligerus of ovum, 561 Diseases of spinal cord, 334 Dorsalis linguae artery. 291 Dorsal interossei muscle, 160-114 Dorsalis pedis artery, 184 hallucis artery. 184 Dorsales indicis artery, 93 pollicis artery, 92 Duct of Gartner, 563 Ductus arteriosus, the 33 Duodenum, 320 Dura Mater of cord, 332 blood supply, 341 nerve supply, 341 sinuses of, 488 veins of, 480 Ear, 568 bones of, 574 internal, 576 intrinsic muscles of, 570 nerve of, 577 pinna, 569 tympanum of, 571 vestibule, 5777 Ejaculatory duct, 567 Elbow joint, 61 ligaments of, 61 Eleventh nerve, 416 Eminentia teres, 443 Emissary veins, 487 Emmet ropia, 375 Enamel of teeth, 311 Encephalon, 341 Encysted hernia, 479 Endocardium, 244 Ensiform appendix, 237 Epigastric region, 309 Epiblast, 331 Epididymis, 568 Epiphysis, 353 Epeneephalon, 341 Epiglottis, 250 Erector clitoridia muscle, 493 Erector penis muscle, 492 spinse muscle, 272 Esophagus, 31 1 coats of, 317 Ethmoid bone, 524 crista galli of, 525 foramina of, 525 nasal slit, 525 processes of, 525 Ethmoid bone, muscles attached, •">-'•' cribriform plate of, 525 Ethmoidal > Ethmoid notch, ">o7 Eustachian tube, .".7 <• valve. 2 1(1 Exophthalmic goitre, -' 16 Extensor carpi-radialis longior muscle 35 Extensor brevis pollicis muscle, 88 digitorum muscle, 157 carpi-radialis brevior muscle, 85 communis digitorum muscle, 85 coccygis muscle, 278 indicis muscle, 91 longus pollicis muscle, 91 digitorium muscle, L52 iiiiiiimi digil i muscle, 87 7 iliac vein, 186 intermuscular septum (leg>, 219 arm), 115 intercostal muscles, 457 jugular vein, 481 lateral ligament . til' malleolar artery, 184 mammary artery, 64 orbital gyrus, 345 plantar artery. 186 nerve. 216 pterygoid muscle, ■">-'!» rectu> muscle, 531 sphincter ani muscle, 190 tarsal arterj ,184 thoracic nerve, us Extrinsic ligaments "t larynx, 250 Eye-ball, 3<;s coal a of, 376 refracting media. 376 blood supply of, 382 Eye-brows, 389 Eye diseases of, 373 Eye lashes, 389 I ye lid-. 389 I \. muscles of, ■">-''' • nsorj ligament .-: Face 1\ mpii.it ice "i . nerves ol 600 INDEX. Facial artery, 391 nerve, 407-439 superficial origin, 106 vein, 480 Falciform process, 220 Fallopian tubes, 559 ampulla, 560 fimbria. 560 isthmus, 560 i u]j proprli, 133 Fasciculus unciformus, 437-443 Fascia arm form-- of, 115 Buck's, 195 cribriform, 218 thigh deep of, 219 description of, 17 band of, 116 lata. 219-220 of leg, 220 obturator, 495 plantar. 223 ■ >f perineum, V.t.~> of pelvic, 495 recto-vesical, 195 superficial of thigh, 2 1 s I auces, 316 I iinale organs of generation external. .">ti2 organs of generation, 556 pelvic, 132 uretbra, 474 Femoral artery, 176 brancbe- of, 178 relations of 176 ■anal. 477 hernia, 477 sheath, 177 ring, 178 brevia hallucis muscle, 162 brevia digitorum muscle, 158 minimi digiti muscle, 1 13 bre\i> pollicis muscle, 11- carpi ulnaris muscle, 81 carpi radialis muscle, 81 sublimit digitorum muscle, 82 of hip joint , 196 longus digitorum muscle, 15*6 longus hallucis muscle, 15 l longus pollicis muscle, 84 profundus digitorum muscle 82 Floating kidney 169 Foramina of Stenson, 538 of Scarp base "f skull, 552 of orbit. 369 of Thebesii, 240 Foramen < tecum, ~ pyramids of Ferrin. 468 pelvis of, 469 relations of its vessel-. 4ds relation of, 468 f. 501 ligament - of, 32 1 lobes of, 324 relations of, 324 superficial vessels 328 gels of, 190 Lobes of cerebellum, 344-361 »f liver. 324 Lobule of ear, 569 Locus coeruleus of brain, 443 Locomotor ataxia. 334 J. iing thoracic artery, 6 1 subscapular nerve, 99 Longitudinal commissures of brain, 340-437 Longissmus dorsi muscle. _'7 1 extremity veins. 192 Lumbar arteries, 152 hernia. 474 nodes, 500 plexus, 208 plexus, blood supply of, 212 region right and left. 307 ganglia of sympathetic, 428 veins. 188 Lumbricales muscles of hand, 113 muscles of foot, 162 Lungs. !!.""> 4 nerves of, 416 roots of, 257 blood supply of, 255 nerve supply of, 256 lymphatics of, 502 Lymph, description of, 117 Lymphatic- of abdomen, 499 Of arm. 198 of bladder. 500 description of, 196 duct. 196 of face. .",ii | of head. .",11 1 Of heart. 503 of intestines, 501-320-322 Of kidney. .",111 of leg, 199 of liver, 501 of lower extremities, 199 of lung, 502 of mouth. 505 of neck. 504 tunic. PI7 superficial and deep, 498 oesophagus ..rbit. ",ii I pan pelvis, 199 Lymphatics of pharynx, 505 rectum, 500 renal, 471 of scalp, 503 of spleen. 501 of stomach. 501 supra-hyoid, 504 Lymphatic system, 490 of testicle, 501 of thoracic wall. 502 of tongue. 