iil.öt, Nin
OFTHE
Kmtltottrrn
EYANSTON, ILL.
^ __£>íí
EIGHTH THOUSAND.
ESSENTIALS OF ANATOMY
and
MANUAL or PRACTICAL DISSECTION.
TOGETHER WITH THE
ANATOMY OF THE VISCERA.
PREPARED ESPECIALLY FOB
STUDENTS OF MEDICINE.
by
CHARLES B. JÍANCREDE, M.D.,
PEOFESSOR OF SDROERY AND OF CUNIOAL BDRQERT IN THE ÜNIVEESITT OF MICHIGAN, ANN
ARBOR; CORRESPONDING MEMBER OF THE ROYAL ACADEMY OF MEDICINE, ROME,
ITALY; LATE SENIOR SURGEON TO EPISCOPAL HOSPITAL; LATE SURGEON
TO JEFFERSON MEDICAL COLLEGE HOSPITAL; FORMERLY LEC¬
TURER ON OSTEOLOOT, ETC., IN MEDICAL DEPARTMENT,
UNIVERSITY OF PENNSYLVANIA; LATE PROFESSOR
OF GENERAL AND OBTHOPiEDIC SURGERY
IN PHILADELPHIA POLYCLINIC, ETC.
THIRD EDITION, EEVISED AND ENLARGED.
BASED UPON THE LAST EDITION OF GRA Y'S ANA TOMY.
30 Handsome Full-Page Lithographic Plates, in Colors,
and 180 Fine Woodcuts.
PHILADELPHIA:
W. B. SAUNDERS,
913 Walnut Street.
London : Henry Renshaw. Melbourne : George Robertson & Co.
1890.
Entered according to Act of Congress in the year 1888, by
W. B. SAUNDERS,
In the OfBce of the Librarian of Congress, at Washington,
COPYRIGHTED, 1889, 1890.
ioS-f
S-,
PREFACE.
The author has endeavored in this little book to embody
only those facts which have appeared to him to he really the
" essentials of anatomy not that he considers it likely that
the student will master every minute detail therein contained,
hut he believes that the knowledge gained by a study of this
work will enable the future practitioner, during the remainder
of his professional life, to recall such general impressions as
will render intelligible current medical literature, or even the
more elaborate monographs, and will at once suggest where to
consult his anatomical text-books for such terms or facts as
may have become indistinct through lapse of time.
While this book cannot replace the larger anatomical works,
sufficient descriptive matter has been introduced to enable the
student to refresh his memory of the more numerous facts
learnt in the lecture and dissecting room, or from his " Gray"
or other text-book, differing in this respect from most of the
works of its class, which are little more than a list of names,
without any distinctive facts connected with them to aid the
student in the difficult task of acquiring a knowledge of a
branch of medical study almost solely dependent upon the
unassisted powers of the memory.
Conciseness, rather than elegance of diction, has been the aim,
so that all words such as the articles " a," " an," " the," have
been omitted, except where absolutely necessary.
Recognizing that a work of this kind should, as far as pos¬
sible, conform to that text-book most commonly used, the last
(v)
vi
PREFACE.
edition of Gray's Anatomy has been chosen as the chief
authority, although free use has been made of the works of
Quain, Leidy, Bock, Allen, Morris On the Joints, Starr On
Diseases of Children (dentition). Tomes Dental Anatomy,
Potter, Frey, Holden, Politzer, H. Thompson, Astley Cooper
On the Breast, and original work of one of the author's former
students.
The author would here acknowledge his obligations and
return his thanks to Prof. Joseph Leidy, of the University of
Pennsylvania, for the kind permission to reproduce numer¬
ous cuts from the first edition of his Anatomy, and to Dr.
F. M. Varrell for much valuable assistance in the correction
of proof.
Charles B. Nancrehe.
Philadelphia, September, 1888.
CONTENTS.
PAGE
Introduction . . 17
Bones of the head , . . .23
The frontal bone 23
Parietal bones 25
Occipital bone 27
The sphenoid 30
The temporal bones . 34
Ethmoid bone . 38
Nasal bones 40
The superior maxillary bones 40
Lachrymal bones 44
Malar bones 44
The palate bones 45
The inferior turbinated bones ...... 47
Vomer 48
The inferior maxillary bone 49
The sutures and fontanelles 51
The cerebral fossae . . 53
The orbital cavities 55
The nasal fossae 58
Bones of the trunk 61
The vertebral column 61
The thorax 64
Hyoid bone 65
The sternum. . 65
Ribs... 66
The pelvic bones 68
The pelvis 73
Bones of the upper extremity 74
(vii)
viii
CONTENTS
The arm ....
The forearm
The hand....
Lower extremity
The thigh
The patella
The leg
The foot ....
The articulations .
Muscles and fasciae .
Muscles of the head
Muscles of the neck
Palatal region .
Vertebral region
Muscles of the back
Muscles of the abdomen .
Muscles of tborax .
Muscles of the forearm .
Fasciae of the hand .
Muscles of the hand
Muscles of lower extremity
Muscles of the leg .
Fasciae of foot.
Muscles of the foot.
Vascular system
The arteries
The veins ....
The lymphatics
Nervous system
The spinal cord
The cranial nerves .
The spinal nerves
Dorsal nerves .
The sympathetic nerve
Visceral anatomy .
The digestive organs
The teeth....
CONTENTS. ix
PAQK
The mouth 220
The pharynx 224
The oesophagus 226
The stomach 227
The small intestine 229
The large intestine 231
The liver 233
The pancreas 238
The ductless glands 239
The spleen 239
The thyroid gland 241
The thymus gland 242
The suprarenal capsules 242
The abdominal cavity 243
The peritoneum 246
Organs of voice and respiration 249
The larynx 249
The trachea and bronchi 254
The lungs 256
The pleurae 259
The urinary organs 260
The ureters 265
The bladder 266
The male urethra 269
Female urethra 271
The male generative organs 271
The penis 272
The testes and their coverings 274
Female organs of generation 279
The vagina 281
The uterus and its appendages 281
The mammary glands 286
The organs of sense . . 287
The skin and its appendages 287
Organs of taste 289
Organs of smell ........ 290
The eye 292
X
CONTENTS.
Sclerotic and cornea ....
The humors
Appendages of eye
Tutamina oculi
The ear
The external ear
The middle ear or tympanum .
The tympanum
The internal ear or labyrinth
Anatomy of inguinal hernia ....
Femoral hernia
Perineum and ischio-rectal regions
Introduction to osteological plates .
Series of osteological plates from Gray's Anatomy
INTRODUCTION
TO
PLATES OF THE VASCULAR SYSTEM.
The great popularity of Dr. Nanerede's " E.-isentials of Anatomy,
suggested to the publisher the desirability of still further extending
its usefulness by the addition of a series of jdates which might make
it of as material service in the dissecting room as are larger and
much more elaborate works. With this end in view, much care was
bestowed upon the selection of illustrations, and we believe that
those presented in the following pages are unrivalled in excellence,
except in the large, cumbersome and expensive charts, which are
not adapted to the student's purposes.
The study of anatomy must be grounded upon dissection. What
the eye sees in a moment, is more indelibly impressed upon the
brain, than the most minute and accurate description. Hence,
after dissection or the examination of preparations would come
trustworthy illustrations. By a study of these the student remem¬
bers not words but facts. AA'hen it becomes necessary for him to
recall the relations of important blood-vessels or nerves, he should
not stumble over what G ray says or Leidy taught, but there should
flash into his memory, without eflbrt, what he has seen and what he
knows. This is said with no thought of decrying the value of text.
Careful description should go hand-in-hand with illustrations, but
should distinctly supplement the latter, since words in themselves,
or even the ideas they convey, are far more difficult to remember
than ocular impressions.
In the following plates* the topographical features of each region
are so beautifully illustrated, that the student can confirm his
dissection at a glance, and can as quickly review his knowledge in
preparing for examination. Dr. Nancrede being out of the city,
with his consent, and at the request of the publisher, the selection
and editing of the plates was supeiwised by
EDW.\RD JIARTIX.
415 S. Fifteenth St., Philadelphia.
June, 1890.
'^'Takea from the works of Maclise, Savage, Nuhn and Hirscbfeld.
PLATE i.
SUPERFICIAL DISSECTION OF THE THORAX
AND ABDOMEN.
A.—Upper bone of the sternum.
B.B,*—Two first ribs.
C.C.*—Second pair of ribs.
B.D.*—Right and left lungs.
E.—Pericardium, enveloping the heart—the right ventricle.
F.—Lower end of sternum.
G.G.*—Lobes of the liver.
H.H.*—Right and left halves of the diaphragm, in section; the right half sepa¬
rating the right lung from the liver, the left half separating the left lung
from the broad cardiac end of the stomach.
I.I,*—Eighth pair of ribs.
K.K.*—Ninth pair of ribs.
E.E.*—Tenth pair of ribs.
M.M.*—The stomach ; m, its cardiac bulge; m* its pyloric extremity.
X.—The umbilicus.
O.O.*—The transverse colon.
P.P.*—The omentum, covering the transverse colon and small intestines.
Q.—The gall bladder,
R.R.*—The right and left pectoral prominences.
S.S.*—The small intestines.
piule II.
PLATE 2.
RELATIVE POSITION OF THE DEEPER ORGANS OF
THORAX AND THOSE OF THE ABDOMEN.
A.—Upper end of the sternum.
B.B.*—First pair of ribs.
C.C.*—Second pair of ribs.
B.—Aorta, with left vagus and phrenic nerves crossing its transverse arch.
E.—Root of pulmonary artery.
F.—Right ventricle.
G.—Right auricle.
H.—Vena cava superior, with right phrenic nerve on its outer border.
I.I.*—Right and left lungs collapsed, and turned outward to show the hearths out¬
line.
M.K.*—Seventh pair of ribs.
—The diaphragm, in section.
BÍ,—The gall bladder, with its duct to form the common bile duct. The hepatic
artery is seen superficial to the common duct; the vena portae is seen
beneath it. The patent orifices of the hepatic veins are seen on the cut
surface of the liver.
0«—The stomach.
P.—Inferior vena cava.
Q,,—The cœliac axis, dividing into the gastric, splenic and hepatic arteries.
R.—The spleen.
S. —The transverse colon, between which and the lower border of the
stomach is seen the gastro-epiploic artery, formed by the splenic and
hepatic arteries.
S«***—Ascending colon, in the right iliac region.
T.—Convolutions of the small intestines, distended with air.
PLATE 3.
DEEP DISSECTION OF THROAT AND ABDOMEN.
A.—The thyroid body.
B.—The trachea,
C.i*.*—The first ribs.
D.l>.*—The clavicles, cut at middle.
E.—Humeral part of great pectoral muscle, cut.
F.—Coracoid process of the scapula.
0.—Arch of the aorta ; G,* descending aorta in throat.
II.—Right bronchus ; H,* left bronchus.
1.—Œsophagus.
K.—Vena azygos, receiving the intercostal veins.
E.—Thoracic duct.
M.M.*—Seventh ribs.
—Diaphragm in section.
O.—Cardiac orifice of stomach.
P.—Liver in section, showing patent orifices of hepatic veins.
—Coeiiac axis, sending off branches to liver, stomach and spleen. The stomach
has been removed to show the looping anastomosis of these vessels around
the superior and inferior borders of tne stomach.
R.—Inferior vena cava, about to enter its notch in the posterior thick part of the
liver, to receive the hepatic veins.
5.—Gall-bladder, communicating by its duct with the hepatic duct, which is lying
upon the vena ports, and by the side of the hepatic artery.
T.—The pyloric end of stomach, joining T.,* duodenum.
F.—The spleen.
"V.V.—The pancreas.
W.—The sigmoid flexure of colon.
X.—The caput coll.
Y.—The mesentery, supporting the numerous looping branches of the superior
ineseuteric artery.
Z.—Some coils of the small intestine.
2.—Innondinate artery.
3.—Right subclavian artery.
4.—Right common carotid artery.
6.—Left subclavian artery.
6.—Left common carotid artery.
7.—Left axillary artery.
8.—Coracoid attachment of the smaller pectoral muscle.
9.—Subscapular muscle.
10.—Coracoid head of the biceps muscle.
11.—Tendon of the latissimus dorsi muscle.
12 —Superior mesenteric artery, with its accompanying vein.
13.—Left kidney.
I'lato III.
Plato l\
PLATE 4.
RELATION OF THE PRINCIPAL BLOOD-VESSELS
OF THE THORAX AND ABDOMEN TO THE
OSSEOUS SKELETON, ETC.
A.—Arch of the aorta.
B.B.—Descending thoracic, part of the aorta giving off h, 6, the intercostal arteries.
Abdominal part of aorta.
D.D.—First pair of ribs.
£.—The xjphoid cartilage.
F.—Right crus of diaphragm.
G.G.*—Right and left kidneys.
H.—Brachio-cephalic artery.
I.—Left common carotid artery.
K.—Left subclavian artery.
B.—Right common iliac artery at its place of division.
m.^Left common iliac artery, seen through the meso-rectum.
N.—Inferior vena cava.
O.O.—Sigmoid flexure of the colon.
P.—The rectum.
Q.—Urinary bladder.
R.—Right iliac fossa.
S.S.—Right and left ureters.
T.—Left common iliac vein, joining the right under the right common iliac artery
to form the inferior vena cava.
F.—Fifth lumbar vertebra.
V.—External iliac artery of right side.
W.—The symphysis pubis.
X.—Án incision made over the locality of the femoral artery.
b.b.—The dorsal intercostal arteries.
c.—The cceliac axis.
<1.—Superior mesenteric artery.
f.f.—Renal arteries.
g.—Inferior mesenteric artery.
b.—The vas deferens, bending over the epigastric artery and the os pubis, after
having passed through the internal abdominal ring.
PLATE 5.
SUPERFICIAL DISSECTION OF THE HEAD
AND NECK.
A.—Third portion of the subclavian artery.
B.—Sieroo-iuastold mtiscle.
C'.—Coramou carolid artery.
I>.—External " "
E.—Internal " "
E.—Couiinualion of the external carotid, through the parotid gland.
<■.—Temporal artery.
II.—External jugular vein.
I.—Biacbial plexus.
K.—Posterior belly of orao-hyoid.
I..—Suprascapular artery.
.11.—T^ansve^^e cervical artery.
K. —Scalenus autieus.
O.—Glandulae concatenatae.
P.—Superficial descending cervical nerves
•—Great auricular nerve.
K.—Occipital aitery and nerve.
S.—Facial nerve.
T.—Duct of StensoD.
v.—Facial vein,
v.—Facial artery.
W.—Submaxillary gland.
X.—Digastric muscle.
Y.—l.yinphatic gland.
Z.—Hyold bone.
1.—Tliyroid cartilage.
2.—Sinerior thyroid artery.
3.—Anterior jugular vein.
4.—Anterior belly of onio-hyold.
6.—Sterno-hyoid (right).
6.—Inter-clavicular notch.
7.—Clavicle.
8.—Trapezius muscle.
9.—S,.lenius capitis.
10.—Posterior belly of occipito-frontalls.
II.—Attolleus aurem
12.—Anterior belly of occipito-frontalis.
13.—Orbicularis jialpebrarum.
14.—Zygomaticus major.
15.—Buccinator.
16.—Depressor aoguli oris.
Plate \'.
eCO.¿ HARRIS t sens Li'n PU/LA.
I'latf \ 1
PLATE 6.
DISSECTION OF THE DEEP CERVICAL AND
FACIAL REGIONS.
A.—InnomiDate artery, at its point of bifurcation.
B.—Subclavian artery, crossed by the vagus nerve.
C«—Common carotid artery, with the vagus nerve at its outer side, and the descen-
deus noui nerve lying on it.
D.—External carotid artery.
E.—Internal carotid artery, with the descendens noni nerve lying on it.
F«—Lingual artery passing under the fibres of the hyoglossus muscle.
G.—Tortuous facial artery.
II.—Temporo-maxillary artery.
I.—Occipital artery, crossing the internal carotid artery and jugular vein.
K.—Internal jugular vein, crossed by some branches of the cervical plexus, which
join the descendens noni nerve,
li.—Spinal accessory nerve, which pierces the sterno-mastoid muscle, to be dis¬
tributed to it and the trapezius.
M.—Cervical plexus of nerves giving off the phrenic nerve to descend the neck
on the outer side of the internal Jugular vein, and over the scalenus muscle.
BT.—Vagus nerve, between the carotid artery and internal jugular vein.
O.—Ninth, or hypoglossal nerve, distributed to the muscles of the tongue.
P.P.—Branches of the brachial plexus of nerves.
Q.—Subclavian artery in connection with the brachial plexus of nerves.
R.R.—Post-scapular artery passing through the brachial plexus.
S.—Transversalis humeri artery.
T.—Transversalis colli artery.
IJ.—Union of the post-scapular and external jugular veins, which enter the sub¬
clavian vein by a common trunk.
V.—Posterior half of the orno hyoid muscle.
W.—Part of the subclavian vein, seen above the clavicle.
X.—Scalenus muscle, separating the subclavian artery from vein.
Y.—Clavicle.
Z.—Trapezius muscle.
1.—Sternal origin of sterno-mastoid muscle of left side.
2.—Clavicular origin of sterno-mastoid muscle of right side, turned down.
3.—Scalenus posticus muscle.
4.—Splenius muscle.
5.—Mastoid insertion of sterno-mastoid muscle.
6.—Internal maxillary artery, passing behind the neck of lower jaw-bone.
7.—Parotid duct.
8.—Genio-hyoid muscle.
9.—Mylo-byoid muscle, cut and turned aside.
10.—Superior thyroid artery.
II.—Anterior half of omo-hyoid muscle.
12.—Sterno-hyoid muscle, cut.
13.—Sterno-thyroid muscle, cut.
PLATE
7.
DEEP DISSECTION OF THE HEAD AND NECK.
A-—Root of common carotid artery.
B.—Subclavian artery at its origin.
Trachea.
!>•—Thyroid axis of subclavian artery.
E.—Vagus nerve, crossing the origin of subclavian artery.
F.—Subclavian artery at third division of its arch.
G.—Post-scapular branch of subclavian artery.
H.—Transversalis humeri branch of subclavian artery.
I.—Transversalis colli branch of subclavian artery.
K.—Posterior belly of omo-byoid muscle, cut.
E.—Median nerve branch of brachial plexus.
M.—Musculo-spiral branch of same plexus.
N.—Anterior scalenus muscle.
O.—Cervical plexus giving off the phrenic nerve, which takes tributary branches
from brachial plexus of nerves.
P.—Upper part of internal jugular vein.
Q.—Upper part of internal carotid artery.
R.—Superior cervical ganglion of sympathetic nerve.
S.—Vagus nerve lying external to sympathetic nerve, and giving off i, its laryngeal
branch.
T.—Superior thyroid artery.
U«—Lingual artery, separated by hyoglossus muscle from
v.—Hypoglossal or ninth cerebral nerve.
W.^ubilngual salivary gland.
X.—Geoio-hyoid muscle.
Y.—Mylo-hyoid muscle, cut and turned aside.
Z.—Thyroid cartilage.
1.—Upper part of sterno-hyoid muscle.
2.—Upper part of omo-hyoid muscle.
3.—Inferior constrictor of pharynx.
4.—Cricoid cartilage.
5.—Crico-thyroid muscle.
6.—Thyroid body.
7.—Inferior thyroid artery of thyroid axis.
8.—Sternal tendon of sterno-mastoid muscle, turned down.
9.—Clavicular portion of sterno-mastoid muscle, turned down.
10.—Clavicle.
11.—Trapezius muscle.
12.—Scalenus posticus muscle.
13.—Rectus capitis anticus major muscle.
14.—Stylo-hyoid muscle, turned aside.
15.—Temporal artery.
Plate \'11
oto S Hkntss í sons, c'-'
PLA'PE y.—Continued.
16.—Internal maxillary artery.
17.—Inferior dental branch of fifth pair of cerebral nerves.
18.—Gustatory branch of fifth pair of nerves.
19 —External pterygoid muscle.
20.—Internal pterygoid muscle.
21.—Temporal muscle,cut to show the deep temporal branches of fifth pair of nerves.
22.—Zygomatic arch.
23.—Buccinator muscle, with buccal nerve and parotid duct.
24.—Masseter muscle, cut on the lower maxilla.
25.—Middle constrictor of pharynx.
PLATE 8.
DEEP DISSECTION OF THE LATERAL REGION OF
THE NECK.
1.—Auricular cartilage.
2.—Parotid gland.
3.—Digastric.
4.—Sterno-cleido mastoid.
5.—Trapezius.
6.—Splenius capitis.
7.—Mastoid process.
8.—Trachelo-mastoid muscle.
9.—Complexos.
10.—Obliquas capitis superior.
11.— " " inferior.
12.—Splenius colli.
13.—Scalenus médius.
14.—Common carotid artery.
15.—Internal carotid artery.
16.—External carotid artery.
17.—Hypoglossal nerve.
18.—Middle sterno-mastoid artery.
19.—Princeps cervicis artery.
20.—Occipital artery.
21.—Posterior auricular artery.
rtiud vin SNds i sivwu svso
IIIA
l'Iule IX.
PLATE 9.
DISSECTION OF THE POSTERIOR ASPECT OF THE
NECK AND HEAD.
I.—Trapezius.
I' I Splenius capitis et colli.
4.—Trachelo-mastoid.
5.—Biveuter cervlcis and coraplezus.
ô.^Semispinalis colli.
7.—Spinous process of axis.
8.—Obliquus capitis ioferior.
9.—llectus capitis posticus major.
10— " '* " minor.
II.—Spinous process of atlas (first).
12.—Sterno-cleido-mastoid.
13.—Digastric.
14.—Posterior arch of atlas.
15.—Veitebral artery.
16—Occipital artery.
17.—Sigmoid vein (split), passing between the arches of the first and second vertebra.
It has many connections with the veins both without and witnin the
spinal canal.
18 —Section of occipital bone.
19.—Right transverse sinus.
20.—Tt)rcular Heropbili.
21.—Longitudinal sinus.
22.—Dura mater.
23.—Occipitalis major.
24 —Posterior branch of the third cervical nerve.
25.—Occipitalis minor.
26.—Supei ficial occipital and mastoid glands.
27.—Section of the skin.
28.—Subcutaneous fat, including the large blood-vessels in its deepest layer.
29 —Section of the aponeurosis occipito-frontalis.
30.—Section of the parietal bone, showing diploe, inner and outer tables.
PLATE 10.
ARTERIAL SUPPLY TO THE BASE OF THE BRAIN.
A.A.—Vertebral arteries.
B.—Anterior spinal branches, forming median anterior trunk.
B.—Posterior inferior cerebellar artery.
E.—Basilar trunk, from convergence of two vertebráis.
F.F.—Transverse arteries.
©.—Anterior inferior cerebellar artery.
If.—Superior cerebellar artery.
I.—Posterior cerebral artery, terminal branching of basilic.
J,—Choroidean artery, posterior.
K.—Posterior communicating artery.
E.—Carotid artery, internal.
M.—Anterior choroidean artery.
N.—Middle cerebral artery.
O.—Anterior cerebral artery.
P.—Point of reflection of anterior cerebral over the corpus callosum.
R.—Anterior communicating artery.
Plate X.
GEO S. HAIfHIS i iJi/i
I'latc XI
seo s. /f«»* î C SCS i-TM ClLÀ
PLATE il.
DISSECTION OF THE AXILLA.
A.—Axillary vein, drawn apart from the artery to show the nerves lying between
both vessels. On the bicipital border of the vein is seen the internal
cutaneous nerve ; on the tricipital border is the nerve of Wrisberg, com¬
municating with some of the intercosto-humeral nerves; c, the common
trunk of the venœ comités, entering the axillary vein.
B.—Axillary artery crossed by one root of the median nerve ; 6, basilic vein forming
with a, the axillary vein, A.
C.—Coraco-brachialis muscle.
D.—Coracoid head of biceps muscle.
E.—Pectoralis major muscle.
F.—Pectoralis minor muscle.
G.—Serratos magnus muscle, covered by the axillary fascia, and perforated at
regular intervals by nervous branches called intercosto-humeral.
H.—Conglobate gland, crossed by nerve called " external respiratory " of Bell, dis¬
tributed to the serratus magnus muscle. This nerve descends from
the cervical plexus.
I.—Subscapular artery.
K.—Tendon of latissimus dorsi muscle.
E.—Teres major muscle.
PLATE 12.
DISSECTION OF THE AXILLARY AND
BRACHIAL REGIONS.
A.—Axillary vein cut and tied ; u, the basrüe vein cut
B.—Axillary artery; brachial artery, in the upper part of its course, having h
the median nerve, lying ral her to its ou.er sMe; 6,* the artery on th<
lower part of its course, with the median nerve tu its inner side.
—Subclavius muscle.
C.*—Clavicle.
D.—Axillary plexus of nerves, of which d is a branch on the coracoid border of thi
axillary artery; c, the musculo-cuianeous nerve, pierciug the coraco
brachialis muscle; /, the uluar nerve; musculo-spiral nerve; h, th
median uerve; t, the circumflex nerve.
F.—Humeral part of the great pectoral muscle.
F.—Biceps muscle.
(.'oraco brachialis muscle.
II,—Thoracic half of the lesser pectoral muscle.
I.—Thoracic half of the greater pectoral muscle.
Ii.—Coracoid attachment of the lesser pectoral muscle.
Ii.*—Coracoid process of the scapula.
F.—Lymphatic glands.
—."^erratas magnus muscle.
X.—Latissimus dorsi muscle.
O.—Teres major muscie.
I»,—Long head of triceps muscle.
—Inner condyle of humerus.
Plate XII
Cffo í. hap^is e sens, uth. phila
I'latc XIII.
ero S HA^iriS X SOfS LT». AMILA
PLATE 13.
SUPERFICIAL AND DEEP DISSECTION OF THE
BEND OF THE ELBOW AND FOREARM.
FIG. I.
A.—Fascia, coveriog the biceps muscle,
n.—Basilic vein, wiih iateroal cutaoeous nerve.
C.—Brachial artery, with the vense comités.
D.—Cephalic vein, with the external cutaueous nerve; dy the median nerve.
E.—A communicating vein, joining the venae comités.
F.—Median basilic vein.
G.—Lymphatic gland.
If .—Radial artery at its middle.
I.—Radial artery of the pulse.
K.—Ulnar artery, with ulnar nerve.
Ij.—Palmaria brevis muscle.
FIG, 2.
A.—Biceps muscle,
li.—Basilic vein, cut.
—Brachial artery.
D.—Median nerve; d, ulnar nerve.
E.—Brachialis anticus muscle ; e, the internal condyle.
F.—Origin of radial artery.
G.—Supinator radii longus muscle.
If.—Aponeurosis of the tendon of the biceps muscle.
I.—Pronator radii teres muscle.
K.—Flexor carpi ul naris muscle.
L.—Flexor carpi radialis muscle.
^I.—Palmaris longus muscle.
N.—Radial artery at middle, with radial nerve on outer side.
O.—Flexor digitorum sublimis.
P.—Flexor pollicis longus.
Q.—Median nerve.
R.—Lower end of radial artery.
S.—Lower end of ulnar artery, in company with ulnar nerve.
T.—Pisiform bone.
E.—Extensor metacarpi pollicis.
PLATE 14.
DISSECTION OF THE WRIST AND HAND.
FIC. I.
Radial artery,
Ii.—Median nerve ; its branches.
4'.—Ulnar artery, forming F, the superficial palmar arch.
1>.—Ulnar nerve; its continuation, branching to the little and ring fingers
etc.
0.—Pisiform bone.
H.—Abductor muscle of the little finger.
1.—Tendon of flexor carpi radialis muscle.
K.—Opponens pollicis muscle.
Ij.—Flexor brevis muscle of the little finger.
M.—Flexor brevis pollicis muscle.
N.—Abductor pollicis muscle.
O.O.O.O.—Lumbricale muscles.
P.P. P.P.—Tendons of the flexor digitorum sublimis muscle.
Q.—Tendon of the flexor longus pollicis muscle.
R.—Tendon of extensor metacarpi pollicis.
S.—Tendons of extensor digitorum sublimis; P^P^P, their digital prolongations.
T.—Tendon of flexor carpi ulnaris.
V.—Union of the digital arteries at the tip of the fingers.
FIC. 2.
A.—Radial artery.
B.—Tendons of the extensors of the thumb.
C.—Tendon of extensor carpi radialis.
D.—Annular ligament.
£•—Deep palmar arch, formed by radial artery giving off e, the artery of the thumb.
F.—Pisiform bone.
O.—Ulnar artery, giving off the branch I, to join the deep palmar arch E, of the
radial artery.
H.—Ulnar nerve; h, superficial branches given to the fingers. Its deep palmar
branch is seen lying on the interosseous muscles,
K.—Abductor minimi digiti.
Ii.—I'lexor brevis minimi digitL
91.—Palmar interossei muscles.
9Í.—Tendon of flexor digitorum sublimis and profundus, and the lumbricales
muscles, cut and turned down.
O.—Tendon of flexor pollicis longus.
P.—Carpal end of the metacarpal bone of the thumb.
Plate XI\'.
PLATK 14r.~C0NTINUED.
FIC. 3.
A. A. A.—Tendons of extensor digltorum communis ; A*, tendon overlaying that of
indicator muscle.
B.—Dorsal part of the annular ligament
1'.—End of the radial nerve, distributed over the back of the hand, to two of the
fingers and the thumb.
D.—Dorsal branch of the ulnar nerve, supplying the back of the hand and the three
outer fingers.
E.—Radial artery, turning round the carpal end of the metacarpal bone of the
thumb.
F.—Tendon of extensor carpi radialis brevior.
O .—Tendon of extensor carpi radialis longior.
II.—Tendon of third extensor of the thumb.
I.—Tendon of second extensor of the thumb.
K.—Tendon of extensor minimi digiti, joining a tendon of extensor communis.
PLATE 15.
SUPERFICIAL DISSECTION OF THE BACK.
1 —Acroraion.
2.—Trapezius,
3.—Laiissiinus dorsi.
4.—RUombuideus major.
5.—Infraspinatus.
6.—Tei es minor.
7.—Teres major,
8 —Deltoid.
9.—Triceps—long head.
Dorsalis scapulae artery.
15 —Dorsal fascia.
!(>.—Splenius capitis.
17.—Intercostal arteries.
18.—Transverse scapular artery.
19.—Dorsal nerves.
20 —Fifth to ninth ribs.
21 —Inferior angle of scapula.
22.—Spine of scapula.
23.—Acromion.
24.—Clavicle.
25.—Transverse ligament.
26.—Capsular ligament.
27.—Insertion of rhomboideus major.
28— " " minor.
29.—Levator angiili scapulse.
30 —Clavicular insertion of trapezius.
31 —Supraspinatus.
32.—Infraspinatus.
33.—Deltoid (cut across).
34 —Teres minor.
35.—Serratus magnus.
36.—External iniercostals.
37.—Dorsalis scapulae artery, nerve and vein.
38.—Transverse scapular artery.
39 — " " vein and nerve.
40 —Supra-scapular artery, nerve and vein.
41 —Recurrent or circumflex, scapular artery and vein.
42.—External oblique.
43.—Intercostal nerves.
44.—Serratas posticus inferior.
45.—Three lower ribs.
((
<c
12.—Intercostal nerves.
13 —Rhomboideus minor.
14.— " major.
I'late X\'
PLATE 15 .—Continued.
46.—Tendinous origin of latîssiinus dorsi.
47 —Esiteroal oblique, back part.
48.—Crest of ileum.
49.—Internal oblique.
50. —Gluteus mazimus.
51.— " médius.
52.—Lowest intercostal nerve.
53.—Superior cutaueous nerves.
54.—Inferior " "
55.—Sacrum.
56.—Coccyx.
57.—Origin ol gluteus maximus.
58.—Greater tiochanler.
59.—Great sacro-sciatic ligament.
60.—Pyriformis.
61.—Obturator internus.
62.—Geruelli muscles.
63.—Quidratus femoris.
64.—Superior gluteal artery and nerve.
55.—Great sciatic nerve.
66.—Sciatic artery and vein.
67.—Cutaneous nerve to posterior femoral region.
68.—Inferior gluteal nerve.
PLATE 16
DEEP DISSECTION OF THE BACK.
1.—Subscapular Euuscle, cross section.
2.—Serratus magnus " "
3.—Teres major.
4.—Triceps, long bead.
5.—Teres miuor, origin.
6.—Acromion.
7.~Humerus, anatomical neck.
8 —Si>leDÍus capitis.
9 —Splenius colli.
10.—Transversalis colli muscle.
11.—Cervicalis ascendens muscle.
12.—Tracbelo-mastoid.
13.—Complexus.
14.—Semi-spinalis dorsi.
15.—Spinalis dorsi.
16.—Ix»ngissimus dorsi.
17.—Sacro-lumbalis; tendinous extension inserted into the nine upper ribs.
18.—Cervicalis ascendens, costal origin from the six upper ribs.
19.—Intercostal muscle (external).
20.—Intercostal artery and vein (passing between the inner and outer layer oí the
internal intercostal muscle).
21.—Supra-spinatus.
22.—Capsule of shoulder joint.
23.—Deltoid.
24.—Triceps muscle, external head.
25.—Triceps " long head.
26.—Teres minor.
27.—Teres major.
28.—Latissimus dorsi.
29.—Sacro-lumbalis.
30.—Venous plexus of the spinal canal.
31.—Lumbar aponeurosis (fascia).
32.—Union of the leaflets of the lumbar fascia.
33.—Levatores costarum breviores.
34.— " " longiores.
35.—Hoots of the lumbar and sacral nerves.
36.—Internal oblique muscle.
37.—Transversalis "
38 —Intercostal artery, vein and nerve (twelfth).
39.—Ileo-hypogastric nerve.
40.—Great sacro-sciatic foramen.
41.—Neck of femur.
42.—Trochanter major.
43.—Trochanter minor.
Plate X\'l
PLATE 16 .—Continued.
44.—Insertion of psoas and iiiacua into trochanter minor.
45.—Tuberosity of the ischium.
46.—External sphincter ani.
47.—Coccyx.
48.—Great sacro-sciatic ligament.
49.—Obturator internus, cut across immediately after passing under great sacro-
sciatic ligament.
50.—Levator ani.
51.—Pyriforrais, cross section immediately after its exit from the foramen magnum.
52 —Gluteal artery, veins and nerve.
53.—Sciatic nerve.
54.—Ischiatic artery.
55.—Internal pudic artery.
56.—Gluteus medius muscle.
57.—Capsule of hip joint.
58.—Tendinous insertion of iliacus and psoas.
PLATE i7.
DISSECTION OF PRINCIPAL BLOOD-VESSELS AND
NERVES OF THE ILIAC AND FEMORAL REGIONS.
A.—The aorta at its point of bifurcation.
11.—Anterior superior iliac spine.
i\—The symphysis pubis.
D.—Poupart's ligament, immediately above which are seen the circumflex iliac and
epigastric arteries, with the vas deferens and spermatic veasels.
E.E.*—Right and left iliac muscles, covered by the peritonaeum; the external
cuianeuus nerve is seen through the membrane.
F.—The vena cava.
G.G.*—The common iliac arteries giving oflf the internal iliac branches on the
sacro-iiiac sympuyses; the right and left ureters.
H.H.*—Right and left common iliac veins.
I.I.—Right and left external iliac arteries; each is crossed by the circumflex iliac
vein.
K.K.—Right and left external iliac veins.
E.—Urinary bladder, covered by peritonaeum.
M.—The rectum intestinum.
N.—The profundus branch of femoral artery.
O.—Femoral vein ; o, saphena vein.
P.—Anterior crural nerve.
Sartorius muscle, cut.
S.—Pectinaeus muscle.
T.—Adductor longus muscle.
v.—The gracilis muscle.
V.—The tendinous sheath given off from the long adductor muscle, crossing the
vessels, and becoming adherent to the vastus internus muscle (forming
Hunter's Canal).
W.—Femoral artery. The letter is on the part where the vessel becomes first
covered by the sartorius muscle.
Plate XML
PI Hic XV'III.
fía 5 nAPi*ii f JflAí í/rM PHtu
PLATE 18.
DISSECTION SHOWING THE SURGICAL RELATIONS
OF THE EXTERNAL ILIAC ARTERY AND THE
INTERNAL ABDOMINAL RING.
A.—That part of the ilium which abuts against the sacrum.
B.—The spine of the ischium.
C.—The tuberosity of the ischium.
I>.—The symphysis pubis.
Situation of the anterior superior iliac spine.
F.—Crest of the ilium.
G.—Iliacus muscle.
H.—Psoas magnus muscle, supportiog the spermatic vesseb.
!•—Transversalis muscle.
K.—Termination of the sheath of the rectus muscle.
I.^. —The iliac, transverse and pelvic portions of the transversalis fascia,
m.—The peritoneum lining groin.
N.—The epigastric vessels lying between the peritoneum, M, and the transversalb
fascia, F2,
O«—The umbilical ligament.
P.—The neck of the sac of an internal inguinal hernia, formed before the sper¬
matic vessels.
—An interval which occasionally occurs between the umbilical ligament and the
epigastric artery. '
R. and R,.—Situations where the direct inguinal hernia occurs when, as in thb case,
the umbilical ligament crosses the space named the internal fossa—the
triangle of Hesselbach.
S.—Lower part of the spermatic cord.
T.—The bulb of the urethra.
U.—External iliac vein, covered by the peritoneum.
V.—External iliac artery, covered by the peritoneum.
W.—Internal iliac artery.
X.—Common iliac artery.
PLATE 19.
DISSECTION OF THE MALE PELVIC ORGANS.
A.—The part of the sacrum which joins the ilium.
B.—The external iliac artery, cut across.
C.—The upper part of the rectum.
B.—The ascending pubic ramus.
E.—The spine of the ischium, cut.
F.—The horizontal pubic ramus, cut.
G.—Summit of the bladder, covered by the peritoneum; G*, its side not covered by
the peritoneal membrane.
IT.H.—Recto-vesical peritoneal pouch.
I.—The vas deferens.
K.—The ureter.
Jj.—^Vesícula seminalis.
M.—The spermatic cord.
Iff.—Corpus cavernosum penis ; n, its artery.
O.—Urethra; o, the bulbous urethra.
I»,—Sphincter ani muscle.
Q,—The coccyx.
R.—The sacro-sciatic ligament.
S»—Pudic artery and nerve.
T.—The sacral nerves.
U.—Pyriforinis muscle, cut.
V.—The prostate.
W.—Lower part of the rectum.
X.—Deep perineal fascia.
Plate XK.
eeo s nAP,vs t sons. uth. fm
Piale XX.
PLATE 20.
SIDE VIEW OF THE FEMALE PELVIS.
B.—Bladder (turned down).
R.—Rectum.
Ij.—Round ligament.
U,—Uterus.
0.—Ovary.
V.—Vagina.
S.—Sacro-iliac synchondrosis.
K.—Kidney.
T.—Fallopian tube.
I*.—Pubic symphysis.
a,—PyriformLs muscle (cut).
b —Gluteal muscles.
c.—Coccygeus muscle.
d.—Obturator internus,
c.—Psoas magnus.
f.—Linea alba.
g.g.—Ureters.
k.—Obturator nerve.
1.—Internal abdominal ring.
k.—Great sacro-sciatic ligament.
1.—Abdominal aorta.
2.—Inferior mesenteric artery.
3, 3.—Common iliac arteries.
4.—Left external iliac artery.
5.—Vena cava inferior.
6,6.—Renal veins.
7, 7.—Common iliac veins.
8.—External iliac vein.
9.—Internal iliac artery (cut).
10.—Gluteal vein.
11.—Ilio-lumbar vein.
12.—Lateral sacral vein.
13.—Sciatic vein.
14.—Pudic vein.
15.—Obturator vein.
16.—Epigastric vein.
17.—Uterine veins.
IS.—Vesico-vaginal veins.
19.—Ovarian veins.
20.—Bulb of the ovary.
21.—Vein to round ligament
22.—Fallopian veins.
PLATE 21.
SHOWING THE RELATIONS OF THE INTERNAL
ILIAC ARTERY AND THE POSITION OF
AN ISCHIATIC HERNIA.
1.—Cross section of two last lumbar vertebrae.
2.— " " " sacrum.
3.— " •' " coccyx.
4.—Vertebral canal.
5. Cross section of the pubic bone.
6.—Right pubic arch.
7.—Tuberosity of the ischium.
8.—Horizontal ramus of the pubis.
9 —Anterior superior spinous process of ilium.
10.—Cnst of the ilium.
11.—Gluieus maximuB.
12.—Greater sacro-sciatic ligament.
13.—Lesser sacro-sciatic ligament (covered by coccygeus muscle).
14.—Pyriformis muscle.
15.—Obturator internus.
16.—Cbturator canal.
17.—Iliacus internus.
18.—Psoas major.
19.—Rectus femoris.
20.—Sartorius.
21.—Adductor longus.
22.—Gracilis.
23.—Adductor magnus.
24.—Iliac artery.
25.—External iliac artery.
26.—Deep epigastric artery.
27.—Circumflex iliac artery.
28.—Femoral artery,
29.—External iliac vein.
30.—Superior obturator vein.
31.—Internal iliac artery.
32.—Ileo-lumbar artery.
33.—Superior gluteal artery.
34.—Lateral sacral artery.
35.—Vesical artery.
36.—Anterior branch of internal iliac artery.
37.—Obturator artery.
38.—Middle hemorrhoidal artery.
39.—Internal pudic artery.
40.—Inferior gluteal or ischiatic artery,
41.—Internal pudic vein.
Plate XXI.
C« S HÁlttlS t SOMS, UTH o/t/CA
PLATE 21 —Continued.
42.—Ischiatic vein.
43.—Union of two last mentioned veins into one vessel.
44.—Inferior obturator vein.
45.—Superior gluteal vein.
46.—Internal iliac vein.
47.—Fifih and portion of fourth lumbar nerves, forming with the sacral nerves the
sacral plexus.
48.—Obturator nerve.
49.—Anterior branches of the sacral nerves.
50.—Sciatic nerve (ischiatic), formed of t^o lower lumbar and two upper sacral nerves.
51.—Pudic nerve.
52.—Mouth of the sack of an ischiatic hernia, above the pyriformis and anterior to
the superior gluteal artery, with the obturator artery above and the
inferior obturator vein below.
PLATE 22.
SUPERFICIAL DISSECTION OF THE INGUINO¬
FEMORAL REGION.
A.—The umbilicus.
B.—The upper margin of the pubic symphysis.
C.—The anterior superior spine of the left iliac bone.
]>.—Tositiun of internal abdominal ring.
The saphenous opening in the fascia lata, receiving e. the saphenous vein.
F.—The lax and pendulous cord, overlying upper part of saphenous opening.
0.—Lymphatic glands, lying on fascia lata, in the neighborhood of the saphenous
opening.
If .—The fleshy, part of the external oblique muscle.
a.—Superficial fascia of the abdomen.
Same fascia, forming an envelope for the spermatic cord and scrotum.
c.—Inguinal glands, lying near Poupart's ligament.
d.—A common venous trunk, formed by branches from thigh and abdomen, and
joining—
e.c.—The saphenous vein.
/.—The middle cutaneous nerve, derived from the anterior crural nerve.
ff.—Femoral lymphatic glands.
A.—Superficial external iliac vein.
1.-Superficial epigastric vein.
k.—External cutaneous branches of nerves from the lumbar plexus.
I'late XXIII,
PLATE 23.
DISSECTION OF THE FIFTH, SIXTH, SEVENTH AND
EIGHTH LAYERS OF THE INGUINAL REGION,
AND THEIR CONNECTION WITH
THOSE OF THE THIGH.
FiC. I.
A,—A nterior superior iliac spine.
B.—The umbilicus.
€.—Spine of the pubis.
I).—External oblique muscle ; d, its tendon.
E.—Internal oblique muscle; c, its tendon.
F.—Transverse muscle ;/, its tendon, farming, with e, the conjoined tendon.
G.—The rectus muscle enclosed in its sheath.
H.—The fascia spermatica interna, covering the cord; k, its funnel-shaped
extremity,
I/.—Epigastric artery.
N.—Femoral artery ; », its profunda branch.
O.—Femoral vein.
I*.—Saphena vein.
—Sartorius muscle.
R.—Sheath of the femoral vessels.
S.—The falciform margin of the saphenous opening.
T.—Anterior crural nerve.
F.—Pubic portion of the fascia lata.
V.—Iliac portion attached to Poupart's ligament.
W,—Lower part of the iliacus muscle.
FIC. 2.
A.B.C, refer to same parts as in Fig. 1.
D.—External oblique muscle ; d, its tendon ; d,* the external ring.
£.—Internal oblique muscle.
F-X',O.I*.Q,.R.S.T.U- and W, refer to same parts as in Fig. 1.
G.—ILntus muscle laid bare.
11.ti.—Fascia spermatica interna laid open, above and below d,* the external ring.
I.—The peritonseum, closing the internal ring.
K.—Fascia transversalis; A:, its pubic part.
I..—Epigastric artery and veins.
ill.—Spermatic artery, veins and vas deferens, bending round the epigastric artery
at the Internal ring; m, the same vessels below the external ring,
v.—Iliac part of the fascia lata.
PLATE 24.
DISSECTION OF THE ANTERIOR CRURAL REGION,
THE ANKLE AND THE FOOT.
FIC. I.
A.—Tendon of the tibialis anticus muscle.
B.—Long saphena vein.
C.C.—Tendon of the tibialis posticus muscle.
D.—The tibia; d, the inner malleolus.
ILK.—Tendon of the flexor longus digitorum muscle.
F.—Gastrocnemius muscle; ft, tendo-Achillis.
a,—Soleus muscle.
If.—Tendon of the plantaris muscle.
I.I.—The venae comités.
K.M.—Posterior tibial artery.
li.li.—Posterior tibial nerve.
DISSECTION OF INNER AND POSTERIOR ASPECT
OF ANKLE AND LOWER THIRD OF LEG.
FIC. 2.