313 of uterus, 500 vessels of body, 496 superficial and deep, 498 M Macula acustica utricularis, 578 Mammary gland. 564 blood supply, 564 nerve supply. 567 Manubrium. 23G Malar bone. ."33 bone zygomatic process of, 534 bone muscles attached, 534 Male organs of generation. 564 Malpighian tuft, 469 pyramids, 469 of kidney, 468 Malleus bone, 574 Marginal gyrus, 346 Masseter muscle. 52m Mastoid foramen. 554 antrum, 574 cells. 57t', process, 517 Meatus auditorius internus, 553 Meat uses ' >i in »se, 551 Meckel's ganglion. 4(14 Mediastinum description of, 460 Mediastinal artery, 44s pleura. 256 Median nerve, 99-101 muscles supplied by, 101 Medullary portion of kidney, 468 Medulli spinal veins, 486 Medullary velum, 437 Medulla oblongata description of, 359 oblongata, 357 fibers of, 360 nucleus of, 360 oblongata surfaces of, 360 Medulla veins of, 488 Meibomian glands, 389 Meissner's plexus. 322 Membrane cochlea, 578 Membrana granulosa of ovary, 561 propria of ovum, 561 Membranous labyrinth of ear, Membrana sacciformis. 119 Membrana semi-circular canal, 578 tympani blood supply, 571 tympani nerve supply, 571 tympani, 571 INDEX. no;, Membrana tensa, 571 Membrane, defiinition of, 405 serous description of, 465 cutaneous description of, 465 mucous description of. 465 synovial description of, 465 Meningo-rachidian veins, 486 Meningeal artery. 293 Mesoblast, 331 Mesentery, The 466 Mesenteric artery, 321 superior and inferior, 326 plexus, 426 Metacarpal bones, 109 articulations of, 109 Metacarpal bones, nutrient artery of, 109 arteries, 92 Metatarsal arteries, 184 Metatarsus bones. 164 nutrient artery, 164 muscles attached, 164 Metatarso-phalangeal articulation, 206 Metencephalon, 341 Middle cerebral artery, 444 cervical ganglion. 422 commissure, 348 of brain, 348-437 cuneiform bone, 164 attachment of muscle^. 164 ear, 568-571 blood supply, 573 nerve supply, 573 hemorrhoidal artery, 172 mediastinum. 460 meningeal artery, 296 radio-ulnar articulation, 78 vesical artery, 173 Midriff, 234 Mitral valve. 242 Moderator band of heart. 242 Mons veneris, 562 Motor fibers sympathetic, 431 impulses indirect route. 435 direct route. 435 tracts of. 435 oculi nerve, 439 paralyses of, 390 oculi nerve, :;s9-368 Mouth, ducts of. 315 lymphatics of. 505 Middle constrictor muscle, 551 Muscular accessorius, 274 Musculo cutaneous muscles supplied by, 102 spiral muscles supplied by, 103 Multifidus spinse muscle, 276 Musculi pectinati, 2 10 Muscles of abdomen, 160 abductor hallucis, 1 58 minimi digiti, 158 minimi digiti, 1 1 3 accelerator urine, 192 addud or brevis, I hi longus. 140 maerous, 140 Muscle, adductor obliquus hallucis. 15s obliquus pollicis, 112 pollicis, 111 t ransA ei sue hallucis, 160 transversus pollicis, 112 anconeus, 87 :int itragicus, 570 aryetnoideus, -'.'._' arj teno-epiglottideus, J~>- of at hi-. 260 attachments of 24 of axis, Jo i asygos uvulae, 549 of hack. 27(1 bicep-. 5s- 1 Hi biventer cervicis, 27 1 brachialis anticus, 79 buccinator, 540 cervicalis ascendens, -'7 1 chondro-glossus, 550 of coccyx, 134 coccygeus, 491 coniplexu-. 274 i ipressor nasi, 539 urethras, 192 urethra. 403 coraco-brachudi-. 58 corrugator cut i- ani, 190 supercilii, cremastei . 46 1 crico-arytenoideus, 251 thyroid, 251 crureus, 138 deltoid, 13 depressor alse nasi, 539 anguli oris, 5 15 labii inferior].-, 54 1 dilator uares posterior, 5 10 digastric, 521 dorsal interossei, 160-1 14 ear, 570 erector clitoridis, 493 penis, 192 spinse, 272 of esophagus, :;i 7 ethmoid hone of. 526 extensor brevis digitorum, 157 pollicis, carpi radialis ho-, ioi 85 carpi radialis longioi . 85 coccygis, 278 communis digitoi um B5 iadicis, '.'l longus digitorum, 1 52 longus pollicis, 91 minimi digiti s 7 longus hallucis, h">i pollicis, m profundus digitorum sublimis din forced inspiratioi expiral ion frontal bone ol iifin in - 606 INDEX. Muscle, gemellus inferior, ill superior. 1 I I genio-hyoideus, .544 byo-glossus, S I I gluteus maximus, 1 1 1 medius, 1 1 1 niininms, 143 gracili ,,f band, L06 helicis major. 570 minor. 570 of hyoid hone. 550 hyo-glossus, 550 iliacus, 135 ilio-costalis, 273 Lnfracostals, 158 inferior lingualis, 551 of inferior maxillary bone, 543 oblique. 538 rectus, 530 infraspinatus, 55 internal cremasteric, 567 intercostal-. 158 pterygoid, 529 rectus, 531 inter spinales, 278 internal sphincter ani, 490 intertransversales, 278 ischio-rectal region, 490 lachrymal hone. 532 of larynx, 250 latissimus dorsi, 52 levatores cost arum, 459 levator ani. 4(H) aneuli oris, 539 anptili scapulas, 54 lahii inferioris, 545 lahii superioris alseque nasi. 539 proprius, 540-534 palate, 523 palpebra 529 longissimus dorsi, 27 1 lumbricales band, foot. 162 malar hone. 534 massetei . 520 middle const i ictoi . 551 multifidus spina-. 27(i mylo-hj oid, 5 1 1 of nasal hone, .",:',_' Dumber of. _':; obliquus aurem, 570 oapitus superior, 278 inferior, 280 externus, 160 internus, hil obi urator externus, 1 1 1 internus, i hi occipital hone- ..• occipito-frontalis, 51 '■'■ omo-hyoid, 59 opponens minimi digiti, 1 13 pollicis, 1 12 orbicularis oris, 540 Muscle, orbicularis palpebrarum, 508 .if orbit, 372-370-529 palate bone. 547 parietal bone 51(1 palmar interossei, 1 14 palmaris brevis, 1 13 longus, 81 pectineus. 13s pectoralis major. 41 minor, 50 of perineum, male, 491 female. 192 peroneus brevis, 157 longus. 156 tertius. 153 of pharynx, 314 plantari.-. 154 plantar inten i.-ci. 160 platysma myoides, 545 popliteus, 154 principles of, 24 pronator radii teres, 79 quadrat us, 84 psoas magnus. 134 parvus, 134 of pubis. 129 pyramidalis, 463 pyriformis. 143 quadrat us femoris, 144 lumhorum. 4f>4 rectus capitus amicus major, 514 minor, 514 posticus major, 278 minor, 278 lateralis, 514 abdominus, 463 femoris, 136 of rectum, 324 ret rahens aurem, 522 rhomboideus minor, 55 rot at ores spinas, 276 of sacrum. 133 serratus magnus, 54 posticus inferior, 272 superior, 271 sartorius, 135 of scapulae, 50 semimembranosus, 1 17 semitendinosus, 14(> semispinalis dorsi, 276 colli, 276 stylo-pharyngeus, 522 of -oft palate, 316 soleus, 153 splenius capitis and colli. 272 sphenoid hone, 528 s| ihincter vagina, 493 spinalis dorsi, i»74 stapedius, 523 sterno-cleido-ma&toid, 4 hyoid. 40 thyroid, 41 stylo-glossus, 522 hyoid, 522 INDIA. 60* Muscle, subcrureus, 138 subclavius. 4_' subanconeus. 79 supinator brevis, 88 longus, 84 subscapularis, 56 superior constrictor. .515 <>f superior maxillary bone, 538 oblique, 530 rectus. 530 supraspinales, 276 supraspin&tus, 55 of temporal bone. 520 temporal. 520-508 tensor vaginae femoris, 135 teres major. 56 minor, 56 tensor tarsi. 532 tympani, 523 palati. 523 of thorax, 457 thyro-arytenoideus, 252 epiglottideus, 252 thyro-hyoid, 550 tibialis anticus. 152 posticus, 156 of tongue. 311 trachelo-mastoid. 274 tragicu.-. 570 triceps. 50 triangularis sterni. 458 transversalis colli, -74 transversalis, 462 transversus perinaei, 491-492 aurem. 570 trapezius. 45 vastus externus. 137 internus, 137 zygomaticus major. 535 minor. 535 extensor ossis metacarpi pollicis, 88 proprius ballucis, L52 external intercosttl 457 rectus, 531 sphincter ani, 490 pterygoid, 529 of eye. 529 of fern ui-. l".i I flexor accessorius, 161 carpi radialis, .Si ulnaris, 81 brevi- minimi digiti. 1 13 (ligitorum. 158 nallucis, 162 pollicis, 1 12 longus digitorum, 156 and joint sensation, 133 Musculo phrenic artery, 1 19 Mucous membrane, description of. 165 Myelon, 341 Mylo-hj oid muscle, 544 Myology, definition of. 17 Myopia. 374 N NasaJ arterj bone, 531 muscles attached cresl -pin-. 5:;s-:,ii7 fossae, 552 ner\ 1 notch. 507 -lit. 52.-, meatuses of, 551 Navicular bone, 163 attachment of muscles, 163 Neck. Lymphatics of, 5111 lymph node- of, 505 Nelaton's line. 196 Nervi-molle-. l.'l Nerve abducent . 392 anterior crural, 210 interosseus, KM tibial, 218 atlas of, 264 axis of, 264 auditory. 579 Vuerbach's plexus, 322 auriculo-temporal, 402 buccal. 402 centers definition ot. 27 cervical, 3' plexus, 304 circumflex, 99 coccygeal plexus, 218 communicans hypoglossi, 306 cranial. 364 origin of, 364 cutaneous, 214 dental, 398 desci ipl ion of, 26 roots ol 27 dorsal, 35 external cutaneous, 21 ■ boracic, 98 plantar. 216 to lac- 398 facial. 4(17 genii o-crural, -'1 8 glosso-pharyngeal, I in it auricular sciatic, 215 superficial petrosal mi to hip-joinl . 212 ilio-hypogastric ilio-ihguinal, 278 inferior dental. 102 gluteal, 21 I maxillai j . 399 internal cutaneous, K 6 1 tioracic, '. 9 plantai 216 to kidney, I7n labial of Lancisi lame, deep pel rosal. \0 1 608 INDEX. Nerve, lesser internal cutaneous, 106 lingual, 402-411 Song sii' scapular. 