A.—Tibialis anticus muscle; a, its tendon.
11. - Extensor longue digitorum muscle ; ft, ft, ft,ft, its four tendons.
Extensor longus polllcis muscle.
D.D.—The tibia.
E.—The flbula; e, the outer malleolus.
F.F.—Tendon of the peronaeus longus muscle.
G.G.—Peronaeus brevis muscle; i, the peronaeus tertius.
If.II.—The fascia.
IÍ.—Extensor brevis digitorum muscle ; k, k, its tendons.
E.E.—Anterior tibial artery, and nerve descending to the dorsum of the foot.
Plate XX I\-
SCO S H Altáis t so^s irTH PK:ÍA
I'I ate XX \',
PLATE 25.
DISSECTION OF THE POPLITEAL SPACE AND THE
POSTERIOR CRURAL REGION.
FIC. I.
A.—Tendon of the gracilis muscle.
It.K. —The fascia lata.
i .e.—Tendon of the semimerabranosus.
1>.—Tendon of the semitendinosus muscle.
K.E,—The two beads of the gastrocnemius muscle.
i\—Popliteal artery.
O.—Po liteal vein, joined by the short saphena vein.
H.—Middle branch of the sciatic nerve.
IÍ.—Posterior tibial nerve, continued from the middle branch of the sciatic, and
extending to behind the inner ankle.
I..—Posterior (short) saphena vein.
M.M.—The fascia, covering the gastrocnemius muscle.
Short (posterior) saphena nerve, formed by the union of branches from
peronseal and posterior tibial nerves.
O.—Posterior tibial artery, appearing from beneath the soleus muscle in lower part
of the leg.
P.—Soleus muscle, joining the tendo-achillis.
.—Tendon of the flexor communis digltorum muscle.
K.—Tendon of flexor longus pollicis muscle.
S.—Tendon of the peronaeus longus muscle.
T.—Peronseus brevis muscle.
IT.E.—Internal annular ligament, binding down the vessels, nerves and tendons in
the hollow, behind the inner ankle.
V. V.—Tendo-achillis. '
W.—Tendon of the tibialis posticus muscle.
X.—The venœ comités of the posterior tibial artery.
FIC. 2.
A.C.D.E.F.O.H.I, refer to same parts as in Fig. 1.
15.—In ner condyle of the femur.
H.—The plantaris muscle, lying upon the popliteal artery.
E.—Popliieus muscle.
—The tibia.
N.\.—The fibula.
O.O.—Posterior tibial artery.
P.—Peronaeal artery.
i^.R.S.T.U.V.W, refer to same parts as in Fig. 1.
X.—The astragalus.
PLATE 26.
DISSECTION OF SOLE OF FOOT.
FIG. I.
A.—The calcaneuni.
B.—Plantar fascia, and flexor brevis digitorum muscle, cut ; b,b,b, its tendons.
Abductor minimi digit! muscle.
D.—Abductor pollicis muscle.
E.—Flexor accessorius muscle.
F.—Tendon of the flexor longus digitorum muscle, subdividing Into /,/,/,/, tendons
for the four outer toes.
C(.—Te don of flexor pollicis longus muscle.
II.—Flexor pollicis brevis muscle; the four lumbricales muscles.
K.—External plantar nerve.
E.—External plantar artery.
M.—Internal plantar nerve and artery.
FIG. 2.
A.—The heel covered by the integument.
B.—Plantar fascia and flexor brevis digitorum muscle, cut ; b^b,b, the tendons of
the muscles.
C.—Abductor minimi digiti.
J>.—Abductor pollicis.
E.—Flexor accessorius, cut.
F.—Tendon of the flexor digitorum longus, cut; b, 6,6, its digital ends.
0.—Tendon of the flexor pollicis.
II.—Head of the first metatarsal bone.
1.—Tendon of the tibialis posticus.
K.—ËKternal plantar nerve.
E.L.—The arch of the external plantar artery.
>I.M.3I.M.—The four interosseous muscles.
N.—External plantar nerve and artery, cut.
I'lute XX\'I
I'late XX\'1I.
PLATE 27.
DISSECTION OF THE SUPERFICIAL STRUCTURES
OF THE MALE PERIN/EUM.
A.—Superficial fascia, coTCring the urethral space
B.—The sphincter ani.
C.—The coccyx.
The right and left ischiatic tuberosities.
E.—The anus.
F.F.—The glutei muscles.
PLATE 28.
DISSECTION OF THE DEEP STRUCTURES OF THE
MALE PERINyEUM.
FIC. I.
A.—The urethra.
B.--Accelerator urinse muscle.
C.—Central perinœal tendon.
D.D.—Right and left erector penis muscle.
E.E.—The transverse muscles.
F.—The anus.
G.G.—The ischiatic tuberosities.
H.—The coccjx.
I.I.—The glutei muscles.
K.K.—Levator ani muscle.
I«.—Left artery of the bulb.
FIC. 2,
A. D. F. G. II. I. K. li, refer to same parts as in Fig. 1.
B.—The urethra.
C.—Cowper's glands, between the two layers of—
E.E.—The deep perinseal fascia.
M.—The bulb of the urethra.
IlIAXX
Plate XX I\.
PLATE 29.
DISSECTION OF THE DEEP STRUCTURES OF THE
MALE PERIN/EUM.
A.B.—The urethra.
C.C.—The two lobes of the prostate.
B.D.—The two crura penis.
E.—The rectum turned down.
F.—The ischiatic tuberosities.
G.—The coccyx.
H.H.—The glutei muscles.
I.1.—The levator ani muscle.
K.—The left artery of the bulb.
E.—The vesiculae seminales.
M—The membranous part of the urethra.
Si.—The base of the bladder.
O.—The two vasa deferentia.
P.—The sacrosciatic ligament.
PLATE 30.
FEMALE PERINEUM AND ISCHIO-RECTAL REGION.
1.—Coccyx.
2.~Gluteus maximus.
3.—Fascia lata, inserted into pubic arcb.
4.—Tuberosity of ischium.
5.—Internal sphincter ani.
6.—External " "
7.—Attachment of sphincter ani to coccyx.
8.—Levator ani. forming floor of ischio-rectal fossa.
9.—Perineum.
10.—Transversas peronei muscle.
11.—Erector clitoridis.
12.—Constrictor vaginae.
13.—Glands of Bartholini.
14.—Urethral opening.
15.—Labia majora.
16.— " minora.
17.—Clitoris.
18.—Hons veneris,
19.—Internal pudic artery.
20.—External hemorrhoidal artery. (The three arteries of this name are shown, the
middle one only being marked.)
21.—Superficial perineal artery. (Supplying anus, perineum, vaginal lips and
erector clitoridis.)
22.—Traosversus peronei artery.
23.—Deep branch of internal pudic artery.
24.—Artery of the bulb (arteria bulbosa).
25.—Internal pudic vein (common).
26.—External hemorrhoidal vein. (Other branches of the same vessel not marked).
I 'late XX X.
ESSENTIALS OF HUMAN ANATOMY.
Give the derivation- and meaning of the term anatomy.
From two Greek words, literally meaning dissection, but it is
used to indicate the study of the physical structure of organized
bodies.
How is human anatomy divided ?
Into two great divisions, viz. ; 1. General or descriptive anat¬
omy, which deals with the separate parts of the human body ; and
2. Surgical or regional anatomy, which describes the relations in¬
dividual parts, such as muscles, nerves, arteries, etc., bear to each
other, in order to enable the surgeon to find or avoid important
structures when operating.
What is osteology ?
A subdivision of general anatomy describing the number, form,
structure, and uses of the bones.
What is the chemical composition of osseous tissue (hone)?
About one-third (33.30) is organic or animal matter, resolvable
into gelatine after prolonged hoiling, with traces of chrondrigen
(the proximate principle of cartilage), and two-thirds inorganic, or
mineral, consisting of calcium phosphate (tribasic) 51.04, calcium
carbonate 11.30, calcium fluoride 2, magnesium phosphate 1.16, and
sodium chloride with traces of sodium dioxide 1.20. Either the
organic or inorganic matter may he removed without afiecting the
form of the bone ; the former by exposure to heat with free access
of air, after which slight force will reduce the bone to powder; the
latter by steeping in dilute hydrochloric acid, which will render
a long bone as pliable as a strip of rubber.
2
18
ESSENTIALS OF HUMAN ANATOMY.
Does an increase of the mineral constituents take place in
old age ; rendering the bones more brittle than in
youth? -
No; although this isi^the common statement in text-books, for
while equal bulks of young and old bones do show marked differ¬
ences in the proportion of earthy and animal constituents, equal
weights do not, so that the elasticity in youth and the brittleness
in age depend upon the greater sponginess of texture in young
bones.
Is bone a homogeneous substance ?
No; for while the exterior is composed of compact (bard, ivory)
layer, the inner portions are formed of spongy or cancellous tissue;
while the interior of long bones is hollow, forming the medullary
(marrow) canal. The compact tissue is used upon the exterior or
in the shaft of long bones where " cross-strain" is greatest, whereas
cancellous tissue enables the articular end of the bones to be large,
for security, yet light, this tissue being capable of bearing enorm¬
ous pressure without yielding, but incapable of bearing much
"cross-strain."
Describe the microscopic structure of bone.
In transverse section, with a low power, a number of holes will
be observed, averaging sigth inch in diameter, surrounded with a
series of tolerably concentric circles, consisting of an interrupted
series of dark spots. With high powers, the holes, called Haver¬
sian canals for the passage of vessels, are seen to be surrounded by
a series of concentric lines, termed lamellae, while the dark spots
reveal themselves as cavities in the bone, called lacunes, intercom¬
municating with each other and the central Haversian canal, by
means of delicate radiating hollow tubes, called canaliculi: this
aggregation of structures is called an Haversian system. The
lacunae contain bone corpuscles, processes of which extend into
the canaliculi. As each Haversian system communicates by its
canaliculi with those of its neighbor, the exterior of the bone, all
portions of its most compact tissue and the medullary canal freely
intercommunicate and receive nutrient material. As these systems
are circular they would leave interspaces where not in contact;
BONE.
19
but these gaps are filled up by layers of bone with lamella and
canaliculi, these portions being called interstitial lamella. In addi¬
tion to the concentric lamella around the Haversian canals, an
examination of a cross-section of a bone long exposed to atmos¬
pheric influences will show that it is composed of a series of cir¬
cumferential fundamental lamella running around the whole cir¬
cumference of the bone.
What is the periosteum?
It is a fibrous membrane serving as a scaffolding to enable the
bloodvessels to reach all portions of the exterior of the bone except
its articular ends and the points of attachment of strong tendons,
the layer in contact with the bone containing many osteoblasts or
bone-forming cells upon which the growth in thickness of the bone
depends.
What is the endosteum ?
This term is applied to the delicate connective tissue lining of
the medullary and cancellous tissues which contains numerous
bone-forming cells (osteoblasts).
Describe the medulla or marrow.
There are two varieties. In adult bones—except the cancellous
tissue of their articular extremities, that of the vertebral bodies,
the sternum, ribs, and cranial bones—the marrow is yellow, consist¬
ing almost solely of fat (adipose) tissue (ninety-six per cent.). In
the other situations just mentioned the marrow is red (fœtal), con¬
tains not more than one per cent, of fat, and numerous oval, many-
nucleated cells (myeloplaxes). This kind of marrow is that found
in the fœtus and infants.
Do bones receive blood only from vessels in the periosteum ?
No, for the medullary tissue of all long bones receives a good-
sized artery (the nutrient artery), which obliquely penetrates the
compact tissue, after which it divides into two main branches, one
ascending the other descending in the medullary canal ; the veins
chiefly emerge through numerous openings near the articular ends
of the bones.
20
ESSENTIALS OF HUMAN ANATOMY.
Bescribe the process of ossification.
There are two methods, viz., the membranous and the cartilagin¬
ous. In the former, at the centre of ossification of a parietal bone
for instance, the bone-forming cells (osteoblasts) arrange themselves
—about the second month of intrauterine life—along the thick
bundles of fibrous tissue which radiate from the centre of the
future bone ; by the deposition of lime-salts in these osteoblasts,
the deposit of bone shoots out in needle-like rays toward the
circumference. Ossification by cartilage is essentially similar;
for protection of vital centres, as at the base of the skull, or to
maintain rigidity of parts and proper tension of muscles, as in the
extremities, certain bones are laid down in cartilage. Just before
ossification commences the cartilage cells multiply, arrange them¬
selves in columns—especially at the epiphyseal ends—and the
intercellular material becomes infiltrated with lime-salts. Now
ossification proper commences by the ingrowth from the peri¬
osteum of buds of young connective tissue covered with bone-form¬
ing cells, which, after causing absorption of the cartilage, become
converted into bone. The first bones to ossify are 1, the clavicle;
2, the inferior maxilla (fifth to seventh foetal week).
Of bow many bones is the adult human skeleton com¬
posed 1
Two hundred, including the os hyoides, but excluding the teeth.
Wormian bones, all sesamoid bones, except the patellae, and the
ossicles of the middle ear.
Into what classes are bones divided, and give a few
instances of each ?
Long bones, as femur, tibia ; flat, as those of the vault of the
skull, scapula ; irregular, as the vertebrae ; and short, such as the
carpal or tarsal bones.
What are Wormian bones ?
Irregular fragments, developed from supplementary centres,
situated at the junction of two or more cranial sutures, where,
during infancy, a membranous interval existed, viz., a fontanelle.
From their triangular form they are often called ossa triquetra.
BONE.
21
What are sesamoid bones ?
Those developed in the substance of tendons, whereby the mus¬
cles obtain additional leverage—i. e., power; the patellae are, by
some, classed with these bones.
Of what parts do long bones consist, and what are their
uses ?
Of a shaft (body, diaphysis), two articular extremities, and
various processes ; they are developed in cartilage, from one prin¬
cipal, and one or more additional (epiphyseal) centres of ossifica¬
tion ; they serve as supports and levers for power and progression.
Where are short bones employed, and why ?
In the carpus and tarsus, where strength with limited motion is
required. They ossify in cartilage.
Describe the structure and uses of flat bones.
They consist of two layers of compact tissue with interposed
cancellous tissue, called diploe; they serve to protect important
viscera, as brain, etc., and aflford extended surfaces for origin of
muscles ; for the most part, they ossify in membrane.
How are bony prominences named ?
Processes, and are described as articular and non-articular.
Give the names and characteristics of the chief articular
processes.
Head, a convex smooth projection, with a constriction or neck
beneath; found in freely moving joints.
Condyles, double projecting processes, may have a constriction
or neck—i. e., neck of condyle of jaw.
Trochanters, short projecting levers near articulations to facilitate
rotation of the bone on its long axis.
Tuberodties, roughened, broad prominences.
Tubercles, similar to the above, but small with reference to the
size of the bone.
Spines and spinous processes, more or less pointed projections.
Apophysis, strictly speaking, any bony process which develops
from the primary centre of ossification, commonly used, however.
22
ESSENTIALS OF HUMAN ANATOMY
for any process, even if an epiphysis, after it has coossified with the
mass of the bone.
What is a diaphysis ?
The main portion of a bone (shaft in a long bone, body in an
irregular one) between the epiphyses.
What is an epiphysis ?
A supplementary centre, usually to provide for growth in length,
developed in cartilage, which remains separated by a layer of epi¬
physeal cartilage until the growth of the bone is completed, when
it coossifies with the diaphysis, and all further growth ceases. Epi¬
physeal centres appear after birth: they coössify in the inverse
order of their appearance, except that of the lower end of the
fibula. This process of coössification commences about puberty,
and the last to unite are those of the upper end of the tibia and
the vertebral bodies—as late as twenty-five years.
Mention some of the non-articular processes, with their
meaning.
Azygos, without a fellow ; coronoid, or coracoid, like a crow's
beak ; mastoid, like a nipple ; rostrum, a beak ; styloid, pen-like ;
squamous, scaly ; vaginal, ensheathing.
Name some of the articular cavities of bone.
Cotyloid, when they resemble a deep cup ; glenoid, when they
have a shallow-cup form ; trochlear, pulley-like ; facet, when
smooth, like one of the surfaces of a cut gem ; sigmoid, when
curved in two opposite directions.
What are the principal non-articular cavities called ?
Fossae, shallow depressions ; sinuses, deep cavities, communicating
with the exterior by small openings; grooves, long nariow depres¬
sions^ fissures, cracks ; notches, deficiencies of edges of bones ; fora¬
mina, holes through bones for transmission of nerves, etc.
THE FRONTAL BONE.
23
BONES OF THE HEAD
Name the bones composing the head.
They are twenty-two in number: eight of which {(kranial) com¬
pose the brain-case, viz., one frontal, two parietal, two temporal,
one sphenoid, one occipital, and one ethmoid ; fourteen are facial.
two superior maxillary, two malar, two nasal, two lachrymal, two
palate, two inferior turbinated, one vomer, and one inferior maxil¬
lary ; the ethmoid also enters largely into the formation of the nasal
cavities.
The Frontal Bone.
Of what parts does this bone consist ?
Of a vertical and horizontal portion.
Describe the points on the outer surface of the vertical
portion.
On each side of the median line are two frontal eminmceê-, between
which are the remains of, or the completely obliterated, inter-frontal
tuture, leaving a slight linear depression, which, above the root of
Fio. 1
c
24
ESSENTIALS OF HUMAN ANATOMT.
the nose, terminates in a rounded, projecting noíál eminence. Ex¬
tending outward from this on each side are two curved, rounded
mperciliary ridges', situated beneath which, between the two tables
of the skull, lie the frontal sinuses'^ (Fig- 2). The junction of the
vertical and horizontal portions forms on each side a curved margin,
the supra orbital arch?-^, notched or perforated toward its inner part
by the supra-orbital notctv', or foramen, transmitting the artery, vein,
and nerve of the same name. Each orbital margin terminates by
two stout processes, called internal angular^ and external angular*
processes. Between the inner projects the nasal spinê, in the rough,
uneven space, called the nasal notch ; the margin of the external
angular process extends upward as a temporal ridg^ (Fig. 1).
Fiu. 2.
t
Describe the points on the inner surface.
In the median line a vertical groove'" (Fig. 2) (for the longitudinal
sinus) exists, whose edges coalesce below to form the frontal crest",
which terminates as a notch, or perhaps complete foramen cœcum'",
which when pervious transmits a small vein.
Describe the horizontal portion.
This consists of two orbital plates" of a triangular outline,
separated by a quadrilateral ethmoidal notch (for articulation with
PARIETAL BONES.
25
that bone). A shallow lachrymal'^'' depression (for gland) exists at
the outer part of the orbit, also a smaller one or sometimes a small
tuberclê^ at the anterior inner part for the pulley of the superior
oblique muscle. Several half cells are seen along the margins
of the ethmoidal notch, which complete the ethmoidal cells
when the ethmoid is in position, as well as two grooves, which are
likewise converted into the anterior and posterior ethmoidal canals,
the fornrer for the nasal nerve and anterior ethmoidal vessels, the
latter for the posterior ethmoidal vessels. On each side of the
nasal spine open the frontal sinuses^* (absent in children), a part of
the nasal cavities, into which they open by the infundibulum. The
inner surfaces of both vertical and horizontal portions present
numerous depressions for the convolutions of the brain, and
branching grooves for the anterior meningeal artery.
"What centres of ossification has this bone ?
Two, near the orbital arches, in membrane, seventh or eighth
foetal week.
With what bones does it articulate ?
With two parietal, the sphenoid, the ethmoid, two nasal, two
superior maxillary, two lachrymal, and two malar—twelve in all.
What muscles arise from it ?
The corrugator supercilii, orbicularis palpebrarum, and temporal,
on each side.
Parietal Bones.
Describe a parietal bone.
It is of a quadrilateral form, convex externally, the most promi¬
nent point called the parietal eminence. Its upper serrated border
forms with its fellow the sagittal suture^-, the anterior serrated
margin articulates with the frontal, forming part of the coronal
suturé; its anterior inferior angle', more prolonged than the
others, articulates inferiorly with the sphenoid [spheno-parietal
suture); the remainder of the inferior border', bevel-edged, is
overlapped by the squamous plate of the temporal {squamo-parietal
suture) ; the posterior serrated border* articulates with the occipital
(pcdpito-parietal part of lambdoid suture) ; while the posterior
26
ESSENTIALS OF HUMAN ANATOMY.
inferior angle® joins the mastoid process of the temporal {masio-
parietal suture). Crossing the middle of the bone, from before
backward, is a curved line, the temporal ridgé, and near the poste¬
rior superior angle is often a. parietal foramen^ transmitting a small
vein to the superior longitudinal sinus (sometimes a small branch
of the occipital artery).
Describe the internal surface.
This is concave, marked with numerous smooth digital depres¬
sions for the brain convolutions, with a shallow half groovê (Fig. 4)
along the superior border for the superior longitudinal sinus, and
Fig. 4.
OCCIPITAL BONE.
27
several Pacchionian depressions. At the anterior inferior angle a
deep groove, branching in various directions, sometimes converted
into a foramen, is found', for the middle meningeal artery, and at
the posterior inferior angle a broad well-marked groove^ for part of
the lateral sinus.
How is it developed?
In membrane, from one centre at the eminence appearing at the
fifth to sixth foetal week.
Give muscular attachments, and articulations.
Temporal muscle: articulates with five bones, parietal, occipital,
temporal, frontal, and sphenoid.
Occipital Bone.
Of what parts does this bone consist?
Of a curved plate of trapezoidal form, whose anterior blunted
angleforms the basilar process^ (Fig. 5), and two \a.teia.\ jugular pro¬
cessed, arising opposite the two articular processes called condgled"^,
which lie on either side of a large opening, the foramen magnumP ;
the long axes of the condyles" converge toward each other from
behind forward and inward.
4
28
ESSENTIALS OF HUMAN ANATOMY.
What points should he noted on the external convex sut'
Midway between the summit and margin of the foramen
magnum t he prominent external ocelpited protuberance ' for attach¬
ment of the ligamentum nuchae ; a median crest^ extending from
this to the margin of the foramen magnum ; a pair of superior
curved íí/ies® extending from the protuberance toward the lateral
angles of the bone ; a second pair of parallel inferior curved line^,
starting about midway along the crest.
Describe the condyles.
They are two kidney-shaped convex articular surfaces on each
side of the foramen magnum, having on their inner sides a rough
tubercle for the check ligaments.
What foramina are situated near them Î
The anterior condyloid''' (constant) for the hypoglossal nerves, and
posterior condyloid foramina (inconstant) for a small vein.
face ?
Fig. 6.
Describe the basilar process.
A strong quadrilateral plate in front of the foramen magnum
with a median tubercular ridge-like pharyngeal spine. Its cerebral
OCCIPITAL BONE.
29
surface is smoothly grooved longitudinally for the medulla oblon¬
gata. At its junction with the jugular processes are the deep
jugular notches forming part of each jugular foramen (foramen
lacerum posterius).
Describe the cerebral surface of the bone.
It is deeply concave, divided into four " by a crucial
grooved ridge^^-^*-'^, crossing at a prominent internal occipital pro¬
tuberance^^-, the two lateral and superior grooves lodge, respec¬
tively, between the layers of the tentorium cerebelli and the falx
cerebri, the lateral, and part of the superior longitudinal sinuses;
the inferior groove, or internal occipital cresê^, has attached the falx
cerebelli, and lodges in two grooves, the occipital sinuses. The upper
surfaces of the jugular processes are deeply grooved^ for the lateral
sinuses.
What do the upper two fossae lodge?
The posterior lobes of the cerebrum.
What do the lower fossae accommodate ?
The hemispheres of the cerebellum.
With what bones does it articulate ?
Two parietal, two temporal, sphenoid, and atlas; six in all.
What centres of ossification has it ?
One in membrane, at the occipital protuberance (eighth foetal
week), one for the basilar, and one for each condyloid portion in
cartilage (seventh or eighth foetal week) : in four pieces at birth;
in sixth year forms one bone.
What muscles are attached to the superior curved line ?
Occipito-frontal, trapezius, and sterno-cleido-mastoid.
What muscles are attached between the curved lines ?
Complexus and splenius capitis.
What muscles are attached below the inferior curved line?
Eectus capitis posticus major and minor, obliquus superior.
30
ESSENTIALS OF HUMAN ANATOMY
What muscles are attached to the basilar process ?
The superior constrictor of the pharynx, the rectus capitis
anticus major and minor.
What muscle is attached to the jugular process ?
The rectus capitis lateralis.
The Sphenoid Bone.
What are its divisions and where is it situated ?
A body^, two lesser wings', two greater wings, two pterygoid plates,
two spinous processed"-", six clinoid processes, and three minor
prominences ; it is situated at the base of the cranium articulating
with all the cranial bones, and many of the face. Named from a
Greek word meaning wedge, in the process of development this is
its function, serving to enlarge the cranial, nasal, orbital, and oral
cavities at puberty.
Bescribe the body of the sphenoid.
It is large, cuboidal, hollowed out (in adult) into the sphenoidal
sinuses"' (Fig. 8). Superiorly, in front, is a sharp projecting ethmoidal
spine^ for the ethmoid; behind this, a smooth surface with a longi¬
tudinal eminence producing two shallow olfactory grooves on either
side, bounding which behind is a transverse optic grooved (Fig. 7),
lodging the commissure of the optic nerves, terminating in two optic
foramina"' (Fig. 7) for the optic nerves and ophthalmic arteries.
Behind the groove is the projectingo/imry process^ (Fig. 7) forming
the anterior boundary of a marked depression, the sella turcica*
(Fig. 7), lodging the pituitary gland and circular sinus. On each
side, in front, are two small projecting middle clinoid processes, while
behind is a square-shaped projecting plate terminating at either
angle by the tubercular posterior clinoid processes, and to them are
attached portions of the tentorium cerebelli. The sides of this
bony plate are notched for the sixth pair of nerves, and the superior
surface, or dorsum* 7), with a broad shallow depression, slopes
obliquely downward and backward, becoming continuous with the
basilar portion of the occipital bone ; it supports the pons Varolii.
A broad cavernous groove^ (Fig. 7) for the carotid artery and cavern-
THE SPHENOID BONE.
31
ous sinus exists on either side of the body. The. posterior'^ (Fig- ^)
rough quadrilateral surface articulates with the basilar portion of
the occipital hone, coössifying from the eighteenth to twenty-fifth
A vertical plate, the rostrurrP--'"' (Fig. 8), projects from the
inferior surface of the body forming part of the nasal septum, having
the irregular openings of the sphenoidal sinuses^ on either side
(absent in child), which open either into the posterior ethmoidal
cells or directly into the nasal cavities. Two thin-curved sphenoidal
turbinated'" bones narrow these orifices to a round opening at their
upper part; these plates articulate with the palate and ethmoid
bones.
The inferior surf ace presents a continuation of the rostrum for the
vomer, having on either side a thin plate, the vaginal process",
under which slips the alae of the vomer, and the pterygo-palatine
grooves, which by articulation with the sphenoidal processes of the
palate hones are converted into the pterygo-palatine canals for the
arteries and nerves of the same name.
Describe the greater wings.
Two strong processes arising from the sides of the body, curving
upward, outward, and backward. The concave cerebral surfacê^ of
each wing forms part of the middle fossae of the skull, presenting a
circular opening at its antero-internal part, the foramen rotundum}*
for the second branch (sup. maxillary) of the fifth pair of nerves;
a second larger ovoidal foramen, the foramen ovalé" (Figs. 7 and 8),
32
ESSENTIALS OF HUMAN ANATOMY.
transmitting the third (inf. maxillary) division of the same nerve
(sometimes the small petrosal nerve and small meningeal artery),
while piercing the sharp, pointed, posterior extremity of the wing,
or spinous process, is seen a short canal (sometimes double), the/ora-
men spinosum}'^ (Fig. 7), for the passage of the middle (great)
meningeal artery. Occasionally, the foramen Vesalii, a small aper¬
ture to the inner side of the oval foramen, opposite to the root of
the pterygoid process, transmitting a small vein, is detectable.
The external surface presents the pterygoid ridge dividing the
temporal from the zygomatic fossa, and at its posterior part the
spinous process^ (Fig. 8), giving origin to the laxator and tensor
tympani muscle, and the internal lateral ligament of the lower jaw.
Fi(i. 8.
The anterior or orbital surface, smooth, quadrilateral, forming
part of the outer orbital wall, bounded above by a serrated edge
for articulation with the frontal, below by a rounded border which
enters into the formation of the spheno-maxillanj fissure, internally
aiding in the formation of í\íq sphenoidalfissure^^, presents a serrated
articular margin for the malar bone, and has a notch at the upper
part of the inner border for a branch of the ophthalmic artery, a
small spine at its lower part, for part of the origin of the external
rectus muscle, and (at times) one or more external orbital foramina.
The circumference has been described above.
Describe the lesser wings.
These^ (processes of Ingrassias) two thin, triangular processes
each arise from the upper and lateral parts of the body, project
THE SPHENOID BONE.
33
transversely outward, to terminate internally in the anterior clinoid
process^ (Fig. 7), externally in a sharp point. By their anterior
borders they articulate with the orbital plates of the frontal hone,
while by their posterior free margin they divide the anterior from
the middle cerebral fossae. Between their roots on each side is the
optic foramen^'' (Fig. 7) for the optic nerve and ophthalmic artery.
Their inferior surface forms on either side the back part of the
orbital roof, and the upper boundary of the sphenoidal ßssure"
(Fig. 7), or foramen lacerum anterius, which is hounded internally
by the sphenoid body, and inferiorly by the orbital margin of the
greater wing, transmitting the third, fourth, ophthalmic branch of
the fifth and sixth nerves, with the ophthalmic vein, filaments
from the cavernous sympathetic plexus, also branches of the
lachrymal and middle meningeal arteries, with a process of the
dura mater.
Describe the pterygoid processes.
These, consisting of an internal^''- and externaP" plate separated
behind by a notch—the pterygoid fossa—descend on each side per¬
pendicularly from the junction of the greater wing with the body.
At the base of the internal plate is the scaphoid fossa, giving origin
to the tensor palati muscle, above which is the orifice of the Vidia)i
canal'" -, this plate terminates by a curved hainular procesá'^, around
which plays the tendon of the tensor palati muscle. The external
pterygoid plate, forming part of the inner wall of the zygomatic
fossa, has arising from its inner surface the internal pterygoid, and
firom its outer the external pterygoid muscle. The triangular notch
below has fitting into it the tuberosity of the palate hone.
Name the bones with which the sphenoid articulates.
The other seven cranial hones and five facial, viz., the two palate,
two malar, and vomer.
By how many centres of ossification is this bone developed ?
By fourteen centres : two for the internal pterygoid plates in mem¬
brane, two for the greater wings and external pterygoid plates, two
for the lesser wings, two for the anterior part of the body, two
for the sphenoidal turbinated hones, two for the posterior part of
the body, two for the Ungula, i. e., posterior part of the outer
3
84
ESSENTIALS OF HUMAN ANATOMY.
margin of the cavernous groove, appearing from the second foetal
month to the third year in cartilage. From the tenth to the twelfth
year the parts are all ossified, except a portion of the sphenoidal
turbinates, which completely unite by the twentieth year.
■What muscles have their origin from the sphenoid bone ?
The temporal, external and internal pterygoids, superior pharyn¬
geal constrictor, tensor palati, laxator tympani, levator palpebrae,
ohliquus superior, superior, internal, external, and inferior recti.
The Temporal Bones.
Where are they situated ?
At the sides and base of the skull.
What parts does each bone present for examination ?
A squamous (scale-like), a mastoid (nipple-like), and sl petrous
(stony hard) portion.
Describe the squamous portion.
The main portion is an irregularly semi-circular, smooth plate,'
grooved posteriorly for the deep temporal arteries, convex exter¬
nally, concave internally,
and here grooved for the
middle meningeal artery,
with digital depressions for
the cerebral convolutions.
Po.st eriorly, a cur ved ridge
(part of temporal ) is seen.
Springing from its lower
part is the long, twisted,
arched zygomatic procesé,
arising by three roots, viz.,
a posterior, forming part
of the temporal ridge, one
running directly inward
in front of the glenoid
fossa, convex, covered with cartilage, forming the eminentia articu-
larié, and a middle, the outer margin of the glenoid fossa*, tho
Fio. 9.
THE TEMPORAL BONES.
35
obliquely transverse, ovoidal socket for the condyle of the lower
jaw, divided into two parts by the Glaserian, fissurâ (Fig. 11),
which transmits the laxator tympani muscle, the tympanic artery,
and lodges the processus gracilis of the malleus: part of the
parotid gland occupies that portion posterior to the fissure. Parallel
to this fissure, in the retiring angle between the squamous and
petrous portions, is the opening of the canal of Huguier for the
chorda tympani nerve. At the junction of the articular eminence
with the zygomatic process is the zygomatic tubercle for the ex¬
ternal lateral ligament of the lower jaw.
Describe the mastoid portion.
This projects', rough, and perforated by numerous foramina (one
large—the mastoid fora¬
men^—transmits a vein to
the lateral sinus, and a
portion of the bone' con-
lined with mucous mem-
The conical tip is termed
whose inner side a deep v
grooved digastric fossa?^
(Fig. 11) exists for the digastric muscle, while parallel, but more
internal, lies the occipital groove" (Fig. 11), lodging the artery of
the same name. A deep, curved groove" (Fig. 10) exists on the
inner surface of the mastoid portion for part of the lateral sinus,
in which can be seen the inner orifice of the mastoid foramen.
Describe the petrous portion.
This is a dense, pyramidal mass, wedged in between the sphenoid
and occipital bones, containing the organs of hearing. Its long
axis is directed from without inward, forward, and a little down-
36
ESSENTIALS OF HUMAN ANATOMY.
ward. Its apex, three surfaces, and three horders must he studied.
The apex^* [¥\^. 10) lies in the angle formed hy the posterior border
of the greater sphenoidal wing and the basilar process of the occi¬
pital, forms the posterior and external boundary of the foramen
lacerum medium, and presents the internal orifice of the carotid
canal.
The base, its upper half covered by the squamous and mastoid
portions, presents the oval, expanded orifice of the meatus audi-
torius externuê, its upper margin smooth, hut surrounded for the
greater part of its circumference hy the rough-edged (for the car¬
tilage of the external ear), curved plate of bone called Üi&auditory
process^.
The anterior surface forming the posterior part of the middle
cerebral fossa, presents an eminence " (Fig. 10) near the centre indi¬
cating the situation of the vertical semi-circular canal of the ear;
external to this a depression over the tympanum ; a shallow groove
(sometimes double) leading backward and outward to an oblique
opening, the hiatus Fallopii^", for the petrosal branch of the Vidian
nerve; a smaller opening (occasionally seen external to the latter)
for the smaller petrosal nerve; the termination of the carotid canaF*'
near the apex; above this canal a shallow depression for the Gas-
serian ganglion of the fifth nerve.
The posterior surface forms the anterior part of the posterior cere¬
bral fossa, presents about its centre the large orifice of the short
(about four lines) meatus audltorius internus directed outward
(closed at its bottom by a vertical perforated plate), which trans¬
mits the facial and auditory nerves (seventh and eighth pairs
cranial), the auditory artery, and is lined hy the dura mater;
behind the meatus is a small slit leading to the aquceductus vesti-
buli^^, transmitting a small artery and vein, and lodging a process
of the dura mater.
The inferior (basilar) surface, from apex to base, presents a
rough quadrilateral surface for the origin of the tensor tympani
and levator palati muscles ; the circular orifice of the carotid canal"^^
(Fig. 11) ascending vertically, then abruptly passing horizont¬
ally forward and inward for the passage of the internal carotid
artery with its sympathetic nerve plexus; to the inner side of this
—a small, triangular opening, the aquœductus cochleaP, transmit-
THE TEMPORAL BONES.
37
ting a vein from the cochlea to the internal jugular; behind these
openings a deep depression, the jugular fossa'* (Fig. 11), which
lodges the lateral sinus, and, with the jugular notch of the occipital
bone, forms the foramen lacerumposterius, transmitting the jugular
vein and eighth pair of cranial nerves ;
a small foramen for Jacobson^ s nerve in
front of the bony ridge separating the
carotid canal from the jugular fossa ;
on the outer wall of the jugular fossa a
small foramen for Arnold's nerve^'-,
posterior to the jugular fossa, a square-
shaped, smooth facet (covered in the
fresh state with cartilage), for articu¬
lation with the jugular process of the
occipital; a broad, sheath-like, bony
plate extending from the carotid canal
to the mastoid process, the vaginal
process which splitting into two 1am-
inse, encloses the base of a long, sharp
spine, the styloid (Figs. 10 and
11), from which arise the stylo-pharyngeus, stylo-glossus, and stylo-
hyoideus muscles, and the stylo hyoid and stylo-maxillary liga¬
ments; between this process and the mastoid, a large orifice, the
stylo-mastoid"^ foramen, for the exit of the facial nerve, and the
entrance of the stylo-mastoid artery ; and, finally, between the
vaginal and mastoid processes, the auricular fissure for the exit of
Arnold's nerve.
At the angle formed by the junction of the petrous and
squamous portions, two canals^^ exist, separated by a thin, bony
s&gtma, ihQ processus cochleariformis, the upper lodging the tensor
tympani muscle, the lower being the bony Eustachian tuhê^.
What-additional points of interest do the borders present ?
The superior is grooved for the superior petrosal sinus, and has
attached to it the tentorum cerebelli ; the posterior has a half-groove
which, with another on the occipital, accommodates the inferior
petrosal sinus.
Fig. 11.
38 ESSENTIALS OF HUMAN ANATOMY.
From how many centres is this bone developed ?
From ten : one for the squamous and zygoma (in membrane),
four for the petrous, two for the mastoid, two for the styloid, and
one for the auditory process (all latter in cartilage), from eighth
foetal week to sixth foetal month—bone coössifies during first year,
except the styloid process.
With what bones does each temporal articulate ?
The occipital, one parietal, sphenoid, one malar, and the inferior
maxillary.
What muscular attachments has it ?
Squamous, the temporal ; zygoma, the masseter ; the mastoid por¬
tion, the occipito-frontal, sterno-mastoid, splenius capitis, trachelo-
mastoid, digastricus, and retrahens aurem. Styloid, the stylo-
pharyngeus, stylo-hyoideus, stylo-glossus. Petrous, the levator
palati, tensor tympani, tensor palati, and stapedius.
Ethmoid Bone.
Of what parts does this bone consist ?
Of a horizontal crihrijorm plate^ (sieve-like, wheilce name), of two
lateral masses of cells depending from this on either side, between
which lies the perpendicular plate ' forming part of the septum of
the nose; the Avhole bone is of a cuboidal form.
Describe the cribriform plate.
Springing from the upper surface is the crusta galli^ (cock's-
comb), a vertical plate running from before backward, whose
anterior border is notched to complete the foramen caecum of the
frontal bone. Two deep, longitudinal olfactory grooves, for the
olfactory bulbs, lie on either side, their bottoms perforated by three
rows of small foramina for filaments of the olfactory nerves, and
on each side in front is a small slit for the nasal branch of the
ophthalmic nerve ; the crest gives attachment to the falx cerebri.
Describe the perpendicular plate.
It is thin, usually deflected to one or other side,-forms part of
the nasal septum, and has upon each side numerous grooves and
canals to accommodate the olfactory nerve filaments.
ETHMOID BONE.
39
Of what are the lateral masses formed?
Of thin-walled cavities, the ethmoidal cells, whose outer limits
are the vertical orbital* plates, while their inner walls form part of
the nasal fossae ; above they are grooved
to form with grooves on the frontal the
two ethmoidal foramina. The upper
outer margins of each mass present a
number of half-cells completely closed in
when articulated with the ethmoid notch
of the frontal bone; posteriorly are also
half-cells completed by the sphenoidal
turbinated and palate bones; again, in
front and below, the cells are completed
by the lachrymal and superior maxillary
bones; interiorly an irregular hook-like
plate projects, the unciform procesé, which
closes in the upper part of the orifice of
the antrum. A narrow oblique fissure,
the superior nasal meatus, subdivides the
inner surface, bounded above by the thin-
curved superior turbinated bone^, below by the convex scroll-like
middle turbinated bone''-, the poster'ior cells open into the upper
part of this fissure, the anterior into the frontal sinus above, and
below by the flexuous infundibulum they communicate with the
middle nasal meatus, which is bounded above by the middle turbi¬
nated bone.
How many centres of ossification has this bone ?
Three ; one for each lateral mass (fourth to fifth fœtal month),
one for the perpendicular and cribriform plates in cartilage during
the first year ; the ethmoidal cells, completing the bone, form about
the fourth or fifth year. '
With how many bones does it articulate ?
Fifteen: the sphenoid, two sphenoidal turbinated, frontal, two
nasal, two superior maxillary, two lachrymal, two palate, two
inferior turbinated, and the vomer.
40
ESSENTIALS OF HUMAN ANATOMY.
Nasal Bones.
Describe them.
They are of oblong form, their outer surfaces concave from above
downward, convex from side to side, marked by many small arte¬
rial furrows and usually presenting at their centres a single or
double venous foramen. Their inner surfaces are convex from
above downward and concave from side to side, traversed longi¬
tudinally by a groove, sometimes a canal, for a branch of the nasal
nerve which escapes by a notch about the middle of the lower thin
margin.
With what bones does each nasal articulate ?
With the frontal, ethmoid, its fellow nasal, and the superior
maxillary. It has no muscular attachments.
How is each developed ?
From one centre in membrane (eighth foetal week).
The Superior Maxillary Bones.
Describe them.
They each consist of a hollow body and four processes ; together
they form the whole upper jaw.
Describe the body.
It is cuhoidal in form and hollowed out into a pyramidal cavity,
the antrum of Highmorê^ (Fig. 14). Of its four surfaces, the ex¬
ternal (facial), directed forward and outward, presents, just above
the incisor teeth, the incisive (myrtiform) fossa' (Fig. 13), more ex¬
ternally the larger canine fossa^ (Fig. 13), separated from the former
by the canine eminence formed by the socket of the canine tooth ;
above this the infra-orbital foramen^ (Fig. 13) giving egress to the
infra-orbital artery and nerve, and, above all, the margin of the
orbit.
The posterior surface is convex, forms part of the zygomatic fossa,
has about its centre several apertures of the posterior dental canals
for the dental vessels and nerves ; at its lower part (especially after
the wisdom tooth is formed) is a rounded eminence, the maxiMary
THE SUPEKIOR MAXILLARY BONES. 41
tuberosity " (Fig. 13), which, articulates by its rough inner surface
with the tuberosity of the palate bone; and just above the rough
surface is an oblique groove running down on the inner side, which
by the apposition of the palate bone forms the posterior palatine
canal^^ (Fig. 14).
The superior (orbital plate) surface^, thin, smooth, and triangular,
forms part of the floor of the orbit, articulates internally by an
irregular margin (from behind forward) with the palate bone, os
planum of the ethmoid and lachrymal ; externally, by its smooth,
rounded edge, it helps to form the spheno-maxillary fissure (some¬
times articulating in front with the orbital plate of the sphenoid),
and in front, part of the orbital margin. Commencing at the middle
of the outer border of this surface is the deep infra-orbital groove^
(Fig. 13), which in front becomes a canal of the same name, opening
by the infra-orbital foramen ; a small canal branching from this
passes into the substance of the anterior wall of the antrum—the
anterior dental canal; at the inner forepart of this orbital surface
is a minute depression for the origin of the inferior oblique muscle
of the eye.
The internal surface, unequally divided horizontally into two parts
by t\i& palate process(Fig. 14), forms above this, part of the outer
wall of the nasal fossae; below, a portion of the cavity of the mouth.
The nasal surface presents a large irregular opening into the an¬
trum, above which are irregular cellular cavities closed in, when
Fig. 13.
Fig. 14.
/ '
a
articulated, by the ethmoid and lachrymal bones. Below the
opening is the smooth surface forming part of the inferior meatus
42 ESSENTIALS OF HUMAN ANATOMY.
of the nose ; behind a rough surface^^ (Fig. 14) for the palate bone
with a groove passing from above downward and forward, the
poiterior palatini' (Fig. 14), which, closed in by the palate bone,
forms the posterior palatine canal; in front, a deeper vertical
groove which by the apposition of the lachrymal and inferior
turbinated bones forms the lachrynw-nasal duct-, and still more
anteriorly the well-marked horizontal, rough-ridged inferior turbi¬
nated crest, for the inferior turbinated bone.
Describe the antrum of Highmore (maxillary sinus).
It is triangular, with apex outward formed by the malar process,
its base the outer nasal wall, and opens, in the fresh state, by a
small orifice of the size of a probe point into the middle nasal
meatus. In the non articulated bone there is a large, irregular
opening, which is narrowed when articulated by portions of the
palate, ethmoid, and inferior turbinated bones. On its posterior
walls are the posterior dental canals, while its floor presents several
conical prominences, produced by the fangs of the first and second
molar teeth ; sometimes the floor is actually perforated. The walls
are very thin.
Describe the malar process.
It is a rough, triangular eminence*, concave on its facial and
zygomatic surfaces, and roughly serrated above for the malar bone.
Describe the nasal process.
This is thick, triangular rising upward, inward, and backward,
with an external concave smooth surface, an internal surface
articulating with the frontal above, and by a rough surface with
the ethmoid, below this is the transverse ridge-like superior turbi¬
nated crest for the middle turbinated bone. Next comes a smooth,
concave surface, part of the middle nasal meatus ; then the inferior
turbinated crest (see ante), and, most inferior of all, the concavity
forming part of the inferior nasal meatus. The anterior border is
thin, serrated for articulation with the nasal bone, and the posterior
border thick, and grooved for the lachrymal duct, which is directed
backward and a little outward ; where the outer margin of the groove
joins the orbital surface, is the lachrymal tubercle.
THE SUPERIOR MAXILLARY BONES.
43
Describe the alveolar process.
This is thick, spongy, with eight cavities of varying depth, that
for the canine tooth being deepest, those for the molars widest and
subdivided.
Describe the palatine process.