99 lumbar L'08 plexus, 208 nie.lian, 99-101 Meissner's plexus, 322 motor definition of, 27 motor oculi, 389-368 musculo-spinal, 103 nasal, 390 obturator. L'12 obturator accessory, 212 ophthalmic, 394 optic, 366 patellar plexus, 210 palpebral, 398 perforating cutaneous, 214 peritoneum to, 467 peroneal, 181-217 pharyngeal, 410 plexus, 315 phrenic, 306 post-auricular, 408 posterior interosseous, 105 thoracic, 98 tibial, 216 popliteal, 180 principles of, 26 pudendal, 214 pudic, 214 pneumogastric, 1 1 1 radial, 105 recurrent laryngeal, 414 Sacro-iliac articulation, sacral plexus, 212 sacro-vertebra! articulation, 280 sensory definition of, 27 small occipital, 305-301 sciatic, 214 splanchnics, 423 spinal accessory, 416 subsartorial plexus, 212 subscapular, 99 suboccipital. 298-300 suprascapular. "IN superior gluteal, 213 maxillary. 396 sympathetic, 418 temporal deep, 400 tongue of, 31 1 tonsillar. Ill t r:in-\ erse cen ical, -* ; < * * v Nerve, trochlear, 368 391 trifacial, :'.!•_' tubular prolongations of, 332 twelfth cranial. 117 t \ mpanic, HO to ureter. 471 visceral blanch.'- of sacral plexus, 213 Wrisberg, km; Nrr\ on- system, 3 \0 Neuroglia, 331 Neuron, 341 Neuroretinitis, 373 Neurology, definition of, 17 Neuron system, 433 Nodes internal mammary, 562 lymphatic, Ninth nerve, 410 Neucleus ambiguus, 410 emboliformis, 361 fastigii, 362 globosiis, 362 Obex of brain, 443 Obliquus aurem muscle, 570 capitus superior muscle, 278 inferior muscle, 280 externus muscle, 460 internus muscle, 461 Obliterated processes vaginalis, 567 Obturator accessory nerve, 212 artery, 172 externus muscle, 144 foramen, 131 fascia, 495 internus muscle, 143 nerve, 212 Occipital artery, 293 Occipito-atlantal ligaments, 260-26] Occipital bone, 511 muscle of, 513 ossification of, 513 basilar process of, 512 lobe, 344 sinus, 489 triangle, 282 vein, 487-481 Occipito-frontalis muscle, 513 Odontoid ligaments, 264 (Esophageal artery, 449-450 (Esophagus lymphatics of, 503 nerves of, 416 Olecranon process, 75 Olfactory bulb, 347-365 foramina, 553 nerve, 439 tracts, 365-437 Olfactory tracts arachnoid of, 366 dura mater of, 366 pia mater of, 366 roots of, 365 Olivary nucleus of pons, 363 Omo-hyoid muscle, 59 Ophthalmic artery, 368-444-383 branches of, 383 ganglion, 394-403 nerve, 394 Optic commissure. 357-366-437 foramen , 368-553-52S nerve, 366-439 lesions of, 367 radiations, 367 thalamus, 347 thalami, 352 [NDEX. 609 Optic tracts, 367 coverings of, 368 Opponens minimi digiti muscle, 113 pollicis muscle. 112 Orbicularis oris muscle. 540 palpebrarum muscle, 508 Orbit, description of, 368 angles of, 370 bones of, 368 boundaries of, 370 foramina of, 369 floor of, 369 lymphatics of, 504 muscles of, 372-376 Organ of corti, 577 generation male, 564 hearing, 568 Os calis bone, 162 Os calcis. attachment of muscles, 162 Osmatic animals, 365 Osteology, definition of, 17 Otic ganglion, 405 Ovaries, 560 Ovary, blood supply of, 561 nerve supply of, 561 corpus luteum of, 561 coats of, 561 Graafian follicles of, .561 ligaments of, 560 location of, 562 normal position of, 561 stroma of. .~>t;i Ovarian arteries. 457 veins. 190 Ovum, description of. 561 Palate bone, 538-547 borders of, 548 surfaces of, 548 muscles attached, 549 nutrient artery, 549 articulation of, 549 Palmaris brevis muscle, 113 Palmar fascia, 116 Palmar interossci arteries, HI muscles, 1 14 Palmaris longus muscles, 81 Palmar recurrent arteries, 95 Palpebral nerve, 398 Pampiniform plexus, 190 Pancreas 326 blood supply of, 326 nerve supply of, 326 lymphatic- of, 326 Pancreatica' parvae arterj . 153 magna artery, 453 Papillae of tongue, 31 1 Papillitis. 373 Paradidymis, 568 Parenchymatous goitre, 246 Pa>ietal bone, articulation of, 510 description of, olid gyri. 346 lobe. :; 1 1 bone muscle of, Mo Parietal bone, nutrienl artery of, 500 ossification, 510 to-occipital fissun Paroophoroi Parosmia, 365 Patellar plexus, 210 ah- major muscle, I 1 minor muscle, II Pectineus muscle, I :^ Peduncles of cerebellum, 362 brain. .;:. I 258 Pelvis. 131 dimensions of. i:;i Pelvic fascia, 195 Pelvis female. L32 Perforating cutaneous nerve, 211 Peni-. bl I supply, 566 dartos 565 a, 565 corpus spongiosum, 565 Penis nerve supplj . 566 Perineum central tendon of, 195 fascia of, 19 1 muscles of female, 47 description of, 165 fund ions of, 166 . 166 .... i 166 ligaments formed by, 466 nerve supplj of, Pi? parietal laj ei i ' . 165 -t i net urea <-<>\ ered bj \ isceral laj ei ol . 165 Pel i on- ganglion, no porl ion tempi n al bone, 517 Peyer's patches, 320 Phalanges bones attachmenl of muaclaa 164 nut rient arterj . 164 Pharynx, 313 boundari f, 313 openings in I 'hi i ynx, blood supply, .'(15 in i -, e supp lymphat ii muscles of. 31 I 610 INDEX. Pharyngeal nerve, 410 nerve of vagus, II 1 plexus, •';! i Pharygneal tonsil, 313 Phrenic artery of aorta, 452 artery, I L8 hernia, 174 nerve, 306 plexus, 125 vein-. 190 l'ia mater of brain, 34 1 of cord, 333 Pillar- of iri-. 380 Pineal gland, 353 Pinna "f ear, 569 Pirogoff's amputation, 194 Placenta, 3 l Plantar digital artery, 184 Plantar fascia, 223 Plate, 161 Plantaris muscle, 154 interossei muscle, Hiit l'lai ysma mj oides muscle, 5 15 Plexus bi achial, 3 i cei \ Leal, 35 coccygeal, 35 definition of, •'■! -anal. 35 Pleura. 256 nerve supply of, 256 blood supply of, 256 Pneumogastric accessorj part. 412 connect tons of, 111 di-t ribul ion of, 1 1 I left . Ill nerve. 111-41 1 cardiac branches, 1 16 pulmonary branches, 1 L6 right, 412 Pocularis sinus, 17:'. Pons, 362 construction of, 363 cru;- cerebri, 363 nei \ e- of, 363 varolii, 357-362-437 veins of, 188 Popliteal artery, 17(1-180 branches of, 1 M Popliteus muscle, 154 space, 180 vein, L92-180 Portal system, 326- is I vein, 324 is:, mo Po tei i' 'i annulai Ligament . 1 16 am iculai nei v e, 408 vein, 181 cai pal art< cardiac \ ein, is.'i cerebral artery, 1 l*> circumflex arterj . 65 communicat ing arterj . commissure, 348 commissure of brain, -;is 137 ci indj I' »id foramen, 55 I Posterior interosseous nerve, 105 ethmoidal artery, 384 ethmoidal foramen, 553 interosseous artery, 95 Posterior external jugular vein, 481 ligament, 62 mediastinum, 460 mediastinal arteries, 450 nodes, 502 nerve root, 333 perforating arteries, 186 perforated space of brain, 441 scapula artery, 1 10 spinal arteries. ■ Y-'<7 tibial artery, 180-185 relation of, 186 thoracic nerve, 98 tibial nerve, 216 vein. MIL' recurrent artery, 782 ulna reeurre. I artel \ . 95 Pouch of Douglas, 558 Poupart 's ligament . 477 Preputium clitoridis, 563 Presbyopia, 375 Prevertebral plexus of symphatic, 123 Princeps pollicis artery, 93 Processus-e-cerebello-ad-te-te-. 354-437 cochleariformis, 520 Profunda artery, 176-180 femora] artery branches of. 178 artery perforating branches of. 180 Pronator quadratus muscle. 84 radii teres muscle, 79 Prosencephalon, 341 Prostate gland. 5IJ4-474 Prostat ie sinus, 473 Pseudocele, 358 Psoas magnus muscle, 134 parvus muscle. 134 Pterygoid artery, 297 processes, 528 Pterygo-maxillary fissure, 555 palatine artery, 298 Pubic artery, 176 bone. 128-127 muscles of, 129 attached. 128 lie! \ e. 214 Pudendal nerve, 214 Pulmonary artery, 284 nerves, 110 Pulsating goitre. 2 16 Pulvinar, 352 l'upillo-dilator fibers, 431 Pyloric, 318 artery, 153 glands, 318 Pyramids of I errein, 468 Pyramidalis muscle, 463 Pyramidal tracts. 334 Idier- of, 435 Pyriformis muscle, 1 13 INDEX, 611 Q Quadratus femoris muscle. 144 Quadrate gyrus, 346 Quadratus lumborum muscle, 164 Quadrilateral space, 77 Question review. 120 lower extremities. 224 Right innominate coronary vein. Rivinian foramen, .">7 1 duel Rhinencephaion, 34J Rhomboideus minor mu- : lungs, 257 res spins i Roux's amputation, 194 Ruga of stomach Rule oi Radial nerve, 10.5 artery relations of, 95 branches of, 92 muscular branches of, 92-95 recurrent artery, 92 region forearm. <>9 Radialis indicis artery. 94 Radius description of, 72 borders of, 72 muscles attached. 75 perimeter of, 73 Radio-ulnar articulation. 79 blood supply of, 79 nerve supply of, 79 Ramus of ischium. 130 Ranine artery, 291 Receptaculum chyli, 497 Recto-vesical fascia, 495 Rectus capitis posticus major muscle, 278 minor muscle. 27s anticu- major muscle, 514 minor muscle, 514 lateralis muscle. 514 abdominis muscle, 163 femoris muscle, 136 Rectum, 320 description of, 324 muscles of, 324 lymphatic- of, 500 Recurrent laryngeal nerve. 414 Keflex impulses. 437 Refracting media of eye, 378 Renal arteries, 456 lymphatic-. 17! plexus, 425 veins, 190 Residua] air, 258 e air, 258 Restiform body, 360 liber- of, 364 Respiratory center, 359 Reticula of spinal cord, 333 Retina, 376 description of, 378 layers "i Retinal hyperesthesia, 374 Retrobulbar neuritis, 37.'') Retrahens aurem muscle 322 Review iiuesiionb, lowei extremity, 22 1 upper exl remity, 120 Rib, firsl and second, 270 descripti m of, 268 Right Innominate vein, 182 Saccule • if i Sacral groove, 132 sympathetii plexus, 213 plexus vi-ceral branch. Sacro-vertebral articulation, .Sacrum. 132 base of, 132 articulation. 133 ate, 133 muscles attached, 133 ossification of, 133 Salivary center, glands, parotid, 579 submaxillary. ,~>su sublingual, 580 Saphenous opening, 220 veins. 