It is a horizontal plate" (Fig. 14), thickest in front, forms most
of the roof of the mouth and floor of the nostril ; has an upper and
lower concave surface. In front, upon the upper surface, is the
upper orifice of the anterior palatine canal, which conducts to a fossa
formed between the two bones, transmitting the anterior palatine
vessels through the foramina of Stenson, the naso-palatine nerves
passing through the intermaxillary suture by the foramina of
Scarpa-, upon the under surface is a longitudinal groove (some¬
times a canal), leading from the posterior palatine canal, for the
posterior palatine vessels and nerve, while in front is seen the lower
orifice of the anterior palatini, fossa (foramen) presenting four
openings ; the inner border is thickened into a ridge on the upper
surfaee forming the nasal crest, between which and its fellow fits
the vomer, and which in front forms the anterior nasal spine.
How is this bone developed ?
Probably by four centres; one for nasal and facial, one for
orbital and malar, one for palatal in membrane, and one for incisive
portion in cartilage at sixth to seventh foetal week. Antrum eom-
mences at the fourth foetal month.
With what bones does it articulate 1
Frontal, ethmoid, nasal, malar, lachrymal, inferior turbinated,
palate, vomer, and the other superior maxillary.
Give the muscular attachments.
Orbicularis palpebrarum, obliquus inferior of eye, levator labii
superioris alaeque nasi, levator labii superioris, levator anguli oris,
compressor nasi, depressor alae nasi, dilator naris posterior, mas-
seter, buccinator, internal pterygoid, and orbicularis oris.
44
ESSENTIALS OF HUMAN ANATOMY.
Lachrymal Bones.
What is their shape and where are they situated ?
They are two small bones situated at the front part of the
inner wall of the orbit, resembling in form, thinness, and size
a finger-nail, hence called os unguis. The external orbital^ sur-
Fig 15 presents a vertical ridge giving origin to the
tensor tarsi muscle, in front of which is a concave
longitudinal groove ^ forming part of the lachrymal
duct below, lodging the lachrymal sac above. Below
is a hook-like process ' articulating with the inferior
turbinated bone, assisting to form the lachrymal
canal. A depressed furrow is seen on the nasal sur¬
face corresponding to the ridge externally; the sur¬
face in front forming part of the middle nasal
meatus, the posterior closing in the anterior ethmoidal cells.
With what bones does it articulate?
With the frontal *, ethmoid superior maxillary ', and inferior
turbinated.
How is it developed ?
From one centre in membrane, at the eighth foetal week.
What muscles arise from it ?
The tensor tarsi of Horner.
Malar Bones.
Describe them.
Two small quadrangular bones placed at the upper outer part of
face, forming the prominence of the cheek, parts of the orbit,
temporal, and zygomatic fossse. The external surface ' is convex,
smooth, perforated by one or more malar foramina', for the passage
of nerves and vessels ; it gives origin to the two zygomatic mus¬
cles. The internal^ concave surface has a rough triangular surface
for the superior maxillary bone. It has superiorly a thick ser¬
rated-edged frontal process^ articulating with the external angular
process of the frontal bone; a thick, strong plate-like orbital
THE PALATE BONES.
45
process, projecting backward, smooth and concave above, forming
part of the floor and outer wall of the orbit, convex below, form¬
ing part of the temporal fossa, and bounding the spheno-maxillary
fissure in front by its free margin,
having upon its upper surfaee the
orifices of one or more temporo-malar
canals for filaments of the orbital
branch of the superior maxillary
nerve. Externally, projecting hack-
ward is the zygomatic process' articulat¬
ing with the zygomatic process of the
temporal bone by a serrated margin.
The upper border smooth and
arched, forms the outer and inferior
margin of the orhit; the lower border^,
thick and rough, gives origin to the
masseter muscle ; the anterior border ®, roughly bevelled, articulates
with the superior maxillary ; while the posterior border*, like an
italie /, is continuous above with the temporal ridge, helow with
the upper border of the zygoma.
How is it developed ?
From one centre (some say two), at the eighth foetal week in
membrane.
With what bones does it articulate ?
With the frontal, sphenoid, temporal, and superior maxillary.
What muscles arise from it ?
The levator lahii superioris, zygomaticus major and minor,
masseter, and temporal.
The Palate Bones.
Describe them.
These two bones, situated at the back part of the nasal fossae,
assist in the formation of the floor and outer wall of the nose, the
roof of the mouth, the floor of the orbit, the inner wall of the
46
ESSENTIALS OF HUMAN ANATOMY.
antrum, and aid in forming the spheno-maxillary and pterygoid
fossae.
Of what parts does each bone consist ?
Of a vertical plate'^, a horizontal plate^, and three processes, the
pterygoid', sphenoidal^, and orbital'.
Describe the points on the vertical plate.
This thin oblong plate, directed upward and a little inward,
presents internally, at its upper part, the superior turbinated crest',
lower a second ridge, the inferior turbinated
Fig. 17. crest'îox the middle and inferior turbinated
bones, between which lies the groove for the
middle nasal meatus, and below the inferior
crest another groove for the inferior meatus.
posterior border articulates with the ptery¬
goid process of the sphenoid; on its external
surface is a deep groove forming the posterior
palatine canal by articulation with the supe¬
rior maxilla, transmitting the vessels and nerve
of the same name, while the upper and back
smooth surface helps to form the inner wall
of the spheno-maxillary fossa, the anterior smooth small lamina
springing from the anterior border of the bone opposite the
inferior turbinated crest—the maxillary process—naxTows the orifice
of the antrum, between which is the rough maxillary surface.
The posterior surface at the lower portion is pyramidal, forming
the pterygoid procesé, is deeply grooved}', forming part of the
pterygoid fossa, with a V-shaped, rough margin for articulation
with the pterygoid plates.
The superior border, deeply notched by the spheno-palatine fora¬
men' (or notch), forms the triangular hollow orbital process', in front,
articulating anteriorly with the maxilla, posteriorly with the sphe¬
noid (its cells here usually opening into the sphenoidal sinus), in¬
ternally, with the ethmoid, and has a free orbital and zygomatic sur¬
face, the latter opening into the zygomatic fossa, with a rounded
border forming part of the spheno-maxillary fissure ; behind, pro¬
jecting upward and inward is the sphenoidal process', grooved on its
THE INFERIOR TURBINATED BONES
47
upper surface by s, pter y go-palatine groove to help to form the same-
named canal ; articulating here with the sphenoid bone, extern¬
ally and posteriorly with the pterygoid process, and having an in¬
ternal concave surface forming part of the outer wall of the nasal
fossa.
Describe the horizontal plate.
This, completing the nasal floor and hard palate, presents on its
inferior surface a transverse ridge for the tensor palati aponeurosis ;
a deep groove assisting in the formation of the posterior palatine
canal " ; near this the orifices of several accessory posterior palatine
canals\ an anterior border, serrated and bevelled for the palate pro¬
cess of the superior maxillary; a smooth concave posterior border,
for the attachment of the soft palate, terminating in the median
line by a projection, which, with its fellow on the other bone, forms
the posterior nasal spine for the azygos uvulae muscle ; and an
internal thickest border, whose upper edge is raised to form, with
its fellow, a crest * articulating with the vomer.
How is this bone developed ?
By one centre in membrane at the angle of junction of the two
plates (seventh to eighth foetal week).
With what bones does it articulate 1
The sphenoid, ethmoid, superior maxillary, inferior turbinated,
vomer, and opposite palate.
Give the muscular attachments.
Tensor palati, azygos uvulse, internal and external pterygoids,
and superior constrictor of the pharynx.
The Inferior Turbinated Bones.
Describe them.
They are two thin, scroll-shaped bones, extended horizontally
along the outer walls of the nasal fossae, just below the orifice of
the antrum, and are attached to the inferior turbinated crests of
the superior maxillary* and palate^ bones, and present three pro-
48
ESSENTIALS OF HUMAN ANATOMY.
cesses for study, a lachrymal^, in front of the upper border, forming
part of the nasal duct by its junction with the lachrymal and
Fig 18.
5 Ô
superior maxillary bones; further back, the ethmoidal process",
joining the unciform process of the ethmoid; and from the lower
border of this process the maxillary process ' projects, curving down¬
ward, and hooking over and narrowing the orifice of the antrum.
The outer surface (from the median plane of the head) is concave ;
its inner convex, roughened, and grooved for arteries and veins.
Name the bones with which it articulates, and its method
of development.
It articulates with the ethmoid, lachrymal, palate, and superior
maxillary bones ; it is developed by one centre in cartilage (fifth
foetal month).
Vomer.
Describe it.
It is single, plowshare-shaped, vertically placed posteriorly in
the nasal fossae (usually deviated to one side), and forms part of
Fig. 19.
the nasal septum. Its superior border * is deeply grooved for the
rostrum of the sphenoid, with lateral wings (alae), which slip under
THE INFERIOR MAXILLARY BONE.
49
the vaginal processes of the same bone. The anterior border * is
grooved for the vertical plate of the ethmoid and the nasal septal
cartilage. The inferior border ^ is received in the groove formed by
the nasal crest of the superior maxillary and palate bones. The
posterior border^ is free, concave, thick above and thin below, and
separates the nasal fossœ behind. On each lateral surface is the
naso-palatine grooved (sometimes a canal) for the nerve of the same
name, and also small furrows for the lodgement of bloodvessels.
Name the bones with which it articulates, and its centres
of ossification.
The sphenoid, ethmoid, both superior maxillary, and both palate
hones. It has but one centre (eighth fœtal week in membrane),
which includes between its two layers the septal cartilage ; ossifi¬
cation is not completed until after puberty.
The Inferior Maxillary Bone.
Enumerate its general characteristics.
It consists of a body^, with two ramp, which are surmounted on
either side by a curved beak-like eoronoid process" in front, and
an articular condyloid process ' posteriorly, the constricted portion
beneath which is termed the neck of the condyle ; the depression
separating these two processes is called the sigmoid notch^, crossed
by the masseteric vessels and nerve.
Describe the body of the hone.
It is horseshoe shaped, and presents the following points for
examination : the prominent triangular eminence in front, the
mental process^, extending upward from which is a median vertical
ridge the symphysis", marking the junction of the two halves of
the bone; on either side, just below the roots of the incisor teeth,
is the incisive fossœ, giving origin sto the levator menti ; and more
externally, below the root of the second bicuspid tooth, the mental
foramen", for the exit of the mental artery and nerve. Extending
outward from the base of the mental process is a distinct ridge'", the
external oblique line, continuous posteriorly with the anterior border
of the ramus ; to it are attached anteriorly the depressor labii infe-
rioris and depressor anguli oris. The lower border *, just in front
4
50
ESSENTIALS OF HUMAN ANATOMY.
of the attachment of the masseter, is grooved for the facial artery.
The internal surface presents an indistinct linear depression, indi¬
cating the point of junction of the two halves of the bone, on either
side of the centre of which are four prominent genial tubercles, dis¬
posed in pairs, sometimes blended into two, or even one irregular
oblique line ( mylo-hyoid ridge) for the same named muscle ; beneath
its edge is the oblong submaxillary fossa, for the submaxillary
gland ; above it the alveolar portion pitted with alveoli (sockets)
for sixteen teeth in adult, ten in child.
Describe the rami.
These ascending, flattened, quadrilateral plates present in front
the curved coronoid process^, giving attachment to the temporal
muscle; the deep siyTOo/cinofcA', forming whose posterior boundary
is the condyloid process"' surmounting its narrow neck, in front of
which is a depression for the tendon of the external pterygoid
muscle, and externally a small tubercle for the external lateral liga¬
ment. The articular surface is oblong, with its long axis trans¬
versely oblique from behind forward and outward, and is convex
from behind forward, and from side to side. Upon the inner surface
of the coronoid process commences a longitudinal r'ldge, with a
groove, for the temporal ahove, the buccinator muscle below. The
outer surface of the ramus has various ridges for the attachment of
the masseter muscles; its inner surface presents a central oblique
aperture, that of the inferior dental canal (communicating with each
alveolus and terminating at the mental foramen) for the vessels
Fiü. 20.
mass, the upper giving origin
to the genio-hyo-glossus, the
lower pair to the genio-hyoid
muscles. Upon each side of
these tubercles is the oval
sublingual fossa for the glands
similarly named, and beneath
each a rough depression for the
origin of the digastric muscle.
Extending obliquely upward
and backward from the sub¬
lingual fossa is the internal
THE SUTURES AND FONTANELLES.
51
and nerve ; in front of this opening a prominent ridge, terminating
behind in a sharp spine for the long internal lateral ligament;
below the spine the myo-hyloid groove for the same named vessels
and nerves, and behind the groove a rough surface, for the internal
pterygoid muscle.
At the junction of the posterior and inferior margins of the
ramus is the angle ^ marked with rough oblique ridges externally for
the masseter, internally for the internal pterygoid muscle.
With what bones does the inferior maxillary articulate ?
With the two temporals.
What ossifie centres has it ?
It is the second bone of the skeleton to ossify (clavicle first), and
is probably developed by only two centres, chiefly in membrane,
partly in cartilage, one for each lateral half, which coossify about
the first year.
Compare the forms of the old and adult jaw.
In old age the alveolar portion being absorbed, the angle formed
by the ramus with the body is very obtuse, and the dental canal is
near the upper surface (important surgically in operating for neu¬
ralgia) ; in adult age the ramus is almost vertical, and the dental
canal lies about the middle of the bone.
Give the muscular attachments.
Fifteen pairs ; to the ramus the masseters, temporals, internal
and external pterygoids ; to the inner surface of the body, the genio-
hyoglossus, genio-hyoid, mylo-hyoid, digastric, superior pharyngeal
constrictor; to the outer surface of the body the depressor labii
inferioris, depressor anguli oris, levator menti, orbicularis oris,
Platysma myoides, and buccinator.
The Sutures and Fontanelles.
What is a suture ?
Rows of interlocking, tooth-like processes, projecting from the
external table of either bone (the inner tables are merely apposed).
How many sutures are there ?
Eighteen.
52 ESSENTIALS OF HUMAN ANATOMY.
Name those at the vertex.
The interparietal (sagittal), the fronto-parietal (coronal), and the
occipito-parietal (lambdoid).
Name those at the sides.
Spheno-parietal, squamo-parietal, and masto-parietal.
Name those at the base.
One baso-sphenoidal, two petro-occipital, two masto-occipital,
two petro-sphenoidal, and two squamo-sphenoidal. The points of
junction of the sphenoid with the frontal and ethmoid, and the
frontal with the ethmoid, are not usually described as sutures.
Which only of the facial sutures has received a name ?
The transverse, that extending from one external angular process
of the frontal to the other, joining that bone with the malar, sphe¬
noid, ethmoid, lachrymal, superior maxillary, and nasal bones.
Why does the skull consist of so many pieces ?
To admit of continuous growth of the bones at their edges, pari
passu with the growth of the brain, hence premature coössification
of all the sutures results in idiocy. Obliteration of the sutures
occurs at variable periods after maturity.
What are the fontanelles ?
They are membranous intervals in the infant's skull, correspond¬
ing to the junction of the four angles of the parietal with the con¬
tiguous bones. They number six, viz., the anterior, of lozenge-
shape, at the junction of the sagittal and coronal sutures, usually
closed not later than the second year ; the posterior, triangular, at
the junction of the sagittal and lambdoid sutures, closed a few
months after birth ; and the lateral, one at the antero-inferior angle,
another at the postero-inferior angle of each parietal bone, which
are closed soon after birth.
How are these spaces closed ?
By a gradual extension of the ossifying process, or by the develop¬
ment of additional centres, forming so-called Wormian bones-
THE CEREBRAL FOSS^.
53
The Cerebral Fossse.
Describe the general characteristics of the anterior fossae
with their foramina a.
Formed by the orbital plates of the frontal \ the cribriform
plate of the ethmoid with its spine', and the lesser wings' of the
sphenoid, they are convex on either side and concave in the
median line. The foramina are one median, the foramen caecum,
which, if pervious, transmits a vein from the nose to the superior
longitudinal sinus ; two slits ' on each side of the crista galli for the
nasal nerves; three rows of olfactory foramina on each side for
the olfactory filaments ; on the outer side of each olfactory groove,
the anterior and posterior ethmoidal foramina, the former transmit¬
ting the anterior ethmoidal artery and the nasal nerve, the latter^
the posterior ethmoidal artery and vein.
Give the boundaries and the foramina of the middle fossse
In front, they are bounded by the posterior margin of the
lesser wings of the sphenoid', the anterior clinoid processes", and
anterior margin of the optic groove ; behind,
by the upper borders of the petrous portion '
of the temporal bones and basilar suture;
externally by the squamous plates of the
temporal* and anterior inferior angles of
the parietals'. The foramina are on each
side, the optic^^ for the optic nerve and
Ophthalmie artery. Thei^spkerwidal fissure
(foramen lacerum anterius), transmitting the
third, fourth, ophthalmic branch of the
fifth and the sixth cranial nerves, and fila¬
ments of the sympathetic, the ophthalmic
vein, branches of the lachrymal and middle
meningeal arteries with a process of the dura
mater ; immediately behind this, the foramen
rotundum^^, for the superior maxillary divi¬
sion of the fifth cranial nerve; more poste¬
riorly, the foramen ovale^^, for the inferior
maxillary division of the fifth nerve, the
Fig. 21.
54
ESSENTIALS OP HUMAN ANATOMY.
small meningeal artery and the small petrosal nerve; between the
two, internally, the foramen vesalii (often absent), for a small vein;
piercing the posterior inferior angle of the greater sphenoidal
wing, the foramen spinosum^'', for the middle meningeal artery,
meningeal veins, and sympathetic nerve branches from the
cavernous plexus; on the inner side of the oval foramen the
foramen lacerum medium^^ (filled in below by a plate of cartilage
in the fresh state), for the internal carotid artery, carotid sympa¬
thetic plexus, large petrosal nerve (Vidian), and a small meningeal
branch from the ascending pharyngeal artery; on the anterior
surface of the petrous portion of the temporal, the hiatus FallopW,
and beneath it, a small foramen for the small petrosal nerve.
What are the posterior fossae
They are deeply concave, and each is formed by the occipital ®,
petrous® and mastoid® portions of the temporal, and the posterior
inferior angle of the parietal '.
What foramina and other openings does each present ?
Th&meafus auditorius internus for the facial and auditory nerves,
and the auditory artery ; the aquaeductus vestibuli for a small artery
and vein; the foramen lacerum posterius^" transmitting the glosso¬
pharyngeal, pneumogastric, and spinal accessory nerves, the
internal jugular vein, and meningeal branches of the ascending
pharyngeal and occipital arteries ; the mastoid foramen (often
absent) for a vein ; the posterior condyloid foramen (often absent)
for a vein of the same name ; the anterior condyloid foramen^^ for
the hypoglossal nerve, and a meningeal branch from the ascending
pharyngeal artery : and separating the two fossae in the median
line, the foramen magnumF, accommodating the medulla oblongata
and membranes, the spinal accessory nerves and vertebral arteries.
What additional foramina or openings are found at. either
side of the base ?
The orifice of the Eustachian tube admitting air to the middle
ear.
The canal for the tensor tympani muscle'^ above the former.
THE ORBITAL CAVITIES.
55
Tlie posterior orifice of the Vidian canal for Vidian nerve and
vessels.
Glaserian fissure for processus gracilis of the malleus, the
laxator tympani muscle, the tympanic artery ;
and close by
The orifice of the canal of Huguier, trans¬
mitting the chorda tympani nerve.
The canal for Jacobson's nerve, the tympanic
branch of the glosso-pharyngeal.
The aquoeductus cochleae, for a small artery
and vein running to the cochlea.
The canal for Arnold's nerve, the auricular
branch of the ¡jneumogastric.
The auricular fissure, for the exit of Arnold's
nerve.
The stylo-niastoid foramen^^, for the exit of
the facial nerve, and the entrance of the stylo¬
mastoid artery.
The anterior'''^ a,nA posterior foramina of the
palatal region have already been sufficiently
described, and this region does not properly
belong to the base of the skull, while those
opening externally at the base and upon the
face have been described sufficiently under the temporal bone, and
the superior and inferior maxillary hones.
The Orbital Cavities.
Describe them.
They are two quadrilateral pyramidal cavities, with bases out¬
ward, their long axes directed from in front inward and backward,
in such directions that if prolonged they would meet about the
sella turcica of the sphenoid. Seven bones contribute to the for¬
mation of each, viz., the frontal'^, ethmoid", sphenoid^, lach¬
rymal", superior maxillary®, palate^®, and malar"; they com¬
municate with the cranial cavity, behind, by the optic foramina'®
and sphenoidal fissures^®, with the nasalfossae through the lachrymo-
56 ESSENTIALS OF HUMAN ANATOMY.
nasal duct, and below, externally, by the spheno-maxillary fissure™
with the temporal, zygomatic, and spheno-maxillary fossœ.
Fig. 2.S
n
What bones compose the roof, and what is its form ?
The orbital plate of the frontal, anteriorly, the lesser sphenoidal
wing behind ; it is concave, and directed downward and forward,
presenting internally a depression'^ for the fibro-cartilaginous
pulley of the superior oblique muscle of the eye, externally the
lachrymalfossa^^ for the gland.
Describe the floor, and of what hones formed.
Nearly flat, formed chiefly by the orbital plate of the superior
maxillary®, and, to a less extent, by the orbital processes of the
malar" and palate bones ; it presents, just external to the lachrymal
canal, a, depression for the inferior ocular oblique muscle; exter¬
nally, the malo-maxillary suture; near the middle the infra-orbital
groove; and posteriorly, ihtpalato maxillary suture.
THE ORBITAL CAVITIES.
57
Give the bones forming, and the points of interest upon
the inner wall.
It is flattened, formed by the nasal process of the superior max¬
illary, the lachrymal os planum of the ethmoid " and sphenoidal
body. It presents in front the lachrymal groove ™ bounded behind
by the lachrymal crest ; further back, respectively, the lachrymo-
ethmoidal and ethrm-sphenoidal sutures.
What forms the outer wall ?
The orbital plate of the malar and the greater wing of the sphe¬
noid, and on it are seen the openings of one or two malar canals^^
and the spheno-malar suture.
Describe the chief points connected with the superior
external angle of the orbit.
Posteriorly, the sphenoidal fissure (foramen lacerum anterius) " for
the entrance of the third, fourth, ophthalmic branch of the fifth
and sixth nerves, and branches of the lachrymal and middle men¬
ingeal arteries, a process of the dura mater, sympathetic nerve
filaments, and the exit of the ophthalmic vein; also the fronto-
malar and fronto-sphenoidal sutures.
What points does the superior internal angle present ?
The suture between the lachrymal, ethmoid, and frontal bones ;
between the junction of the two latter bones, the anterior ethmoidal
foramen'' for the anterior ethmoidal artery and nasal nerve, and the
posterior ethmoidal foramen for the posterior ethmoidal artery and
vein.
What points does the inferior external angle present ?
The spheno-maxillary fissure'^ transmitting the infra-orbital
vessels and superior maxillary nerve, the ascending branches from
the spheno-palatine ganglion, and the orbital branch of the supe¬
rior maxillary nerve.
How is the inferior internal angle formed 1
By a suture, the union of the lachrymal and os planum of the
ethmoid with the superior maxillary and palate bones.
What foramen does the orbital margin present ?
The supra-orb'ital^ at the junction of the inner and middle thirds,
transmitting the supra-orbital artery, veins, and nerve.
58 ESSENTIALS OF HUMAN ANATOMY.
What foramen opens at the apex of the orbit ?
The optic between the two roots of the lesser wing of the
sphenoid, transmitting the optic nerve and the ophthalmic artery.
Recapitulate the openings communicating with the orbit.
The optic", sphenoidal fissure" (foramen lacerum anterius),
spheno-maxillary fissure", infra-orbital canal ^ anterior'' and
posterior" ethmoidal foramina, malar foramina", supraorbital
foramen, and lachrymal canal " (occasionally, in addition, one
or more external orbital foramina).
The Nasal Fossae.
Describe them.
They are two irregular cavities, extending from the base of the
cranium above to the roof of the mouth below ", separated in the
median line by a thin osteo-cartilaginous septum, opening upon
their facial aspect by two large apertures, the anterior nares* ",
and into the pharynx by the posterior narea*^. Each fossa com¬
municates with four sinuses and four cavities.
Of what parts is the nasal septum composed ?
In front, the crest of the nasal bones, and the frontal nasal spine;
its middle portion, the vertical plate of the ethmoid; behind, the
rostrum of the sphenoid and the vomer ; below, the crests of the
superior maxillary and palate bones.
What points does the roof of each fossa present ?
In front, the slit for the nasal nerve; numerous foramince iar
the olfactory filaments ; most posteriorly the opening of the sphe¬
noidal sinus".
The floor ?
In front, the anterior nasal spine*") behind this the upper open¬
ing of the anterior palatine canal**) internally the nasal crest*"-*''
of the superior maxillary and palate bones.
Describe the chief points of interest in the outer wall of
each fossa.
This presents three irregular longitudinal passages, formed by
THE NASAL FOSSJE.
59
three projecting bony plates, called the superior middle and
inferior meatuses^^.
Describe each meatus.
The superior occupies the posterior third of the wall, lies be¬
tween the superior® and middle' turbinated bones (processes of the
ethmoid), and has opening into it two foramina, the spheno-pala-
tine posteriorly, the posterior ethmoidal cells in front part of the
upper wall.
Fio. 24.
The middle'''" occupies the posterior two-thirds of this wall, lies
between the middle and inferior turbinated bones, and has opening
into it, in front, the wfund'ibulum-, in its centre, the antrum''".
The inferior " lies between the inferior turbinated bone and the
nasal floor, extends along the whole length of the outer wall, and
has opening into it, in front, the lower orifice of the lachrymo-
nasal duct (and the anterior palatine canal in the macerated bone,
not in the natural state).
Describe the position and boundaries of the temporal fossa.
Situated at the lateral region of the skull, each fossa is marked
out upon the skull-cap by the temporal ridge, which extends in a
curved line first upward and backward from the external angular
process of the frontal bone, then downward behind to form the
60
ESSENTIALS OF HUMAN ANATOMY.
posterior root of the zygomatic process. Its anterior boundaries
are the frontal, malar, and greater wing of the sphenoid, above and
behind the temporal ridge, below the pterygoid ridge on the greater
wing of the sphenoid, externally the zygomatic arch; it opens
below into the zygomatic fossa, and is filled by the temporal
muscle, and is traversed by grooves, for branches of the deep
temporal artery.
Describe the zygomatic fossa, its boundaries, and commu¬
nicating fissures.
It is bounded, anteriorly, by the tuberosity of the superior max¬
illa, and the ridge descending from its malar process ; superiorly,
by the pterygoid ridge of the greater sphenoidal wing and squamous
plate of the temporal ; behind, by the posterior border of the ptery¬
goid process ; below, by the alveolar border of the superior maxilla ;
internally, by the external pterygoid plate ; and externally, by the
ramus of the lower jaw and the zygoma. The spheno-maxillary and
pterygo-maxillary fissures open into its inner upper part.
What does it lodge ?
The internal and external pterygoid and part of the temporal
muscle, the internal maxillary artery and inferior maxillary nerve
and their branches.
Describe the spheno-maxillary fissure.
It runs horizontally, opens into the outer back part of the orbit,
lying between the lower orbital border of the greater wing of the
sphenoid and the outer border of the orbital plate of the superior
maxillary and a small part of the palate bone ; externally is a small
part of the malar, while, internally, it joins the pterygo-maxillary
fissure at a right angle ; it transmits the infra-orbital artery, the
superior maxillary nerve, with its orbital branch, ascending
branches from Meckel's ganglion, and serves to connect the orbit
with the spheno-maxillary, temporal, and zygomatic fossae.
What are the boundaries of the pterygo-maxillary fissure,
and what passes through it ?
It is bounded, in front, by the maxillary tuberosity ; behind, by
the pterygoid plate of the sphenoid ; descends at right angles from
THE VERTEBRAL COLUMN.
61
the inner extremity of the spheno-maxillary fissure, transmits
branches of the internal maxillary artery, and connects the zygo¬
matic and spheno-maxillary fossae.
Describe the spheno-maxillary fossa.
Situated at the junction of the spheno-maxillary and pterygo-
maxillary fissures, it is bounded, above, by the under surface of
the body of the sphenoid, and by the orbital process of the palate ;
in front, by the superior maxillary bone ; behind, by the pterygoid
process of the sphenoid ; internally, by the vertical plate of the
palate. In this fossa terminate the sphenoidal, spheno-maxillary,
and pterygo-maxillary fissures. The orbital, nasal, and zygomatic
fossae communicate with it, and also the cranial cavity.
How many foramina open into it?
Five (sometimes seven or eight) ; three in the back wall, viz.,
above, the foramen rotundum ; more internal and inferior, the
Vidian ; and lowest and most internal, the pterygo-palatine ; on
the inner wall is seen the spheno-palatine foramen ; below, the upper
orifice of the posterior palatine canal, and sometimes two or three
accessory posterior palatine canals.
BONES OF THE TRUNK.
The Vertebral Column.
How are the vertebrae divided ?
By regions, viz., into cervical (7) ; dorsal (12) ; lumbar (5) ; sacral
(5) ; and coccygeal (4) ; 33 in all.
What are the sacral and coccygeal vertebrae called to dis¬
tinguish them from the remaining bones ?
False, the others being called true (false described with pelvic
bones).
V-
Wh^ parts are common to all vertebrae ?
A iody'; posteriorly on each side a pedicle^, supporting two
fawiwœ', which, joining behind enclose the spinal foramen*", from
62
ESSENTIALS OF HUMAN ANATOMY.
the junction projects a spinous process^: from other parts six
additional processes arise, viz., two transverse ', and four articular '
Describe a vertebral body.
Composed of cancellous bone, with a thin, compact láyer exter¬
nally, its sides are concave from above downward, while its upper
surface is, in the cervical region, concave laterally, forming a lip at
either side, while the lower surface \s, convex from side to side, and
concave from before backward, forming an anterior lip ; in the
dorsal region it is flat above and below; and in the Iwnbar region,
flattened, or slightly concave above and below. Articular facets
and demi-facets for the heads of the ribs, mark the dorsal bodies,
neither the lumbar nor the cervical bodies having these.
Describe the pedicles.
They project backward in all but the cervical vertebrae, where
they are directed obliquely outward. They present intervertebral
notches above and below (deepest above in the cervical vertebrae;
below in the dorsal and lumbar spine), forming, when articulated,
intervertebral foraminae for the exit of the spinal nerves, and the
entrance of vessels.
Fia. 25.
What are the lamins ?
Two broad plates closing in the spinal foramen, roughened at
their upper margins and their inferior internal surfaces for the
ligamenta subflava.
THE VERTEBRAL COLUMN.
63
Describe the transverse processes.
They are bifid in the cervical and perforated by the vertebral
foramen for the vertebral vessels; thick, strong, and long, with
anterior articular facets, in the dorsal ; long and slender in the
lumbar: they spring from the junction of the pedicle and lamina,
and also from the side of the body in the cervical region.
Describe the articular processes.
Two are superio'r and two inferior, projecting from the junction
of the laminae and pedicles. The upper pair look upward and
backward in the cervical region ; backward and outward in the
dorsal, inward and slightly backward in the lumbar ; the lower
pair are exactly the reverse of the upper in each region.
Describe the spinous processes.
Bifid, short, and horizontal in the cervical ; long, triangular,
directed obliquely downward in the dorsal ; and thick, broad,
quadrilateral in the lumbar.
Describe the spinal foramen.
It is largest and triangular in the cervical, smallest and round in
the dorsal, medium and triangular in the lumbar.
Name the peculiar vertebrae of each region, and describe
them.
The first cervical, or atlas; the second cervical, or axis; the
seventh cervical, or vertebra prominens; the first, ninth, tenth,
eleventh, and twelfth dorsal, and the fifth lumbar.
The atlas supports the head, and is formed of two lateral masses
joined by an anterior and posterior arch ; the former presents a
facet posteriorly for the odontoid process. Upon the upper surface
of each lateral mass is an articular facet, looking upward, inward,
and backward for the occipital condyles, while the inferior facet
looks downward and directly inward; a small tubercle represents
the spinous process. Development is by one centre for anterior
arch (first year); one for each lateral mass (sixth foetal week).
The axis has surmounting the body the odontoid process, with a
facet in front for articulation with atlas, another behind for the
transverse ligament, with a roughened apex, to which are attached
64
ESSENTIALS OF HUMAN ANATOMY.
the check ligaments ; on each side of the odontoid, facing upward
and outward, are the superior articulating processes. Development
is like other vertehrae, except three additional centres for odontoid,
two appearing at the sixth fœtal month.
The vertebra prominens is so called because of its long, spinous
process, to which is attached the ligamentum nuchae. Develop¬
ment, like other vertebrae, except one additional centre for anterior
part of transverse process.
The dorsal vertebrae.
The first has an entire facet and a demi-facet on body; the
ninth has a demi-facet on body above, and a facet on the trans¬
verse process; the tenth has one facet on the body and one on
the transverse process ; the eleventh and twelfth, one facet on the
body, none on the transverse processes, the latter also closely
resembling those of a lumbar vertebra.
The fifth lumbar has a markedly wedge-shaped body, with the
base forward.
How are the ordinary vertebrae developed ?
By one centre for the body, one for each lamina (sixth to eighth
fœtal week) ; at sixteen years, one centre for the tip of each trans¬
verse, and two for the spinous process ; and at twenty-one years, a
plate upon the upper and lower surface of the body; the lumbar
vertebrae have two additional centres tipping the superior articular
processes; coössification at thirty years.
The Thorax.
Give its structure, form, and boundaries.
It is conical in form, and its osseo-cartilaginous framework is
formed by the dorsal vertebral bodies behind, the ribs laterally,
and the costal cartilages and sternum in front ; its base is formed
by the diaphragm. Through its apex, the great cervical vessels,
the pneumogastric, phrenic, and sympathetic nerves, the trachea,
oesophagus, and thoracic duct pass (it is also said, the apices of
the lungs during inspiration).
HYOID BONE
—THE STERNUM.
65
What are the most important structures this cavity con¬
tains ?
The trachea, primitive bronchi and lungs, the heart, aorta and
its primary branches, the internal mammary arteries,, the venae
cavae, bronchial and azygos veins, the pneumogastric, phrenic, and
splanchnic nerves, the œsophagus, thoracic duct, lymphatic vessels
and glands.
Hyoid Bone.
Describe this bone and its development.
It consists of a body and two greatér and two lesser cornna ; the
greater cornua project backward from the lateral surfaces of the
body, and have attached to their tubercular ends the thyro-hyoid
ligaments ; the lesser cornua, attached to the junction between the
body and greater cornua, give attachment, by their apices, to the
stylo-hyoid ligaments; it is developed by five centres: one for
body, and one for each greater horn toward the end of fœtal life ;
one for each lesser horn some months after birth.
Give the muscular attachments.
The sterno-hyoid, thyro-hyoid, omo-hyoid, digastric, stylo-hyoid,
mylo-hyoid, genio-hyoid, genio-hyo-glossus, hyo-glossus, middle
pharyngeal constrictor, and sometimes the lingualis.
The Sternum.
Describe it.
The breast-bone consists of tbree segments, viz., the manubrium
(handle), the gladiolus (sword), and the ensiform (xiphoid) car¬
tilage. Upon the upper border of the manuhrium^ is the inter¬
clavicular notch^^ \ upon either side of which is the facet^'^ for the
clavicle ; lower, another for the first rib ; below, a demi-facet"^ for
the second rib.
The gladiolus^ has a demi-facei' above for the second rib, another
below for the seventh', and, between, facets for the third
fourth, fifth, and sixth ribs.
The ensiform cartilage has a demi-facet ' above for the cartilage
of the seventh rib.
5
66
ESSENTIALS OF HUMAN ANATOMY.
How is this bone developed ?
By six centres; one for manubrium, four for gladiolus, one for
ensiform cartilage (fifth foetal month to eighteen years) ; the three
pieces rarely coössify.
What muscles are attached to this bone ?
Above, the sterno-cleido-mastoid, the sterno-hyoid, and sterno¬
thyroid ; below, the rectus abdominis, external and internal
oblique, transversalis, and diaphragm ; in front, the pectoralis
major; behind, the triangularis sterni.
Ribs.
What is their number, and how are they divided 1
Twelve on each side,' seven of which are trut, or those articu¬
lating with the sternum by a separate cartilage; five /a/se, three
of which indirectly articulate through the medium of the seventh
cartilage ; while the two lowest, having their anterior extremities
free, are c&Weà. floating ribs.
RIBS.
67
Of what parts does a rib consist ?
A head, neck, shaft, angle, and tuberosity, except the eleventh
and twelfth ribs.
Describe these parts.
The head'^ (except first, tenth, eleventh, and twelfth ribs having
only one facet) is divided into two facets by a ridge for the inter-
articular ligament. The neck^ is flattened, roughened upon its upper
border for the anterior, and upon its posterior surface for middle
costo-transverse ligaments ; in front it is smooth. tuberosity^
(absent in eleventh and twelfth), placed at the base of the neck,
presents a facet for the transverse process of the next lower ver¬
tebra, and a rough surface for the posterior costo-transverse liga¬
ment. The shaft^ is twisted on its long axis (except first and
second), externally convex, its upper border rounded, its lower
grooved*' for the intercostal vessels and nerve, and presents at its
anterior extremity an oval depression^ for the costal cartilage. The
angle*, at a variable distance in front of the tuberosity, is indicated
by a rough line.
Fig. 27.
How are the ribs developed ?
By three centres (except eleventh and twelfth, two centres), one
each for head, shaft, and tuberosity (for shaft sixth foetal week) ;
for head and tuberosity (sixteen to twenty years) ; coössifies at
twenty-fifth year.
68
ESSENTIALS OF HUMAN ANATOMY.
Describe the peculiar ribs.
They are the first, second, tenth, eleventh, and twelfth ribs.
First rib «, broad, short, flat, one facet on head, angle absent ; on
upper surface two parallel grooves, the anterior for the subclavian
vein, the posterior for the artery, and between them a tubercle' for
the anterior scalene muscle a sure guide to the subclavian artery.
Second rib, also flattened, the tuberosity and angle nearly coin¬
cide, and presents near its middle a rough eminence, for the attach¬
ment of part of the first, and all of the second digitation of the
serratus magnus.
Tenth rib one facet on head.
Eleventh rib, one facet on head, no tuberosity, no neck, slight
angle.
Twelfth rib, one facet on head, neither neck, angle, nor tuberosity.
The Pelvic Bones.
What are they ?
The ossa innominata, the sacrum, and the coccyx.
Describe the innominate bones.
They are formed by the union, about puberty, of three bones,
the ilium', ischium'', and pubes.' At their point of junction is the
acetabulum^ (cotyloid cavity) for the head of the femur—the
pubes forming one-fifth, the ilium and ischium each about two-
fifths. A rough central depression at the bottom of the acetabulum
lodges a vascular mass of fat covered with synovial membrane,
while the anterior lower margin is interrupted by the cotyloid natch,
bridged across by the transverse ligament, beneath which passes
the nutrient vessels and ligamentum teres, which latter arises
from either side of the notch externally ; the whole margin has
attached to it the cotyloid ligament. Between the pubes and
ischium, on the anterior surface, is the obturator foramen^ (thy¬
roid), closed by the membrane of the same name, except above
externally where the obturator vessels and nerve escape; the fora¬
men is a large ovoidal opening in the male, a smaller and triangular
one in the female.
THE PELVIC BOXES.
69
Describe the ilium.
This is the upper expanded portion of the bone, presenting
along its upper border the cret^ with its outer and inner lips,
terminating in front by the anterior superior spinous process^, giv.
ing origin to Poupart's ligament, the sartorios and tensor vaginae
femoris muscles, and behind hy t\xe posterior superior spinous pro¬
cess^", to which are attached part of the erector spinae muscle and
the oblique band of the sacro-iliac ligament. Below both the
anterior® and posterior spines'® is a process called, respectively,
the anterior^ (for straight tendon of the rectus femoris muscle)
and posterior inferior spinous^^ (for great sacro-sciatic ligament) ; by
these projections a notch is formed in front and behind, the former
giving partial origin to the sartorios muscle and transmitting the
Em. 28. Fio- 29.
external outaneous nerve. Between the posterior inferior spine
and the spinous process of the ischium is situated the greater
sacro-sdatic notch", giving egress to the pyriformis muscle, the
greater and lesser sciatic, superior gluteal and pudic nerves,
also one to the obturator externus muscle, and the sciatic, gluteal
and pudic vessels. About two inches from the posterior superior
70
ESSENTIALS OF HUMAN ANATOMY.
spine, passing downward and outward from the crest, is the supe¬
rior curved line'', from the surface back of which arise the gluteus
maximus muscles and a few fibres of the pyriformis; about an
inch behind the anterior superior spine, passing from the crest
downward and backward to the upper part of the great sacro-
sciatic notch, is the middle curved linê, the gluteus medius arising
from the space between these two lines ; passing downward and
backward, from the upper part of the anterior inferior spine to the
front of the sacro-sciatic notch, is the infer'ior curved liné, between
which and the middle arises the gluteus minimus. Above the ace¬
tabulum is a groove for the reflected tendon of the rectus femoris
muscle. The inner surface presents the large, smooth concave
Venter (internal iliac fossa)' (Fig. 29), limited below by the promi¬
nent ¿íío-pecímeaí line, and behind the iliac fossa is the rough auricu¬
lar surface, the lower part for articulation with the sacrum, the
upper for the posterior sacro-iliac ligaments.
Describe the ischium.
It consists of a body, tuberosity, and ramus, and forms the lowest
part of the innominate bone. The external surface of the body'' forms
two-fifths of the acetabulum ; below this is a groove for the obturator
externus tendon ; its inner surface forms the lateral boundary of the
true pelvis; fromtheposteriorborder, below the centre, projects the
spine of the ischium}^ (Fig. 29), above and below which are the
greater^' and lesser sacro-sciatic notches'^, the latter giving egress to
the obturator externus muscle and its nerve, and ingress to the
pudic vessels and nerve. The lowest portion presents a tuberosity'^,
with an outer and inner lip—to the latter being attached the
greater sacro-sciatic ligament; above is a groove for lodgement of
the internal pudic vessels and nerve. Passing upward and inward
from the tuberosity to join the ramus of the pubes, and bounding
the obturator foramen in front, is the thin, flattened ascending
ramus'''.
Describe tbe pubes.
This bone (also called pectineal) consists of a body' or hori¬
zontal" and a descending (perpendicular) ramus". The outer end
forms one-fifth of the acetabulum; above, a rough ilio-pect'ineal
THE PELVIC BONES.
71
eminence?'^ indicates the point of junction with the ilium ; the inner
end is the oval symphysis^^ with eight or nineriá^'ís for attachment
of the fibro-cartilage ; the upper triangular surface presents pos¬
teriorly the pectineal portion of the ilio-pectineal fiW ; the ante¬
rior surface presents the crest'*, ending externally in the pubic
spine"' giving attachment to Poupart's ligament, internally in the
angle ; below is a groove for the obturator vessels and nerve ; the
descending ramus'^, t\ún and flat, joins that of the ischium, com¬
pleting the anterior boundary of the obturator foramen.
How are these bones developed ?
By three primary centres, one for each bone {from the eighth
foetal week to fifth foetal month); and one for the crest, one for
the tuberosity, one for the anterior inferior spine, one for sym¬
physis, and one Y-shaped, joining the three pieces forming the
acetabulum, appearing about puberty ; bone coössifies completely
about twenty-fifth year. (For order of junction, see Gray.)
What muscular attachments has the innominate bone ?
Those of the abdomen, some of the thigh, those of the peri¬
neum, pelvic floor and rotators of the thigh.
Describe the sacrum.
It is composed of five consolidated vertebrae, is of triangular
form with broad base and blunted apex and lateral expanded
masses or alae ; its anterior surface is concave, its posterior convex,
and with the coccyx it forms the posterior wall of the true pelvis.
Its anterior surface is marked by four transverse ridges', indicating
the lines of junction of the segments; e'ght anterior sacral fora-
rnincd with broad shallow grooves for the anterior sacral nerves
open on this surface ; the point of junction with the last lumbar
vertebra forms the promontory (sacro-vertebral angle) ; and upon
each side are the alee'—the expanded portions of the bone. Pos¬
teriorly are three or four median tubercles (rudimentary spinous
processes) ; externally are the laminae, those of the fifth and
sometimes the fourth being deficient ; outside these is a row of
rudimentary articular processes. On each side of the spine is a
broad sacral groove, lodging the origin of the erector spina«»
muscle ; externally are the four posterior sacral foramina on each
72
ESSENTIALS OF HUMAN ANATOMY.
side; at the posterior inferior portion of the bone are the two
cornui—articulating surfaces for the coccyx; each lateral surface
Fio. 30.
Fig. 31.
has on its anterior upper part an auricular surface^ for articulation
with the ilium ; on each side of the apex below is a deep notch,
for the fifth sacral nerve ; the basé resembles the upper surface
of a lumbar vertebra, with the last of which it articulates ; the
apexP, directed downward and forward, has an oval concave
articular surface for the coccyx ; ïke. sacral canal runs the whole
length of the bone, triangular above, small and flattened below
and deficient in its posterior wall at the lower part ; it lodges the
sacral nerves, and into it open the anterior and posterior sacral
foramina.
What centres of ossification has the sacrum ?
Thirty-five, appearing from the eighth foetal week to the twen¬
tieth year, coössification being complete from the twenty-fifth to
thirtieth year. The bodies have each three centres ; each lamina
one centre ; the lateral masses three centres each ; the lateral
surfaces two each.
Give the muscular attachments.
The pyriformis, coccygeus and iliacus in front, the gluteus
maximus, latissimus dorsi, multifidus spin®, erector spinae, and
sometimes the extensor coccygis behind.
Describe the coccyx.
Usually composed of four rudimentary vertebrae, more or less
coössified, it forms a triangular bone whose base^ articulates with
THE PELVIS.
73
the sacral apex. The first piece presents two cornual, projecting
upward from either side of the base for articulation with the
sacral coruua, their junction completing the fifth sacral foramina
for the posterior branches of the fifth nerves. The apex^ is ronnded
and occasionally bifid or turned to one side; two rudimentary
tramverseprocesses^ are seen on the first piece.
Describe its development.
From four centres : one for each segment, the first piece com¬
mencing at hirth ; second, five to ten years ; third, ten to fifteen
years ; fourth, fifteen to twenty years ; coössification varies as
to time and manner.
Give the muscular attachments.
Laterally the coccygei; behind the gluteus maximus and ex¬
tensor coccygeus (when present) ; apex, sphincter ani ; in front
levator ani.
The Pelvis.
Describe the pelvis.
Formed by the two innominate bones, the sacrum and the
coccyx, all above the ilio-pectineal line is called the false pelvis,
consisting of the two iliac fossa.-, all below, the true pelvis.
Describe the true pelvis.
Its hrim, or inlet, somewhat heart-shaped, is formed oy the linea
ilio-pectinea at the sides, completed in front by the spine and
Fig. 32.
74
ESSENTIALS OF HUMAN ANATOMY.
crest of the pubes, behind by the anterior margin of the base of
the sacrum and promontory of the sacrum. Its average diameters
in the female are, antero-posterior'^, four and one-half inches ; trans¬
verse"", five and a quarter inches ; the oblique five inches; its long
axis, if extended, would pass from the middle of the coccyx to the
umbilicus ; in the male these measurements are diminished by at
least one-half inch.
Describe the cavity.
This is bounded in front by the symphysis pubis, behind by the
concavity of the sacrum and coccyx, on either side by the broad,
smooth, quadrangular inner surface of the body of the ischium,
forming a curved canal wider in the middle than at its outlets,
measuring in depth at the symphysis one and one-half inches, three
and one-half inches in the middle axial line, and four and one-
half inches posteriorly, perhaps as much as five and one-half
inches in males.
Describe the lower circumference of the pelvis.
This is called the outlet, is bounded on each side by the tuberosi¬
ties of the ischium, the pubic arch in front and tip of the coccyx
behind. Its diameters are four and one-quarter to four and three-
quarters inches transverse, antero-posterior and oblique four and
one-half increased to five by pressure on the coccyx ; in the male,
the diameters average three and one-half inches.
What are the chief differences between the male and
female pelves ?
The strength of the bones, distinctness of the muscular impres¬
sions, the depth and narrowness of the cavity, and large obturator
foramina mark the male pelvis •. the lighter bones, broader iliac
fosste, the less-curved sacrum, the wider pubic arch, and the uni¬
versally greater diameters, distinguish the female pelvis.
Bones of the Upper Extremity.
Name the bones.
The clavicle, scapula, humerus, radius, ulna, scaphoid, semi¬
lunar, cuneiform, pisiform, trapezium, trapezoid, os magnum, unci¬
form, five metacarpal, and fourteen phalangeal bones.
BONES OF THE UPPEE EXTEEMITY.
75
Describe the clavicle.
It is a long bone, curved like the italic letter /, its outer third
flattened from above downward, and concave anteriorly ; the inner
two-thirds are cylindrical and convex anteriorly, and it extends
almost horizontally between the sternum and scapula, the two ex¬
tremities being respectively termed tbe sternal^ and acromial.
Describe the chief points presented by the clavicle, com¬
mencing at the outer extremity.
The upper surface has impreasiom, that in front for the deltoid,'
that behind for the trapezius ; at the outer end is a faceP articu¬
lating with the acromium process of the scapula ; at the posterior
border, beneath, is the conoid tubercle,^ just above the coracoid
process of scapula, for the conoid ligament; extending from the
tubercle, forward and outward, nearly to the outer end of the
anterior border is the oblique line for the trapezoid ligament; occa¬
sionally at the centre of the anterior border of the outer third is
the deltoid tubercle. The under surface of the middle portion pre¬
sents the subclavian groove^ for the same named muscle—here
appears the nutrient foramen directed outward; the inner third of
the superior border bears an impression for the sterno-mastoid
muscle® {k, Fig. 33), while the inner half of the anterior margin
has another impression for the pectoralis major muscle. Beneath
the posterior border of the sternal end is the rhomboid impression^
for the rhomboid or costo-clavicular ligament. The sternal end^
is triangular in form, its inner surface for articulation with the
sternum, this surface being continuous with a facet beneath, for
articulation with the first costal cartilage.
Fio. 33.
s
76 ESSENTIALS OF HUMAN ANATOMY.
Give its development.
By two centres; cue for the shaft earliest in the body (thirtieth
day) ; one for sternal end (eighteenth to twentieth year) ; uniting
about the twenty-fifth year.
Give the muscular attachments.
Steruo-cleido-mastoid, trapezius, pectoralis major, deltoid, sub-
clavius, sterno-hyoid, and platysma.
Describe the scapula.
The shoulder-blade, a large, fiat, triangular bone, extends from
the first to the eighth ribs on the back and side of the thorax, its
posterior margin lying nearly parallel to, and one inch from the
spinous processes of the vertebrae.
The venter (anterior surface) or subscapular fossa} is concave,
presents some transversely oblique ridges for the tendinous
intersections of the subscapular muscle, and a marginal surface^
along the inner border—triangular above and below, linear between
—for the serratus magnus muscle. The angle is the transverse
depression at its upper part where the fossa is deepest.
The dorsu-m} (posterior surface) (Fig. 35) is divided by a promi¬
nent bony ridge, the spind", affording attachment to the deltoid
Fig. 34.
Fig. 35.
BON'CS OF THE UPPER EXTREMITY.
77
and trapezius muscles and ending in the acromion process into the
supror^ and infrorspinatuê fossa, for the origin of similarly named
muscles ; in the latter is the nutrient foramen)^. The external
border presents a marginal surface", divided by tbe oblique line at
the junction of the lower and middle thirds, into two surfaces, the
lower for the teres major, the upper for the teres minor muscle;
about the junction of the middle and upper thirds of this border
is a groove for the dorsalis scapulae vessels. The sjiine posteriorly
presents a triangular surface^^, over which plays the trapezius
muscle.
The acromionprocess'^'^ (summit of the shoulder) is a triangular
flattened process, curving outward, forward, and upward, to over¬
hang the glenoid fossa; giving attachment along its outer margin
to the deltoid; its inner margin, the trapezius; by its apex to tbe
coraco-acromial ligament; and having on its inner margin, behind
the apex, an articularfacet^ (Fig- 34) for the clavicle.
Describe the coracoid process of the scapula.
The coracoid process^ (Fig. 34)*^; (Fig. 35) (like a crow's beak)
rises by a broad base from the upper part of the neck of the
scapula, curving over the inner upper part of the glenoid cavity.
To the anterior margin, near the tip, is attached the pectoralis
minor muscle, and from its aj)ex arise the short head of the biceps
and the coraco-brachial muscle. To the inner side of the root is a
rough impression for the conoid ligament, whence runs obliquely
forward and outward on its upper surface a ridge for the trapezoid
ligament.
Describe the scapular borders.
The superior border '—the shortest—presents, at the base of the
coracoid, suprascapular notch* (Fig. 35), becoming a foramen
when the transverse ligament is in situ, through which passes the
suprascapular nerve, above which passes the suprascapular artery;
from the border, just internal to the notch, arises the omo-hyoid
muscle. The axillary border^—the thickest—presents just below
the glenoid fossa a rough surface^ for the long head of the triceps
muscle, succeeding which is a longitudinal groove for part of the
subscapular muscle. The vertebral border "—the longest—presents
78
ESSENTIALS OF HUMAN ANATOMY.
an anterior lip for the serratus magnus muscle, a,posterior Hp for the
supra- and infra-spinatus muscles, and &riintermediide space for the
levator anguU scapulae above, for the rhomboideus minor from the
edge of the triangular base of the spine, and for the fibrous arch of
the ihomboideus major muscles below.
Give the points of interest connected with the angles.
The superior angle * (Fig. 34) afibrds partial attachment to the
serratus magnus, to the levator anguli scapulae, and supra-spinatus
muscles. The inferior angle'' (Fig. 35) affords attachment to the
teres major muscle, part of the serratus magnus, and (at times) a few
fibres of the latissimus dorsi. The external angle or head® presents
a shallow pyriform glenoid fossa^" (Fig. 34) for the head of the
humerus, deepened, in the fresh state, by the glenoid ligament
attached around its circumference, from the upper part of which
the long head of the biceps flexor cubiti arises. The neck^ (Fig.
35) is the slightly depressed surface surrounding the head ; the
surgical neck is well posterior to the head, passing through the
suprascapular notch*-® (Fig. 35).
How is this bone developed ?
By seven centres; one for body (seeond foetal month); two for
coracoid (one at first year, one at fifteenth to seventeenth year) ;
two for acromion; one for vertebral border; one for inferior angle
(all these last, fifteen to seventeen years) ; coössification (twenty-
two to twenty-five years).
Give the muscular attachments.
Subscapular, supra- and infra-spinatus, deltoid, trapezius, omo¬
hyoid, serratus magnus, levator anguli scapulae, rhomboideus minor
and major, triceps, teres minor and major, biceps, coraco-brachial,
pectoralis minor, platysma, occasionally latissimus dorsi.
The Arm.
Describe the chief processes and the general character¬
istics of the humerus.
This, the only arm bone, articulates above with the scapula.
THE ARM
79
below with the ulna and radius. The upper extremity, the hecL(P,
nearly hemispherical, facing upward, inward, and slightly back¬
ward, forrûs, with the glenoid fossa of the scapula,
the shoulder or scapulo-humeral joint. Best marked
superiorly is the constriction called the anatomical
indicating the capsular attachment above;
external to the head is the greater tuberosity*' with
three facets for the supra- and infra spinatus and * ||h
teres minor muscles ; in front, directed inward and M
forward, is the lesser tuberositif for the subscapular ¡ iÊ
muscle ; commencing between these two projections, , 'ji .J'
and extending- for the upper third of the bone, is ¡ ','¡1
the bicipital groove, passing obliquely downward and j ij
inward, lodging the long head of the biceps muscle;
into the anterior lip ' of this groove is inserted the j , jl
pectoralis major muscle, into the posterior lip^ the ß
latissimus dorsi and teres major; while about the H
centre of the inner border of the bone is a rough ;||
impression for the coraco-brachial muscle, just below , M
which is the nutrient canal*", directed downward.
The constriction beneath the tuberosities is called j ,»
the surgical neck. The shaft, cylindrical above, pris-
moid and flattened below, presents upon the mid-
die of its outer surface a roughness" for the deltoid
muscle, and below it, winding from behind forward tgl'iii.'" "
and downward, on the back of the bone, is the mus-
cuh-spir at groove, for the musculo-spiral nerve and superior profunda
artery, internal and external to which arise the inner and outer
heads of the triceps muscle. The lower extremity presents an inner**
(very prominent) and an outer condyle*", extending from each of
which, upward on theshaft, are the internal*" knàexternal condyloid*"
ridges*"; from the external ridge arise the external lateral ligament
and extensor and supinator muscles ; from the inner condyle and
ridge arise the internal lateral ligament and the flexor and round
pronator muscles. Projecting from the lower front portion of the
outer condyle is the radial head** (capitellum), for the head of the
radius ; while internal to this, extending from the anterior to the
posterior surface of the bone, is the pulley-like trochlear surface*^
80
ESSENTIALS OF HUMAN ANATOMY.
for the greater sigmoid cavity of the ulna. The coronoidfossa^'' in
front of the trochlea receives the coronoid process of the ulna
during flexion of the forearm, while the olecranon fossa, similarly
placed behind, accommodates the tip of the olecranon during
extension.
How is the humerus developed ?
By seven centres : one for shaft (fifth fcetal week) ; one for head
(first to second year) ; one (sometimes two) for tuberosities (second
to third year; by fifth year the centres for head and tuberosities
have coössified) ; one for radial head (second year) ; one for internal
condyle (fifth year); o'ne for trochlea (twelfth year); one for
external condyle (thirteenth to fourteenth year). The lower
centres are all coössified with the shaft by the sixteenth or seven¬
teenth year except that for the internal condyle, which unites at
eighteen years, while the head unites at the twentieth year.
Give the muscular attachments.
The supra- and infra-spinatus, teres minor, subscapular, pecto-
ralis major, latissimus dorsi, teres major, deltoid, coraco-brachial,
brachialis anticus, triceps, subanconeus, pronator radii teres, flexor
carpi ulnaris, palmaris longus, flexor digitorum sublimis, flexor
carpi radialis, supinator longus, extensor carpi radialis longiorand
brevior, extensor communis digitorum, extensor minimi digiti,
extensor carpi ulnaris, anconeus, and supinator brevis.
The Forearm.
Describe the ulna.
This, the inner forearm bone', longer than the radius, forms the
greater part of the articulation with the humerus, while it is
excluded from the wrist-joint by the interarticular fibro-cartilage.
Its upper extremity forms the point of the elbow. The olecranon
presents upon its anterior part a saddle-shaped articular
surface which, with its continuation on the coronoid process, is
the greater sigmoid cavity ' for the trochlea of the humerus ; continu¬
ous with this upon the outer side is the lesser sigmoid cavity ' for the
head of the radius; to the posterior surface is attached the triceps
THE FOREARM.
81
Fig. 37
r
tendon, and the apex is accommodated by the olecranon fossa of
the humerus during extension. Projecting forward below the ole¬
cranon is the eoronoidprocesé, fitting into the same
named fossa of the humerus during flexion, its upper
surface forming part of the greater sigmoid cavity ;
it presents, where it joins the shaft, a tubercle for
the oblique ligament, and a rowjh impression for the
brachialis anticus muscle above and internally. At
the front is a small eminence for the flexor sublimis
digitorum, whence descends à ridge for the pronator
radii teres. The shaft-, large and prismatic above,
smaller and rounded below, has on its anterior sur¬
face the nutrient foramen, directed upward, and by
its external sharp border'' affords attachment to the
interosseus ligament. The lower carpal extremity,
or head^, articulating, by its outer surface, with the
sigmoid cavity of the radius, and, by its lower, with
the triangular flbro-cartilage, has projecting inter¬
nally and behind, the styloid process^, to whose apex
is attached the internal latenal ligament, to a de¬
pression at its base the flbro-cartilage; upon the
posterior surface is a groove for the tendon of the
ul no-carpal extensor.
How is this bone developed ?
By three centres; one for shaft (eighth foetal week); one for
head (fourth year) ; one for olecranon (tenth year, joining shaft
at sixteenth year) ; head coössifled with shaft by twentieth year.
Give the muscular attachments.
Triceps, anconeus, flexor carpi ulnaris, brachialis anticus, pro¬
nator radii teres, flexor sublimis and profundus digitorum, flexor
longus pollicis (occasionally), pronator quadratus, flexor and
extensor carpi ulnaris, anconeus, supinator brevis, extensor ossis
metacarpi and secundi internodii pollicis, and extensor indicis.
Describe the radius.
Shorter than the ulna, situated upon the outer side of the fore¬
arm, with a small upper extremity, forming only a small part of
6
82
ESSENTIALS OF HUMAN ANATOMY.
the elbow-joint, its lower end is large, forming the chief part of
the wrist-joint. It is slightly curved, and of a prismatic form.
The Aeac?'' (upper extremity) is cylindrical, with slightly cupped
upper surface, articulating with the radial head of the humerus,
by its sides, with the lesser sigmoid cavity of the ulna and the
orbicular ligament by which it is embraced; the constriction
beneath the head is the nec¿" ; below, and to the inner side, is the
tuberosity^^, rough toward its posterior margin for the biceps tendon,
smooth in front for a bursa; the í/ío/¿*" is prismoid, curved out¬
ward, smaller above than below, having a sharp mietnaX interosseous
border"' for the interosseous ligament, with the nutrient foramen
directed upward at the junction of the middle and upper thirds of
the anterior surface.
The lower carpal extremity""' has on its lower face an articular
surface divided by a slight ridge into two facets for the semilunar
and scaphoid bones; upon its inner side the shallow sigmoid cavity
for the ulnar head; externally the styloid process'^ giving attach¬
ment hy its apex to the external lateral ligament, by its base to the
supinator longus muscle; and on its posterior and external convex
surfaces are five grooves for the extensor tendons.
How is this bone developed ?
By three centres ; one for shaft (eighth foetal week) ; one for
carpal extremity (second year) ; and one for head (fifth year,
joins shaft at puberty) ; bone coössified by about twentieth year.
Give the muscular attachments.
The biceps, the supinator brevis, flexor digitorum sublimus and
longus pollicis, pronator quadratus, the extensor ossis metacarpi
and primi internodii pollicis, pronator radii teres, and supinator
longus.
The Hand.
Into what segments is the hand divided ?
Into the carpus (eight bones) ; metacarpus (five bones) ; and
phalanges (fourteen bones) ; total, twenty-seven bones.
THE HAND.
83
Describe the arrangement of the carpal bones.
They are placed in two rows of four each ; thus, enumerating
from the radial to the ulnar side, with palm upward ; First, or
proximal row : scaphoid®, semilunari, cuneiform®, pisiformp.
Second, or distal row : trapeziumt, trapezoid',t, os magnum', unci¬
form".
Fig. 38.
With how many bones does each articulate?
Scaphoid, five ; semilunar, five ; cuneiform, three ; pisiform,
one; trapezium, four; trapezoid, four; os magnum, seven; unci¬
form, five ; total, thirty-four.
Describe the chief peculiarities of each bone.
The scaphoid^ (boat-shaped) has on the thumb side a tuberosity,
a transverse groove on the dorsum parallel to the convex articular
surface for radius ; facets for os magnum and semilunar bones on
its inner lower face; on its lower for the trapezium and trape¬
zoid.
The semilunar^ (half-moon) presents a convex facet above for
radius ; on its outer face a semilunar facet for scaphoid ; on its
lower, a concave one for os magnum ; a quadrilateral one on the
inner face for cuneiform.
The cuneiform'^ (wedge-shaped) .has an oval facet in front for
pisiform ; one external for semilunar ; an inferior concave facet for
84
ESSENTIALS OF HUMAN ANATOMY.
unciform ; a superior convex facet for interarticular fibro-carti-
lage.
Thtpisiformv is rounded, with one ovoidal facet for cuneiform.
The trapezium^ is obliquely grooved on its palmar surface for the
tendon of the flexor carpi radialis ; superiorly is a concave facet
for scaphoid; below, a saddle-shaped one for thumb-metacarpal;
internally, one large concave facet for trapezoid, and a smaller for
second metacarpal.
The trapezoids is wedge-shaped, apex palmar, has four articular
surfaces touching, separated by sharp edges, the external for
trapezium; inferior (like a ridge-roof), for second metacarpal;
internal, for os magnum ; superior, for scaphoid.
The OS magnum' has superiorly a convex head for scaphoid and
semilunar, a neck and body ; below, facets for three metacarpal
bones; externally,one for trapezoid; internally, one for unciform.
The unciform'^ is triangular, has a sigmoid internal articular
facet for cuneiform ; two facets below for fourth and flfth meta¬
carpals ; one, external, for os magnum ; from the palmar surface
projects the curved unciform process.
"When do these bones ossify ?
Os magnum and unciform, during first year ; cuneiform, third
year; trapezium and semilunar, flfth year; scaphoid, sixth year;
trapezoid, during eighth year ; pisiform, about twelfth year.
(The muscular attachments to the carpal and tarsal bones will
be given under the Muscular System.)
Describe the metacarpal bones.
They are five long bones, with shaft, head, and base. The first
metacarpal (sometimes considered a phalanx) is shorter, has only
one facet on base, and has one ossifie centre for shaft (eighth foetal
week), and one for haze (third year). The second metacarpal has
four facets on base for trapezium, trapezoid, os magnum, and third
metacarpal ; it, in common with the rest, has one ossifie centre for
shaft (eighth foetal week), and one for head (third year; they
coössify hy twentieth year). The third metacarpal articulates only
with the OS magnum, on the ulnar side has two small facets for
fourth metacarpal, a single facet on the radial "side for second
THE THIüH.
85
metacarpal, and the outer angle of its base is much prolonged.
The fourth metacarpal has two facets for unciform and os magnum,
a single facet on ulnar side for fifth metacarpal, and two small
ones on radial side for third metacarpal. The fifth metacarpal
articulates with unciform by a concavo-convex facet, has only a
lateral facet on the radial side for fourth metacarpal, and on the
ulnar side a prominent tubercle for the extensor carpi ulnaris
tendon.
Describe the phalanges.
Fourteen in number—three for each finger, two for thumb—they
are long bones, having a shaft, base, and condyles, except those of
the distal row. The bases of first row, cup-shapcd, articulate with
heads of the metacarpals; those of second and third have a double
concavity, separated by a median ridge, and articulate with the
condyles of the row above ; the distal extremities of the ungual
phalanges have rough, horse-shoe shaped tubercles on their palmar
surfaces tor attachment of the pulp of the finger; they ossify by
one centre for the shaft (eighth foetal week), and one for base (third
to fifth year) ; uniting, from eighteen to twenty years.
LOWER EXTREMITY.
The Thigh.
Describe the femur.
It is the longest bone of the skeleton, and inclines toward its
fellow to bring the knee-joint near the centre of gravity during
walking, this obliquity being greater in the female, from thebreadth
of the pelvis, and in a short than a tall person of either sex.
The headP-, forming rather more than a hemisphere, directed
upward, inward, and forward, has behind and below its centre an
ovoid dépression for the ligamentum teres. The ncc¿', joining the
head with the shaft, is flattened and pyramidal ; in the adult male
it forms an obtuse angle with the shaft; in the female it approaches
a right angle; in very old and debilitated subjects its direction
becomes horizontal. The great trochanter^ is a large, irregular.
86
ESSENTIALS OF HUMAN ANATOMY.
Fig.
quadrilateral eminence, directed upward, outward, and backward,
marked on its external surface by a diagonal line for the gluteus
medius ; below and behind this is a smooth surface for a bursa
beneath the gluteus maximus ; in front, from above downward, are
inserted the internal obturator and gemelli muscles,
the pyriformis, and the gluteus minimus ; upon its
: ^ inner surface is the digital fossa for the tendon of
the obturator internus muscle.
The lesser trochanter^, small and conical, projects
from the lower back part of the base of the neck,
receiving the insertion of the psoas muscle above,
and the iliacus below.
The anterio'd' and posterior intertrochanteric lines
connect these processes, the latter being the more
prominent, while to the former is attached the an¬
terior portion of the capsular ligament. Extending
from the middle of the posterior intertrochanteric
line, for about two inches down the shaft, is the
linea quadrati for the quadratus femoris muscle.
The shafd^, broad and cylindroid at either ex¬
tremity, narrow and triangular in the centre, slightly
curved forward, has its nutrient foramen at the junc¬
tion of the middle and lower thirds of its posterior
surface, directed upward; and from its anterior
surface arise the crureus and subcrureus muscles.
The linea aspera, a prominent longitudinal ridge
occupying the middle third of the posterior sur¬
face, has an external and an internal lip, and an
intermediate space; above, it divides into three
lines, one directed upward to base of greater, one to base of lesser
trochanter, a third, the most internal continuous with the anterior
intertrochanteric line, forming, with it, the spiral linê, while below
the linea aspera bifurcates to inclose the smooth popliteal space, the
inner division grooved for the femoral vessels. In general terms,
this line and its subdivisions have attached the following muscles:
the vastus internus and externus, the pectineus, the three adduc¬
tors, the biceps and gluteus maximus.
Of the two condyles, the internal^ is the longer by about half an
THE PATELLA.
87
inch, to bring both condyles on the same horizontal plane in the
normally oblique position of the femur; above each condyle,
behind, is a depression for the gastrocnemius (above the external the
plantar muscle also originates) ; separating them is the intercon-
dyloid notch, to whose sides are attached the crucial ligaments ; in
front, the condyles form a continuous cartilaginous-covered articu¬
lar surface ; the outer, as well as the inner condyle, presents a tuhe-
rosity^-^^ upon its free surface for the lateral ligaments, beneath
which, on the outer condyle, is a groove'^'' for the tendon of origin
of the popliteus muscle ; above the internal tuberosity " is a small
tubercle for the tendon of the adductor magnus.
Give the development of the femur.
By five centres ; one for shaft (fifth fœtal week) ; one for condyles
(ninth fœtal month) ; one for head (end of first year) ; one for greater
trochanter (fourth year) ; one for lesser trochanter (thirteenth to
fourteenth year) ; all coössified by twentieth year in the reverse
order of their appearance.
Give the muscular attachments.
The three glutei, pyriformis, two obturators, gemelli, quadratus,
psoas, iliacus, two vasti, biceps, pectineus, three adductors, crureus,
subcrureus, gastrocnemius, plantaris, and popliteus.
The Patella.
Describe the patella.
It is flat, triangular, placed at front of the knee-joint, and, being
developed in the quadriceps tendon, is considered a sesamoid bone
by some ; the convex anterior surface is roughened ; the posterior
surface is divided by a vertical ridge into two smooth facets for either
femoral condyle, the outer being the broader and deeper ; the apex
gives attachment to the ligamentum patella ; and the superior and
lateral borders to the rectus femoris, crureus, and vasti muscles. It
is developed by one centre (about three years) ; the muscular attach¬
ments have been already given.
88
ESSENTIALS OF HUMAN ANATOMY-
Fiö 40.
The Leg.
Describe the tibia.
The shin-bone, situated at the inner front part of the leg, is only
second in length to the femur ; the head^-^, or upper extremity, is
large and expanded on each side into two lateral tuberosities'-^,
be'aring upon their upper surfaces smooth concave ovoidalfacets for
the femoral condyles, between which is the vertical,
bifid spine* for the extremities of the semilunar
fibre-cartilages, the depressions in front and behind
its base giving origin to the crucial ligaments. Be¬
low, medianally, in front of the head, is the tuber¬
cle^ for the ligamentum patellae; separating the
tuberosities behind is the popliteal notch, giving
attachment to the posterior crucial ligament; on
the posterior surface of the inner tuberosity is a
transverse groove for the insertion of the semi¬
membranosus tendon ; upon the back of the outer
tuberosity, facing downward, is a facet for the head
of the fibula; running obliquely from this facet,
downward and inward, on the posterior surface, is
the oblique line for the popliteal fascia, parts of the
soleus, flexor longus digitorum, and tibialis posticus
muscles; just below the line, directed downward,
is the nutrient canal, the largest in the skeleton.
The prismoid shaft' has three borders, of which
the anterior, called crest or shin^, and the external
or interosseous ridge, for the interosseous membrane,
only are of importance. The lower extremitxp,
smaller than the upper, has an inferior concave
surface for the astragalus, an external rough trian¬
gular surface for articulation with the flbula; it
is grooved posteriorly for the flexor longus pollicis tendon ; has
projecting downward, internally, the internal malleolus^, which
articulates by its outer surface with the side of the astragalus, is
grooved behind for the tibialis posticus and flexor longus digitorum
tendons, and has attached to its tip the internal lateral ligament.
i;
THE LEG.
89
How is this hone developed ?
By three centres : One for shaft (seventh foetal week) ; one for
head (at birth); one for lower end (second year); bone coössified
by twentieth year (some authors say twenty-fifth year).
Give the muscular attachments.
Semimembranosus, tibialis anticus and posticus, biceps, extensor
and fiexor longus digitorum, sartorius, gracilis, semitendinosus,
popliteus, soleus, and quadriceps femoris.
Describe the fibula (peroneal bone).
It is long, slender, and is placed externally nearly parallel to
the tibia.
The head^" or upper end articulates by a flattened facet with
the external tibial tuberosity®, and is prolonged upward behind
into the styloid process for the biceps tendon and the external
lateral ligament; below and behind is attached the long external
lateral ligament.
The shaffi, triangular and twisted, has three ridges, the internal
or interosseous ridge being for same-named ligament; about the
middle of the anterior internal surface is Ihe nutrient foramen
directed downward. The external malleolus " forming the lôwer ex¬
tremity, longer than the internal, articulates by its inner surface
with the outer side of the astragalus; is grooved behind for the
peroneus longus and brevis tendons; to its summit is attached the
middle, and to rough depressions in front and behind the anterior
and posterior fasciculi of the external lateral ankle-ligament.
Describe its development.
By three centres ; One for shaft (eighth foetal week) ; one for
malleolus (second year); one for head (fourth year); bone coössi¬
fied by twenty-fifth year, but, contrary to rule, the lower epiphysis
unites first.
Give the muscular attachments.
Biceps, soleus, three peroneals, the extensor and flexor of the
great toe, and extensor longus digitorum, and tibialis posticus.
90
ESSENTIALS OF HUMAN ANATOMY.
The Foot.
Into what segments are the hones of the foot divided ?
Into the farms (7); metatarsus (5); and phalanges (14); total, :^6
bones.
Name the tarsal hones.
Calcaneum' (os caléis), astragalus', cuboid®, scaphoid*, internaP,
middle®, and external' cuneiform.
Give the chief peculiarities of each tarsal bone.
The astragalus^ has a large rounded head^, a neck, a body^, supe¬
riorly a trochlear surface broader in front than behind, for the tibia,
and continuous with it on either side facets for the internal and
external malleolus; the under surface presents two articular facets
—that behind for the caléis, that in front partly for calcis but
chiefly for the calcaneo-scaphoid ligament—separated by a groove
for the calcaneo-astragaloid ligament, running obliquely forward
and outward; it articulates with the tibia, fibula, os calcis, and
scaphoid, and is developed by one centre (seventh fœtal month).
The OS calciê, the largest tarsal bone, forms by its tuberosity^ be¬
hind the heel, has a groove on its upper surface to correspond to
that of the astragalus; behind and in front of which are two artic¬
ular facets for the same bone: on the inner side projects the susten¬
taculum tali supporting the internal articulating surface; beneath
this process the inner surface of the bone is deeply concave for the
flexor tendons, plantar vessels, and nerves ; its anterior concavo-
convex surface articulates with the cuboid; on the under surface
are an inner and outer tuberosity, it articulates with the astragalus
and cuboid, and is developed from two centres, one for main mass
(sixth fœtal month) ; one for tuberosity (tenth year) ; union after
puberty.
The cuboid has one articular surface each for os calcis, external
cuneiform, the fourth and fifth metatarsals, and sometimes the
scaphoid ; upon the under surface is a deep groove for the peroneus
longus tendon, and behind this a ridge terminating externally in a
tuberosity, it is developed from one centre (ninth fœtal month).
THE FOOT.
91
The scaphoid, situated internally, is concave behind for the head
of the astragalus; is convex in front with three facets for the three
cuneiform hones; externally is a facet for the cuboid ; and intern¬
ally, below, is the tuberosity for part of the pos¬
terior tibial tendon; it is developed from one
centre (fourth year).
The internal cuneiform, the largest, is placed
at the inner side of the foot, has its base down¬
ward, upon which is the tuberosity for part of
the tendon of the posterior tibial muscle; in
front is a kidney-shaped facet for first meta¬
tarsal ; externally are two facets for the second
metatarsal in front, the middle cuneiform he-
hind; posteriorly a facet for the scaphoid; it
is developed by one centre (third year).
The middle cuneiform, the smallest, has its base
upward, a triangular facet in front for second
metatarsal, another behind for the scaphoid ;
along the posterior and superior borders of the
inner face a facet for the internal cuneiform;
and externally a smooth facet for the external
cuneiform ; it is developed by one centre (fourth
year).
The external cuneiform is intermediate in size
with base upward, has an anterior triangular facet for third meta¬
tarsal; another posterior for the scaphoid; two upon internal sur¬
face for second metatarsal and middle cuneiform; and two upon
outer surface for fourth metatarsal and for cuboid: it is developed
by one centre (first year).
Describe the metatarsal bones.
These five long bones have prismoid shafts', anteriorly a head
for articulation with the phalanges, posteriorly a base articulating
with the tarsus and one another.
The first metatarsal is shorter, much stouter, and articulates only
with the internal cuneiform: developed by one centre for shaft
(seventh fœtal week) ; one for base (fifth year), united by the
twentieth year.
92
ESSENTIALS OF HUMAN ANATOMY.
The second metatarsal, the longest, articulates posteriorly with
the middle cuneiform, and laterally with the other cuneiforms,
presenting, therefore, three facets on base; developed hy one centre
(seventh foetal week) for shaft, one for head (third year), united at
twenty years.
The third metatarsal has a facet on base for external cuneiform,
two on its inner side and one on its outer for the contiguous meta¬
tarsal ; developed like second.
The fourth metatarsal articulates behind with cuboid, has a facet
on inner side divided into anterior portion for third metatarsal, a
posterior for external cuneiform, and externally one facet for fifth
metatarsal : developed like second.
The fifth metatarsal has a triangular oblique surface for the
cuboid, continuous internally with one for fourth metatarsal ; ex¬
ternally a tubercular emnewee; developed like second.
Describe the phalanges.
They resemble closely those of the hand, except that they are
strongly compressed from side to side, instead of from before back¬
ward : ossification also, similar but later. Thus, the shaft centres
appear from two to four months, except distal at seventh foetal
week.
THE ARTICULATIONS.
How are the articulations classed ?
In three divisions ; 1. Synarthroses, immovable, as most of cranial
articulations ; 2. Amphiarthroses, including synchondroses, or sym¬
physes, yielding (limited motion), as those between the vertebral
bodies, the pubic and sacro-iliac symphyses ; 3. Diarthroses, freely
movable.
Into what classes are the synarthroses divided ?
1. Sutura vera, consisting of interlocking serrations, including
three sub-classes of S. dcntata, when the bony projections are
tooth-like, as the inter-parietal suture ; S. serrata, when like a fine
saw, as the inter-frontal ; S. limhosa, when the edges are bevelled in
addition to dentation, as the fronto-parietal. The Sutura notha (false
THE ARTICULATIONS.
93
sutures) include S. squamosa, formed by two overlapping bevelled
edges, as the squamo-parietal suture; and the S. harmonía, mere
apposition of roughened surfaces, as the two superior maxillary
bones.
2. Schindelysis, where a thin edge is received into a cleft or fissure,
as the vomer between the superior maxillary bones.
3. Gomphosis, the insertion of a conical process into a socket, as
teeth in their alveoli (not really a bony articulation, as teeth are
not bones).
How are diarthroses classed ?
As arthrodia, gliding joints—the articular processes of the verte¬
brae; enarthroses, ball-and-socket joint—hip- or shoulder-joints;
ginglymus, hinge-joint—elbow-joint; diarthrosis rotatoria, or lateral
ginglymus, a pivot turning within a ring, or a ring on a pivot, as
the superior radio-ulnar and atlo-odontoid.
What varieties of motion do joints enjoy?
Flexion, extension, adduction, abduction, circumduction (a com¬
bination in succession of the four preceding), rotation, and gliding.
What structures are essential to the formation of each of
the three classes of articulations ?
For synarthroses, two or more bones, an interposed layer of
fibrous tissue (sutural ligament) or, perhaps, cartilage (base of
the skull) ; symphyses, an interposed bond of fibro-cartilage, with
strong bands of white fibrous tissue, i. e., ligaments (ligaments
are sometimes composed of yellow elastic tissue, as the liga-
menta suhflava or ligamentum nuchae); diarthroses, two or more
cartilaginous-coated surfaces (reducing friction), sometimes inter-
artieular fibro-cartilages to deepen joint surfaces, as those of the
knee- and temporo-maxillary joints, a complete fihrous capsule,
and often additional ligamentous bands, some inter-articnlar, i. e.,
within the joint cavity, and a synovial (serous) membrane lining
the interior of the capsule, but not extending upon the cartilages;
a similar membrane also forms sacs (hursae) outside the joints, with
which they often eommunicate, serving to reduce friction of the
tendons, ligaments, etc. ; the layer of bone beneath the articular
94
ESSENTIALS OF HUMAN ANATOMY.
cartilage is denser, contains neither Haversian canals nor canali-
culi, and has larger lacunae.
What is the rule as regards the nerve supply of joints ?
The interior of the joint, the muscles moving it, and the skin
over their insertions, are supplied by the same trunk or trunks of
nerves (this explains the reflex contractions of diseased joints).
Describe the vertebral articulations.
Formed by the contiguous surfaces of the vertebral bodies and
articular processes, their ligaments are as follows :
An intervertebral connecting fibro cartilage, between the bodies of
all true vertebrae, except the atlas and axis.
An anterior common ligament^ passing medianally over the fronts
of the vertebral bodies, most flrmly attached to their margins.
A. posterior common ligament, similarly disposed behind.
Short intervertebral ligaments, fibres running at most over three
vertebrae, firmly uniting the bodies where the anterior and pos¬
terior common ligaments are deficient.
Ligamenta subflava, of yellow elastic tissue, connecting the
laminae.
Supra- and inter-spinous, the former connecting the tips, the latter
the remainder of the spinous processes.
Capsular^, enclosing the articular processes, and lined with syno¬
vial membrane.
Inter-transverse, connecting transverse processes; nerves, spinal
in each region ; arteries, vertebral and ascending cervical arteries
in neck, intercostals in dorsal region, lumbars in loin.
Describe the occipito-atloid articulation.
It is a ginglymo arthrodial joint formed by the condyles of the
occipital bone and the superior articulating processes of the atlas.
Its ligaments are.
An anterior occipito atlantaP (Fig. 42), extending from the an¬
terior margin of the foramen magnum to the anterior arch of the
atlas, about one inch broad, blending on either side with the
capsular ligaments.
A posterior occipito-atlantal, much broader, from the posterior
margin of the foramen magnum between the condyles, to the pos-
THE ARTICULATIONS.
95
tero-superior border of the posterior arch of the atlas, and is incom¬
plete on each side for the ingress of the vertebral artery, and egress
of the suboccipital nerve.
Two capsular ligamenW, lined with synovial membrane, surround¬
ing the articular surfaces.
Two lateral {oT anterior oblique), passing upward and inward from
the transverse process beyond the vertebral foramen to the inner
edge of the jugular foramen;
nerve, suboccipital ; arteries, from
vertebral.
Describe the atlo - axoidean
points.
The lateral joints are arthrodia,
that I etween the atlas and odon¬
toid process a double diarthrosis
rotatoria. The ligaments of the
lateral joints and arches are.
The anterior atlanto-axoidean*,
membranous, passing between lower front border of atlas to front
of the axis.
The posterior atlanto-axoidean, stretching between the postero-
inferior edge of the ring of the atlas to the superior edge of the
arch of the axis behind ; it is pierced on each side by the second
spinal nerve.
The anterior 3.nA.posterior common ligaments are continued over
the median portions of the above to the occiput.
Two capsulari^^ synovial-lined, surrounding the articulating
processes.
The ligaments of the central atlanto-axoidean joints are :
The transverse^ (F'g- 43), extending between the tubercles on the
inner surface of each lateral mass of the atlas; it holds the odon¬
toid process in place, and between the two is a synovial membrane
surrounded by a capsule, the odonto-transverse joint ; between the
odontoid process and the posterior surface of the anterior arch of
the atlas, is the atlo-odontoid articulation, surrounded by a capsule
lined with synovial membrane; passing upward and downward,
are two strong vertical bands, attached above to the cranial surface
Fig. 42.
96
ESSENTIALS OF HUMAN ANATOMY.
of the basilar margin of the foramen magnum, below, to the upper
half of the body of the axis, forming the occipito-axiodean liga-
or vertical portion of the crucial ligament; nerves, all these
joints are supplied by the second cervical or loop between it and
the suboccipital ; arteries, are branches of vertebral.
What other ligaments connect the axis and occiput ?
The posterior common ligament extends upward, to be attached
far up the basilar process; beneath this is,
The occipito-cervical or cervico-basilar ligament, attached above to
the basilar groove of the occiput, below, to the third cervical
Fig. 43. FIG. 44.
body and that of the axis ; (next comes the vertical part of the
crucial already described) ; deepest of all are the,
Occipito-odontoid, or eheclc', extending from the sides of the apex of
the odontoid to inner edge of the anterior portion of the occipital
condyles, while stretching between the odontoid tip and the under
surface of the basilar process close to the foramen magnum, is the
Central occipito-odontoid, or ligamentum Suspensorium.
Describe the temporo-maxillary articulation.
The upper compartment is arthrodial, formed by the glenoid
fossa and eminentia articularis of the temporal bone and the upper
surface of the fibro-cartilage ; the lower is ginglymoid, between
the under surface of the fibro-cartilage and the condyle of the
lower jaw. The ligaments are capsular, passing between maxillary
and temporal bones near their margins, consisting of ligamentous
fibres, which are thicker at certain parts, and are described as
THE ARTICULATIONS.
97
The external lateral ligament^, attached above to nearly the whole
length of the lower edge of the zygoma and its tubercle, below to
the outer side of the neck of the condyle of the jaw.
The short internal lateral ligament, extending between the spine
of the sphenoid and inner edge of the glenoid fossa, and a ridge
on the inner side of the neck of the condyle.
The long internal lateral ligament, stretching between the spine
of the sphenoid and the forepart of the tip of the inferior dental
foramen.
The inter-articular fibro-cartilage, concavo-convex on the upper
surface, concave obliquely transversely below, dividing the joint
into two separate synovial cavities.
The stylo-maxillary ligament^, extending from the styloid process
to the angle of the jaw, is really a process of the deep fascia;
nerves, the masseteric and auriculo-temporal branches of the infe¬
rior maxillary nerve ; arferies, temporal, middle meningeal, ascend¬
ing pharyngeal, posterior auricular, tympanic branch of the
internal maxillary and ascending palatine.
Describe the costo-vertebral articulations.
These are each formed (1) between the head of a rib and the
bodies of two adjoining vertebrae (except first, tenth, eleventh,
and twelfth, which articulate with but one vertebra each), being
ginglymoid; and (2) between the tubercle of each rib (except
eleventh and twelfth) and the transverse process of a vertebra,
and is arthrodial.
Describe the costo-central articulations.
Ginglymoid, the ligaments are (1) : Eio. 45.
A capsular ligament*', attached all
around each articular surface, the syno¬
vial lining being subdivided into two
cavities by the
Inter-articular, or costo-vertebral liga¬
ment^, passing between the ridge on the
head of the rib to the intervertebral
fibro-cartilage.
The stellate ligament, arising from the
7
98
ESSENTIALS OF HUMAN ANATOMY.
anterior surface of the neck of the rib, whence the fibres radiate
to the vertebra next above and below to the one the rib belongs
to, and to the intervertebral disk; nerves, anterior branches of
spinal nerves ; arteries, the intercost.ils.
Describe the costo-transverse articulations.
Arthrodial, ten in number, their ligaments are :
Capsular, attached beyond the margins of the articular facets.
Superior cosio-transversê (except first rib), passing between upper
border of neck of rib to lower margin of transverse process of the
vertebra above.
Middle costo-transverse, connecting the back of neck of rib with
the contiguous portion of transverse process of vertebra to which
rib belongs.
Posterior costo-transverse, stretching from the tip of transverse
process to rough projection beyond facet on the tubercle of rib;
nerves, posterior branches of dorsal nerves ; arteries, intercostals
and posterior spinal.
Describe the (1) costo-stemal articulations, (2) the counec-
tiou between the ribs and costal cartilages, and (3) the
interchondral joints.
(1) The first is synarthrodial, the other six joints are ginglymoid.
The costal (2) cartilages are firmly attached to the cup-like depres¬
sion at the end of each rib, and by the periosteum continued over to
form the perichondrium ; in like manner, the cartilage of the first
rib unites with the sternum. The cartilages of the remaining six
ribs are bound to the sternum by a.
Complete capsular ligament, the anterior and posterior thicker
segments sometimes described as.
Anterior and posterior costo sternal ligaments. Occasionally there
is an interarticular ligament, notably in the second costal joint,
dividing the synovial cavity into two.
The (3) interchondral articulations, arthrodial, are usually, but not
always, found between the edges of the fifth to tenth ribs, inclusive,
having each an interchondral ligament and a capsular, lined with
synovial membrane ; they are commonly found only from the sixth
to the ninth cartilages; in addition, the costo-xiphoid ligament
THE ARTICULATIONS.
99
binds the xiphoid cartilage and sixth and seventh cartilages
together; nerves, intercostals; arteries, internal mammary or its
branches.
Describe the ligaments of the sternum.
All three segments are bound together by the so-called,
Anterior and posterior ligaments, with a layer of cartilage between
tbe manubrium and gladiolus (an amphiarthrodial joint, that be¬
tween ensiform cartilage and gladiolus being synarthrodial).
Describe the sacro-vertebral articulation.
Similar to other vertebral articulations, but has, in addition.
The sacro-lumbar ligament, extending from the transverse
processes, pedicles, and body of the fifth lumbar vertebra to the
non-articular portions of the base of the sacrum and periosteum
of the contiguous portions of ilium.
The ilio-lumhar ligament^ (Fig. 46), extending from the front
surface and back of the tip of the transverse processes of the fifth,
and lower edge and front surface, the transverse processes and
pedicles of the fourth lumbar vertebra, to the back part of the
iliac crest ; nerves, fourth and fifth lumbar, sympathetic ; arteries,
ilio-lumbar, last lumbar, lateral sacral.
Describe the sacro-iliac articulations.
They are amphiarthrodial, formed between the auricular surfaces
of the ilium and sacrum, and have the following ligaments upon
each side, in addition to the symphyseal cartilage:
The anterior sacro-iliac^ (Fig. 47), from the first three pieces of
the sacrum to the ilium above the great sacro-iliac foramen.
The posterior sacro-iliac^ (Fig. 46), very strong, extending be¬
tween back of the sacrum and posterior two inches of the iliac
crest, including the posterior superior spine.
The oblique, stretching between the third transyerse tubercle of
the sacrum to the posterior superior iliac spine.
Superior and inferior, bands of fibrous tissue closing in the joint
abov'e and below.
The interarticular (interosseous), strongest of all, consists of
numerous ligamentous bands passing between the contiguous
100
ESSENTIALS OF HUMAN ANATOMY.
rough surfaces of the sacrum and ilium ; nerves, from posterior
sacral and lumbo-sacral cords; arteries, gluteal, ilio-lumbar, and
sacral spinal.