192 Sartorius muscles, 135 Scapula description of. 15 articulation of. Is ligament- o Is muscles of, 50 Scalp lympha Scarpa'- foramina, 538 Scarpa'- triangle, 176 Schneiderian membrane Sciatic artery, 17 1 Sclerotic coat of . \ . 376 description of Scrotum. 568 Second ner\ . Segment- of cord Semicircular canal of , Semilunar fibro-cartilages, 200 valves, 241 Semimembranosus muscle, l 17 endinosis muscle, i 16 Semi-pinali- colli muscll dor-i muscle, 276 Sen- iry, council impulses, routi Septum lucidun -. p..-l icu- SU| i.s muscle* af Se\ enl h 612 INDEX. Sharpnell's membrane, 571 Shoulder join! . 18 ligaments 1)1 1 supply of, 18 net \ e supply nf, 48 Small meningeal arterj . 297 occipital nerve, 301-305 sciatic nen e, 21 I Smell, center of, 36 I diseases of, 365 Sinus, definition of, 17 nous, 189 circular, 189 Sinuses of dura mater, 488 inferior longitudinal, 489 petrosal 490 !. 189 Sinus of larj ax, 250 of Morgagni, 31 5 occipital, 489 rhomboidalis, 33 I straight, 489 -upei ii ii lmiirit udinal, 4SX petrosal, 189 torcular Herophili, 489 transverse, 490 valsalva of, 242 Sigmoid artery, 455 gyrus, 346 flexure, 320 Sixth nerve, 392 Skej '- amputation, 19 I Skin of back, 280 Skull, base foramina of, 552 Sofl palate, 315 muscles of, 3] 6 Solar plexus, I- I function of. 131 Solitary gland, 321 Soleus muscle, L53 Sounds of hear;. 246 matic artery. 576-456 cord, 566 plexus, 125 veins, 576-190 Spheno-maxillary artery, 297 fossa, 555 B lire 555 Spheno palat tne artery, 298 branches of, 297 Sphenoidal fissure, 553 528 Sphenoid bone, 526 nutrient ai terj of, 529 foi amina i if, 527 t i — «ii < s of, 528 lessei wings of, 528 muscles ai tached, 528 orbital surface of, 527 pterygoid processes of, 528 tin lunate, 1 bom wings of, 527 Sphincter vagina muscle, 193 Spina bifida Spina] accessor} nei ve, H 6-441 Spinal canal, 133 column fractures of, 334 veins of, 486 Spinal cord, 330 diseases of, 334 ascending fibers of, 335 descending fibers, 335 blood supply, 336 enlargements of, 330 fissures of, 335 gray matter of, 336 membranes of, 332 Begments of, 337 veins of, 486 white matter of, 330 Spinal nerve first, 298 Spinalis dorsi muscle, 274 Spinous process of vertebra;, 258 Spiral canal of car. 578 Splanchnology definition of, 17 Splanchnic nerve greater, 423 lesser, 123 Spleen, 248 relations of, 248 blood supply of, 248 nerve supply of, 248 dimensions of, 24S lymphatics of, 501 Splenic artery, 327-453 plexus, 125 Splenic vein, 484 Splenius capiti: muscle, 272 colli muscle, 272 Stapes bone, 574 Stapedius muscle. 523 Steno s duct . 315 Stenson foramina, 538 Stephanion, 555 Sterno-pericardial, 238 clavicular articulation, 38 cleido-mastoid muscle, 40 hyoid muscle. 4 thyroid muscie, 11 sternal arteries, 448 Sternum, 236 muscles attached, 237 Stomach, 318 blood supply of, 318 nerve supply of, 318 muscles of, 318 relations of, 319 glands of, 318 lymphatics of, 501 Stroma of ovary, 561 Straight sinus, 189 Strangulated hernia, 175 Structures of heart, 243 Styloglossus muscle, 51':' hyoid muscle, 522 pharyngeus muscle, 522 Styloid process, 519 Subanconeus muscle, 79 Subarachnoid spaces, 335 Subastragaloid amputation, 194 [NDEX. 613 Subscapular nerve-. 99 Subclavian artery, 4-1.5 relations of 44t>- 1 17 vein, 482 triangle, 282 Subcrureus muscle, 138 Subdural space. 332 Subflava ligament, 266 Submaxillary ganglion, 405 Submaxillary triangle, 282 Submental artery. 292 Suboccipital nerve, 300-298 triangle. 282 Subclaviu> muscle, 12 Subscapular^ muscle, 56 Subscapular artery. 65 Subsartorial plexus, 212 Substantia gelatinosa rolandi, 330 Sulci. 342-343 Suprahyoid lymphatics. 504 Suprarenal artery. 456 capsules. 248 blood supply of, 248 nerve supply of. 249 vein. 190 Suspensory ligament of ovary, 561 Superficiali< volae artery. 92 Suprascapular artery, 449 nerve, 98 Supraorbital artery, 384 nerve. 394 notch. 372-506 vein, 487-480 Suprarenal plexus. Supratrochlear nerve 394 Superficial circumflex iliac artery ■ 178 Superficial cervical artery. 449 descending artery. 288 external pudic artery, 178 epigastric artery. 178 femoral artery 176 lymphatic vessels. 498 palmar arch. 96 temporal artery. 29 1 Superior maxillary nerve, 396 cervical ganglion. 