Describe the ligaments connecting the sacrum and ischiatic
bones on each side.
They are the,
Greater sacro-sciatic^, thin, triangular, passing from posterior
inferior iliac spine, fourth and fifth transverse sacral tubercles and
lower lateral margins of sacrum and coccyx, to the inner margin
of the ischiatic tuberosity.
The lesser sacra-sciatic'', posterior to former, of same shape,
stretching between lateral margins of sacrum and coccyx, and the
spine of the ischium.
These ligaments convert the two sacro-sciatic notches into the
greater (by lesser ligament) and lesser (by greater ligament) sacro-
sciatic foramina, described under iliac and ischiatic bones.
Describe the sacro-coccygeal articulation.
Amphiarthrodial, its ligaments are,
An interarticular fibro-cartilage, like that of a vertebra.
An anterior sacro-coccygeal, a continuation of the anterior common
vertebral.
Fig. 46,
THE ARTICULATIONS.
101
A ■posterior sacro-coccygeal, a continuation of the posterior com¬
mon vertebral.
hdcr-cornual inter-transverse bands, connecting parts of same
name ; ■nerves, anterior and posterior branches of the fifth sacral
and coccygeal, posterior division of fourth, and probably second
and third sacral; arteries, lateral and median sacral.
Describe the pubic articulation.
Amphiarthrodial, between the two pubic bones ; its ligaments are
An interossew fibro-cartilage.
A supra-pubic, extending along crest of pubes on each side,
blending with fibro-cartilage.
Kposterior, little more than periosteum.
An anterior, thick, strong, decussating, attached to contiguous
portions of body and rami.
An inferior, or sub-pubic, arched, filling up angle between pubic
rami ; nerves and arteries of no special moment.
The obturator ligament? is a fibrous membrane filling the same
named foramen, except at upper outer part.
Describe the sterno-clavicular articulation.
An arthrodial ]oint formed between the sternal end of the clavicle,
and the sternum and cartilage of the first rib, having an inter-
articular fibro-cartilage usually dividing the joint into two distinct
synovial sacs ; its ligaments are,
A capsular (usually described as anterior, posterior, etc.) passing
between the articular margins, and firmly connected with the fibro-
cartilage.
The inter-clavicular, passing from the posterior superior angle of
the inner extremity of each clavicle, and attached to the sternum
between.
The rhomboid, or costo-claiAcular, stretching from the upper
border of the first costal cartilage to the rhomboM impression of
the clavicle ; nerves, from descendons noni ; arteries, contiguous
muscular branches.
Describe the acromio-clavicular articulation.
An arthrodial joint formed by the outer extremity of the clavicle
and the acromion process of the scapula ; it frequently has an inter-
102
ESSENTIALS OF HUMAN ANATOMY.
articular fibro-cartilage and two synovial sacs, otherwise there is
only one sac ; its ligaments are,
The capsular^, attached to anterior and posterior borders, upper
and lower surfaces of the acromion and clavicle.
The coraco-clavicular^, composed of the conoid'', conical, attached
by apex to base of coracoid process, by base to conoid tubercle of
clavicle and a line internal to it.
Trapezoid', broad and thin, quadrilateral, stretching between
ridge on upper surface of coracoid to oblique line on under surface
of clavicle ; nerves, supra-scapular, anterior circumflex • arteries,
supra-scapular, anterior circumflex, acronjial thoracic.
What ligaments bind together the scapular processes ?
The coraco-acromial^, a triangular flat band, attached by apex to
summit of acromion, by base all along outer border of coracoid
process.
What other ligament of the scapula has not yet been
described ?
The transverse', bridging across the supra-scapular notch.
Describe the shoulder-joint.
An enarthrodial joint formed by head of the humerus and glenoid
fossa of the scapula. Its synovial membrane is reflected upon the
tendons of the biceps, subscapular, and infra-spinatus muscles, and
the joint has numerous bursae in its vicinity, with some of which
it communicates, notably the subacromial and subscapular ; the
ligaments are.
Capsular', from the margin of the glenoid fossa above, below,
and behind, in front extending up on the venter half an inch or
more, to be attached by its upper half to the anatomical neck of the
humerus, its lower some distance from the articular margin.
Ccrraco-humeral^, a superadded band stretching from coracoid
process of scapula to greater humeral tuberosity.
The glenoid, a dense fibro-cartilage, triangular in cross-section,
attached to circumference of fossa, deepening the socket, and con¬
tinuous above with the long head of biceps muscle', which really
serves as one of the chief ligaments ; nerves, supra-scapular, cir-
THE ARTICULATIONS.
103
cumflex, subscapulars ; arteries, supra-scapular, subscapular, dor-
salis scapulae, anterior and posterior circumflex.
Describe the elbow-joint.
Ginglymoid, formed by lower end of the humerus, greater sig¬
moid cavity of ulna and head of radius, its ligaments are.
FIG. 47. Fig. 48.
A capsulé, large, capacious, and usually described as anterior,
posterior, irUemal, and external ligaments.
The anterior segment^ extends from humerus, above articular
surface and coronoid fossa, to front of coronoid process of ulna
and neck of radius.
The posterior segment extends from the back of the humerus,
from condyle to condyle, and above the oleeranon fossa, to be
attached all around the olecranon process, close to its articular
margin, and to back of neck of the radius and coronary ligament
of the same.
104
ESSENTIALS OF HUMAN ANATOMY.
The external lateral radiates from lower part of condyle to outer
side of neck of radius and coronary ligament.
The internal lateral^, triangular, rises from antero-inferior aspect
of inner condyle, and is attached to inner side of shaft of ulna
and olecranon process; nerves, musculo-cutaneous, ulnar, median,
musculo-spiral ; arteries, the two profunda arteries, anastomotica
magna, anterior and posterior ulnar récurrents, posterior interos¬
seous recurrent, and radial recurrent.
Describe the superior radio-ulnar articulation.
It is a diarthrosis rotatoria, or trochoides, formed by head of
radius and lesser sigmoid cavity of ulna, its synovial membrane
being continuous with that of elbow-joint ; its only ligament is the
Orbicnilar^, surrounding the head of the radius, forming only
three-fourths of a circle by most of its fibres, but some, continued
below the sigmoid cavity, form a complete circle : nerves and arte¬
ries, those of elbow.
Describe the inferior radio-ulnar articulation.
A lateral ginglymus, formed by ulnar head and sigmoid cavity of
radius ; its synovial membrane is so loose as to be called the mem¬
brana saccifonnis ; the ligaments are,
The triangular fibro-cartilage, attached by apex to fossa at base
of styloid process of ulna, by its base to margin of radius below
sigmoid cavity.
The anterior radio-ulnar stretches between anterior edge of sig¬
moid cavity of radius to rough surface above articular surface of
ulna.
The ^posterior radio-ulnar is similarly attached behind ; nerves,
median and posterior interosseous ; arteries, anterior and posterior
interosseous and carpal arch.
What other ligaments bind the radius and ulna together ?
interosseous membrane^, passing obliquely downward from the
interosseous ridge of the ulna to that of the radius.
The obliqued, attached to the tubercle at base of coronoid process
of ulna above, and below to the lower posterior edge of the
tubercle of radius ; nerves and arteries are from anterior interos¬
seous nerve and artery.
THE ARTICULATIONS.
105
Describe the wrist-joint.
Is ginglymoid, with a hinge-movement, not only of flexion and
extension, hut adduction and abduction, a combination of these
producing circumduction, thus providing a joint with nearly
every movement of a ball-and-socket joint, without its insecurity.
It is formed between the radius and triangular fibro-cartilage
above, and the first row of carpal bones below ; its ligaments are.
An anterior radio-carpal, passing between the radius above the
articular face and the flbro-cartilage, and the first and second
rows of carpal bones.
A posterior radio-carpal, similarly disposed, except that, above,
it is in addition attached to styloid process of ulna.
An interruxl lateral, fan-shaped, passing from styloid process of
ulna to pisiform, and side and back of cuneiform bones.
An external lateral, radiating from tip and front of styloid process
of radius to scaphoid, os magnum, and trapezium ; the posterior
annular ligament also assists the wrist ligaments proper; nerves,
ulnar, median, and posterior interosseous; arteries, anterior and
posterior carpal arches, radial and ulnar.
Describe the carpal articulations.
Arthrodial, they consist of (1) the joints between the first row ;
(2) those between the second ; and (3) those between the two rows,
the medio-carpal.
(1) The pisiform has a separate capsular ligament, with two
bands connecting it with the unciform and base of fifth metacarpal,
and a separate synovial membrane ; the other three hones of this
rows are connected by two
Interosseous ligaments, between scaphoid and lunar, and lunar
and cuneiform; and
Two dorsal and two palmar ligaments, binding together the same
bones.
(2) The bones (4) of second row have
Three interosseous ligaments, connecting the os magnum with the
trapezoid externally, the unciform internally ; a third between the
trapezium and trapezoid ; and
Three dorsal and three palmar ligaments, passing between the con¬
tiguous bony surfaces.
106
ESSENTIALS Of HUMAN ANATOMY.
(3) The two rows are united by
A dorsal and palmar ligament and two laterals, continuous with
those of the wrist-joiiit ; the anterior annular ligament, passing from
the hook of the unciform and from pisiform to the trapezium and
scaphoid bones, is an important carpal ligament. The synovial
membrane is common to all the carpal joints, except pisiform-,
nerves, posterior interosseous, median and ulnar; arferie«, anterior
and posterior carpals of radial and ulnar, carpal of anterior inter¬
osseous, interosseous recurrent, carpal of deep palmar arch, and
terminal twigs of anterior and posterior interosseous.
Describe the carpo-metacarpal articulations.
That of thumb is arthrodial, and enjoys all movements but rota¬
tion of the metacarpal on its own axis ; it possesses a distinct
synovial sac, and its only ligament is the
Capsule attached around the articular surfaces of trapezium and
first metacarpal.
The other four metacarpals form aríAroííiaí joints with the adja¬
cent carpal bones, with three dorsal ligaments, passing from trape¬
zium, trapezoid, and os magnum to second bone ; two ligaments
from OS magnum to third ; two ligaments—one from magnum, the
other from cuneiform—to fourth ; one ligament connecting the fifth
metacarpal and unciform.
One palmar ligament passes from trapezium to second metacarpal ;
one ligamentQa.c\i from trapezium, magnum, and unciform to third;
one ligament connects unciform and fourth bone; one tigament
passes from unciform to fifth metacarpal.
An interosseous ligament connects the contiguous inferior angles
of OS magnum and unciform with adjacent surfaces of third and
fourth metacarpal bones ; the synovial membrane is that common
to intercarpal joints, sometimes the joint formed between fourth
and fifth metacarpals and unciform forms a separate synovial sac ;
nerves and arteries are same as medio-carpal joint.
Describe the union of the metacarpal bones with one
another.
That of the thumb is isolated ; the bases of the others are in
contact, forming arthrodial joints, lined by prolongations of syno-
THE ARTICULATIONS.
107
vial sac of carpus, and are bound together hy palmar, dorsad, and
interosseous ligaments', a transverse ligament binds together their
heads.
Describe the metacarpo-phalangeal and interpbalangeal
articulations.
Ginglymoid, they are connected by two lateral ligaments, and an
anterior fibro cartilage, or glenoid ligament, except for thumb, where
this is replaced by two sesamoid bones, while behind an expan¬
sion of the extensor tendon and some loose areolar tissue completes
each little synovial lined capsule; nerves and arteries from digitals ;
the inter-phalangeal joints resemble the metacarpo-phalangeal in
every respect.
Describe the hip-joint.
An enarthrodial, but not so freely moving joint as that of the
shoulder, it is formed by the head of the femur and the acetabulum
on the OS innominatum ; the ligaments are
capsular^, arising near to acetabular margin, and from outer
surface of the transverse ligament, it is attached at the femur, in
front to the trochanter major, the spiral line (chiefly formed by
anterior intertrochanteric line), and behind, to the neck from one-
half to two-thirds of an inch from the posterior intertrochanteric
line ; the capsule has a thicker anterior segment, or superadded
band, called
The ilio-femoraV', or Y-ligament, arising from the anterior inferior
iliac spine to be attached to the anterior intertrochanteric line,
the outer and inner margins so well marked as to seem like distinct
ligamentous bands.
The ligamentum teres^", arising by separate heads from each side
of the cotyloid notch externally, passes beneath the transverse
ligament covered by the synovial membrane to be attached to a
depression on the head of the femur.
Cotyloid, a marginal fibro-cartilage attached all around the
acetabular margin and upper surface of the transverse ligament,
deepening the socket.
Transverse, a band of unyielding ligamentous fibres bridging the
cotyloid notch, converting it into a foramen ; nerves, from anterior
108
ESSENTIALS OF HUMAN ANATOMY.
crural, obturator, accessory obturator, nerve to quadratus femoris
muscle, great sciatic or lower part of sacral plexus ; arteries, inter-
Fig. 49.
nal and external circumflex, obturator, gluteal, and sciatic. The
synovial membrane commonly communicates with the bursa beneath
the ilio-psoas muscle.
Describe the knee-joint.
Ginghjmoid, formed by condyles of femur, upper surface of tibial
head, and patella, it has the largest synovial sac of any joint, send¬
ing a prolongation beneath the popliteus muscle and either another
two or three inches up the front of the femur, or communicating
with a bursa there placed heneath the quadriceps tendon; the
bursa between the semi-memhranosus and internal head of gas¬
trocnemius, and inner condyle, usually communicates with the
joint, and often one or more of the remaining bursse near the
articulation ; its ligaments consist of.
An anterior or ligamentum patella^ (Fig- 51). a continuation of the
quadriceps tendon attached to the tubercle of the tibia helow,
which, with the fibrous hood formed by the two vasti tendons
attached to the patellar margins and the oblique lines on the head
THE ARTICULATIONS.
109
of tibia extending upward from the tubercle, cover in the joint in
front blending with the lateral ligaments.
The posterior or ligamentum Winslowii^ (F'g- 50), formed of dense,
interlacing fibres, having incorporated with it part of the semi¬
membranosus tendon' (Fig. 50), arises close above the femoral
condyles and intercondyloid notch from one lateral ligament to
the other, and is fixed to the border of the outer tibial tuberosity,
the bone below the popliteal notch and the shaft below the inner
tuberosity.
The internal lateral^, a strong flat band passing from the depres¬
sion on inner femoral condyle to the inner border and surface of
shaft of tibia for an inch and a half below the head: it is attached
to the internal semilunar fibro-cartilage.
7he external laterals, two in number:
7 he long*', a rounded cord attached above to external tuberosity
of femur, below to outer part of head of fibula embraced by tendon
of biceps ;
The short, behind and parallel to above, attached above to lower
part of outer femoral tuberosity, below to summit of styloid process
of fibula; it is intimately connected with capsule; all the preced¬
ing ligaments together form a complete
Fiq. 50.
Fig. 51.
B'
no
ESSENTIALS OF HUMAN ANATOMY.
Capsular ligament, within which are,
The internal ligaments ;
The anterior crucial'', from inner side of depression in front of
spine of tibia to inner back part of outer condyle of femur;
The posterior cruciaP, from hack part of depression behind tibial
spine and popliteal notch to outer fore part of inner condyle—both
crucial ligaments are attached to respective extremities of external
semilunar fibro-cartilage.
Two semilunar fibro-cartilages^-'' (Fig. 51), attached by extrem¬
ities to the depres.sions in front and behind the spine of tibia;
they serve to deepen the sockets for femoral condyles, and are at¬
tached to head of tibia by the coronary ligaments, short bands pass¬
ing between their outer margins and the tibial head, they are also
connected to one another, in front, by the small hand-like trans¬
verse ligament*-, stretching from front of joint, below patella, to front
of intercondyloid notch, is the triangular fold of synovial mem¬
brane called the
Ligamentum mueosum, from whose sides extend upward and out¬
ward to the sides of the patella, the fringe-like folds termed liga-
menta alaria; nerves, internal and external popliteal, anterior
crural, obturator; arteries, five articular from popliteal, anastomo-
tica magna from femoral, recurrent anterior tibial ; in addition to
bursa, already mentioned there is one over patella and its liga¬
ment, one beneath ligamentum patellae, one between inner ham¬
strings and tibial head, and one or more, not always present,
beneath contiguous tendons.
Describe the inferior tibio-fibnlar articulation.
Arthrodial, formed between facets on fibular head and outer
tuberosity of tibia, its ligaments are really a capsule, described as,
Anterior superior tibio-fibular'" (Fig. 51), directed obliquely up¬
ward and inward from fibula^ to tibia ,
Posterior superior tibio-fibular'° (Fig. 50), similarly disposed be¬
hind; the synovial membrane communicates with that of knee in
twenty-five per cent, of specimens ; nerves, from external popliteal ;
arteries, some of those of knee.
Describe the so-called middle tibio-fibnlar articulation.
The contiguous borders of the bones are connected by the inter-
THE ARTICULATIONS
111
osseous membrane" (Fig. 51), deficient above for passage of anterior
tibial artery, below it is perforated by anterior peroneal vessels ; its
fibres pass from fibula upward to tibia.
Describe the inferior tibio-fibular joint.
Arthrodial, formed superiorly by the rough surfaces of the con¬
tiguous bones, below by small cartilage-coated surfaces ; its syno¬
vial membrane is part of that of the ankle.
The ligaments are :
Inferior interosseous, really thicker part of interosseous membrane
passing between the rough surfaces of the two bones.
Anterior and posterior inferior tibio fibular, oblique fibrous bands
binding together the contiguous bony surfaces in front and be¬
hind.
Transverse, a narrow band passing from external malleolus to
tibia behind the joint; nerves, those of ankle; arteries, some of
those of ankle.
Describe the ankle-joint.
Ginglymoid, formed by lower end of tibia with its malleolus and
the external malleolus, and the upper surface and sides of the
astragalus ; its ligaments are the.
Anterior^ (Fig. 53), connecting the articular margins of the tibia
and fibula with the rough upper surface of the astragalus.
Posterior'' (Fig. 52), thin and imperfect, extends between the ex¬
ternal malleolus, back of lower end of tibia and posterior tibio-
• Fio. 52.
Fig. 53.
112
ESSENTIALS OP HUMAN ANATOMY.
fibular ligament above, and the posterior surface of astragalus
from one lateral ligament to the other below.
Internal lateral^ (Fig. 52), (deltoid) radiates from lower border
of inner malleolus to astragalus behind and below, in front to
scaphoid, and passes almost perpendicularly to the os calcis.
External lateral^, ', ® (Fig. 53), composed of three fasciculi from
anterior margin, apex, and back of external malleolus, it is
attached to the astragalus and os calcis : nerves, internal saphen¬
ous and anterior tibial ; arteries, anterior and posterior tibials,
anterior and posterior peroneals.
Describe the tarsal joints.
Those of the first row are arthrodial : the astragalus and calcis
have three ligaments ;
External calcáneo astragaloid, from outer surface of astragalus to
same of calcis ;
The posterior calcaneo-astragaloid connects the posterior end of
astragalus with upper surface of calcis;
The interosseom, the chief bond, filling up the grooves on the
under surface of astragalus and upper of os calcis ; there are two
synovial sacs, one posterior, the other anterior continued between
astragalus and scaphoid : raerves, posterior tibial or plantar; arteries,
posterior tibial, tarsal, external malleolar (from ant. tibial), and
terminal twigs of peroneal.
Those of second row, scaphoid, cuboid, and cuneiforms have.
Dorsal ligaments, small bands connecting the contiguous bones,
and.
Plantar ligaments, similarly disposed ; also four
Interosseous ligaments, connecting the sides of the scaphoid and
cuboid, the internal and middle cuneiforms, the middle and ex¬
ternal cuneiforms, the external cuneiform and cuboid ; nerves,
anterior tibial, internal and external plantars ; arteries, metatarsal
and plantars.
Those between the two rows, or medio-tarsal. (1) The calcaneo-
scaphoid, arthrodial, has
The superior calcáneo cuboid ligament, connecting the dorsal
surfaces of calcis and cuboid.
The internal [interosseous) calcaneo-cuboid, connecting inner
THE ARTICULATIONS.
113
under part of front of calcis with inner postero-inferior angle and
contiguous part of cuboid.
The long calcaneo-mboid [plantar) arises from under surface of
calcis between posterior tubercles and anterior tubercle, to be
attached to oblique ridge of cuboid and bases of second, third,
fourth, and fifth metatarsal bones, completing canal for the long
peroneal tendon.
The short plantar arises from the anterior calcaneal tubercle and
the bone in front, to be attached to the under surface of cuboid
behind the ridge, except the outer angle ; the synovial sac is dis¬
tinct from that of other tarsal joints.
The (2) astragale-scaphoid articulation is the only enarthrodial
(ball-and-socket) joint of tarsus, and communicates with the ante,
rior calcaneo-astragaloid ; its ligaments are.
The superior calcaneo-scaphoid, dense and thick, extending from
anterior internal extremity of calcis to under surface of scaphoid.
The inferior calcaneo-scaphoid, passing obliquely forward from
neck of astragalus to upper surface of scaphoid ; nerves of medio-
tarsal joint are, external branch of anterior tibial, sometimes
musculo-cutaneus or external plantar; arteries, anterior tibial,
tarsal, metatarsal, or external plantar.
Describe the tarso-metatarsal articulations.
Arthrodial, between the three cuneiforms and the cuboid, and
the bases of the five metatarsals ; their ligaments are.
Dorsal, one for first metatarsal and internal cuneiform ; one
from each cuneiform to second ; one from external cuneiform to
third ; one each from cuboid to fourth and fifth metatarsals.
Plantar, more irregularly disposed ligamentous fibres.
Interosseous, one connecting outer extremity of inner cuneiform
to adjacent angle of second metatarsal; one between outer cunei¬
form and angle of second metatarsal ; one connecting outer angle
of external cuneiform with side of third metatarsal ; nerves, ante¬
rior tibial and plantars ; arteries, from dorsalis pedis, metatarsal,
and deep plantar arch.
Describe the articulations of the metatarsal bones with
one another.
Except the first, their bases are bound together hy dorsal, plantar,
8
114
ESSENTIALS OF HUMAN ANATOMY.
and interosseous ligaments ; the distal extremities are united by the
transverse metatarsal ligament.
Describe the metatarso-phalangeal and inter-phalangeal
articulations.
They resemble in all respects those of hand, which see.
How many distinct synovial sacs have the tarsus and
metatarsus ?
Six, viz. : (1) Between calcis and astragalus, posterior to inter-
osseus ligament; (2) in front of same ligament, between calcis and
astragalus, also between astragalus and scaphoid ; (3 ) between calcis
and scaphoid ; (4) between scaphoid, cuboid, aud cuneiforms, com¬
municating between the middle and external cuneiforms with the
joints formed between those bones and the bases of the second
and third metatarsals ; (5) between the sides and bases of the fourth
and fifth metatarsals and the cuboid ; (6) between the base of
first metatarsal and internal cuneiform.
Muscles and Fascis.
Describe a muscle.
It is a structure connected with bones, cartilages, ligaments, or
skin, directly or through the medium of a tendon or aponeurosis,
whose structure is capable of shortening when irritated mechanic¬
ally or by nerve stimulus, this property being called muscular
contractility or irritability.
How are muscles divided ?
According to their form into narrow, broad, penniform (when
their fibres converge like the plumes of a pen to one side of the
tendon) ; bipennijorm when so arranged on both sides of a tendon,
radiated, etc.
Is there only one variety of muscular tissue 1
No, there are two, one variety consisting of prismatic fasciculi
about T^th of an inch in diameter, marked by transverse striae,
each bundle surrounded by a sheath or perimysium ; each fasciculus
is formed of a number of fibrilla, ryJinrth of an inch in diameter,
MUSCLES AMD FASCIA.
115
surrounded by a tubular, transparent elastic membranous sarco-
lemrna-, every fibril is striated, and consists of a row of minute
particles, Bowman's " sarcous elements ; " this variety of tissue forms
the voluntary, striped muscles, or those of animal life, being under
the control of the will ; the involuntary, unstriped, or the muscles of
organic life, are not under the control of the will, and consist of
elongated, spindle shaped, flattened, nucleated cells, ^^th to-jJ^jth
of an inch long, to -s-sVîyth. broad, and are held together in
bundles by a cement substance containing a few connective-tissue
corpuscles, the bundles being further collected into larger fasciculi,
or flattened bands, bound together by ordinary areolar tissue ; this
kind of muscle is that found forming the contractile coats of the
stomach, intestines, bladder, arteries, veins, lymphatics, ureters,
urethra, iris, ciliary body, etc. ; when irritated a part contracts,
slowly relaxes, while another contiguous portion is contracting,
which action being continued produces the vermicular (worm-like),
peristaltic movements of the intestines. The spontaneously coagu¬
lable albuminous substance composing muscle is called myosin-,
so-called syrUonin is a modification produced by chemical agents.
What are tendons and aponeuroses ?
Tendons are glistening white cords or bands, of white inelastic
fibrous tissue, almost without blood- or nerve-supply, and connect
the muscular tissue with the part to be moved ; aponeuroses are
membranous expansions of the same tissue serving similar pur¬
poses.
What are the fasciae ?
They are laminae of fibrous or fibro-areolar tissue investing
the soft tissues; the superficial fasciae are usually fibro-areolar,
lie beneath the skin, and are loaded with fat; the deep fasciae
resemble aponeuroses, are dense and inelastic, ensheathing mus¬
cles, or serving for their attachment, and tend to preserve the
form of the part, since partitions descend between various muscles
to become attaehed to the periosteum of the osseous framework.
To what are the tendons attached ?
To the periosteum and perichondrium with which they become
blended, to the subcutaneous tissue, and to ligaments.
116
ESSENTIALS OF HUMAN ANATOMY.
What is meant by the origin and insertion of a ninscle?
The origin is the most fixed and central point from which the
muscle acts ; the insertion the movable point to which the muscular
force is directed; but, in many muscular acts the part usually
described as the insertion becomes the fixed point and the origin,
the movable one.
Do not some muscles have double origins, although single
insertions ?
Yes; as the occipito-frontal, digastric, and omo-hyoid.
Muscles of the Head.
Describe the origin, insertion, action, and nerve supply of
the following muscles.
Occiplto-frontalis^ : origin, occipital portion, outer two-thirds of
superior curved line of the occipital bone and mastoid process of
the temporal ; frontal portion, from pyramidalis nasi, corrugator
supercilii, and orbicularis palpebrarum ; insertion, into an aponeu¬
rosis covering the vertex of the skull ; action, raises eyebrows and
transversely wrinkles forehead ; nerves, facial, posterior auricular
branch of same, sometimes the small occipital.
Attolens aurem* : origin, occipito-frontalis aponeurosis ; insertion,
superior portion of pinna of ear ; action, raises pinna ; nerve, occip¬
italis minor.
Atrahens aurem : origin, lateral margin of occipito-frontalis ten¬
don ; insertion, a projection on front of helix ; action, draws the
pinna forward and upward ; nerve, facial.
Retrahens aurenf' : origin, mastoid portion of temporal ; insertion,
lower part of concha ; action, draws ear back ; nerve, posterior
auricular branch of facial.
Orbicularis palpebrarum^ : origin, internal angular process of the
frontal, nasal process of superior maxillary bone, and the anterior
surface and margins of the tendo oculi ; insertion, skin of eyelids
and contiguous portions of forehead, temple, and cheek, blending
with the occipito-frontal and corrugator supercilii muscles ; action,
closes eyelids ; nerve, facial.
MUSCLES OF THE HEAD.
117
Corrugator supercHH: origin, inner end of superciliary ridge;
insertion, under surface of orbicularis palpebrarum ; action, draws
eyebrow downward and inward ; nerve, facial.
Tensor tarsi (Horner's muscle): origin, crest of lachrymal bone;
insertion, by two slips into tarsal cartilages near puncta ; action,
compresses lachrymal sac, and keeps puncta in contact with globe ;
nerve, facial.
Levator palpebroe superioris^: origin, lesser wing of sphenoid;
insertion, upper border of superior tarsal cartilage ; action, elevates
upper lid; nerve, third cranial (motor oculi).
Pyramidalis nasP: origin, occipito-frontalis; insertion, into com¬
pressor naris ; action, depresses inner angle of the eyebrow ; nerve,
facial.
Levator labii superioris aiœque nasP : origin, upper part of nasal
process of superior maxillary bone; insertion, the cartilage of ala
Fio. 54.
118
ESSENTIALS OF HUMAN ANATOMY.
of nose, and into upper lip blending with orbicularis and levator
labii ; action, draws upward the upper lip, and dilates nostril; nerve,
facial.
Dilator nan's anterior: origin, cartilage of ala; insertion, integu¬
ment near its margin ; action, dilates nostril ; nerve, facial.
Dilator naris posterior : origin, of nasal notch of superior
maxilla and the sesamoid cartilages ; insertion, skin near margin of
nostril ; action, dilates nostril ; nerve, facial.
Compressor nasi": origin, above and external to incisive fossa of
superior maxilla; insertion, fibro-cartilage of nose, and is continu¬
ous with its fellow and th > aponeurosis of pyramidalis nasi ; action,
dilates nostril, by increasing breadth of nose ; nerve, facial.
Compressor narium minor : origin, alar cartilage ; insertion, skin
of tip of nose; action, dilates nostril; na-ve, facial.
Depressor aloe nasi: origin, incisive fossa of superior maxilla;
insertion, septum and back of ala ; action, narrows nostril ; nerve,
facial.
Levator labil superiorly : origin, lower margin of orbit above
infra-orbital foramen ; insertion, muscular substance of upper lip ;
action, elevates lip ; nerve facial.
Levator anguli or/V®: origin, canine fossa of superior maxilla;
insertion, angle of mouth ; action, elevates angle of mouth ; nerve,
facial.
Zygomaticus major^^ : origin, malar bone ; insertion, angle of mouth ;
action, elevates angle of lip ; nerve, facial.
Zygomaticus minor^" : origin, malar bone anteriorly ; insertion,
angle of moutb ; action, same as zygomaticus major ; nerve, facial.
Levator labii inferioris (levator menti) ; origin, incisive fossa of
lower jaw; insertion, skin of lower lip ; action, elevates lower lip;
nerve, facial.
Depressor labii inferioris (quadratus menti) : origin, external
oblique line of lower jaw; insertion, skin of lower lip; action, de¬
presses lower lip ; nerve, facial.
Depressor anguli or/s": origin, external oblique line of lower
jaw ; insertion, angle of mouth ; action, depresses angle of mouth ;
nerve, facial.
Orbicularis oris^": origin, nasal septum and superior and inferior
MUSCLES OF THE HEAD.
119
maxillary borders by accessory fibres called accessorii orbicularis
superioris and inferioris, and naso-labialis ; insertion, the bucci¬
nator, and other muscles converging to the mouth ; action, closes
mouth ; nerve, facial.
Buccinator^^: origin, behind, from the pterygo-maxillary liga¬
ment, above and below, the external surfaces of alveolar processes
of the three molar teeth ; insertion, orbicularis oris ; action, com¬
presses cheek ; nerve, facial and buccal branch of inferior max¬
illary.
Bisorius [Santorini) ; origin, fascia over masseter muscle ; inser¬
tion, angle of mouth; action, laughing muscle; nerve, facial.
Masseter^'^: origin,ihe superficial portion, from the malar process
of the superior maxilla and the anterior two-thirds of the lower
border of the zygomatic arch, the deep portion, from the posterior
third of the lower border and the inner surface of the zygomatic
arch ; insertion, upper half of ramus and outer surface of coronoid
process of lower jaw ; action, raises, protracts, and retracts lower
jaw, a masticatory muscle ; nerve, inferior maxillary.
Temporal: origin, temporal fossa and fascia; insertion, coronoid
process of lower jaw ; action, raises and retracts lower jaw, a muscle
of mastication ; nerve, inferior maxillary.
Internal pterygoid : origin, inner surface of external pterygoid
plate and grooved surface of palate bone, the tuberosity of the
palate and superior maxillary bones; insertion, lower back part
of inner side of ramus as high as dental foramen, and angle of
jaw; action, draws lower jaw forward, a muscle of mastication;
nerve, inferior maxillary.
External pterygoid : origin, pterygoid ridge on greater wing of
sphenoid, the bone included between it and base of pterygoid
process, the outer surface of external pterygoid plate; insertion,
depression in front of neck of condyle of lower jaw and inter-
articular fibro-cartilage ; action, draws jaw forward, a triturating
masticatory muscle; îierwe, inferior maxillary. Sometimes the in¬
ternal maxillary artery passes between the two heads of this muscle;
sometimes pierces it ; often lies below it.
120
ESSENTIALS OF HUMAN ANATOMY.
Muscles of the Neck.
Platysma myoides : origin, clavicle, acromion, and fascia of pec¬
toral, deltoid, and trapezius muscles; insertion, lower jaw beneath
oblique line, angle of mouth, cellular tissue of face ; action, wrinkles
skin of neck, depresses jaw and angle of lip; nerves, facial, super¬
ficial branches cervical plexus.
Sterno-cleido-mastoid^^ (Fig. 55): origin, upper front part of ster-
Fio. 55.
num, innerthird upper border of clavicle ; insertion, mastoid process
of temporal and outer two-thirds superior curved line of occipital
bone ; action, acting singly, flexes head sideways, and rotates chin to
opposite side, both acting flex head on neck, and then on chest ;
nerves, spinal accessory, deep branches of cervical plexus.
Sterno-hyoid^^: origin, riband like, from posterior surface of
sternum and inner end of clavicle ; insertion, body of hyoid bone;
action, depresses hyoid bone ; nerve, filaments from loop between
descendens and communicans noni.
"Sterno-ihyroid^^ : origin, posterior surface of sternum and cartilage
of first rib ; insertion, oblique line on ala of thyroid cartilage ; oc-
tion, depresses larynx ; nerve same as sterno-hyoid.
MUSCLES OF THE NECK.
121
Thyro-hyoid^^: origin, oblique line of thyroid cartilage; insertion,
lower border of body and greater cornu of hyoid bone ; action, may
elevate larynx when hyoid is fixed ; nerve, hypoglossal.
Omo-hyoid^^ •. origin, from upper border of scapula near supra¬
scapular notch, perhaps, also, from transverse ligament ; insertion,
body of hyoid bone, its central tendinous portion being held down
by a process of deep cervical fascia prolonged down to be attached
to cartilage of first rib ; action, depresses hyoid bone, larynx, and
draws them backward to one or other side ; nerve, from loop between
descendens and communicans rami.
Digastric : origin, has two fleshy bellies with an intermediate
rounded tendon, the posterior' is attached to digastric groove of
mastoid process of temporal, the anterior^ to depression on inner
side of lower border of jaw near symphysis ; insertion, tendon per¬
forates stylo-hyoid, and is held to side of body of hyoid bone by
aponeurotic loop lined with synovial membrane ; action, raises the
hyoid bone; if this be fixed by its muscles, depresses lower jaw;
nerves, posterior belly by facial, anterior by mylo-hyoid branch of
inferior dental.
Stylo-hyoid* : origin, middle of outer surface of styloid process of
temporal ; insertion, body of hyoid at junction with greater cornu,
it is perforated by digastric tendon ; action, same as digastric ; nerve,
facial.
Myb-hyoid^: onyire, mylo-hyoid ridge of lower jaw; insertion,hoàj
of hyoid bone and median raphé ; action, same as digastric and
stylo-hyoid ; nerve, mylo-hyoid branch of inferior dental ; it forms
the muscular floor of the mouth.
Genio-hyoid^ : origin, inferior genial tubercle of lower jaw; in¬
sertion, body of hyoid bone ; action, same as mylo-hyoid ; nerve,
hypoglossal.
Genio-hyo-glossus'' : origin, superior genial tubercle of lower jaw;
insertion, body of hyoid bone, side of pharynx and tongue from base
to apex ; action, protrudes tongue by posterior and inferior fibres,
retracts it by anterior fibres, both muscles acting render tongue
concave from side to side, as in sucking ; nerve, hypoglossal.
Hyo-glossus^: origin, body, lesser, and whole length of greater
cornu of hyoid bone; insertion, side of tongue; action, draws down
sides of tongue, making it convex ; nerve, hypoglossal.
122 ESSENTIALS OF HUMAN ANATOMY.
Sty/o-glossus^ : origin, near centre of antero-external surface of
styloid process and stylo-maxillary ligament ; insertion, side of
tongue and hyo-glossus muscle ; action, draws tongue upward and
backward ; nerve, hypoglossal.
Lingualis : origin, forms bulk of tongue lying between hyo-glossus
and genio-hyo-glossus on each side, running from base to apex,
some fibres being attached to hyoid bone ; action, renders tongue
convex from before backward ; nerve, chorda tympani.
Palatal Region.
Levator palati : origin, under surface of apex of petrous portion
of temporal bone and contiguous portion of cartilaginous Eus¬
tachian tube; insertion, into posterior surface of soft palate;
action, elevates soft palate ; nerve facial through petrosal nerve of
Vidian.
Tensor palati : origin, scaphoid fossa, outer side of Eustachian
tube, spine of sphenoid, edge of tympanic plate; insertion, after
reflection around hamular process, into forepart of aponeurosis of
soft palate and under surface of palate bone ; action, renders soft
palate tense ; nerve, branch from otic ganglion.
kzygos u voice ; origin, posterior nasal spine and palatal aponeu¬
rosis; insertion, xw\x\ä.\ action, Ta,ises uvula; nerve, facial through
petrosal of Vidian ; it is not a single muscle as the name implies.
Paiato-giossus (anterior pillar of fauces) : origin, anterior surface
of palate external to uvula ; insertion, side and dorsum of tongue ;
action, as one of its names implies, constrictor isthmii faucium;
nerve, palatine branches Meckel's ganglion.
Paiato-pharyngeus (posterior pillar of fauces) : origin, soft palate;
insertion, posterior border of thyroid cartilage and side of pharynx ;
action, closes posterior fauces ; nerve, same as for palato-glossus.
Vertebral Region.
Rectus capitis anticus major: origin, by four tendinous slips from
anterior tubercles of transverse processes of third, fourth, fifth,
and sixth cervical vertebrae; insertion, basilar process of occipital
bone ; action, flexes head ; nerves, suboccipital, deep branches of
cervical plexus.
MUSCLES OF THE BACK.
123
Rectus capitis anticus minor: origin, front of lateral mass of
atlas and root of its transverse process ; insertion, basilar process
of occipital bone bebind preceding muscle; action, flexes head;
nerves, suboccipital, deep branches of cervical plexus.
Rectus lateralis : origin, upper surface transverse process of atlas ;
insertion, jugular process of occipital bone ; action, draws head
laterally when one acts, flexes when both act ; nerves, suboccipital,
deep branches of cervical plexus.
Longus colli ; origin, superior oblique portion from anterior trans¬
verse tubercles of third, fourth, and fifth cervical vertebrae; inser¬
tion, tubercle on anterior arch of atlas; the inferior oblique portion
arises from bodies of first two or three dorsal vertebrae; insertion,
transverse processes of fifth and sixth cervical vertebrae ; vertical
portion extends between bodies of upper three dorsal and lower
three cervical, and those of second, third, and fourth cervical
vertebrae ; action, flexes and slightly rotates cervical spine ; nerves,
anterior branches from lower cervical nerves.
Scalenus anticus'"' (Fig. 55): origin, tubercle on upper surface of
first rib ; insertion, anterior tubercles of transverse processes of
third, fourth, fifth, and sixth cervical vertebrae ; action, lateral
flexion of cervical spine or elevation of ribs ; nerves, anterior
branches lower cervical nerves.
Scalenus mediu^' : origin, upper surface of first rib behind sub¬
clavian groove ; insertion, posterior tubercles' of transverse pro¬
cesses of lower six cervical vertebrae; action, similar to preceding;
" nerves, anterior branches from lower cervical.
Scalenus posticus: origin, outer surface of second rib; insertion,
posterior tubercles of lower two or three cervical vertebrae ; action,
flexes neck laterally, or elevates second rib; nerves, anterior
branches from lower cervical.
Muscles of the Back
First layer :
Trapezius : origin, inner third of superior curved line of occipital
bone, ligamentum nuchae, spinous processes of seventh cervical
and all dorsal vertebrae, and corresponding portion of supra-spinous
ligament ; insertion, outer third posterior border of clavicle, inner
124
ESSENTIALS OF.HUMAN ANATOMY.
margin of acromion process, the superior lip of crest of spine of
scapula, and tubercle at its inner extremity ; action, one acting
draws head to its own side, both acting, draw head backward,
and with head fixed, elevate point of shoulder; middle and lower
fibres partially rotate scapula on chest ; nerves, spinal accessory,
deep branches of cervical plexus.
Ligamentum nuchas (a thin band of condensed cellulo-fibrous
membrane); origin, external occipital protuberance; insertion,
spinous processes of all cervical vertebrae except atlas ; a rudiment
of strong elastic ligament sustaining head in herbivora, etc.
Latissimus dors!*-, origin, by an aponeurosis from spinous pro¬
cesses of lower six dorsal vertebrae, those of lumbar and sacral
vertebrae and supra spinous ligament, also external lip of iliac
crest behind external oblique, and from three or four lower ribs;
insertion, inner lip and bottom of bicipital groove of humerus;
action, acting on humerus, draws it downward and backward
while rotating it inward, with fixed arms, raises lower ribs in
forcible inspiration, assists greater pectorals and abdominal mus¬
cles in drawing trunk forward as when climbing, using crutches,
etc. ; nerve, long subscapular nerve.
Second layer :
Levator anguli scapulas^"-, origin, by three or four tendinous
slips from posterior^ tubercles of transverse processes of three or
four upper cervical vertebrae ; insertion, posterior border of scapula
between superior angle and triangular surface at root of spine ;
action, raises scapular angle; «erves, filaments from fifth cervical
and from deep branches cervical plexus.
Rhomboideus minor origin, ligamentum nuchae, and spinous
processes of seventh cervical and first dorsal vertebrae ; insertion,
margin of triangular surface at root of spine of scapula ; action,
draws inferior angle backward and upward ; nerve, fifth cervical.
Rhomboideus major^^ : origin, spinous processes of upper four or
five dorsal vertebrae and supra-spinous ligament ; insertion, tendi¬
nous arch stretched from triangular surface at root of spine of
scapula to inferior angle, the arch being connected with scapular
border by thin membrane ; action, draws inferior angle upward
and backward ; nerve, fifth cervical.
MUSCLES OF THE BACK,
125
Third layer :
Serratas posticus superior: origin, by thin aponeurosis from
ligamentum nuchae and spinous processes of seventh cervical and
Fio. 56.
two or three upper dorsal vertebrae ; insertion, by fleshy digitations
into upper borders of second, third, fourth, and fifth ribs a little
beyond their angles ; action, elevates ribs during inspiration ;
nerves, external posterior branches of cervical nerves.
Serratas posticus inferior^^: origin, hy aponeurosis from spi¬
nous processes of last two dorsal and upper two or three lumbar
126 ESSENTIALS OF HUMAN ANATOMY.
vertebrae and interspinous ligaments ; insertion, by four digitations
into lower borders of four lower ribs, beyond their angles ; action,
depresses ribs in expiration; nerves, external branches of dorsal
nerves.
Splenius capitis et colli^' " : origin, tendinous from lower half of
ligamentum nuchae, the spinous processes of last cervical and of
upper six dorsal vertebrae, and supraspinous ligament; insertion,
(S. capitis^'') mastoid process and rough surface beneath superior
curved line of occipital bone {S. colli}*-), posterior tubercles of trans¬
verse processes of upper three or four cervical vertebrae; action,
together, draw head directly backward, singly, flex head laterally
and slightly rotate to same side; nerves, external posterior branches
of cervical nerves.
Fourth layer ;
Erector spince *, ® (Fig. 57) : origin, sacro-iliac groove, the
anterior surface of lumbo-sacral tendon, which is attached intern¬
ally to spines of sacrum, the spinous processes of lumbar and three
lower dorsal vertebrae and supraspinous ligament externally, the
baek part of inner lip of iliac crest, with the rudimentary trans¬
verse processes of the sacrum and great sacro-sciatic ligament ; this
muscle opposite last rib divides into sacro-lumbalis and longissi-
mus dorsi muscles ; action, maintains spine erect and bends body
backward; nerves, external posterior branches of lumbar and
dorsal nerves.
Sacro-lumbalis '' : origin, is part of erector spinas ; insertion, by
six or seven tendons into angles of six lower ribs ; action, same as
erector spinae ; nerves, same as erector spinae.
Musculus accessorius ad sacro-lumbalem : origin, by flattened ten¬
dons from angles of six lower ribs ; insertion, angles of six upper
ribs ; action, same as erector spinas ; nerves, those of erector spinae.
Cervicatis ascendeos: origin, angles of four or five upper ribs;
insertion, posterior tubercles of transverse processes of fourth, fifth,
and sixth cervical vertebrae; action, keeps neck erect; nerves, ex¬
ternal posterior branches of cervical nerves.
Longissimus dorsi^: origin, is part of erector spinae; insertion,
posterior surface of lumbar transverse processes, tubercles at back
of articular processes, tips of transverse processes of all the dorsal
MUSCLES OF THE BACK.
127
vertebrae, and from six to eleven ribs between their tubercles and
angles ; action and nerves same as erector spinae.
Transversatis colli^,^ : origin, tendinous from summits of six upper
dorsal transverse processes ; insertion, posterior tubercles of trans¬
verse processes from second to sixth cervical vertebrae; action, keeps
neck erect; nerves, external pos-
r"""' 57. terior branches of cervical nerves.
Tracheto-mastoid''■. origin, by ten-
' I from transverse processes of
sÏÏoir third, fourth, fifth, and sixth dorsal
áfMWt vertebrae and articular processes of
the three or four lower cervical;
insertion, posterior margin of mas¬
toid process; action, flexes head
laterally; nerves, external posterior
branches of cervical nerves.
Spinalis dorsi : origin, by tendons
from spinous processes of last two
dorsal and first two lumbar verte¬
brae ; insertion, by separate tendons
into spinous processes of from four
fM|||/WmH to eight dorsal vertebrae; action,
erects spine; nerves, external pos-
terior branches of dorsal nerves.
Spinalis colli: origin, fifth and
sixth cervical spinous processes,
fWiW also sometimes those of first and
second dorsal (this muscle is some-
• 'ii\ xiM mamK "afe-aJ
Mtimes absent); insertion, spinous
Í" process of axis, occasionally those
V V\^Ury'W''iW vertebrae below ; action,
jLr^/ *ir extends cervical spine ; nerves, ex-
ternal posterior branches of cervi-
cal nerves.
Complexas": origin, by seven ten¬
dons from tips of transverse processes of upper three dorsal and
seventh cervical vertebrae, and articular processes of the three cer¬
vical vertebrae above this ; insertion, internally between curved
lines of occipital bone ; action, both draw head backward, singly.
128
ESSENTIALS OF HUMAN ANATOMY.
lateral flexion with rotation turning face to opposite side ; nerves,
internal posterior branches of cervicals, sub-accipital and great
occipital : (the biventer cervieis being usually blended with this
muscle will receive no separate description).
Fifth layer :
Semispina/is dorsi^": origin, by small tendons from transverse
processes of from tenth or eleventh to fifth or sixth dorsal verte¬
brae; insertion, by five or six tendons, into spinous processes of
upper four dorsal and lower two cervical vertebrae ; action, erects
spinal column ; nerves, internal posterior branches of dorsal nerves.
Semispinalis co/li^^: origin, tendinous and fleshy from upper four
dorsal transverse processes and articular processes of lower four
cervicals ; insertion, second, third, fourth, and fifth cervical spinous
processes; action, erects cervical spine; nerves, internal posterior
branches of cervical nerves.
Multifidus spincB^^-. origin, back of sacrum, aponeurosis of erector
Spinae (sacral region); posterior superior iliac spine, posterior sacro¬
iliac ligaments (iliac regions) ; articulating processes (lumbar and
cervical regions); transverse processes (dorsal region); insertion,
lamina and spinous process of third or fourth vertebra above
(most superficial), second or third above (middle layer) ; two con¬
tiguous vertebrae (deepest layer); keeps spine erect and rotates it;
nerves, internal posterior branches of cervical, dorsal, lumbar, and
sacral nerves.
fíotatores spinœ (eleven pairs in dorsal region only) : origin, each
from upper back part of transverse process ; insertion, lower outer
part of lamina of vertebra above; action, as name implies; nerves,
internal posterior dorsal branches.
Supra-spinales; origin and cervical spinous processes;
action, extend cervical spine; nerves, branches of cervical.
/nter-spina/es : origin, variable in number, there are usually six
cervical pairs commencing between apices of second and third ver¬
tebral spines; two, occasionally three dorsal pairs, between first
and second, eleventh and twelfth, sometimes second and third ver¬
tebrae; four lumbar pairs; sometimes a pair between last dorsal
and first lumbar, and fifth lumbar and sacrum; action, extend
spine ; nerves, internal posterior nerves of regions.
MUSCLES OF THE ABDOMEN.
129
Extensor coccygis : origin, last bone of sacrum, or first of coccyx;
insertion, lower part of coccyx, behind ; action, as named ; nerve,
posterior sacral.
Intertransversales^^ : origin and insertion, between anterior and
posterior tubercles of transverse processes in cervicaF, occupy
intertransverse spaces in other regions (twelve dorsal and four
lumbar); action, lateral flexion, singly, steady spine when both
sides act ; nerves, posterior spinal branches of each region.
Rectus capitis posticus major^^: origin, spinous process of axis;
insertion, inferior curved line of occipital bone and surface below;
rotates head ; nerves, suboccipital and great occipital.
Rectus capitis posticus minor^'^ : origin, tubercle on posterior arch
of atlas; insertion, rough surface beneath inferior curved line,
nearly as far as foramen magnum ; action, extends head ; nerves,
suboccipital and great occipital.
Obfiquus capitis inferior^^: origin, apex of spinous process of
axis; insertion, apex of transverse process of atlas; action, rotates
atlas and head ; nerves, suboccipital and great occipital.
Obliquas capitis superior^*: origin, tendinous from upper part of
transverse process of atlas ; insertion, between curved lines of occi¬
pital bone external to complexus ; action, extends head ; nerves,
suboccipital and great occipital.
Muscles of the Abdomen.
Externa! oblique^''-, origin, by eight fleshy digitations from ex¬
ternal surface and lower borders of the eight inferior ribs ; inser¬
tion, anterior half of outer lip of iliac crest, by an aponeurosis
joining its fellow of opposite side it forms the linea alba, a median
tendinosis raphé, is connected with ensiform cartilage, symphysis,
spine, and pectineal line of pubes; it is continuous above with
aponeurosis of pectoralis major, below it forms a broad infolded
band, continuous with fascia lata, stretching from anterior iliac
spine to pubic spine, i. e., Poupart's ligament, reflected from which
into the pectineal line, is a portion called Oimhernat's ligament-,
just above crest of pubis is the triangular external abdominal ring,
its external border being Poupart's ligament, its inner, aponeurotic
fibres, both called pillars of the ring ; action, compresses viscera,
9
130
ESSENTIALS OK HUMAN ANATOMY.
flexes thorax on pelvis, or flexes pelvis on thorax, according to
which is the fixed point, also assists expiration ; nerves, lower inter¬
costal, ilio-hypogastric, ilio-inguinal.
Internal oblique : origin, fleshy from outer half of Poupart's
ligament, anterior two-thirds of middle lip of iliac crest, and pos-
Fig. 58.
t«rior lamella of lumbar fascia; insertion, crest and pectineal line
of pubis with transversalis muscle — forming conjoined tendon
part of inner boundary of internal abdominal ring—cartilages of
lower four ribs, and by an aponeurosis, which splits for its upper
MUSCLES OF THE ABDOMEN.
131
three-fourths to enclose the rectus muscle, into linea alba, the ante¬
rior layer blending with aponeurosis of external oblique, the pos¬
terior with that of transversalis muscle, the undivided lower fourth
passing in front of rectus ; action and nerves, same as external
oblique.
Transversalis : origin, fleshy from outer third of Poupart's liga¬
ment, anterior three-fourths of inner lip of iliac crest, inner surface
of six lower costal cartilages, and by a broad aponeurosis from
lumbar spinous and transverse processes; insertion, v/iih internal
oblique as the conjoined tendon into pubic crest and pectineal line,
by its aponeurosis into linea alba, the upper three-fourths passing
behind rectus abdominis, the remainder in front of that muscle;
action and nerves similar to external oblique.
Lumbar fascia: the vertebral aponeurosis of the transversalis
divides into an anterior thin layer attached to front of lumbar
transverse processes and to lower margin of last rib, thus forming
the Ugamentum arcuatum extermim-, a middle, stronger layer,
attached to apices of transverse processes; and a posterior layer
attached to apices of spinous processes; the quadratus lumborum
lies between anterior and middle layers, the erector spinas between
the middle and posterior; the last receives the attachment of the
internal oblique, and blended with the aponeuroses of the serratus
posticus inferior and latissimus dorsi, forms the lumbar fascia.
Rectus abdominis^^: origin, by two tendons from pubic crest and
ligaments over symphysis pubis ; insertion, cartilages of fifth, sixth,
and seventh ribs; this muscle is enclosed in a sheath, the upper
three-fourths in front formed by the aponeurosis of the external
oblique and half of that of the internal oblique, behind for the
same extent of the transversalis aponeurosis with the posterior
division of that of the internal oblique ; at the lower fourth the
aponeuroses of all these muscles pass in front of the rectus ; from
two to five tendinous intersections traverse the muscle called linece
transversas, while the linece semilunares, two curved tendinous lines
corresponding to the outer border of the recti muscles, extend on
either side from the eighth costal cartilage to the pubes ; action,
flexes thorax on pelvis, and vice versa, also compresses abdominal
viscera; nerves, same as external oblique.
Pyramidalis : origin, tendinous from pubic bone and anterior
132
ESSENTIALS OF HUMAN ANATOMY.
pubic ligament, lying in front of, but in same sheath with rectus ;
insertion, linea alba midway between pubes and umbilicus ; action,
a tensor of linea alba ; nerves, same as those of external oblique.
Quadratus lumborum^^ (F'g- 57): origin, ilio-lumbar ligament,
adjacent two inches of iliac crest, and upper borders of transverse
processes of third, fourth, and fifth lumbar vertebrae ; insertion,
one-half of lower border of last rib, apices of transverse processes
of upper four lumbar vertebrae; action, flexes trunk—both acting;
flexes laterally—one acting ; depresses ribs with fixed pelvis and is
then an expiratory muscle ; nerves, anterior branches of lumbar
nerves.
Muscles of Thorax.
Externa! intercosta/s^^ (Fig- 58) (eleven pairs): origin, each from
outer lip of groove on lower border of each rib from tubercle
to costal cartilage ; insertion, pass obliquely downward and for¬
ward to upper border of rib below for same distance ; action, raise
and evert ribs in inspiration ; nerves, intercostale.
Internal intercostals (eleven pairs) : origin, each from inner lip
of groove on lower border of rib reaching from angle to sternum ;
insertion, passing downward and backward to upper border of rib
below; action, depress and invert the ribs in expiration; nerves,
intercostals.
Infracostales : vary in number, most common between lower
ribs; origin, from inner surface of one rib ; insertion, inner surface
of first, second, or third rib below, passing obliquely downward
and backward ; action, inspiratory muscles ; nerves, intercostals.
Triangularis sterni: origin, lower part of side of sternum, inner
surface of ensiform cartilage, and sternal ends of costal cartilages
of three or four lower true ribs ; insertion, by fleshy digitations
into lower border and inner surfaces of costal cartilages of second,
third, fourth, and fifth ribs ; action, draws down costal cartilages
in expiration ; nerves, intercostals.
Lemtores costarum: origin (twelve pairs), extremities of dorsal
transverse processes ; insertion, rough surface between tubercle and
angle of rib below ; action, assist external intercostals in raising
ribs; nerves, intercostals.
MUSCLES OF THORAX.
133
Diaphragm: origin, arched and conve.K toward chest, from ensi-
form cartilage in front, on either side, inner surfaces of cartilages
and bony portions of lower six or seven ribs, behind, from the
ligamentum arcuatum externum' and internum®, and by its crura*,®,
the left from bodies of second and third, the right, from those of
second, third, and fourth lumbar vertebrae ; imeriion, into central
cordiform tendon',',® ; action, chief respiratory muscle, increasing
capacity of chest by becoming flattened when contracted ; also aids
all eflbrts of expulsion as of feces, etc. ; nerve», phrenic and
phrenic plexus of sympathetic.
Fig. 59.
Openings of the Diaphragm : the aortié, median, in front of verte¬
bral bodies—really behind diaphragm—for aorta, vena azygos
major, thoracic duct, sometimes left sympathetic nerve ; the œso-
phageaP, elliptical, muscular, formed by crura, for oesophagus and
pneumogastric nerves ; the opening for vena cava}", highest, quadri¬
lateral bounded by four tendinous bundles meeting at right angles;
the right ems', transmits the sympathetic, greater and lesser
splanchnic nerves ; the left crus*', the left greater and lesser
splanchnic nerves, and vena azygos minor.
134 ESSENTIALS OF HUMAN ANATOMY.
Muscles of shoulder and arm.
PectoraHs major(Fig- 58): origin, anterior surface inner half of
clavicle, half the breadth of anterior surface of sternum as low as
sixth or seventh rib, cartilages of all true ribs except first or seventh,
or both, and from aponeurosis of external oblique; insertion, fibres
converge and overlap, the lower being folded back upon them¬
selves, to be attached by a flat tendon to anterior lip of bicipital
ridge of humerus; acfion, draws arm forward and inward; with
fixed arm, an accessory muscle of forced inspiration ; nerve,
anterior thoracic.
PectoraHs minor^ (F'g- 58) : origin, tendinous from upper margin
and outer surface of third, fourth, and fifth ribs near cartilages, and
aponeurosis over intercostal muscles ; insertion, anterior border
coracoid process of scapula ; action, depresses point of shoulder,
elevates ribs during inspiration when scapula is fixed; nerves,
anterior thoracic.
Subclavias^ : origin, tendinous from first costal cartilage; inser¬
tion, groove on middle third of under surface of clavicle ; action,
draws clavicle downward and inward toward the thorax ; nerve,
branch from cord formed by fifth and sixth cervical.
Serratas magnas* (Fig. 58) : origin, by nine fleshy digitations
from outer surface and upper border of upper eight ribs (second
rib has two) and aponeurosis covering upper intercostal spaces;
insertion, whole length of anterior aspect of posterior border of
scapula; action, elevates ribs in inspiration with fixed scapula,
also raises point of shoulder by rotating bone on chest wall; nerve,
posterior thoracic.
Deltoid'^ (Fig. 58) : origin, outer third of anterior border and
upper surface of clavicle, outer margin and upper surface of acro¬
mion process, and the whole length of lower border of spine of
scapula ; insertion, tendinous into rough prominence on middle of
outer side of shaft of humerus; action, raises arm to right angle,
also draws it forward by anterior fibres, or slightly backward by
posterior portion ; nerve, circumflex.
Sabscapaiaris* (Fig. 60) : origin, inner two-thirds of subscapular
fossa ; insertion, lesser tuberosity of humerus ; action, rotates head
of humerus inward ; nerve, subscapular.
Sapraspinatus*"' (Fig. 56) : origin, internal two-thirds of same-
MUSCLES OF THOEAX.
135
named fossa and the fascia covering it ; insertion, highest facet of
greater tuberosity of humerus ; action, assists deltoid, fixes head of
humerus in socket ; nerve, suprascapular.
Infraspinatus^* (Fig. 56): origin, internal two-thirds of infra-
spinous fossa; insertion, tendinous, middle facet of greater tuber¬
osity of humerus; action, rotates head of humerus outward; nerve,
suprascapular.
Teres minor^* (Fig. 56): origin, upper two-thirds of dorsal sur¬
face of axillary border of scapula and intermuscular septa; inser¬
tion, lowest facet on greater tuberosity of humerus ; action, rotates
head of humerus outward ; nerve, circumflex.
Teres major^* (Fig. 56) : origin, dorsal aspect of inferior angle of
scapula and intermuscular septum separating from teres minor
and infraspinatus; insertion, internal lip of
bicipital groove; action, draws humerus
downward and backward when raised, also •' -i
rotates it inward ; nerve, lower subscapular.
Coraco-brachialis* (Fig. 60) : origin, fleshy
from apex of coracoid process of scapula;
insertion, tendinous, into rough ridge at
middle of inner side of shaft of humerus;
action, draws humerus forward and inward,
also elevates it; nerve, musculo-cutaneous,
which perforates the muscle.
Biceps flexor cubitf (Fig. 60) : origin, short
head, tendinous, in common with coraco-
brachialis from tip of coracoid process of
scapula, long head, upper margin of glenoid
cavity by rounded tendon continuous with
glenoid ligament; insertion, tendinous into
back part of tuberosity of radius (a bursa
is interposed in front), and by a broad apo¬
neurosis opposite elbow, into fascia of fore¬
arm ; action, flexes and supinates forearm,
renders forearm fascia tense ; nerve, muscu¬
lo-cutaneous.
Brachia/is anticus* : origin, lower half of outer and inner surfaces
of shaft of humerus, embracing insertion of deltoid ; insertion, ten-
136
ESSENTIALS OF HUMAN ANATOMY.
dinous into anterior surface of coronoid process of ulna ; action,
flexes forearm ; nerves, musculo cutaneous and musculo-spiral.
Triceps extensor cubiti^": origin, scapular or long head, from
rough triangular depression below glenoid fossa, the external head
from posterior surface of shaft between upper part of musculo-
spiral groove and insertion of teres major, the internal head from
posterior surface below musculo-spiral groove ; insertion, tendi¬
nous, back, upper surface of olecranon process of ulna; action, ex¬
tends forearm and arm ; nerve, musculo-spiral.
Subanconeus; origin, humerus above olecranon fossa; insertion,
posterior ligament of elbow; action, prevents loose capsule from
being pinched during extension; nerve, musculo-spiral.
Muscles of the Forearm.
Anterior, or flexor and pronator group: All take origin from in¬
ternal condyle, except pronator quadratus.
Superficial layer.
Pronator radii teres* (Fig. 61): origin, double, above, from in¬
ternal condyle and common tendon, fascia of forearm and inter¬
muscular septum, below, from inner side of coronoid process of
ulna ; insertion, tendinous, into rough ridge on middle of outer
surface of shaft of radius; ac^io/i, pronates forearm, aids flexion;
nerve, median.
Flexor carpii radialis^: origin, internal condyle by common
tendon, forearm fascia, and intermuscular septa; insertion, tendin¬
ous, into base of index metacarpal ; action, flexes wrist, then fore¬
arm ; nerve, median.
Palmaris longus^ : origin, inner condyle by common tendon,
fascia, and intermuscular septa; insertion, tendinous, into anterior
annular ligament and palmar fascia ; action, tightens palmar
fascia ; nerve, median.
Flexor carpi ulnaris^ : origin, double, by common tendon from
inner condyle and from inner margin of olecranon by aponeu¬
rosis, and from upper two-thirds of posterior border of ulna and
intermuscular septum ; insertion, tendinous, into pisiform bone,
annular ligament and base of little finger metacarpal ; action, flexes
band on forearm ; then forearm on arm ; nerve, ulnar.
MUSCLES OF THE FOREARM.
137
Flexor sublimis digitorurn' {perforatus) : origin, by three heads, one
from internal condyle by common tendon and from internal lateral
ligament and intermuscular septa, a second from inner side of the
coronoid process of ulna, the third from oblique line of radius;
insertion, by four tendons, each of which
splits for the passage of the deep flexor ten-
dons, each half becoming attached to middle
of lateral margins of second phalanges;
action, flexes fingers, then hand on forearm,
then forearm on arm ; nerve, median.
Deep layer.
Flexor profundus digitorurn [perforons) : ori¬
gin, upper two-thirds of antero-internal sur¬
face of shaft of ulna, inner side of coronoid
process, by an aponeurosis from upper two-
thirds of posterior border of ulna and ulnar
half of interosseous membrane; insertion,
into bases of last phalanges by four tendons,
which pass between the two slips of flexor
sublimis tendons ; action, flexes fingers, then
wrist on forearm ; nerves, ulnar and anterior
interosseous.
Flexor longus poUicis : origin, upper two-
thirds of front of shaft of radius, adjacent
interosseous membrane, sometimes from base
of coronoid process ; insertion, base of last
phalanx of thumb ; ojction, flexes last thumb
phalanx ; nerve, anterior interosseous.
Pronator quadratus : origin, oblique line on
lower fourth of anterior surface of ulna, the
bone below, the anterior border of ulna and
aponeurosis over muscles ; insertion, lower fourth of anterior sur¬
face and external border of radius ; action, pronates hand ; nerre,
anterior interosseous.
Radial Region : all the extensors and supinators arise, at least
partially, from the external condyle and ridge of the humerus.
Supinator longus^^: origin, upper two-thirds of external condyloid
138 ESSENTIALS OF HUMAN ANATOMY.
Fig. 62.
ridge and external intermuscular septum; insertion, base of styloid
process of radius ; action, supinates forearm after it has been pro-
nated, flexes forearm on arm, second in power only to biceps ; nerve,
musculo-spiral.
Extensor carpi radialis iongior^ (¥\g. 62): origin, lower third of
external condyloid ridge and external intermuscular septum ; inser¬
tion, radial side of base of metacarpal bone
of index finger ; action, extends wrist ; nerve,
musculo-spiral.
Extensor carpi radialis brevier^: origin, ex¬
ternal condyle by common tendon, external
lateral ligament, the covering aponeurosis
and the intermuscular septa; insertion, radial
side of base of metacarpal of middle finger;
action, extends wrist ; nerve, posterior inter¬
osseous.
Extensor communis digitorum^: origin, ex¬
ternal condyle by common tendon, deep
^fascia and intermuscular septa; insertion,
second and third phalanges of each finger
by three main tendons, one of which sub¬
divides into two ; action, extends fingers,
then hand, finally forearm on arm; nerve,
posterioi interosseous.
Extensor minimi digiti^ : origin, common
tendon and intermuscular septa; insertion,
with tendon of common extensor into second
and third phalanges of little finger; notion,
extends little finger ; nerve, posterior inter¬
osseous.
Extensor carpi ulnaris^" : origin, by common
tendon from external condyle, middle third
of posterior border of ulna below aconeus
and forearm fascia ; insertion, ulnar side of
base of fifth metacarpal; action, extends
nerve, posterior interosseous.
Anconeus : origin, back of outer condyle of humerus ; insertion,
side of olecranon and upper fourth of posterior surface of shaft
of ulna; action, extends forearm; nerve, musculo-spiral.
wrist
FASCIA OF THE HAND.
139
Supinator breyis": origin, external condyle of humerus, external
lateral ligament and orbicular ligament of radius, oblique line of
ulna, triangular depression in front of it and aponeurosis covering
muscle; insertion, back inner part of neck of radius, bicipital
tuberosity, and oblique line; action, supinates forearm; nerve,
posterior interosseous which pierces it.
Extensor ossis metacarpi pollicis " : origin, posterior surface of
shaft of ulna below anconeus, interosseous ligament, and middle
third of posterior surface of shaft of radius ; insertion, base of
thumb-metacarpal ; action, extends thumb-metacarpal ; nerve,
posterior interosseous.
Extensor primi internodii /do///c/s" : origin, posterior surface of
shaft of radius and interosseous membrane ; insertion, base of first
tbumb-phalanx ; action, extends phalanx on metacarpal ; nerve,
posterior interosseous.
Extensor second! internodii pollicis^* : origin, posterior surface of
shaft of ulna and interosseous membrane below extensor ossis
metacarpi; insertion, last phalanx of thumb; action, extends
thumb ; nerve, posterior interosseous.
Extensor indicis : origin, posterior surface of shaft of ulna below
extensor secundi; fnsertio/i, with tendon of common extensor into
second and third phalanges of index finger ; action, extends index
finger ; nerve, posterior interosseous.
Fasciae of the Hand.
The anterior annular ligament is stretched between pisiform bone
and unciform process of unciform bone on one side, and the tuber¬
osity of scaphoid and ridge of trapezium on the other ; it is con¬
tinuous with forearm and palmar fascia, and receives the insertion
of the palmaria longus muscle and partially that of flexor carpi
radialis, which pierces it ; beneath it pass the median nerve and, in
one synovial sheath, the tendons of the flexor sublimis and pro¬
fundus digitorum and the flexor longus pollicis.
The post rior annular ligament, continuous with forearm fascia,
is attached on dorsum internally to ulna, cuneiform, and pisiform
bones and palmar fascia, externally to ridges on back of and margin
of radius. Six separate synovial compartments exist for the ex-
140 ESSENTIALS OF HUMAN ANATOMY.
tensor tendons; from without inward, they are: (1) outer side oi"
styloid process, for extensor ossis metacarpi and extensor primi
internodii pollicis ; (2) behind same process, for extensor carpi radi¬
alis longior and brevior; (3) next for extensor secundi internodii
pollicis ; (4) more internally still, for extensor communis digitorum
and extensor indicis ; (5) opposite interval between radius and
ulna, for extensor minimi digiti ; and (6) back of ulna, for extensor
carpi ulnaris.
The palmar fascia^ (Fig. 61 ), consisting of a central and two lateral
portions, invests muscles of band forming their common sheath ; the
central segment is triangular, attached to anterior annular ligament
above, below dividing into four slips opposite metacarpal heads, each
slip dividing again to enclose flexor tendons and he inserted on
sides of first phalanges; strong transverse fibres connect the
separate processes, and vertical septa, continuous on each side with
interosseous aponeurosis, separate the middle from lateral palmar
groups of muscles ; beneath is the superficial palmar arch, median
and ulnar nerves; the lateral portions of this fascia thiuly invest
the muscles of the thenar and hypothenar eminences.
Muscles of the Hand.
Abductor polHcis^^ (Fig. 61) : origin, ridge of trapezium and an¬
nular ligament ; insertion, tendinous into radial side of base of
first thumb-phalanx ; action, draws thumb from median line—i. e.,
abducts it; nerve, median.
Opponens pollicis : origin, palmar surface of trapezium and an¬
nular ligament; insertion, whole length of radial side of thumb-
metacarpal ; action, flexes metacarpal ; nerve, median.
Flexor brevis pollicis^^ (Fig. 61) : origin, by two heads between
which lies flexor longus pollicis tendon, the external from trape¬
zium and outer two-thirds of annular ligament, the internal from
trapezoid, os magnum, base of third metacarpal, and sheath of
tendon of flexor carpi radialis; insertion, sides of base of first
thumb-phalanx by two tendons each containing a sesamoid bone;
action, as name implies ; nerves, median and ulnar.
Adductor pollicis : origin, whole palmar length of metacarpal of
middle finger; insertion, ulnar side of base of first thumb-phalanx
MUSCLES OF LOWER EXTREMITY.
141
and internal sesamoid bone ; action, draws thumb toward median
line; nerve, ulnar.
The preceding muscles form the thenar eminence.-
Palmaris breris^": origin, tendinous from annular ligament and
palmar fascia; insertion, skin on inner border of palm; action,
wrinkles skin on inner palmar side ; nerve, ulnar.
Abductor minimi digiti : origin, pisiform bone and expansion of
tendon of flexor carpi ul naris; insertion, ulnar side of base of first
little finger phalanx ; action, draws little finger from median line ;
nerve, ulnar.
Flexor brevis minimi digiti : origin, tip of unciform process and
annular ligament ; insertion, base of first little finger phalanx with
the abductor ; action, flexes little finger ; nerve, ulnar.
Opponens minimi digiti: origin, beneath preceding, from unci¬
form process and annular ligament ; insertion, whole length of
little finger metacarpal ; action, flexes fifth metacarpal ; nerve,
ulnar.
The four preceding muscles form the hypothenar eminence.
Lumbricales: origin, tendons of deep flexor; insertion, tendinous
expansion of extensor communis tendon over dorsum of each
finger; they are four in number ; action, aid in extending second
and third phalanges (Duchenne, Hutchinson) ; nerves, two outer
by median, two inner by ulnar.
Dorsal interossei (four in number) : origin, by two heads from
adjacent sides of the metacarpal bones ; insertion, into bases of
first phalanges and aponeurosis of common extensor ; action, ex¬
tend second and third phalanges, abduct fingers from middle
line passing through centre of middle finger ; nerve, ulnar.
Palmar interossei (three in number) : origin, from entire length
of palmar surfaces of second, fourth, and fifth metacarpal' bones ;
insertion, into bases of first phalanges of same fingers ; action,
adduct (draw) fingers toward middle finger; nerve, ulnar.
Muscles of Lower Extremity.
Psoas magnu^^ (Fig- 63) : origin, sides of bodies, intervertebral
substances and bases of transverse processes of last dorsal and all
the lumbar vertebrae ; insertion, tendinous, with iliacus, into lesser
142
ESSENTIALS OF HUSlAN ANATOMY-
trochanter ; action, flexes thigh on pelvis, or vice versâ, also rotates
femur outward; nerves, anterior branches of lumbar nerves.
Psoas parvus (often absent) : origin, sides of bodies and inter¬
vertebral substance between last dorsal and flrst lumbar vertebrae ;
insertion, tendinous into ilio-pectineal eminence and iliac fascia ;
option, tensor of iliac fascia ; nerves, anterior branches of lumbar
nerves.
Uiacus^"-. origin, iliac fossa and inner margin of iliac crest, ilio¬
lumbar ligament and base of sacrum, anterior superior and inferior
iliac spines, the notch between them, and capsule of hip-joint;
ùiscrtion, with tendon of psoas magnus into lesser trochanter;
action, same as psoas magnus ; nerve, anterior crural.
The fascia lata, or deep fascia, is attached above to Poupart's
ligament and iliac crest, behind to margins of sacrum and coccyx,
internally to pubic arch and linea ilio-pectinea, and below to con¬
dyles of femur, tuberosities of tibia, and head of fibula; two strong
intermuscular septa pass from the inner surface to whole length of
linea aspera ; numerous smaller septa provide separate sheaths for
each muscle; just below Poupart's ligament, at the upper inner
aspect of thigh, is the large oval saphenous opening, formed by the
margins of the pubic and iliac portions of the fascia lata ; Poupart's
ligament is an artificial production, being in reality the Jhickened
lower portion of the external oblique aponeurosis where the fascia
lata becomes continuous with it.
Tensor vagince femoris* : origin, anterior part of outer lip of iliac
crest and anterior superior iliac spine ; insertion, fascia lata one-
fourth down thigh, whence fascia is continued down to tibial
head as the ilio-tibial band; action, tensor of fascia lata; nerve,
superior gluteal.
Sartorios^: origin, anterior superior iliac spine and upper half of
notch below it; insertion, aponeurotic, into upper inner surface of
shaft of tibia; action, flexes leg upon thigh, thigh upon pelvis, at
same time drawing limb inward, thus crossing one leg over the
other; nerve, anterior crural.
Rectus femoris^ : origin, by two tendons, the straight from anterior
inferior iliac spine, the reflected from groove above acetabulum ;
insertion, psXeWa. in common with three next muscles; action, ex¬
tends leg; nerve, anterior crural.
MUSCLES OF LOWER EXTREMITY.
143
Vastus externas'' : origin, tubercle of femur, great trochanter,
rough line leading thence to linea aspera and whole outer lip of
linea aspera; insertion, aponeurotic into outer border of patella;
action, extends leg; nerve, anterior crural.
Vastus internus and crureus^: origin, line leading from inner side
of neck of femur to linea aspera and its whole inner lip, internal
intermuscular septum, internal, anterior, and external surfaces of
Fig. 6.3.
Ftg. 64.
the shaft of femur between the anterior intertrochanteric line and
the lower fourth of the bone; insertion, aponeurotic, into inner side
144
ESSENTIALS OF HUMAN ANATOMY.
of patella, blending with other portions of quadriceps tendon ;
action, extends leg; nerve, anterior crural. The preceding four
muscles are called the quadriceps extensor®,',', whose tendon con¬
tains the patella', and which is inserted into tubercle of tibia by
ligamentum patellae.
Subcrureus : origin, by two heads from lower part of shaft of
femur ; insertion, upper part of synovial pouch of knee ; action,
draws up synovial sac: nerve, anterior crural.
Graci/is^^ : origin, aponeurotic from inner margin of ramus of
pubes and ischium ; insertion, upper inner surface of shaft of tihia
above and behind sartorios ; action, flexes leg and adducts thigh ;
nerve, obturator.
Pectineus^' : origin, linea ilio-pectinea, bone in front of it, and
tendinous prolongation of Gimbernat's ligament ; insertion, rough
line passing from lesser trochanter to linea aspera ; action, flexes,
adducts, and rotates thigh outward; nerves, obturator, accessory
obturator, anterior crural.
Adductor longus^^ : origin, tendinous from angle of pubes ; inser¬
tion, middle third of linea aspera; action, adducts and flexes thigh;
nerve, obturator.
Adductor brevis : origin, outer surface of descending ramus of
pubes; insertion, upper part of linea aspera; action, adducts and
flexes thigh ; nerve, obturator.
Adductor magnus'* : origin, descending ramus of pubes, ascending
ramus, outer margin, and under surface of tuberosity of ischium;
insertion, rough line running from great trochanter to linea aspera,
whole length of linea aspera, and by a tendon into tubercle above
inner condyle of femur, between these portions of muscle is an
angular interval for passage of femoral vessels, the lower orifice of
Hunter's canal ; action, adducts and rotates thigh outward ; nerves,
obturator and great sciatic; the external portion of the muscle
presents four apertures, the three upper for the perforating arteries,
the lowest for termination of profunda artery.
Gluteus maximus^ (Fig. 64): origin, superior curved line of ilium
and portion of bone and crest just behind it, posterior surface of
last piece of sacrum, side of coccyx, aponeurosis over multifidus
spinas muscle and the great sacro-sciatic ligament ; insertion, fascia
lata and rough line running from great trochanter to linea aspera
MUSCLES OF LOWER EXTREMITY.
145
between vastus externus and adductor magnus; action, maintains
trunk erect upon thigh, extends, abducts, and rotates thigh out¬
ward ; nerves, small sciatic, and branch from sacral plexus.
Gluteus médius^ (Fig. 64); origin, outer surface of ilium between
superior and middle curved lines, outer lip of crest between, and
gluteal aponeurosis; insertion,
tendinous into oblique line on Fig. 65.
great trochanter ; action, supports
trunk, the posterior fibres rotate
thigh outward, the anterior fibres
rotate thigh inward, it also ah-
ducts and draws thigh forward;
nerve, superior gluteal.
Gluteus minimus^ (Fig. 65) : ori-
jcire, outer surface ofilium between
middle and inferior curved lines
and margin of sciatic notch ; in¬
sertion, anterior border of great
trochanter; action, àv&y/s, forward,
abducts and rotates thigh inward,
aids in maintaining trunk erect ;
nerve, superior gluteal.
Pyriformis^ : origin, by three
fleshy digitations from hone be¬
tween first, second, third, and
fourth anterior sacral foramina,
likewise grooves leading from them, from margin of great sacro-
sciatic foramen, and great sacro-sciatic ligament ; insertion, passing
out of pelvis by great sacro-sciatic foramen is attached to upper
border of great trochanter ; action, an external rotator of thigh,
which, when flexed, is abducted by this muscle, also draws pelvis
forward with fixed femur ; nerves, branches of sacral plexus.
Obturator internus^^ : origin internal surface of obturator mem¬
brane and tendinous arch for passage of vessels, and inner side of
obturator foramen ; insertion, upper border of great trochanter
after leaving pelvis by lesser sacro-sciatic foramen; four or five
tendinous bands pass in the substance of the muscle (Bigelow)
10
146 ESSENTIALS OF HUMAN ANATOMY.
from origin to insertion; action, similar to pyriformis; neri;e\
branches of sacral plexus.
Gemellus superior^": origin, spine of ischium; inaertion, with
tendon of obturator internus into upper border of great trochanter;
action, rotates thigh outward ; nerves, branches of sacral plexus.
Gemellus inferior'-'^ ; origin, tuberosity of ichium ; insertion, great
trochanter with obturator internus ; action, an external rotator of
thigh ; nerves, branches of sacral plexus.
Obturator externus : origin, inner margin of obturator foramen
externally, and inner two thirds of outer surface of obturator mem¬
brane; insertion, digital fossa of femur; action, an external rotator
of thigh ; nerve, obturator.
Quadrates femorls " : origin, outer border of tuberosity of ischium ;
insertion, linesi quadrati on back of trochanter major; action, ex¬
ternal rotator of thigh ; nerves, branches of sacral plexus.
Biceps^^ (Fig. 65) ; (Fig. 64) : origin, by two heads, the long^^
(Fig 65) from lower inner facet on tuberosity of ischium by tendon
common to semitendinosus, the short head^ (Fig. 64), from linea
aspera between adductor magnus and vastus externus, and from
intermuscular septum ; insertion, outer side of head of fibula, the
tendon splitting to embrace external lateral ligament of knee, one
band extending down as far as outer tuberosity of tibia ; this mus¬
cle forms tl^e outer hamstring-, action, flexes leg, after which it
slightly rotates it outward ; nerve, great sciatic.
Semitendinosus^ (Fig. 64), (Fig. 65) ; origin, by common tendon
with preceding muscle from tuberosity of ischium and adjacent
aponeurosis; insertion, upper inner surface of shaft of tibia, be¬
hind sartorius and below gracilis; action, flexes leg on thigh;
nerve, great sciatic.
Semimembranosus' (Fig. 64) : origin, tendinous from upper outer
facet on tuberosity of ischium ; insertion, groove on inner tuber¬
osity of tibia; action, flexes leg on thigh, after which it assists
popliteus in rotating leg inward ; nerve, great sciatic; the tendons
of sartorius^" (Fig. 64), gracilis' (Fig. 64), semimembranosus' (Fig
64), and semitendinosus' (Fig. 66) (enumerated from before back¬
ward), form the inner hamstring.
MUSCLES OF THE LEG.
147
Muscles of the Leg.
Tibialis anficus^ (Fig- 66) = origin, outer tuberosity and upper two-
thirds of external surface of shaft of tibia, adjacent interosseous
membrane, deep surface of fascia, and intermuscular septum ; in¬
sertion, inner under surface of internal cuneiform bone, base of
first metatarsal ; action, flexes and adducts tarsus ; nerve, anterior
tibial.
Extensor proprius poUicis^ : origin, middle two-fourths of anterior
surface of fibula, and to same extent from interosseous membrane ;
insertion, base of last phalanx of great toe; action, extends great
toe and, continuing action, flexes tarsus on leg; nerve, anterior
tibial.
Extensor iongus digitorum* : origin, outer tuberosity of tibia, upper
three-fourths of anterior surface of fibula, interosseous membrane,
deep surface of fascia, and intermuscular septa; insertion, divides
into three tendons, and one subdivides making four tendons, which
are attached to second and third phalanges of four lesser toes;
action, extends toes, then flexes tarsus on leg ; nerve, anterior tibial.
Peroneus tertius^ (part of preceding muscle) : origin, lower fourth
of anterior surface of fibula, interosseous membrane, and inter¬
muscular septum ; insertion, upper inner part of base of little toe
metatarsal ; action, same as long extensor; nerve, anterior tibial.
Gastrocnemius^" : origin, by two heads from upper back part of
condyles of femur and supra-condyloid ridges; insertion, with
tendons of soleus and plantaris Iongus forms tendo-Achillis, which
is inseided into posterior tuberosity of os caléis; action, extends
foot ; nerve, internal popliteal.
Soleus","-. origin, tendinous, from back of head of fibula and
upper third of postero-internal surface of shaft, from oblique line
of tibia and from middle third of its inner border ; insertion, tuber¬
osity of OS caléis by tendo-Achillis ; action, extends foot ; nerve,
external popliteal.
Plantaris : origin, lower part of outer bifurcation of linea aspera
and posterior ligament of knee-joint ; insertion, posterior surface of
OS calcis with tendo-Achillis ; action, extends foot ; nerve, internal
popliteal.
148 ESSENTIALS OF HUMAN ANATOMY.
Popliteus^ (Fig- Ö7) : origin, depression on outer side of external
condyle of femur and posterior ligament of knee-joint; insertion,
inner two-thirds of triangular surface above oblique line of tibia
posteriorly, and tendinous expansion covering muscle; action,
flexes leg upon tbigb, then rotates tibia inward ; nerre, internal
popliteal.
Fig. 66. Fio. 67.
Flexor iongus pollicis^ (Fig. 67) : origin, lower two-tbirds of postero¬
internal surface of shaft of fibula, except its lowest inch, lower
part of interosseous membrane, intermuscular septum, and fascia
covering tibialis posticus ; insertion, base of last phalanx of great
FASCIA OF THE FOOT.
149
toe ; action, flexes great toe, then extends foot ; nerve, posterior
tibial.
Flexor longue digitoruní' (Fig. 67) (perforans) : origin, Tposteñoi
surface of tibia below oblique line internal to tibialis posticus, ex¬
cept lower three inches, also intermuscular septum, tendon passes
behind malleolus in groove with tibialis posticus, but in separate
synovial sheath ; insertion, bases of phalanges of lesser toes by four
tendons, each passing through a fissure in the tendon of the flexor
brevis; action, flexes phalanges, then extends foot; nerve, posterior
tibial.
Tibialis posticus^ (Fig. 67) : origin, by two pointed processes, be¬
tween which pass the anterior tibial vessels, from whole of pos¬
terior surface of interosseus membrane except lowest part, posterior
surface of tibia, external to flexor longus, between oblique line
above and middle of external border below, and from upper two-
thirds of internal surface of fibula ; insertion, tuberosity of sca¬
phoid and internal cuneiform bones; action, extends tarsus on leg,
adducts foot; nerve, posterior tibial.
Peroneus longue'' (Fig. 66) : origin, head and upper two-thirds of
outer surface of shaft of fibula, deep surface of fascia, and inter¬
muscular septa, passes behind outer malleolus in groove with pero¬
neus brevis® (Fig. 64), then traverses groove of cuboid; insertion,
outer side of base of great toe metatarsal and internal cuneiform ;
action, extends foot, then everts it ; nerve, musculo-cutaneous.
Peroneus brevis" (Fig. 66) : origin, lower two-thirds of outer sur¬
face of shaft of fibula, intermuscular septa ; insertion, passes with
preceding muscle behind external malleolus in a groove lined with
a synovial sheath common to both tendons, to be attached to
dorsum of base of fifth metatarsal ; action, same as peroneus longus ;
nerves, musculo-cutaneous.
Fasciae of Foot.
The anterior annular ligament consists of (1) an upper vertical por¬
tion binding down the extensor tendons, attached to lower ends of
tibia and fibula, continuous above with leg fascia, and containing
only one synovial sheath situated internally for tendon of anterior
tibial, the extensor longus digitorum, peroneus tertius, and ex-
150
ESSENTIALS OF HUMAN ANATOMY.
tensor proprius pollicis tendons, and anterior tibial vessels and
nerve passing beneath it without a distinct sheath; and (2) a
horizontal portion attached externally to upper surface of os caléis,
and internally to inner malleolus and plantar fascia, containing
three sheaths, that internal for anterior tibial tendon, the next for
extensor proprius pollicis tendon, and that most external for ex¬
tensor longus digitorum and peroneus tertius.
The interna! annular ligament is a strong band extending from
inner malleolus to inner margin of calcis, converting the bony
grooves on its surface into canals for the flexor tendons and plantar
vessels ; it is continuous with deep fascia of leg, plantar fascia,
and origin of abductor pollicis muscle. Its three fibro-osseous
canals transmit, enumerated from within outward, the tendons of
posterior tibial, flexor longus digitorum, posterior tibial vessels and
nerve—through broad space beneath ligament—and tendon of
flexor longus pollicis.
The externa! annular ligament stretches between the extremity of
the outer malleolus to outer surface of calcis, forming a common
sheath for peroneal tendons.
The plantar fascia, the densest of all fibrous membranes, consists
of a central and lateral portions ; the former, thick and narrow he-
hind, arising from inner tubercle of os calcis, divides into a process
for every toe, each again splitting opposite metatarso-phalangeal
joints into twoelips—between which pass the flexor tendons—to
be attached to sides of metatarsal bones and transverse metatarsal
ligament; two chief and several subordinate intermuscular septa
are given off, separating the muscular layers ; the outer and inner
segments are thin, and of no special interest.
Muscles of the Foot.
Dorsal region.
Extensor brevis digitorum : origin, outer surface of os calcis, exter¬
nal calcaneo-astragaloid ligament, and annular ligament ; insertion,
by four tendons, the first into first phalanx of great toe, the other
three into outer sides of long extensor tendons of second, third,
and fourth toes ; action, accessory to long flexor on four inner toes;
nerve, anterior tibial.
MUSCLES OF THE FOOT.
151
Fig. 68.
Plantar region. First layer.
Abductor po/licis^ (Fig- 68): origin, inner plantar tubercle of os
caléis, internal annular ligament, plantar fascia, and intermuscular
septum; insertion, with innermost tendon
of flexor brevis pollicis into inner side of
base of first great toe phalanx ; action, ab¬
ducts great toe ; nerve, internal plantar.
Flexor brevis digitorunfi : origin, tendinous
from inner plantar tubercle of calcis, central
part of plantar fascia and intermuscular
septa; insertion, by four tendons for four
lesser toes, perforated opposite middle of
first phalanges by tendon of long flexor, be¬
yond the perforation the tendon splitting to
be inserted into sides of second phalanges;
action, flexes lesser toes; nerve, internal
plantar.
Abductor minimi digiti* : origin, outer plantar
tubercle of os calcis, bone in front of both
tubercles, plantar fascia, and intermuscular
septum ; insertion, with short flexor of little
toe into outer side of base of first little toe
phalanx; action, abducts little toe; nerve,
external plantar.
Second layer.
Flexor accessorius : origin, by two heads, from concave surface of
calcis and calcaneo-scaphoid ligament and os calcis in front of
outer tubercle, and from plantar ligament ; insertion, outer margin
and upper and under surfaces of tendon of long flexor of toes ;
eLction, aids long flexor ; nerve, external plantar.
Lumbricates' : origin, tendons of long flexor ; insertion, expansion
of long extensor and bases of first phalanges ; action, accessory to
flexors ; nerves, the two inner lumbricales by internal, the two outer
by external plantar nerve.
Third layer.
Flexor brevis pollicis : origin, inner border of cuboid and contigu¬
ous portion of external cuneiform, and prolongation of posterior
152
ESSENTIALS OF HUMAN ANATOMY.
tibial tendon ; insertion, inner and outer side of base of first great
toe phalanx by two tendons, each containing a sesamoid bone, the
inner tendon blending with that of the abductor pollicis, the outer
with that of adductor pollicis ; action, flexes great toe ; nerves, in¬
ternal plantar, sometimes external plantar.
Adductor pollicis: origin, tarsal extremities of second, third, and
fourth metatarsal bones and sheath of tendon of peroneus longus ;
insertion, with outer portion of the short flexor into outer side of
base of first phalanx of great toe ; action, adducts great toe ; nerve,
external plantar.
Flexor brevis minimi digiti : or/g'i«, base of little toe metatarsal and
sheath of peroneus longus tendon ; insertion, outer side of base of
first phalanx of little toe; action, flexes first, extends second
phalanx ; nerve, external plantar.
Transversas pedis : origin, under surface of head of fifth metatar¬
sal bone and transverse metatarsal ligament ; insertion, with adductor
pollicis into outer side of first phalanges of great toe ; action, ad¬
ducts great toe ; nerve, external plantar.
Fourth layer.
Dorsal interossei (four) : origin, each by two heads from adjacent
sides metatarsal bones; insertion, tendinous into bases of first pha¬
langes of corresponding toes and aponeurosis of common extensor;
action, abducts toes from imaginary line passing through centre of
second metatarsal ; nerve, external plantar.