421 branches of, 421 constrictor muscle, 515 external angle of orbit, 370 epigastric artery, 449 fibular artery, 182 gluteal nerve, 213 hemorrhoidal artery, 456 intercostal artery, 449 laryngeal artery, 288 longitudinal sinus, 488 maxillary bone, 535 areolar pr< » antrum of Highmore, 537 lachrymal groove, 537 surfaces of, 537 palate proce-> of, 53S muscles attached, 538 mediastinum, 460 mesentery artery, 454 nteric vein, 484 plexus oblique muscle. perforating arte petrosal sinus, 189 profunda artery, 66 radio ulnar articulation, 7^ rectus in 1 . thoracic artery, 62 thyroid artery, 288 vena vesica] artery 17_' Supinator brevis muscle, sv longus mu- Supraspinous ligament - Supraspinatus muscle, 55 Supraspinales muscle, - Sura' arteries, 182 Suspensory Ligament ol e\e 378 Sylvian fis-ure. 343 Syme amputate ". '94 -'ympathetic neM ll v acceleratore to lieart. 431 cervical region, 420 dorsal, 420 lumbar, 420 sacral, 120 development of, 12 gross anatomy of, 431 lumbar, 423 lumbar, 423 sacral, 423 motor libers to eye. 143 thoracic ganglia, !-'_' Synarthrosis divisions of, 25 Syndesmology definition of, 17 Synovia] membrane description of, 405 Systole of heart. 245 Taenia semicircularis of brain, 350-437 Bemicircularis, 356-352 Talepes description of. l! 1 -' calcaueous, 194 arcuatus. 194 valgus, I'M varus, 194 equinus, 194 plantus, 194 Tarsal plate- of li Tarsus, metatarsus joints, 206 joints, ligament - of, 20 1 reeth, descirption of, 309 310 nerves of, :>b> Tegmenl um of pon najor muscli Tela choroide inferior of brain, 1 1 1 ro-maxillarj vein, I s " sphenoidal fissure, 3 1 1 lobe, 344 614 INDEX. Temporal artery deep, 297 bone, 51b articulation of, 520 auditory meatus of, 517 inferior surface, 519 muscles of, 520 mastoid process of, 511 nutrient artery of, 520 processus cochleariformis, 520 process of. 519 petrous portion, 517 zygomatic process, 516 Temporal gyri, fossa, 554 muscle, 520-508 nerves ileep, 400 ridges, 507 veins. 4S7-4S0 Tendino-trochanteric band, 196 Tendon, definition of. 17 Tenth nerve. 41 1 Tentorium cerebelli, 360 Tensor palati muscle, 523 tarsi muscle, 532 tympani muscle, 523 vagina- fenioris muscle, 135 Testicle-. 567 covering; of, 567 lobules of, 568 lymphatics of. 501 Thalamencephalon. 341 The mesentery, 466 Thigh superficial fascia, 218 Third nerve, 390 ventricle, 358 boundaries of, 437 Thoracic aorta. 451 branches of. 450 duct, 496 coats of, 497 relation of, 497 ganglia sympathetic, 422 wall lymphatic of, 512 Throat, 316 Thorax, description of, 232 muscles of, 457 openings of, 232 Thorax structures passing through superior open- ing, 232 Thymic vessels. 503 Thymus gland, 248 blood supply, 248 nerve supply, 248 Thyroid gland, 246 diseases of, 246 blood supply of. _'17 nerve supply of, 247 Thyroid axis. 449 Thyro-arytenoid ligament, 250 arytenoideus muscle, 252 epiglottideus muscle, 252 hyoid muscle, 550 Tibia, bone, 166 nutrient artery, 168 Tibia, attachment of muscles, 168 Tibialis anticus muscle, 152 posticus muscle, 156 Tibio-fibular joint superior. 202 Tidal air of lungs, 258 Tongue nerves of. 311 Tongue, 311 muscles of. 311 papilla?, 311 lymph vessels of, 313 blood supply of, 313 Tonsils description of, 315 Tonsillar artery, 291 nerve, 411 Torcular Herophili, 489 Trachea. 254 blood supply of. 254 nerve supply of, 254 Tracheal artery, 449 Tracts of cord. 433 Tragicus muscle, 570 Tragus of ear 570 Trachelo-mastoid muscle, 274 Tranquil inspiration, 236 Trapezius muscle. 45 Transversalis colli artery. 449 Transversalis colli muscle. 274 muscle, 462 Transversus aurem muscle. 570 perimei muscle, 491-492 Transverse aorta, 284 commissure of brain, 437-339 cervical nerve, 306 fissure of brain, 343 ligament, 196 of atlas. 262 process of vertebra?. 258 -inus, 490 Triangles of neck, 280 Triangularis sterni muscle, 458 Triangular ligament. 494-477 Triceps muscle, 50 Tricuspid valve of heart. 241 Trigonum hypoglossi of brain. 443 Trifacial nerve, 392-439 Trochlear nerve. 391-439-368 Trophic centers, 334 Tuber annulare, 347 cinereum of brain, 441 Tubercle of Lower, 240 Tubercula quadrigemina, 347 Tuberosity of rib, 268 Tubes of Ferrein, 470 Turbinated bones sphenoidal, 528 Turbinated processes of ethmoid bone, 525 Tubo-ovarian, 561 Tubuli seminiferi. 568 Tuberculum acusticum of brain, 443 Tunica fibrosa of ovary. 561 propria of ovary, 561 vaginalis, 567 Twelfth cranial nerve, 417 Tympanic artery. 