Plantar interossei (three) : origin, base and inner sides of shaft of
third, fourth, and fifth metatarsal bones ; insertion, inner sides of
bases of phalanges of same toes; action, adduct toes toward a
line passing through middle of second toe ; nerve, external plantar.
Vascular System,
What is the pericardium ?
A closed fibro-serous sac of conical form, its apex surrounding
the great a essels for about two inches above their origin, its base
downward, attached to the central tendon of diaphragm. The
outer fib' ous coat is continued as tubular prolongations, lost upon
the ext( rnal coats of the roots of all the great vessels except the
inferioL vena cava, and is finally traceable as continuous with the
VASCULAR SYSTEM.
153
deep layer of the cervical fascia ; the serous coat lines the sac,
forming a, parietal layer, is reflected over the heart and great vessels,
forming a visceral layer ; its function is the secretion of a thin fluid
in sufficient amount to moisten the surfaces, thus lessening friction
during the heart's movements.
Describe the heart.
It is a hollow, conical muscle, with four distinct cavities, situ¬
ated obliquely between the lungs, the base upward, backward, and
to the right, the apex" (Fig. 69) downward, forward, and to the
left, corresponding to fifth intercostal space, one and a half inches
below and three-fourths of an inch to the right of the left nipple.
Give the points upon the exterior of the thorax corre¬
sponding to space occupied by the heart.
The upper border corresponds to a line drawn across the sternum
on a level with the lower borders of the second costal cartilages; its
lower border to a line crossing gladiolus from right side of costo-
xiphoid joint to apex point above described ; the right border
extending from median line of sternum three inches, its left, one
and one-half inches; as the lungs partially cover the heart in
front, the '' area of heart's dulness " can be roughly indicated,
according to Holden, by " a circle one inch in radius, the centre of
which is midway between the left nipple and the end of the
sternum."
Give the size and weight of the heart.
In adults it measures five inches long, three and one-half broad,
and two and one-half thick ; weighs in male ten to twelve ounces,
in proportion to body 1 to 169; in females, eight to ten ounces, 1
to 149.
What are the four cavities of the heart called ?
The right auricle' and right ventricle', the left auricle and left
ventricle, separated by a longitudinal septum—indicated externally
in front and behind by the interventricular grooves—dividing the
heart into lateral halves, the right, or venous heart, the left, or
arterial heart ; a transverse auriculo-venlricular groove on the ex¬
terior corresponds to the division between auricles and ventricles.
15-4 ESSENTIALS OF HUMAN ANATOMY.
Describe the right auricle and the chief points requiring
study.
Larger than the left auricle, with a capacity of about two fluid
ounces, its walls are about one line thick; the venous blood is
poured in by the superior' and inferior venae cavae" and the coro-
nory sinus; note the following points ;
The sinus, the large quadrangular cavity between the two venae
cavae ; the appendix auriculœ, a conical pouch with dentated edge,
projecting forward to the left over the root of the aorta®; the
openings 0Ï ihe two venae cavae, also that of the coronary sinus®'', its
orifice guarded by a semicircular fold of the auricular lining called
coronary valve—sometimes at its junction with the great coronary
vein a valve with two unequal segments is found ; the tubercle of
Lower^, a small projection on the right wall directing blood from the
superior cava toward auriculo-ventricular opening ; the foramina
Thebesii, the mouth of numerous minute veins returning blood
from the heart muscle ; the semilunar Eustachian valvê' between
the anterior margin of the inferior vena cava and auriculo-ventri-
cular opening—it is larger in the foetus, serving to direct the blood
of the inferior cava through the foramen ovale; the fossa ovali^',
an oval depression at the lower part of the septum auricularum,
the site of the oval foramen in the fœtus; the annulas oralis, the
prominent margin of fossa ovalis; the. musculipectinati,sm3i\\ promi¬
nent muscular columns, running across the inner surface of the
appendix and adjoining wall of the sinus; the oval atiriculo-ven-
tricular orifice, about one inch in diameter, communicating with
the right ventricle, its margins formed by a fibrous ring covered
by the lining membrane, and guarded by the tricuspid valve.
Describe the right ventricle.
It is triangular, with apex downward, not quite reaching that of
the heart, forming with the right auricle the anterior, rather than
the right side of the heart; its capacity has been variously esti¬
mated at from two to six fluid ounces ; it presents the following
points for examination :
Above is the conical prolongation called the conus arteriosus,
from which opens the orifice of the pulmonary artery placed to the
left of the auriculo-ventricular orifice anteriorly, corresponding to
VASCULAR SYSTEM.
155
junction of third left costal cartilage with sternum, and is sur¬
rounded by a fibrous ring ; the pulmonary semilunar valves guard
this orifice; the tricuspid valvé'yi'" formed of three triangular
segments—the largest on the left side—by a reduplication of the
lining membrane with interposed fibrous tissue, which are pre¬
vented from being forced into the auricle by the,
Chordce iendineœ'", fine tendinous cords stretching from (1) the
columnae carneae to the attached margin, (2) to the centres of the
leaflets, and (3) to their free margins.
The columnae carneae^', three varieties of muscular columns, (1)
simple ridges, (2) bands attached by both extremities, and (3) three
or four musculipapilläres, muscular eminences from which arise the
chordae tendineae.
The VaxcQpulmonary semilunar valves^, two anterior and one pos¬
terior, formed by a reduplication of the lining membrane with
interposed fibrous tissue, with their free margins strengthened by a
bundle of fibrous tissue, whose fibres radiate from a fibro-cartilagi-
nous nodule—the corpus Araniii—to all parts, except to two narrow
lunated portions on either side of the nodule, which are forced in
contact when the valves are closed; above and behind each valve
is a dilatation, the sinus of Valsalva.
Describe the left auricle.
Resembles the right in having a principal cavity or sinus and an
appendix, but its walls are thicker, measuring about one and one-
half lines. The following points should be studied :
The openings of the pulmonary veins, usually four in number, two
emptying into the right and two into the left side ; frequently the
latter terminate by a common opening.
The oval auriculo-veniricular opening, surrounded by a fibrous
ring, smaller than the right ; the musculipectinati fewer and smaller
than on the right side ; a depression over site of the fossa ovalis
of the right auricle.
Describe the left ventricle.
Larger and more conical than the right it forms but little of the
left side, most of the posterior surface and all the apex" of the
heart, its walls being three times as thick as those of the right
ventricle; its inner surface presents for examination.
156
ESSENTIALS OF HUMAN ANATOMY.
The circular aortic opening, with the usual fibrous ring, in front
and to the right of the auriculo-ventricular opening, between them
intervenes one of the segments of the mitral valve ; the aortic
orifice is opposite the left half of the sternum, on a line with the
lower border of the third costal cartilage, its mouth being guarded
by three semilunar valves; the mitral valve, composed of two
Fig. 69.
irregular segments—the larger in front—similar to those of the
trieuspid valve, but larger and thicker, the leafiets being provided
with chordae tendineœ, whose mode of attachment is identical with
those of the right side. The semilunar aortic valves resemble those
of the pulmonary artery, but are larger and stronger ; sinuses, like
the sinuses of Valsalva of the pulmonary artery, are found behind
the aortic valves.
THE ARTEKIES.
157
The columnœ carneœ are more numerous, but smaller than on the
right side, while there are only two musculi papilläres.
What is the endocardium ?
The delicate lining membrane of the heart continuous with the
intima of the great vessels, by its reduplications forming the
various valves.
Describe the heart structure.
It consists of striated anastomosing muscular fibres taking origin
from the fibrous rings surrounding the aortic, pulmonary, and
auriculo-ventricular openings, disposed in the auricles in a deep
layer composed of looped and annular fibres, and a superficial
transverse layer ; in the ventricles numerous layers have been de¬
scribed, the deepest of which run circularly, the more superficial
spirally, curving round the apex to form the whorl or vortex, those
fibres from in front curving around to enter posteriorly, and vice
versa ; the most superficial fibres, especially those behind, pass
across the septum from one ventricle to the other.
The Arteries.
What are the arteries ?
Cylindrical tubular vessels conveying blood from both ventricles
to all parts of the body ; the blood they carry is called arterial;
the pulmonary artery arising from the right ventricle conveying
blood to the lungs, and the four pulmonary veins returning it to
the left auricle, constitute the lesser or pulmonic circulation, while
the aorta arising from the left ventricle carrying blood to the
body generally, and the veins returning it, finally emptying by the
two cavse into the right auricle, form the greater or systemic circu¬
lation. In their distribution the arteries freely communicate with
one another, the large branches as well as the small forming what
are called anastomoses or inosculations, permitting the establish¬
ment of the collateral circulation after obliteration of "a main
artery.
Describe the structure of the arteries.
They possess three coats, an (1) internal (serous) or intima; (2)
158 ESSENTIALS OF HUMAN ANATOMY.
Fio. 70.
a.middle (meciia), composed in small vessels almost purely of cir¬
cular muscular fibres, in the larger chiefly of yellow elastic tissue;
this prevents the arteries from collaps¬
ing when cut across; (3) an external
(adveiitiii.a) composed of connective
tissue. Every vessel, except the intra¬
cranial vessels, is included with its vein
or veins in a fibro-areolar sheath.
How are the arteries nourished
and their calibre regulated ?
The larger vessels are supplied by
minute vasa vasorum, bloodvessels dis¬
tributed in a fine network to their ex¬
ternal and middle coats ; while intri¬
cate nerve networks (plexuses), chiefly
derived from the sympathetic with
branches of the spinal system, supply
the same coats of the large vessels—
the smaller are usually supplied only
with single filaments.
What are capillaries?
The intermediate vessels between
the arteries and veins, disposed in the
form of a network, of an average di¬
ameter of one-three-thousandths of an
inch, formed of a fine transparent layer
of endothelial cells united by a cement
substance.
Describe the aorta\(Fig. 70).
^ ^vIm This, the main trunk of the systemic
^ ' arteries, arises from the upper part of
' «"W 2ä jgfj. yentricle, ascends and then
arches backward to the left over the root of the left lung to descend
within the thorax on the leftside of the vertebral column, entering
the abdominal cavity by the aortic opening» through the diaphragm,
where it terminates opposite the fourth lumbar vertebrae in the
THE ARTEEIES.
159
two common iliac arteries^'; the aorta is divided for convenience
of study into the arch', thoracic^, and abdominal aorta®, while the
arch is described as consisting of an ascending, transverse, and de¬
scending portion. The branches of each subdivision are,
TT íí if Two coronary. Left common carotid',
I'rom the arch, \ ■" «
t Innominate', Left subclavian®.
f Pericardiac, Posterior mediastinal.
From the thoracic aorta .j Bronchial®, Intercostals",
ŒsophageaP".
From the abdominal aorta. Two phrenic'®. Two spermatic''®".
f Gastric'®, Inferior mesenteric",
Coeliac axis" -j Hepatic",
Splenic'®, Eight lumbar'®.
Superior mesenteric'®,
Two supra renal'", Sacra media".
Two renal®".
Describe the coronary arteries.
The right arises from the aorta above the free margin of the right
semilunar valve, passes in groove between right auricle and ven¬
tricle to posterior interventricular groove, where, dividing into two
branches, one continues onward anastomosing with the left coron¬
ary, the other descends along the interventricular groove to apex
of heart anastomosing with descending branch of left coronary;
the left coronary, the smaller, arises above the free edge of left
semilunar valve, passes forward between pulmonary artery and left
appendix, thence obliquely to anterior interventricular groove,
where it divides, one branch passing around to join the right
vessel, the other descending in the groove to anastomose at apex
with descending branch of right vessel.
Describe the innominate artery*.
Arising from the commencement of transverse portion of arch,
it is from one and a half to two inches long and bifurcates at
upper border of right sterno-clavicular articulation into right
common carotid® and subclavian®, sometimes it sends off a middle
¿Ayroid branch—occasionally no innominate exists, the right carotid
and subclavian springing directly from the aorta.
160 ESSENTIALS OF HUMAN ANATOMY.
Describe the cammon carotid®/.
The right arises opposite right sterno-clavicular joint from in¬
nominate, the left from summit of aortic arch. In the neck their
course corresponds to a line passing from the sterno-clavicular
joint to a point midway between the mastoid process and angle of
lower jaw ; below, the trachea only separates them, above there is
a wide interval ; a common sheath of deep fascia encloses the in¬
ternal jugular vein, the pneumogastric nerve (posterior to both),
and artery, enumerated from without inward, while upon the sheath
lies the descending branch of the ninth cranial nerve (descendens
noni); the vessel is overlapped for most of its course by the
anterior margin of the sterno-cleido-mastoid muscle, while about
its middle it is crossed by the omo-hyoid muscle, the anterior
jugular, and middle thyroid veins, while above the omo-hyoid
Fio. n.
muscle, the sterno-mastoid artery, and ihe superior thyroid vein
cross it; at the lower part of the neck the right internal jugular
vein diverges from the artery, but the left often crosses the lower
part of corresponding artery ; opposite the upper border of the
thyroid cartilage, each vessel divides into the internal and external
carotid.
THE ARTERIES.
161
Name the branches of the external carotid artery with
their subdivisions.
Superior thyroid*, arising below greater cornu of hyoid bone; its
branches are
Muscular, Hyoid, Superior laryngeal,
Superficial descending (sterno-mastoid), Crico-thyroid.
Lingual arises between thyroid and facial running heneath hyo-
glossus muscle to under surface of tongue ; its branches are
Hyoid, Dorsalis Linguae, Sublingual, Ranine.
Facial^ arises just above lingual to cross lower jaw just anterior
to masseter muscle ; its branches are
Inferior or ascending palatine, Muscular'", Lateralis nasi".
Tonsillar, Inferior labial". Angular'",
Submaxillary, Inferior coronary".
Submental", Superior coronary".
Oedpital^^ arises posteriorly opposite facial, lies in occipital
groove of temporal bone ; its branches are
Muscular, Meningeal, Cranial ( (distributed
I over occiput).
Auricular, Arteria princeps
Sterno-mastoid. cervicis.
Posterior auricular*^ arises opposite styloid process, ascends
beneath parotid gland to groove between cartilage of ear and
mastoid process ; its branches are
Stylo-mastoid, Auricular, Muscular, Parotid.
Ascending pharyngeal, running between carotid and side of
pharynx; its branches being
External | ^"d pjjaryngeal. Meningeal.
I nervous).
Temporal, the smaller terminal branch, commences in substance
of parotid gland, crosses root of zygoma, two inches above which it
divides into anterior"* and posterior"" temporal ; its branches are
Transverse facial"" (Fig. 71), Middle temporal"" (Fig. 71),
Anterior auricular.
Internal maxillary^, the larger terminal branch passes inward at
right angles to the vessel at the inner side of neck of condyle of
the lower jaw; it is divided into three portions, (1) maxillary,
(2) pterygoid, and (3) spheno-maxillary.
11
162 ESSENTIALS OF HUMAN ANATOMY.
(1) Anterior tympanic, Small meningeal,
Middle meningeal, j Incisor,
1 Mental.
(2) Deep temporal Masseteric,
anterior and posterior.
Pterygoid, Buccal.
(3) Alveolar, Vidian,
Infra-orbital, Pterygo-palatine,
Posterior or descending Nasal or spheno-palatine.
palatine.
Fig. 72.
Plan of the Branches Í'C .'oâmiUfgrMiu
/fflddfa Menlvfffttt
Mfntitj/ta Tarvt
TymftaniC'
l7]fiTitr ffentai-
Describe the internal carotid artery.
It runs in front of the transverse processes of the three upper
cervical vertebrae in contact with the pharynx and tonsil to the
carotid canal of temporal bone, enters the skull, passes through
the cavernous sinus and pierces the dura mater near the anterior
clinoid processes when it divides into its terminal branches.
Give its branches.
Tympanic (deep), from artery in carotid canal, anastomosing with
tympanic branch of internal maxillary, stylo-mastoid, and Vidian
arteries.
Arteria receptaxuli, small vessels supplying cavernous and in¬
ferior petrosal sinuses, pituitary body, Gasserian ganglion; one to
the dura mater anastomosing with the middle meningeal is called
the anterior meningeal,
Ophthalmic, from cavernous portion, enters orbit by optic fora-
THE ARTERIES.
163
men, dividing at the inner angle of the eye into two terminal
divisions, the frontal and nasal] its branches are
Anterior cerebral passes forward in the great longitudinal cere¬
bral fissure, and communicates with its fellow by the anterior com¬
municating artery, a vessel about two lines long.
Middle cerebral, the largest branch is lodged in the Sylvian fissure
and divides into an anterior branch to pia mater ; a middle branch
to small lobe at outer extremity of fissure; and a posterior branch,
supplying middle cerebral lobe.
Anterior choroid, to hippocampus major, corpus fimbriatum,
velum interpositum, and choroid plexus.
Posterior communicating runs back to anastomose with posterior
cerebral, a branch of basilar artery.
Describe the circle of Willis.
It consists of a vascular anastomosis at the base of the brain,
between the branches of the carotids and basilar artery, whereby
pressure on, or blocking of any two of the main trunks, will not
prevent both sides of the brain from receiving a supply of blood.
Its formation is as follows : The two vertebráis by their junction
form the basilar, which divides into two posterior cerebral, these latter
being connected with the back part of the internal carotids on
each side by a posterior communicating, while the anterior termi¬
nals of the carotid, viz., the anterior cerebral on each side, is con¬
nected in front with its fellow by the short anterior communicating
artery before mentioned.
Describe the subclavian.
On the right side it springs from the innominate, on the left
directly from the aortic arch. It is divided into three portions,
viz., that internal to the anterior scalene muscle, that behind the
muscle, and that external to the scalene, this muscle intervening
between the artery and subclavian vein ; it ceases to be called sub-
Lachrymal,
Supraorbital,
Posterior ethmoidal.
Anterior ethmoidal.
Palpebral,
Frontal,
Nasal,
Muscular,
Anterior ciliary.
Short ciliary.
Long ciliary.
Arteria centralis retinae.
164
ESSENTIALS OF HUMAN ANATOMY.
clavian at the lower border of the first rib, being termed axillary.
All the branches arise from the first portion, except the superior
intercostal on the right side, which comes from the second portion;
its branches are.
The vertebral, which passes through the foramina in cervical
transverse processes except that of seventh, enters skull through
foramen magnum, joining its fellow at the lower border of the pons
Varolii to form the badlar artery, its branches are,
Lateral spinal. Anterior spinal.
Muscular, Posterior spinal.
Posterior meningeal, Posterior inferior cerebellar.
The basilar, formed by the vertebráis, gives off the following
branches :
Transverse, Anterior inferior cerebellar, Superior cerebellar. Pos¬
terior cerebral.
Thyroid axis divides almost at once into
Inferior thyroid, to same named gland, giving off
Laryngeal, Muscular, Œsophageal,
Tracheal, Ascending cervical.
Suprascapular, chiefly to shoulder-joint and supra-spinous fossa;
it anastomoses with acromial thoracic, posterior circumflex, the
posterior and subscapular arteries.
Transversalis colli, larger than preceding, passes transversely out¬
ward to trapezius, beneath which it divides into the
Superficial cervical. Posterior scapular.
Internal mammary arises from under surface of first portion, oppo¬
site thyroid axis, descends upon costal cartilages a short distance
from the sternum to the sixth interspace, where it divides into
musculo-phrenic and superior epigastric, the latter anastomosing
with the deep epigastric of external iliac ; the branches are,
Superior phrenic (comes Anterior intercostal,
nervi phrenici). Perforating,
Mediastinal, Musculo-phrenic,
Pericardiac, Superior epigastric.
Sternal.
Superior intercostal, its branches are,
Intercostals, Posterior muscular. Spinal,
THE AETEKIES.
165
Profunda cervicis, supplying posterior cervical muscles and anas¬
tomosing with arteria princeps cervicis from occipital.
Describe the axillary.
It extends from lower border of first rib to lower border of tendons
of latissimus dorsi and teres major muscles, when it takes the name
of brachial ; its branches are,
Superior thoracic, supplying pectoral muscles and thoracic wall.
Acromial thoracic, supplying the deltoid by acromial branches,
the serratus magnus, and pectorals by thoracic and descending
branches.
Long thoracic, to chest muscles and mammary gland.
Alar thoracic, supplies axillary glands.
Subscapular, anastomosing with supra- and posterior scapular
arteries, and giving off the dorsalis scapulae.
Posterior circumflex, to deltoid muscle and shoulder-joint; it
anastomoses with the anterior circumflex, supra-scapular, acromial
thoracic, and superior profunda arteries.
Anterior cireumjlex, to joint and deltoid; it anastomoses with
posterior circumflex and acromial thoracic arteries.
Describe the brachial.
A continuation of axillary, extending from lower border of teres
major and latissimus dorsi tendons to its bifurcation into radial
and ulnar, usually just below bend of elbow; the median nerve
crosses it from without inward about midway in its course ; its
branches enumerated from above downward are,
Superior profunda, descending arm in musculo-spiral groove,
giving oif posterior articular artery, which anastomoses with the
interosseous recurrent, posterior ulnar recurrent, and anastomotica
magna, or inferior profunda, while the terminal twigs of the main
trunk inosculate with the recurrent radial.
Nutrient artery, to humerus.
Inferior profunda, anastomosing with anterior and posterior
ulnar récurrents and anastomotica magna.
Anastomotica magna, anastomosing with posterior articular, infe¬
rior profunda, anterior and posterior ulnar récurrents.
Muscular, to arm muscles.
166 ESSENTIALS OF HUMAN ANATOMY.
Describe the radial artery.
It appears to be a continuation of brachial, but much smaller,
extending from bifurcation at elbow along radial side of forearm
to wrist, where, winding beneath the thumb, it passes between the
two heads of the first dorsal interosseous muscle to palm, there
inosculating with the deep or communicating branch of the ulnar
to form
The deep palmar arch, having as branches three to four palmar
interossei; sometimes described as also giving ofi" the radialis
indicis, perforating, and recurrent branches, here credited to main
vessel.
The branches of radial are,
Forearm, Wrist,
Riidiitl recurrent, Posterior carpal,
Muxcular, Metacarpal,
Superficialis voice, Porsalis pollicis.
Anterior carpal. Dorsalis indicis.
Hand,
Princeps pollicis.
Radialis indicis,
Perforating,
Interosseous.
Describe the ulnar.
Larger than the preceding, it passes from bifurcation obliquely
inward to middle of forearm, thence runs along its ulnar border,
across annular ligament to radial side of pisiform bone, curving
across palm where, either with or without anastomosing with the
superficialis volae of the radial, it forms the
Superficial palmar arch, whose branches are the four digitals.
The branches of the ulnar are, in the
Forearm,
Anterior ulnar recurrent.
Posterior ulnar recurrent,
T , f Anterior interosseous.
Interosseous 1 '
I Postervor interosseous.
Muscular.
THE ARTERIES.
167
W rist,
Anterior carpal,
Posterior carpal.
Hand,
Deep, or communicating branch.
Digitals.
Describe the thoracic aorta^ 73).
Commencing at left side of lower
border of fifth dorsal vertebra, it ter¬
minates at the aortic openings, in dia¬
phragm in front of body of last dorsal
vertebra; its branches are,
Pericardiac, variable in number and
origin, for pericardium.
BronchiaP, irregular in number and
origin, usually one right and two left,
for lung-tissue proper.
(Esophageal, commonly numbering
four to five, anastomosing around the
gullet with branches of inferior
thyroid, phrenic, and gastric arteries.
Posterior mediastinal, numerous and
small to glands and areolar tissue.
Intercostals^^, usually ten on either
side, each dividing into an anterior
and posterior branch, the former sub¬
dividing into two at the angle of the
ribs, one branch running in groove at
lower border of rib above, the other
running along the upper border of the
rib below, in front both anastomosing
with anterior intercostal branches of
the internal mammary, with thoracic
branches of axillary, with epigastric,
phrenic, and lumbar arteries ; the pos¬
terior division supplies the vertebrae,
spinal cord, dorsal muscles, and skin.
Fig. 73.
168
ESSENTIALS OF HUMAN ANATOMY.
Describe the abdominal aorta^.
It commences at the aortic opening®, of the diaphragm in front
of body of last dorsal vertebrae, whence descending a little to left
of vertebral column it terminates on the body of the fourth
lumbar vertebra by dividing into the common iliacs^'; its branches
are,
Coeliac axis'*, arises opposite margin of diaphragm, passes for
half an inch forward to divide into the
Gastrio^^, passing along greater curvature of stomach, anas¬
tomosing with aortic oesophageal, and branches of splenic and
hepatic arteries.
Hepatic^'', dividing in transverse hepatic fissure into right and
left branches for same lobes of liver ; its branches are.
Pyloric, f .
Gastro-duodenalis, \ Gastro-epiploica dextra,
Pancreatico-duodenalis superior,
whereby it supplies the parts indicated by names of vessels, and
anastomoses with splenic, gastric, and superior mesenteric arte¬
ries.
Splenià^, the largest braneh, passes behind upper border of
pancreas to spleen, giving off the
Pancreáticas parvae. Gastric (vasa brevis).
Pancreática magna, Gastro-epiploica sinistra.
(One of the phrenics may arise from the coeliac axis.)
Phreniê^, one on each side (sometimes one from coeliac axis
instead of aorta) to under surface of diaphragm.
Superior mesenteric^* comes off about one-quarter inch below
coeliac axis, arching forward and downward to the left, supplying
all of small intestine, except first part of duodenum, also coecum,
ascending, and transverse colon, giving off,
Inferior pancreatico-duodenal, Ileo-colic,
Vasa intestini tenuis, Coliea-dextra,
Cólica media.
Inferior mesenteritp, arising from left side of aorta two inches
above bifurcation, passes down into left iliac fossa and pelvis, sup¬
plying descending colon, sigmoid fiexure, and greater part of
rectum, anastomosing above with the middle colic of superior
mesenteric ; its branches are.
THE ARTERIES.
169
Cólica sinistra, Sigmoid, Superior hemorrhoidal.
Suprarenal, each arises opposite superior mesenteric to supply
suprarenal bodies.
BenaP", spring nearly at right angles from sides of aorta below
superior mesenteric, the right longer than left ; each divides into
four or five branches before entering hiluin of kidney, intervening
between the renal vein in front, and the ureter behind.
Spermatic^'"' (ovarian in female), spring from front of aorta on
each side, a little below renais, run behind peritoneum to pass in
male through abdominal ring to testes, in female between the
laminae of the broad ligaments to the ovaries. Fallopian tubes,
uterus, and integument of labium and groin.
Lumbar'^'', commonly four on each side corresponding to inter¬
costale, and like them dividing into
Dorsal branches to vertebrae, spinal cord and back muscles, and
abdominal branches, passing forward to anastomose with twigs
from epigastric, internal mammary, intercostals, ilio-lumbar, and
circumflex iliac.
Middle sacraP^, springs from bifurcation, descends along middle
of sacrum and coccyx, sending branches to rectum, lateral sacral
arteries, etc.
Describe the common iliac arteries.
They extend from the aortic bifurcation to left of umbilicus—
corresponding to a line touching the highest point of iliac crests—
to divide opposite the intervertebral disk between the last lumbar
vertebrae and the sacrum, into the internal and external iliac \ the
right vessel is somewhat the longer, both being about two inches
long, and each at its bifurcation is crossed by the ureter.
Describe the internal iliac.
It measures about one and a half inches, arising at point of bifur¬
cation of common iliac, to divide at upper margin of great sacro-
sciatic foramen into the anterior and posterior trunk ; its branches
are
Anterior division.
Superior vesical, part of foetal hypogastric artery ; it supplies vas
deferens and ureter, as well as bladder.
170 ESSENTIALS OF HUMAN ANATOMY.
Middle vesical, usually branch of former to bladder and vesiculse
seminales.
Inferior vesical (vaginal in female), arising in eommon with
middle hemorrhoidal, and is distributed to base of bladder, pros¬
tate gland, and seminal vesicles.
Middle hemorrhoidal, supplies rectum.
Uterine (in female), anastomosing with ovarian.
Obturator, passes through obturator canal to thigh, there dividing
into an internal and external branch, anastomosing with twigs of
internal circumflex; inside the pelvis its branehes are
Iliac, to same named bone and muscle anastomosing with ilio¬
lumbar ; a vesical, to bladder ; and a pubic, inoscula^ng back of
pubes with epigastric; in two out of every three eases the obtu¬
rator springs from internal iliac, in one case in three and a half
from epigastric.
Internal pudic, the smaller terminal of anterior division, is dis¬
tributed to the external organs of generation ; giving ofi" the fol¬
lowing branches
Inferior hemorrhoidal. Artery of the bulb,
Superflcial perineal. Artery of the corpus cavernosum.
Transverse perineal. Dorsal artery of the penis.
Sciatic, the larger terminal, supplies muscles on back of pelvis ;
its branches are.
Muscular (internal). Coccygeal, Muscular (external).
Hemorrhoidal, Inferior gluteal. Articular (hip),
Vesical. Comes nervi ischiadici.
Posterior division.
Ilio-lurribar, dividing into an iliac and lumbar branch supplying
muscular, spinal, and bone branches, anastomosing with gluteal,
circumflex iliac, external cireumflex, and epigastric arteries, ete.
Lateral sacral, superior and inferior on each side anastomosing
with gluteal.
Gluteal, the termination of posterior division, divides into a
superficial and deep branch, giving oif
Muscular, cutaneous, nutrient (to ilium), and articular branches,
anastomosing with circumflex iliac and external circumflex
arteries.
THE ARTERIES.
171
Describe the external iliac.
Passes along inner border of psoas muscle from bifurcation of
common iliac to Poupart's ligament ; a line drawn from left side of
umbilicus to the midpoint between symphysis pubis and anterior
superior iliac spine (in females a little nearer the former), indi¬
cates its course ; its branches are
Mnacular, Lymphatic (to glands).
Deep epigastric, usually coming off just above Poupart's ligament,
passing between peritoneum and transversalis fascia to pierce the
lower third of sheath of the rectus abdominis muscle, continuing
hack of which it anastomoses with internal mammary and inferior
intercostal îlrteries ; its branches are
Cremasteric, Pubic, Muscular.
Deep circumflex iliac, arises externally nearly opposite epigastric,
running along inner side of iliac crest to its middle, there to pierce
the transversalis muscle ; it anastomoses with ilio-lumbar, gluteal,
lumbar, and epigastric arteries.
Describe the femoral artery.
Extending from Poupart's ligament, where the letters N. A. V.
indicate its relation with the anterior crural nerve and femoral
vein—it terminates at the opening in the adductor magnus (com¬
mencement of Hunter's canal) ; the upper two thirds of a line
drawn from the midpoint between the anterior superior iliac spine
and symphysis pubis to inner side of internal condyle of the femur
indicates its course. The artery and vein are enclosed in a strong
fibrous sheath, hut separated by a partition from each other, and
lie very superficially above, in " Scarpa's triangle," bisecting it.
What is Scarpa's triangle ?
It is a space bounded above by Poupart's ligament, internally
by the adductor longus, and externally by the sartorios, the floor
being formed chiefly by the iliac, psoas, pectineus, and long ad¬
ductor muscles, the inner margin of the latter intervening between
the artery and capsule of the hip-joint.
The femoral gives off the
Superflcial epigastric^, to inguinal glands, fascia, and skin, anas¬
tomosing with deep epigastric and internal mammary.
172 ESSENTIALS OF HUMAN ANATOMY.
Superficial circumflex iliaâ, to skin of groin, glands, etc., anasto¬
mosing with deep circumflex iliac, gluteal, and external circumflex.
Fiq. 74.
THE ARTERIES.
173
Superficial externalpudic^, to skin of genitals, anastomosing with
internal pudic.
Deep external pudié, to skin of genitals and perineum, anasto¬
mosing with superficial perineal.
Profunda femoris', springing from outer back part of femoral
from one to two inches below Poupart's ligament, terminating at
lower third of thigh by the small fourth perforating artery; it
gives off
External^ and Internal drcumjlex?. Three perforating^".
Muscular", chiefly to sartorius and vastus internus.
Anastomotica magna", arises just above Hunter's canal, and
divides into a superficial (cutaneous), and a deep branch ; anasto¬
mosing with the superior" internal and external articular, and
recurrent tibial."
Describe the popliteal artery.
It commences at the opening in the adductor magnus, and pass¬
ing obliquely downward and outward behind the knee-joint,
divides opposite the lower border of the popliteus muscle into the
anterior and posterior tibial arteries. Its branches are
Superior muscular, Azygos articular,
Cutaneus, Inferior internal articular,
Superior external articular. Inferior external articular,
Superior internal articular. Inferior muscular or sural.
These anastomose with the inferior perforating terminal branches
of profunda, comes nervi ischiadici, anastomotica magna, recur¬
rent tibial and with each other, except the muscular ; the azygos
articular enters back of joint to supply the synovial membrane
and intra-articular ligaments.
Describe the anterior tibial artery.
Commencing at lower border of popliteus muscle, passing be¬
tween the two heads of the posterior tibial muscle by the defect at
the upper part of the interosseous membrane, lying upon its anterior
surface and that of the lower third of the tibia, it terminates at
the front of bend of the ankle in the dorsalis pedis artery ; the
anterior tibial nerve lies in close contact externally ; it gives off the
Recurrent tibial'^. Muscular, Internal" and External*' malleolar.
174
ESSENTIALS OP HUMAN ANATOMY.
Describe the dorsalis pedis artery'.
It extends from front of bend of ankle to back part of first
interosseous space, where it divides into the
Dorsalis hallucis', supplying the great toe and adjoining side of
second toe, and the
Col^unicating', dipping down between heads of first dorsal
interosseous muscle to reach the sole of foot, and form with ex¬
ternal plantar the plantar arch ; the other branches are the
Tarsal, arching outward across tarsus.
Metatarsal^, runs anterior to preceding over bases of metacarpal
bones, giving off
Three interossei, from which arise seven digitals.
Describe the posterior tibial artery.
It extends as a large vessel obliquely downward from lower border
of popliteus muscle along tibial side of leg to the midpoint of the
depression between the inner ankle and heel, where, beneath the
adductor pollicis muscle it divides into the internal and external
plantar ; the posterior tibial nerve lies first to its inner side, but
soon crosses it, to remain close to the outer side ; it gives off the
Peroneal, along back of fibular side of leg, giving off
Anterior peroneal, piercing interosseous ligament two inches above
outer malleolus, anastomosing with external malleolar and tarsal
arteries ; it also gives muscular branches and nutrient artery to
fibula: the posterior tibial also gives off the
Nntrient (of tibia), largest to any bone.
Muscular, to posterior leg muscles.
Communicating, to peroneal, passing transversely across back of
tibia about two inches above ankle.
Internal calcanean, several large branches to inner muscles of
sole, fat and skin of heel, anastomosing with peroneal and internal
malleolar.
Describe the internal plantar.
The smaller terminal of posterior tibial, it runs along inner side
of foot and great toe.
Describe the external plantar artery.
It passes obliquely outward and forward to base of fifth meta-
THE ARTERIES.
175
tarsal, wlience it curves inward to interval between bases of first
and second metatarsal bones, there anastomosing with the commu¬
nicating branch of the dorsalis pedis, completing plantar arch,
whose branches, in addition to numerous muscular ones, are,
Posterior perforating, passing up the three outer interosseous
spaces to anastomose with the interossei from the metatarsH
Four digitals, by division supplying both sides of the three outer
toes, and the outer side of the second—both sides of the great and
inner side of the second toe being supplied by the communicating
branch of dorsalis pedis.
Describe the pulmonary artery.
It is a wide vessel conveying venous blood from the right ven¬
tricle to the lungs, about two inchÄ long, and springs, in front of
the aorta, from left side of the base of the right ventricle, lying
for most of its course within the pericardium, passing obliquely to
the left, upward and backward, dividing at the under surface of
the aortic arch into a right and left pulmonary artery, the former
the longer ; each vessel passes horizontally outward to its respective
lung, where it divides into two main branches, one of those of the
right subdividing to supply the third lobe; these vessels subdivide
to terminate in the pulmonary capillaries.
Describe the collateral circulation after ligature of the
common carotid.
The chief communications are between superior and inferior
thyroids, the profunda cervicis and princeps cervicis of the occi¬
pital, the vertebral taking the place of the internal carotid within
the cranium. (The student must remember that while alf^the
anastomosing vessels coming otf above and below the site of liga¬
ture enlarge, and should, therefore, be carefully impressed upon
the mind where enumerated,in the preceding pageg, yet the blood,
by dissection, has been found to pass chiefly by the vessels men¬
tioned under each caption. )
After ligature of the subclavian.
Between the supra-scapular and posterior scapular with sub¬
scapular, the internal mammary and the long and short thoracic-
and subscapular.
176
ESSENTIALS OF HUMAN ANATOMY.
After ligature of axillary.
If below acromial thoracic, chiefly between the subscapular and
other scapular arteries of subclavian, and long thoracic, through
intercostals with internal mammary; if below subscapular, the
posteygr circumflex anastomosing with supra-scapular and acro¬
mial thoracic, and inosculations between the subscapular and
superior profunda.
After ligature of brachial.
(1) Upper third, by anastomoses between circumflex and sub¬
scapular and superior profunda; (2) below the profunda arteries,
by branches of the profund» anastomosing with recurrent ulnar,
radial, and interosseous.
When thoracic aorta is obliterated.
The internal mammary anastomosing with intercostals; phrenic,
by musculo-phrenic and comes nervi phrenici and deep epigas¬
tric, superior intercostal and first aortic intercostal; inferior
tbyroid with first aortic intercostal ; transversalis colli with pos¬
terior branches of intercostals ; axillary and subclavian branches
to side of chest with lateral branches of intercostals.
When abdominal aorta is tied.
The deep epigastric communicating with the internal mammary,
the intercommunications of superior and inferior mesenteric, or
the latter with the internal pudic, and the anastomoses of the
lumbar with branches of internal iliac.
After common iliac is tied.
The anastomosis of hemorrhoidal branches of internal iliac
with superior hemorrhoidal from inferior mesenteric, the inoscu¬
lations of the uterine and ovarian, and of vesicals of opposite
sides, that of lateral sacral with sacra media, of epigastric with
internal mammary, intercostal and lumbar, of ilio-lumbar with
last lumbar, of obturators with one another and deep epigastric,
of gluteal with posterior sacral branches.
After internal iliac is tied.
Same as above, except obturator also communicates with internal
THE VEINS.
177
circumflex, the circumflex and perforating branches of femoral
with sciatic, and the circumflex iliac with ilio-lumbar and gluteal.
After external iliac is tied.
The anastomoses between the ilio-lumbar and circumflex iliac ;
the gluteal and external circumflex; the obturator and internal
circumflex ; the sciatic with superior perforating and circumflexes ;
the internal pudic with external pudic and internal circumflex.
After common femoral is tied.
Anastomoses of gluteal and circumflex iliac with external cir¬
cumflex ; obturator and sciatic with internal circumflex ; ilio¬
lumbar with external circumflex; comes nervi ischiadici with
surals.
After superficial femoral is tied.
Branches from profunda anastomosing with superior and inferior
articulara of knee, anastomotica magna, surals, and origins of
anterior and posterior tibial.
(The popliteal is never tied except for wound, when the articu¬
lar arteries, anastomotica magna, recurrent tibial, perforating
branches, and surals would convey the blood.)
The Veins.
Describe the veins.
They are vessels returning venous blood—i. e., blood surcharged
with carbonic acid, to the heart, and have the same coats as arte¬
ries, but not so thick, especially the middle, in consequence col¬
lapsing when divided. One set of veins only carries other than
venous blood, viz., the pulmonary, conveying arterial blood from
the lungs to the left auricle. Certain of the veins, usually the
superficial, have their lining membrane forming semilunar redupli¬
cations or valves, arranged in pairs opposite one another, which
prevent any reflux of blood. The large arteries are accompanied
by deep veins of the same name, generally included in the same
.sheath, while such vessels as the brachial, radial, ulnar, etc., have
two veins each, called venœ comités. The superficial veins run be¬
tween the layers of the superficial fascia, terminating in the deep
12
178
ESSENTIALS OF HUMAN ANATOMY.
veins, and are not usually accompanied by arteries. All veins freely
anastomose, and even those dignified with special names have
very irregular origins and distributions.
What are sinuses?
Venous channels, found only within the skull, formed by a sepa¬
ration of the layers of the dura mater, lined with endothelium con¬
tinuous with that of the veins.
How are the veins classed ?
As belonging to the pulmonary, systemic, or portal systems, the
latter an appendage of the systemic.
Name the principal veins which have no valves.
The venae cavae, hepatic, portal, renal, uterine, ovarian, cerebral,
spinal, and pulmonary.
Name the veins of the head and neck.
(1) Those of the exterior :
Facial, Internal maxillary. Posterior auricular.
Temporal, Temporo-maxillary, Occipital.
(2) Those which return the blood from head and face :
External j ugular. Anterior j ugular.
Posterior external jugular. Internal j ugular.
Vertebral.
(3) Veins of diploë and cranium :
Veins of diploë. Cerebral,
Cerebellar, Ventricular, or venae galenae.
Name the cerebral sinuses.
Superior longitudinal. Straight sinus.
Inferior longitudinal. Lateral sinuses (2),
Occipital (2), Cavernous (2),
Circular, Transverse,
Superior petrosal. Inferior petrosal.
How is the internal jugular'' (Fig. 76) formed ?
By the junction of the lateral and inferior petrosal sinuses just
outside jugular foramen; at base of neck the internal jugular
unites with subclavian vein to form the innominate vein—at, or
THE VEINS.
179
above the junction is a pair of valves; into the jugular empty
the facial, lingual, pharyngeal, superior and middle thyroid, and
sometimes occipital veins.
Where do the following veins empty ?
The external jugular^ ; into subclavian vein external to internal
jugular; posterior external jugular, into internal jugular; the
anterior jugular, into termination of external jugular or the sub¬
clavian vein ; the vertebral, descends through vertebral foramina
in transverse processes of cervical vertebrae to empty into hack of
innominate vein, valves guarding the orifice.
Describe the veins of the upper extremity.
They consist of superficial and deep, the latter being the vence
comités oí the arteries; commencing as digitals these empty into
the interossei, these into palmar until the deep radial and ulnar
are formed, which, uniting, form the so-called brachial vein, really
consisting of two venae comités with transverse anastomoses. The
superficial veins running in the superficial fascia are called
Describe the axillary vein.
It is a continuation of brachial and basilic, receiving veins of
corresponding names with the arteries of the axilla, and is con¬
tinued beneath the clavicle under the name of the subclavian vein^ ;
it has valves opposite lower border of subscapular muscle, also at
mouths of cephalic and subscapular veins.
Describe the subclavian vein®.
It extends from lower border of first rib to back of sterno¬
clavicular joint, there uniting with internal jugular to form the
vena innominata—the subclavian vein lies in front of the artery
with the anterior scalene muscle interposed at its second part ; its
branches are, the external and anterior jugular and branch of
cephalic; on right side the right lymphatic duct empties at the
Eadial
Anterior and
Posterior ulnar
Median
-
Axillary.
180
ESSENTIALS OF HUMAN ANATOMY.
junction of the axillary and internal Jugular veins, and at the
same point on the left side the thoracic duct.
How are the venae innominatae'/ formed?
Each by the subclavian and internal jugular, which unite just
below the first costal cartilage to form the superior vena cava*;
the right innominate is about one and a
Fig- half inches long, receiving blood by right
a_D J vertebral, internal mammary, inferior
thyroid, and superior intercostal veins ;
the left vein is larger and about three
inches long; the left vertebral, internal
mammary, inferior thyroid, superior inter¬
costal, and occasionally some thymic and
pericardiac veins empty into it.
Describe the superior vena cava*.
It measures from two and a half to
three inches and is formed by the union
of the two innominate veins®,®, is half
covered by the pericardium and enters
upper part of right auricle ; it returns the
blood of the upper half of body and re¬
ceives the vena azygos major and small
mediastinal and pericardiac veins.
À Describe the azygos veins.
They connect the superior and inferior
cavsB, taking the place of those
' IIP vessels in that part of the chest occupied
by the heart.
The right azygos^" commences opposite
first and second lumbar vertebrae by a
branch from right lumbar or renal vein,
or from inferior vena cava, enters thorax
by aortic opening, arches over root of right lung to empty into
superior cava, receiving in its course the nine or ten right lower
intercostal veins, the vena azygos minor, oesophageal, medias-
THE VEINS.
181
tinal, vertebral, and right bronchial veins, also at times it is con¬
nected with right superior intercostal vein.
The left lower azygos^^ (vena azygos minor) commences by a
branch from left lumbar or renal vein, enters thorax through left
crus of diaphragm, passes across from the left side of vertebral
column at sixth or seventh dorsal vertebra to enter the right
azygos vein, receiving veins from four or five lower intercostal
spaces ; also mediastinal and oesophageal branches.
The left upper azygoi^ is formed by veins, usually two to tbree,
from the intercostal spaces between left superior intercostal and
highest branch of left lower azygos, and empties into right azygos
or left lower azygos ; it is sometimes absent, its place being taken
by left superior intercostal.
Name the other principal veins of base of the neck and of
the thorax.
Internal mammary, Mediastinal,
Inferior thyroid. Pericardiac,
Intercostah, Bronchial.
Briefly describe the spinal veins.
They are the dorsi-spinal on the exterior of the spinal column,
forming plexuses around vertebral spines, laminae, and processes,
emptying into intercostal, lumbar, and sacral veins respectively.
The meningo-rachidian, lying between vertebras and theca spinalis
forming plexuses, one running along the posterior surfaces of ver¬
tebral bodies forming the anterior longitudinal veins receiving the
venae basis vertebrarum, the other on the inner surface of the lami¬
nae, the posterior longitudinal veins, both extending the whole length
of the spinal canal; the posterior emptying into dorsi-spinal, the
anterior into vertebral, intercostal, and sacral veins, respectively.
The venœ basis vertebrarum, in vertebral bodies, empty into an¬
terior longitudinal.