295 membrane, 571 INDEX. lil/i Tympanic nerve, 410 walls of, 573 u Ulnar artery, 95 branches of, 95 relations of, 96 nerve muscles supplied by, 102 Ulna, description of, 75 anterior posterior borders of, 76 muscles of, 77 nutrient artery of, 77 olecranon process of, 75 Umbilical arteries, 472 hernia, 475 coverings of, 478 regions, 309 veins, 472 Umbo of tympani, 571 Uncinate gyrus, 346 Urachus, 471 Ureter description of, 471 blood supply of, 471 nerve supply of. 471 Urethra, coats of, 473 description of, 472 divisions of, 473 female, 474 Urinary system organs of, 469 Uriniferous tubules, 468 Uterine artery, 174 Uterus, 557 dimensions of, 558 fundus of, 558 ligaments of, 558-559 os, 558 blood supply of, 559 coats of, 559 nerve supply of, 559 lymphatics of, 500 Utricle of ear, 577 Uvula vesica, 472 Vagina, 556 blood supply of 557 Vaginal coats of, 557 Vagus nerve, 411 Vallecula, 361 Valvular conniventes, 321 Valves of heart, 241 location, 246 of Vieussens of brain, 441 Vasa aberrant ia, 69 l.n\ ia, 453 efferentia, 568 intestini tenuis, 454 motor center, 359 fibers to head, 431 Vas aberrans, 567 deferans, 566 Vastus extemus muscle, 137 interim- muscle, 137 Velum interpositum, :;.">l Vena azygos ma joi . 183 minor, 1M tertius, 184 Venae basis \ ertebrarun Vena cava inferior, 188 superior, 483 Venae comil es leg, 192 Galeni, i^ Thebesii, 245 l«6 Ventricle of brain, 3 10 descripti f, 357 number of, 358 Ventricularis terminales Vermiform appendix, ;'._'_' Vermis of cerebellum, 355 Vertebra?, description of, 258 cervical, _'.">s coccygeal, 258 dorsal, 258 lumbar, 258 sacral, 258 peculiarities of, 259 Vertebral artery. 447 column hi 1 supply nerve supply of, 339 ligament- of, 266 vein. 481 Vesiculse seminales 567 Vessels i if liver, 190 Vestibule of ear, 577 Vestigial fold of Marshall, 238 Veins of abdomen, 186 angular, 480 anterior cardiac, 486 jugular, 181 tibial, 192 axillary. 118-482 basilar, 188 of broad Ligament , 190 bronchial. Is I cardiac, 2 1 1 cerebellar, 488 cerebral, 187 Venae corporis striati, 188 choroidea, 188 coat- of, 30 coronary sinus, 186 cystic, 185 Veins deep. IIS cervical, 182 description of, 30 desci n" i"" of diploe, 187 dorsi spinal, 186 of dura mater, 180 emissarj 187 in t ii ioi head and external iliac, 186 . Is 1 facial, 160 femoral, frontal 187 180 616 INDEX. Veins, gastric, 484 great cardiac, 485 of heart, 485 hepatic, 190 iliac, 188 inferior cerebral, 487 mesenteric. In 1 innominate, 482-483 internal jugular, 481 iliac, 188 mn.Tri1lB.ry, 480 left cardiac, 485 lower extremity, 192 lumbar, 188 of medulla, 488 medulli spinal, 486 meningo rachidian, lsc> occipital, 487-481 ovarian, 190 phrenic, 190 of pun.-, 488 popliteal, 180-192 portal, 324-190-485 posterior auricular, 481 cardiac, 485 tibial, 192 external jugular, 481 pulmonary, 30 renal, 190 right coronary, 486 saphenous, 192 subclavian, 482 spermatic, 190-567 of spinal cord, 486 column, 486 -picnic, 484 superior mesenteric, 484 superficial, 117 supraorbital, 487-480 suprarenal, 190 systemic, 30 temporo-maxillary, 480 temporal, 480-487 umbilical, 472-34 Veins, valves of, 32 vena cava inferior, 34 azygos major, 483 minor, 484 vena cava superior, 483 vena' corporis striati. INN choroidea, 488 Veins, vense basis vertebrarum, 48' Galeni, 488 Thebesii, 486 vertebral, 481 Villi, 320 Visceral branches sacral plexus, 21; Viscus description of, 309 Vital capacity of lungs, 258 Vitreous humor, 376 Vicq'cl azyr fibers of, 349 Vocal cords, 250 Vomer bone, 54(5 muscle attached, 547 nutrient artery, 547 w Wharton's duct, 315 White line of perineum, 495 rami communicant es, 429-423 Wirsung's duct, 326 Wolffian body, 564 Worm of cerebellum, 361 Wrist-joint, 78 arteries of, 92 joint ligaments of, 78 nerve supply of, 78 synovial membrane of, 119 Xiphoid appendix, 237 Y-ligament, 194 Yellow cartilage, 250 eastic tissue, 26-561 spot of retina, 387 (macula lutea), Yellow spot of ovary, 561 (corpus luteum), Zygomatic fossa, 555 Zygmaticus major muscle, 535 minor muscle, 535 Zygomatic process temporal bone, 516 proce.-s, 534 University of California SOUTHERN REGIONAL LIBRARY FACILITY 405 Hilgard Avenue, Los Angeles, CA 90024-1388 Return this material to the library from which it was borrowed. 2 -at - -d PRINTED IN U.S. CAT NO 24 161 / Lau ghlin, William R Anatomy in a nutshell. QSU L3T^a 1905 Laugl An ilin, William R atomy in a nutshell. QSU L3T^a 1905 MEDICAL SCIENCES LIBRARY UNIVERSITY OF CALIFORNIA, IRVINE IRVINE, CALIFORNIA 92664 WNTIt M U • A. jijjjjljj jH; tWfiliiiffltiu' iiUliHUtl'lrfl iiiiiiiii mmv. \ , i'i'.' ' '■ > > i'i \-t !>j-l'i.i-^f* Jill ( , - - i j i ; * \ H !|| -i-'ii'HUslvmilf ''i'i'IiI'mhIi i *> kr»ii fi ^ticitfiitfirtti