The medulli-spinal, those of the cord itself, forming a minute
plexus over cord between the pia mater and arachnoid, near base
of skull converging to form two or three trunks terminating in the
inferior cerebellar veins or petrosal sinuses.
182
ESSENTIALS OF HUMAN ANATOMY.
Describe the chief veins of the lower extremity.
They are deep and superficial, the former commence as venae
comités of digitah, which form the interossei, these the anterior
and posterior tibial and peroneal accompanying same named
arteries, which uniting, form the popliteal, in the thigh to be
called the femoral, being joined by profunda femoris and internal
saphenous veins, which again changes its name to external iliac
above Poupart's ligament ; into external iliac empty the epigastric
and circumflex iliac veins.
The superficial veins are the
Ixjdemal or long saphenous, commencing on inner side of dorsum
of foot, running up on inside of leg and thigh to enter femoral
vein after passing through the saphenous opening of fascia lata ;
its branches are
Cutaneous, Superficial circumflex iliac,
Superficial epigastric, Communicating,
Pudic.
External or short saphenous, commences at outer side of dorsum
of foot, passes behind the external malleolus, up the middle of leg
posteriorly to empty into popliteal vein between heads of gastroc¬
nemius.
Describe the internal iliac vein.
It is formed by the venae comités of all branches of external iliac
artery except the umbilical, and unites opposite sacro-iliac articu¬
lation with external iliac vein to form the common iliac vein ; it
receives the following veins,
Gluteal, Internal pudic. Hemorrhoidal, Uterine and vaginal.
Sciatic, Obturator, Vesico-prostatic Plexuses, in female.
Plexuses, in male.
Dorsal vein of penis.
Describe the common iliac veins.
Formed by the junction of the external and internal iliac veins,
and receiving the ilio-lumbar, occasionally the lateral sacral, and
the left iliac the middle sacral vein, they unite at an angle upon
the intervertebral substance between the fourth and fifth lumbar
vertebrae to form the inferior vena cava.
THE VEINS.
183
Describe the inferior vena cava'.
It runs upward from junction of the two common iliacs, along
the right side of the aorta, pierces the central tendon of dia-
phraghm, and terminates at back of right auricle, being partially-
covered by serous layer of the pericardium ; it returns the blood
from all parts below the diaphragm, and receives the following
branches.
Lumbar, Suprarenal, sometimes Middle sacral.
Right spermatic. Phrenic,
RenaP, Hepatic.
Describe the portal system of veins.
Formed by the union behind the head of the pancreas of the
svperior and inferior mesenteric, splenic, and gastric veins, .collecting
the blood from the viscera of digestion, the resulting portal vein
divides in the transverse fissure of the liver into a branch each for
the right and left lobe, which ramify to form a venous plexus in
the liver tissue; the hepatic artery sends branches within the
liver to the portal vein, and external to the organ the vein re¬
ceives the smaller gastric and the cystic vein; the portal blood
is returned to the inferior vena cava by the hepatic veins.
What veins return the blood from the substance of the
heart ?
Great cardiac vein. Anterior cardiac veins.
Middle cardiac vein. Right or small cardiac vein.
Posterior cardiac veins. Vence Thebesii,
What is the coronary sinus ?
A dilatation of about one inch of the great cardiac vein in pos¬
terior part of left auriculo-ventricular groove, covered by the mus¬
cular tissue of the left auricle and receiving the posterior cardiac
veins, and an oblique vein from back of left auricle ; its orifice is
guarded by the coronary valve.
Describe the pulmonary veins.
Commencing in the lung capillaries they form a main vein for
each lobule, which unite into two trunks for each lung, opening
separately into the left auricle ; at times there are three veins on
the right side, or the two left terminate by a common opening.
184 ESSENTIALS OF HUMAN ANATOMY.
The Lymphatics.
What are lymphatics ?
Delicate vessels with transparent walls formed of same three
coats as arteries and found in all parts of the body probably, ex¬
cept the nails, cuticle, hair, and cartilage; they have numerous
valves producing their characteristic beaded appearance ; they are
supplied with nutrient arteries but not with nerves.
What are the lacteals ?
The lymphatics of the small intestine, conveying chyh during
digestion, lymph at other times.
Describe the lymphatic glands.
They are small solid, round, or ovoid glandular bodies, situated
in the course of the absorbent vessels which previous to entering
a gland break up into several afferent vessels, form a plexus within,
and emerge by several efferent vessels which soon unite to form a
single trunk ; each gland is surrounded by a fibrous capsule which
sends partitions inward, forming alveoli in which lies the gland-
pulp or lymphoid tissue consisting of a rete whose meshes are filled
with lymph-cells. The glands are chiefly found in the mesentery,
along great vessels, in the mediastinum, axilla, neck, at front of
elbow, groin, and popliteal space, being usually named from their
locality, as axillary, etc.
Describe the thoracic duct.
This conveys the bulk of the lymph and chyle into the blood,
being the common lymph-trunk, except for right upper extremity,
right side of head, neck, and thorax, right lung, same side of heart,
and convexity of liver.' It commences by the triangular receptac-
ulum chyli, on the front of body of second lumbar vertebra, enters
the thorax by aortic opening, and opposite the upper border of
seventh cervical vertebra it curves downward to empty at the
junction of the left internal jugular and subclavian veins.
Describe the right lymphatic duct.
It is about one inch long, receiving lymph from those parts ex¬
cited in the account of the thoracic duct, and empties at the j une-
NERVOUS SYSTEM.
185
tion of the right internal jugular and subclavian veins; both ducts
have double semilunar valves at their orifices, preventing regurgi¬
tation of blood.
Nervous System.
What are the two divisions of the nervous system ?
The cerebrospinal or that presiding over animal life, and the
sympathetic, that regulating organic life.
Describe the structure of the nervous tissue.
It is composed chiefly of two structures, the gray or vesicular
originating impulses and receiving impressions ; and white or
fibrous, conducting impressions ; in the sympathetic system is
found a third structure, gelatinous nerve-tissue-, seventy-five per
cent, of nerve-tissues is composed of water, the remainder being
albumen, phosphorized-fat, and salts.
Describe the microscopic structure of the white nerve-
tissue.
It is formed of tubular fibres each consisting of a central axis-
cylinder, surrounded by the white substance of Schwann, the whole
enclosed by the tubular membrane or primitive sheath. A bundle of
these fibres invested by a fibro-areolar membrane, the perineurium
(neurilemma), constitutes a nerve, receiving a special blood-supply
by the vasa urrvorum-, the gelatinous variety consists of finely
granular fibrillse enclosed in a sheath—by some these are not con¬
sidered to be nerves.
Describe the gray or vesicular nerve-tissue.
This consists of large granular cells containing nuclei and
nucleoli, ovoid, or with one or many processes [unipolar, multipolar'),
some of which become continuous with an axis-cylinder.
How do nerves terminate ?
Peripherally sensory nerves end in minute plexuses, end-bulbs,
tactile corpuscles, and Pacinian corpuscles; in the special organs
they end in cells and in other not well ascertained ways ; motor
nerves end peripherally in plexuses or by " motorial end plates."
The central terminations are not well understood.
186
ESSENTIALS OF HUMAN ANATOMY.
What organs compose the cerebro-spinal system ?
The brain, spinal ganglia, and the cranial and spinal nerves.
Name the membranes of the brain.
The dura mater, the arachnoid, and pia mater.
Describe the cerebral dura mater with its processes.
It is a dense fibrous membrane lining the interior of skull, con¬
stituting the internal periosteum, is continuous with that of spinal
cord, and is prolonged to outer surface of the skull through the
various foramina; by separation of its layers the cerebral sinuses
are formed; its smooth under surface is covered with endothelial
cells ; its processes are the,
Falx cerebri, a sickle-shaped layer occupying the longitudinal
fissure of the brain ; along the upper and lower border respectively
run the superior and inferior longitudinal sinuses.
Tentorium cerebelli, covering the upper surface of the cerebellum;
it supports the weight of the posterior lobes of the cerebrum ; it is
attached to the horizontal arms of the occipital cross, enclosing the
lateral sinuses, to the upper margin of the petrous bone, including
the superior petrosal sinuses, whence it extends to anterior and
posterior clinoid processes; to the mid-line, above, the falx cerebri
is attached antero-posteriorly, and below medianly the base of the
Falx cerebelli, a small triangular process passing between cere¬
bellar lobes behind.
What are the Pacchionian bodies ?
Numerous aggregations of small whitish granulations of un¬
known function formed upon outer surface of dura mater near
superior longitudinal sinus, lying in depressions in the bone, in
the superior longitudinal sinus, on the inner surface of the dura
mater, and on the pia mater; unknown in infancy, rare before
third year ; they are usually found after tenth year.
Describe the arachnoid.
It is a delicate membrane lying between the pia mater and dura
mater, being separated from the latter by the subdural space-, it
bridges over the convolutions, forming part of subarachnoidean
space, and at the base, by being stretched between the middle lobes,
NERVOUS SYSTEM.
187
the anterior suharachnoidean space is left ; while between the cere¬
bellar hemispheres and medulla oblongata lies the posterior su6-
arachnoidean space, the two communicating across the crura cere-
belli, and by an opening in its lower boundary with the fourth
ventricle; these spaces contain the cerebro-spinal fluid, forming
an elastic water-cushion for the encephalon ; it consists of inter¬
woven bundles of fibrous and yellow elastic tissue covered with a
layer of endothelium.
What is the pia mater ?
It consists of a minute plexus of bloodvessels derived from the
internal carotid and vertebral arteries, held together by fine areolar
tissue ; it dips between the convolutions, forms the velum inter-
positum and choroid plexuses of the fourth ventricle, and contains
nerves and lymphatics.
What are the divisions of the brain called ?
The cerebrum, cerebellum, pons Varolii, and medulla oblongata.
What is the weight of the brain?
Forty-nine and a half ounces, on the average, in males, and
forty-four ounces in females ; heaviest male brain recorded sixty-
eight and three-eighths ounces, lightest thirty-four ounces ; female
brain, heaviest fifty-six ounces, lightest thirty-one ounces ; idiots'
brains seldom weigh more than twenty-three ounces.
Name the fissures and lobes of the cerebrum.
Each half, or hemisphere, has its external surface subdivided
into five lobes by the
Fissure of Sylvius, f. Sy. p., beginning at anterior perforated space,
it passes to external surlace of hemisphere and subdivides, one arm
(/. Sy. a.) ascends toward longitudinal fissure, one passes nearly
horizontally backward.
The fissure of Balando, f. Ro., commences at or near middle of
the longitudinal fissure, running downward and forward to a little
above the horizontal branch of the Sylvian fissure.
Farieto-occipital fissure, par. oc. f, commences about midway
between posterior extremity of brain and fissure of Rolando, run¬
ning downward and forward for a variable distance.
188
ESSENTIALS OF HUMAN ANATOMY.
The frontal lobe lies in front of the fissure of Rolando, and above
the horizontal part of the Sylvian fissure; its under surface is
called the orbital lobe.
The parietal lobe is bounded in front by fissure of Rolando,
behind by parieto-occipital fissure, and below by horizontal limb
of Sylvian fisure.
The occipital lobe lies behind parieto-occipital fissure.
The temporo-sphenoidal lobe occupies middle cerebral fossa of
skull, and is limited above and in front by Sylvian fissure.
The central lobe, or island of Reil, lies in the fissure of Sylvius
at the base of brain.
The inner or median surface of each hemisphere presents five
fissures :
The calloso-marginal fissure, c. m. f. (Fig. 78), separating the
marginal convolution from the gyrus fornicatus, g.f.
The parieto-occipital fissure, par. oc.f., a continuation of that of
same name on outer surface of hemisphere.
The calcarme fissure, calc.f., runs from back of hemisphere hori¬
zontally forward to posterior inferior extremity of gyrus fornicatus,
g.f.', it is joined by the parieto-occipital fissure.
The collateral fissure, coll. f., runs below and nearly parallel to
preceding, separated by the uncinate gyrus.
Fig. 77.
Tcaporo— SplieiioidAl. L
Convolutions of outer surface of brain.
NERVOUS SYSTEM.
189
The dentate fissure, d. commences below posterior extremity
of corpus callosum, running forward to end at recurved part of
uncinate gyrus.
The transverse fissure, between the middle lohe and crus cerebri,
admitting pia mater into the lateral ventricles.
Mention the principal convolutions of the brain.
The convolutions, or gyri, are elevated ridges covered with gray
matter, separated by deep-furrows, or sulci, thus securing a great
extent of gray matter ; while not uniform in all brains, nor sym¬
metrical, certain principal convolutions are constant, such as
The gyrus fornicatus, g.forn., that lying over corpus callosum.
The marginal, marg. c., forming anterior superior margin of the
great longitudinal fissure.
T\iq ascending frontal, asc.fr. c. (Fig. 77), forming anterior boun¬
dary of fissure of Rolando.
Fig. 78.
The ascending parietal, asc. par. c., the posterior boundary of
same fissure.
Angular gyrus, any. c., lying between back of horizontal limb of
Sylvian fissure, and a short fissure running upward from it.
Other convolutions are indicated by contractions of names on
the diagrams, so that with the preceding explanations of points of
reference no further details are requisite.
190
ESSENTIALS OF HUMAN ANATOMY.
What is the quadrate lobe (Fig- 78), and what is the
cuneus (Fig. 78)?
The former is the marginal convolution between the calloso-
marginal fissure in front and the parieto-occipital behind ; the
latter lies between the parieto-occipital and calcarine fissures.
•Mention the various objects seen on the under surface of
cerebrum, naming them from before backward.
Longitudinal fissure^ (Fig. 79), antero-posterior.
Fia. 79.
Base of brain.
Corpun callosum, the transverse commissure, connecting cerebral
hemispheres.
NERVOUS SYSTEM,
191
Lamina cinerea, a thin layer of gray substance, extending from
end of corpus callosum back to tuber cinereum above optic tracts.
Fissure of Sylvins separating by its horizontal limb the frontal
and parietal lobes from temporo-spbenoidal;(o/dKo??ie«cfe<Mre) sep¬
arates anterior and middle lobes chiefly by the ascending or pre-
central limb.
Anterior perforated spaces'', between roots of olfactory nerve on
each side for passage of vessels into corpus striatum.
Optic commissure'''^, union of optic tracts.
Tuber cinereum, an eminence of gray matter, part of floor of third
ventricle.
înfundibulum^, a hollow conical process of gray matter projecting
from middle of under surface of tuber cinereum, communicating
with third ventricle.
Pituitary body, a vascular, two-lobed body projecting from apex
of infundibulum into sella turcica of sphenoid.
Corpora albicantio?, the two small rounded, infolded terminations
of the anterior crura of fornix.
Posterior perforated space'",'bcii'vi ecu corpora albicantia in front,
pons Varolii behind, and cerebral crura on either side, forms part
of floor of third ventricle, and gives passage for vessels to optic
thalami.
Crura cerebri" [peduncles of cerebrurn) connect the cerebrum
with cerebellum, medulla oblongata, and spinal cord.
Pons Varolii" (see page 195).
Name the Ave great ganglia of the brain, other than the
gray matter of the cerebral and cerebellar hemi¬
spheres and medulla oblongata.
Olfactory bulbs^'V Optic thalami. Pons Varolii",
Corpora striata, Tubefcula quadrigemina.
Describe these ganglia.
Olfactory bulbs'", the ganglia of the sense of smell, lie in olfac¬
tory grooves of cribriform plate of the ethmoid, and arise by two
white roots, one crossing Sylvian Assure from a nucleus of gray
matter in middle lobe, the other from inner back part of frontal
[orbital) lobe, and a gray root from under surface of same lobe.
192
ESSENTIALS OF HUMAN ANATOMY.
Corpora striata, chief part of motor tract, lying in lateral -ventri¬
cles, the intra-ventricular gray portion called caudate nucleus, the
extra-ventricular, the lenticular nucleus, the internal capsule dividing
the two.
Optic thalami, they are white externally, the ganglia of general
sensation, forming the lateral boundaries of the third ventricle,
each presenting an anterior tubercle in lateral ventricle, and pos¬
teriorly two small internal and external geniculate bodies.
Corpora quadrigemina (optic lobes) are four rounded eminences
situated bebind third ventricle and posterior commissure; the
anterior pair are the nates, the posterior pair the testes ; they are
the centre of vision.
Thejoorw Varolii, containing much gray matter and one special
mass called the superior olivary body, might be considered a fifth
ganglion.
What are the commissures ?
Connecting bands of white or gray matter.
Enumerate them.
Those pursuing an antero-posterior course, are
Olfactory tracts. Fornix,
Taenia semicircularis, Oyrus fomicatus.
Crura cerebri, Fasciculus unciformis.
Peduncles of pineal gland. Processus e cerebello ad testes.
Striae longitudinales.
Those passing transversely, are
Anterior, Pons Varolii,
Middle, Fornix (also a longitudinal
Posterior, commissure),
Corpus callosum. Posterior medullary velum.
Optic chiasm. Valve of Vieussens.
What are the ventricles of the brain?
Five serous cavities in the brain, four of which intercommuni¬
cate ; they are two lateral, a third, a fourth, and a fifth.
Describe the lateral ventricles.
The corpus callosum roofs them in ; each has an anterior oornu,
curving outward and forward into the anterior lobe, a middle cornu
NERVOUS SYSTEM.
193
descending into the middle lobe downward and backward, then
turning downward and forward, containing the curved hippocampus
major, and a posterior cornu curving downward and inward into
the posterior lobe, containing the hippocampus minor ; the floor
from before backward is formed by the corpus striatum, tœnia semi-
circularis, optic thalamus, choroid plexus, corpus fimhriatum, and
fornix-, the septum lucidum forms the inner wall.
Describe the following parts :
The corpus callosum-, it is a thick arched layer of transverse
fibres at the bottom of the longitudinal fissure, anteriorly curving
upon itself, giving off two peduncles to the entrance of the Sylvian
fissure, posteriorly it becomes continuous with the fornix ; a
median linear depression on its upper surface is called the raphè,
parallel to which on each side run two or more elevated longitu¬
dinal bands, the striœ longitudinales or nerves of Lancisi.
The tœnia semicircularis-, lies in a depression between corpus
striatum and optic thalamus and is a commissure between these
bodies.
Choroid plexus ; the vascular margin of the velum interpositum,
communicating with that of opposite side just behind anterior
pillars of fornix, through the oval foramen of Monro ; posteriorly,
it descends into the middle horn, becoming there continuous with
pia mater through transverse fissure.
The corpus fimhriatum {tœnia hippocampi) ; the lateral edge of
the posterior pillar of the fornix, forming a white band just behind
choroid plexus.
The fornix ; continuous with corpus callosum behind, consisting
of a triangular body with apex forward, two anterior crura, curving
downward to base of brain, there to form the corpora albicantia
and terminate in the optic thalami, and i^o posterior crura, rym-
ning down the middle cornua of the lateral ventricles, as the
hippocampi majores ; on the back under surface, between posterior
crura, certain transverse longitudinal and oblique lines have been
termed the lyra.
The septum lucidum ; is a vertical septum, attached above to
under surface of corpus callosum, below to anterior part of fornix
and prolonged portion of corpus callosum ; it is triangular in form,
13
194
ESSENTIALS OF HUMAN ANATOMY.
and consists of two lamina of white nerve matter lined internally
with gray matter, the space between forming the fifth ventricle, not
communicating with other ventricles.
What is the pes hippocampi ?
The rounded elevations of lower extremity of hippocampus
major.
What is the pes accessorius ?
A white projection at the junction of the two hippocampi.
What is the fascia dentata ?
The gray substance of the dentate convolution, seen by raising
the edge of corpus fimbriatum.
What is the internal capsule ?
A large tract of white matter belonging to pyramidal tract, con¬
sisting of two limbs, the anterior lying between anterior part of
lenticular nucleus and caudate nucleus, the posterior between
posterior part of lenticular nucleus and thalamus, which, by their
junction, form a projection inward, the knee or genus.
What is the external capsule ?
A small tract of white matter lying between the outer part of
the lenticular nucleus and cerebral cortex.
Describe the third ventricle.
Narrow and oblong, the lateral walls being the optic thalami
and peduncles of pineal gland ; above the under surface of the
velum interpositum roofs it in, containing the choroid plexuses of
this ventricle; the lamina cinerea, tuber cinereum, infundibulum,
corpora albicantia, and posterior perforated space form its floor; it
is limited in front by the anterior crura of the fornix and part of
anterior commissure ; behind, by the posterior commissure, beneath
which opens the iter e tertio ad guartum ventrieulum ; while in front
by the foramen of Monro it communicates with the lateral ven¬
tricles; the cavity is crossed by an anterior and posterior white
commissure and a middle gray one.
NERVOUS SYSTEM.
195
Describe the fourth ventricle.
It is the space between posterior surface of the medulla oblongata
and pons in front, and the cerebellum behind. Its roof is the valve
of Vieussens and that portion of the cerebellum called the nodulxis,
uvula, and amygdalœ ; the lateral boundaries on each side are the
processus e cerebello ad testes, and posterior pyramids and restiform
bodies of the medulla oblongata; the floor consists of the posterior
surface of the medulla oblongata and the pons, upon the former of
which will be seen the posterior median fissure obliterated above,
terminating below in front of calamus scriptorius at the orifice of a
short blind canal, the remains of the foetal central canal of cord ; on
each side of median fissure are two convex longitudinal eminences,
the fasciculi teretes-, external to these, opposite crus cerebri on each
side, is the locus cœruleu»—a ganglionic mass ; a thin streak of this
embedded gray matter continued to top of ventricle is called the
tœnia vialaceœ, and certain white lines, the lineœ transversos : this
cavity communicates with that of the third by iter e tertio, etc.,
and with the subarachnoid space, through an opening in the pia
mater extending between the medulla oblongata and cerebellum.
The fifth ventricle has been described with septum lucidum,
p. 194.
Describe the pons Varolii.
It is the bond of union between the different segments of the
encepbalon ; bridging the medulla oblongata is a broad transverse
band forming the middle peduncles or crura cerebelli : longitudinal
fibres pass up from the medulla oblongata to form the two crura
cerebri, which become connected with the corpora striata and optic
thalami, through which they pass to reach the gray matter of the
hemispheres forming the corona radiata : the locus niger, a mass of
gray matter, is found in the substance of each crus ; the third nerve
emerges from inner side of each crus, the fourth nerve around the
outer side from above, while the optic tract is adherent by its upper
border.
Describe the corpora quadrigemina.
These are four rounded projections placed just behind third
ventricle beneath posterior border of corpus callosum : they are
196
ESSENTIALS OF HUMAN ANATOMY.
the centre of vision. Two white bands on each side connect them
with optic thalamus and optic tracts, those passing from the an¬
terior pair, or nates, to thalamus are the brachia anteriora, those
running from the posterior pair, the testes, to the thalamus are the
brachia posteriora ; passing from the testes to the cerebellum on
each side is the processus e cerebelh ad testes or inferior cerebellar
peduncle.
What is the valve of Vieussens ?
A thin lamina of nerve tissue, stretching from the vermiform
process of cerebellum from one processus e cerebello ad testes to
the other, forming the roof of the iter e tertio, etc. : a little ridge
descending upon the upper part from the corpora quadrigemina is
the frcenulum, and on either side are the transverse fibres connect¬
ing the fourth nerves.
What is the pineal gland ?
A reddish conical body lying beneath the nates, connected by
its base by two peduncles to the anterior crura of fornix : the gland
has a small cavity—said by some to open into that of the third
ventricle—containing a viscid fluid and a sandy substance, the
acervulus cerebri, composed of calcium carbonate and phosphate,
magnesium and ammonium phosphate, with some animal matter.
Describe the medulla oblongata.
It is the upper enlarged part of sjiinal cord, extending from
upper border of atlas to lower border of pons Varolii ; its posterior
surface forms the floor of the fourth ventricle, its anterior rests on
the basilar groove of the occiput. It contains the vaso-motor, car¬
diac, and respiratory centres, also those of deglutition, mastication,
etc. Divided into lateral halves by the anterior (d, Fig. 80) and.
Posterior median fissures, it presents on each side of anterior
fissure.
The anterior pyramid {p, a. Fig. 80) formed by antero-lateral
columns of the cord, these latter fibres decussating above d (crossing
from one pyramid to that of the other) at the lower part; behind
the pyramid is the olivary bodyo containing in its interior a capsule
of gray matter, the corpus dentaium ; behind the olivary body is,
NERVOUS SYSTEM.
197
The lateral tract continuous with lateral tract of the cord; hack
of this is the resiiformr body, continuous with posterior columns of
cord helow, above passing into corresponding hemisphere of cere¬
bellum forming "ts inferior peduncle ; running along the posterior
median fissure on either side are the
Posterior pyramids continuous with posterior median columns
of cord ; diverging above, they form the lateral boundaries of the
calamus scriptorius.
Describe the cerebeilum.
It is that portion of the encephalon contained in the inferior
occipital fossse composed of laminae covered with gray matter ; on
the upper surface the two hemispheres are seen connected by a
median elevated lobe, the superior vermiform process, while they are
separated in front and behind by notches respectively called the
incisurce cerebelli anterior and posterior ] the superior vermiform pro¬
cess consists of a lobulus centralis in incisura anterior, the monti-
culus cerebelli the central projecting portion, and the commissura
simplex, near the incisura posterior.
Describe the under surface of the cerebellum.
It is divided by a central longitudinal depression, the valley, into
two hemispheres. Projecting from the bottom of the valley is the
inferior vermiform process, consisting of the commissura brevis in
the posterior notch, in front of the conical pyramid, more ante¬
riorly, the uvula, lying between two rounded lobes the amygdalae or
tonsils, and which projects into fourth ventricle, and finally in front
of uvula the nodule ; attached to each side of nodule and also to
flocculus, is a thin white layer which together form the posterior
medullary velum.
Name the lobes of the cerebellum.
Below, from before backward, they are, on each side,
Tlh.e flocculus, or pneumogastric lobule, a prominent tuft below and
behind middle peduncle.
The amygdala, just described.
The digastric, on outside of tonsils, partially connected with
pyramid.
198
ESSENTIALS OF HUMAN ANATOMY.
The slender, behind former, connected with commissura brevis
and back of pyramid.
The inferior posterior, joining the coramiasura brevis in the
valley.
Only one fissure—the great horizontal—pertains to the cerebellum,
commencing in front at pons, and passing horizontally round free
margin of each hemisphere to median line ; from this numerous
secondary fissures proceed, marking out lobes, as two on the upper
cerebellar surface on each side, viz., the anterior, or square globe, ex¬
tending back to posterior edge of vermiform process, and the pos¬
terior, or semilunar, passing from preceding to great horizontal fis¬
sure.
How many peduncles has the cerebellum ?
Three; the transverse fibres of pons Varolii, or middle peduncle;
on each side the restiform bodies of medulla oblongata, or inferior
peduncles; and the processus e cerebello.ad testis, forming the supe¬
rior peduncles.
Describe the arrangement of the gray matter of the cere¬
bellum.
A vertical section reveals a central stem of white matter con¬
taining a capsule of gray matter, the corpus dentatum. From the
central white stem ten or twelve plates, or laminœ, spring, giving
origin to smaller secondary and tertiary laminse, covered externally
by a layer of gray matter, so that the cut surface presents the foli¬
ated appearance giving origin to the name arbor vitce.
The Spinal Cord.
What is the spinal cord ?
The elongated cylindrical part of the cerebro-spinal axis con¬
tained in the vertebral canal, measuring about seventeen inches in
length, extending from upper border of atlas to lower border of
body of first lumbar vertebra, presenting a cervical enlargement
from third cervical to first or second dorsal vertebra, and a lumbar
enlargement opposite last two or three dorsal vertebrae; it terminates
by a slender filament of gray substance, the filum terminate. The
THE SPINAL CORD.
199
white matter is disposed externally, the gray internally in the form
of two crescents joined by a transverse commissure, the anterior
thicker extremities, forming the anterior comua, or hams, the pos¬
terior posterior cornua.
How many membranes has the cord ?
Three ; the dura mater, continuous with that of brain, but sepa¬
rated from bony walls by loose areolar tissue, containing a plexus
of veins ; the arachnoid, continuous with cerebral arachnoid, also
having a subdural and subarachnoidean space, the latter communi¬
cating with general ventricular cavity of brain by the foramen of
Magendie, an aperture in pia mater of fourth ventricle—this space
contains an abundant serous secretion, the cerebrospinal fluid-, and
the pia mater, sending processes down into anterior and posterior
median fissures, having medianly in front a fibrous band, the linea
splendens, and on each side another, the ligamentum denticulatum,
whose outer border presents about twenty serrations, the apices of
each attached to inner surface of dura mater, serving to support
the cord.
Describe the fissures.
They are the anterior and posterior median, dividing cord into two
lateral halves, joined medianly by a white commissure-, on each
side of anterior fissure is a series of foramina for the exit of anterior
roots of nerves ; this line of openings is called the antero-lateral fis¬
sure-, iyio postero-lateral fissures run parallel to posterior median fis¬
sure, giving exit to posterior roots ; finally, a delicate groove on
each side between the postero-lateral and posterior median fissures
exists, marking off posterior pyramids.
Name the columns of the cord marked off by these fissures.
On each side the anterior, continuous with the anterior pyramid
of medulla oblongata.
The lateral, continuous with lateral tract of medulla oblongata.
The posterior, continuous with restiform body of medulla oblon¬
gata.
The posterior median, continuous with posterior pyramid of
medulla oblongata.
200
ESSENTIALS OF HUMAN ANATOMY.
What is the ventricle of the cord ?
The fœtal central canal, usually obliterated, except for a few
lines below floor of fourth ventricle of brain.
The Cranial Nerves.
How many pairs of cranial nerves are there ?
Nine, according to most anatomists ; twelve, according to others.
Describe each of the following nerves, giving their number
according to each classification.
First, Olfactory'' (Fig. 80), nerve of smell; superficial origin, by
one root from middle lobe, two from anterior lobe (see p. 191) ;
deep origin, gray nucleus in
temporo-spbenoidal lobe, cor¬
pus striatum, and gyrus forni-
catus ; escapes, by foramina of
cribriform plate of ethmoid;
distribution, nasal (Scbneider-
ian) mucous membrane ; may
be regarded as lobe of cere¬
brum.
Second, Optic", nerve of
sight; deep origin, from optic
tracts"', which arise from
optic thalami, corpora geni-
culata, and nates of corpora
quadrigemina; is also attached
to crus cerebri and receives
fibres from tuber cinereum,
lamina cinerea, and, according
to some, the taenia semicircu-
laris and gyrus fornicatus ; in
front of tuber cinereum lies
the optic chiasm or commis¬
sure, formed of six sets of
fibres, viz., a set crossing from right side of brain to left eye, a
second pursuing the same course from the opposite side, decussating
THE CRANIAL NERVES.
201
fibres-, a third, anterior, connecting the two retinae—inter-retinal
fibres-, a fourth and fifth, lateral, cerebro-retinal, connecting the
hemisphere of one side with retina of eye of same side; and a
sixth, posterior—inter-cerebral—connecting one optic tract with the
other; distribution, retina.
Third"', Motor oculi; superficial origin, inner surface of crus
cerebri ; deep origin, a nucleus for each in floor of iter e tertio ad
quartum ventriculum ; escapes, by sphenoidal fissure ; distribution,
to all eye muscles including iris, except external rectus and
superior oblique.
Fourth" (Fig. 80), Patheticus, moUix, superficial onjrm, outer side
crus cerebri ; deep origin, floor of aqueduct of Sylvius ; escapes
through sphenoidal fissure; distribution to superior oblique of eye.
Fig. 81.
Fifthv (Fig. 80), Trigeminus or Trifacial, nerve of general sensa¬
tion, motion, and taste ; superficial origin, by a motor and a sensory
root from side of pons Varolii ; deep origin, sensory root from upper
expanded posterior gray horns of medulla at junction with resti-
202
ESSENTIALS OF HUMAN ANATOMY.
form body—the Qdsserian ganglion formed on this root lies on apex
of petrous portion of temporal bone ; the motor root arises from a
mass of gray cells to inner side of nucleus of sensory root; escapes,
ophthalmic' (Fig. 81) by sphenoidal fissure, superior maxillary*
(Fig. 81) by foramen rotundura, inferior maxillary' (Fig. 81) by
foramen ovale.
Ophthalmic division' (Fig. 81), purely sensory, supplies eyeball,
ciliary muscle, iris, lachrymal gland, nasal and ocular mucous
membrane, skin and muscles of eyebrow, forehead and nose, and
ciliary ganglion; its branches are
Frontal, Lachrymal, Nasal.
Superior maxillary division* (Fig. 81), sensory, is distributed to
temple, cheek, lower eyelid, nose, upper lip, and teeth, and, by
Meckel's ganglion connected with this nerve, the palate and
pharynx ; its branches are
Orbital,
Anterior dental.
Inferior maxillary division' (Fig. 81), nerve of common sensa¬
tion, motion, and taste; supplies ma.sticatory muscles, teeth, gums,
skin of temple and of external ear, lower part of face and lower
lip, the tongue, otic and submaxillary ganglia; its branches are
Masseteric, Auriculo temporal.
Two deep temporal, Oustatory ' yoid,
Sixth, Abducens" (Fig. 80), motor; superficial on<7/«, between
anterior pyramid and pons Varolii ; deep origin, from nucleus of
fasciculus teres on floor of fourth ventricle ; escapes, by sphenoidal
fissure; distribution, external rectus muscle.
Seventh, Facial*" (Fig. 80) or portio dura of the seventh Tierce,
the motor nerve of the muscles of expression, of platysma, buc¬
cinator, two muscles of external ear, posterior belly of digastric,
stylo-hyoid, stapedius, through chorda tympani, the lingualis,
through otic ganglion, the tensor tympani, through Vidian, the
levator palati and azygos uvulae muscles ; superficial origin, medulla
Spheno-palatine,
Posterior dental.
Buccal,
Pterygoid,
Inferior dental
THE CRANIAL NERVES.
203
oblongata, from groove between olivary and restiform bodies ; deep
origin, from nucleus of fasciculus teres in floor of fourth ventricle
and nucleus of motor root of fifth nerve ; escapes, by internal audi¬
tory meatus to aquseductus Fallopii, and thence by stylo-mastoid
foramen ; didribation, to muscles already mentioned ; its branches
are
Tympanic, ( Temporal,
Chorda tympani, Temporo-facial Malar,
Posterior auricular, ( Infra-orbital,
The communications of the facial are
With auditory nerve ; with Meckel's ganglion by large petrosal
nerve ; with otic ganglion by small petrosal nerve ; with sympa¬
thetic on middle meningeal by external petrosal nerve ; with pneu-
mogastric, glosso-pharyngeal, carotid plexus, auricularis magnus,
auriculo-temporal and with the three divisions of fifth nerve.
Eighth, Auditory^"' •• (Fig. 80), or portio mollis of the seventh
nerve, nerve of hearing ; superficial origm, from medulla oblongata
in groove between olivary and restiform bodies at löwer border of
pons; deep origin, superior vermiform process of cerebellum,
gray substance of posterior pyramid and restiform body ; escapes,
by internal auditory meatus ; distribution, to internal ear ; its
branches are.
Vestibular, to the vestibule. Cochlear, to the cochlea (see p. 320).
Ninth, Glosso-pharyngeal » (Fig. 80) or first divsion of eighth
nerve, nerve of general sensation and taste; superficial origin,
medulla oblongata just behind olivary body; deep origin, gray
nucleus at lower part of floor of fourth ventricle; escapes, at
central part of jugular foramen, after which it presents two gan-
gliform enlargements, the jugular and petrous ganglia-, distrihu-
tion, to muscles of pharynx, mucous membrane of pharynx, fauces,
tonsil, and tongue, and the middle ear ; its branches are
Tympanic (Jacobson's), Pharyngeal, Tonsillar,
Carotid, Muscular, Lingual.
Digastric,
Stylo-hyoid,
204 ESSENTIALS OF HUMAN ANATOMY.
Tenth, Pneumogastric* (Fig. 80) or par vagum of the eighth
nerve-, both motor and sensory; superficial origin, from lateral
tract of medulla oblongata behind olivary body and below the
glosso-pharyngeal ; deep origin, gray nucleus lower part of floor of
fourth ventricle—the motor filaments probably come from spinal
accessory; escapes, by jugular foramen presenting a gangl i form en¬
largement, ganglion of the root, and lower another, ganglion of the
trunk ; distribution, to organs of voice and respiration, the pharynx,
oesophagus, stomach, and heart ; the branches are
Auricular, Anterior pulmonary,
Pharyngeal, Posterior pulmonary,
Superior laryngeal, Œsophageal,
Recurrent laryngeal, Gastric,
Cervical cardiac. Hepatic (to hepatic sympathetic
Thoracic cardiac, plexus).
Eleventh, Spinal accessoryxi (Fig. 80), or third division of the
eighth nerve, a motor nerve; superficial origin, lateral tracts of
medulla oblongata below roots of vagus, and from same part of
spinal cord as low as sixth cervical vertebra ; deep origin, gray
matter below nucleus of vagus and anterior horn of gray matter
of cord; it sends filaments to ganglion of root of vagus and
pharyngeal and superior laryngeal branches of same nerve;
escapes, by jugular foramen, the spinal portion first entering skull
through foramen magnus ; distribution, to sterno-cleido-mastoid
and trapezius muscles, communicating with second, third, and
fourth cervical nerves.
Twelfth, Hypoglossal"" (Fig. 80), or ninth nerve, motor nerve of
tongue ; superficial origin, groove between pyramidal and olivary
bodies by numerous filaments ; deep origin, special nucleus at
lowest point of fourth ventricle; escapes, by anterior condyloid
foramen ; distribution, to thyro-hyoid, genio-hyoid, stylo-glossus,
hyo-glossus, genio-hyo-glossus, and by descendons noni to sterno¬
hyoid, sterno-thyroid, and omo-hyoid muscles; it communicates
with the pneumogastric, gustatory of fifth, sympathetic, and first
and second cervical nerves ; its branches are
Descendens noni, Muscular, Thyro-hyoid, Meningeal.
THE SPINAL NEKVES.
205
The Spinal Nerves.
How many pairs of spinal nerves are there ?
Eight cervical, twelve dorsal, five lumbar, five sacral, and one
coccygeal—thirty-one in all.
Describe their origin.
Each nerve arises by an anterior motor root, emerging from the
antero-lateral fissure, and a posterior sensory, having a ganglion on
it, springing from postero-lateral fissure ; these unite to pass out
through the intervertebral foramina—except first cervical, which
emerges between the atlas and occiput—after which they break
up into an anterior and posterior division, the latter, the smaller,
supplying the spine, dorsal muscles, and integument, while the
anterior larger divisions form plexuses whence the remainder of
the trunk and limbs receive their nerve-supply.
Describe the cervical plexus with its branches.
It is formed by the anterior divisions of the four upper cervical
nerves lying upon the levator anguli scapulae and scalenus medius
muscles ; its branches are.
Describe the phrenic nerve (internal respiratory nerve of
It arises from third and fourth nerves with a branch from fifth,
runs obliquely over scalenus anticus muscle, passes across sub¬
clavian artery, enters chest across root of internal mammary
artery, to be distributed to pericardium, pleura, and under surface
of diaphragm and phrenic plexus; it is joined by filaments from
sympathetic, fifth and sixth cervical, the nerve to subclavios
muscle, and one from union of descendons noni with the spinal
nerves.
Superficialis colli,
Auricularis magnus.
Occipitalis minor.
Sternal,
Clavicular,
Acromial,
Communicating,
Muscular,
Communicans noni,
Phrenic.
Bell).
206
ESSENTIALS OF HUMAN ANATOMY.
Describe the brachial plexus with its branches.
The anterior divisions of the fifth and sixth, with a branch ot
the seventh cervical nerves form the outer cord, the eighth cervical
and first dorsal form the inner cord, a branch from the latter and
one from the united fifth and sixth join the seventh nerve to form
the posterior cord-, this is the usual, but not wyariaife arrangement;
its branches are,
Communicating, above clavicle to phrenic.
Muscular, to longus colli, scaleni, rhomboidei, and subclavias
muscles.
Posterior or long thoracic (external respiratory nerve of Bell),
from fifth, sixth, and seventh nerves, to serratus magnus muscle.
Suprascapular, from outer cord; to supra- and infra-spinatus
muscles and shoulder-joint.
External anterior and internal anterior thoracic, the former from
outer cord, the latter from inner cord ; both to pectoral muscles.
The three scapular, the upper/row communicating branch from
outer to posterior cord, the other two from posterior cord ; to sub¬
scapular, teres major, and latissimus dorsi muscles.
Circumflex, from posterior cord with musculo-spiral ; to deltoid
and teres minor muscles, the shoulder-joint, and skin of lower
deltoid region.
Musculo-cutaneous (external cutaneous), from outer cord and
pierces the coraco-brachial muscle; to coraco-brachial, biceps,
brachialis anticus muscles, elbow-joint,^and skin of outer half of
front of forearm.
Internal cutaneous, from inner cord with ulnar and inner head of
median ; to skin over biceps and that of inner half of forearm in
front and behind.
Lesser internal cutaneous (nerve of Wrisberg), from inner cord
alone, or a branch from this joined with intercosto-humeral (the
lateral cutaneous branch of second intercostal nerve, piercing ex¬
ternal intercostal muscle to supply skin of upper half of inside of
arm), or, again, the intercosto-humeral may entirely replace it ; to
skin of inner side of arm.
Median, from outer and inner cords by two roots which embrace
the axillary artery uniting in front or to its outer side, first lying
external to brachial artery, then crossing to its inner side, passing
between heads of pronator radii teres muscle to run between deep
THE SPINAL NERVES.
207
and superficial flexor of fingers to within two inches of wrist,
when it hecomes superficial ; its branches are,
Muscular, to all anterior superficial forearm muscles except flexor
carpi ulnaris.
Anterior interosseous, to deep forearm muscles except inner half
of flexor profundus digitorum.
Palmar cutaneous, piercing fascia above wrist; to skin of palm
to radial side.
Muscular, to abductor, opponens, and outer head of flexor brevis
pollicis.
Five digitals, supplying both sides of thumb, index, middle, and
radial side of ring fingers.
Ulnar, from inner cord runs behind inner condyle, thence passing
into forearm between heads of flexor carpi ulnaris to run some dis¬
tance from ulnar artery at upper third, but close to it for rest of its
extent; it partially supplies elbow and wrist-joints, both sides of
little and ulnar side of ring finger and skin of forearm and hand ;
its branches are,
Articular.
Muscular, to flexor carpi ulnaris, inner half of flexor profundus
digitorum, the little finger muscles, the interossei and lumbricals,
palmaris brevis, adductor, and inner head of flexor brevis pollicis.
Cutaneous, Superficial palmar.
Dorsal cutaneous, Deep palmar (muscular).
Musculo spiral, from posterior cord and branch of inner cord,
running in same-named groove with superior profunda vessels to
divide in front of condyle into the radial and posterior interosseus\
its branches are.
Radial, Muscular,
Cutaneous, Posterior interosseous.
Radial, to skin of ball and outer side of thumb, and that on back
of index, middle, and part of ring fingers ;
Posterior interosseous, supplying wrist-joint and all muscles on
back of forearm except anconeus, supinator longus, and extensor
carpi radialis longior.
Muscular, to triceps, anconeus, supinator longus, extensor carpi
radialis longior, and brachialis anticus.
Cutaneous, to skin of lower, outer, and back part of arm, forearm,
and hand.
208
ESSENTIALS OF HUMAN ANATOMY.
Dorsal Nerves-
Describe them.
Twelve in number on each side, the first escapes between first
and second dorsal vertebrae, the last between the last dorsal and
first lumbar; they divide into an anteriora.nàposterior division, the
latter supplying spine, extensor muscles of back and dorsal integu¬
ment; the former (anterior) are.
The intercostal nerves, each connected by one or two filaments
with the adjacent sympathetic ganglia: the anterior division of
the first nerve aids in the formation of the brachial plexus, its in¬
tercostal branch is small and gives off no lateral cutaneous branch :
the lateral branch of the second nerve is the intercosto-humeral (see
p. 206) : the remaining nerves give off lateral cutaneous branches
supplying skin of front of thorax and abdomen, while they give
muscular branches to the intercostal and abdominal muscles.
Describe the lumbar nerves.
The posterior branches resemble in origin and arrangement those
of the dorsal region, while their anterior branches form the lumbar
and part of the sacral plexuses.
Describe the lumbar plexus and branches.
It is formed by loops-of communication between the anterior
divisions of the four upper lumbar nerves in the substance of the
psoas muscle, thus.
The first nerve gives off,
nio-hypogastric, to skin of gluteal and hypogastric regions.
Uio-inguinal, to internal oblique muscle and skin of scrotum
(labium in female), and upper inner part of thigh, and
A communicating hop, to second lumbar nerve, from which arises,
in conjunction with a branch from the third nerve, the
External cutaneous, to skin of antero-external and posterior sur¬
faces of thigh : from the second nerve and loop from first nerve
comes, the
Genito-crural, to cremaster muscle and skin of front of upper part
of thigh ; and a
Communicating hop, h third lumbar nerve. By a branch of the
third and fourth nerves with fibres from the second is formed the
DORSAL NERVES.
209
Obturator, to obturator externus and adductor muscles, hip- and
knee-joints, also sometimes to skin of thigh and leg.
The accessory obturator, either from obturator or formed by two
filaments from third and fourth nerves, to pectineus muscle and
hip-joint.
Communicating hop, between third and fourth nerves.
Communicating loop, between fourth and fifth nerves.
Anterior crural, from third and fourth, with communicating
branch from second lumbar nerve. It descends beneath Poupart's
ligament external to artery between the psoas and iliacus muscles
after emerging from former, and divides into an anterior and pos¬
terior division : its branches are, within the pelvis,
Muscular to iliacus internus, to femoral artery, external to pelvis.
Middle cutaneous.
Internal cutaneous. Articular (hip and knee).
Long saphenous. Muscular.
It supplies all the anterior thigh-muscles except tensor vaginae
femoris, and skin of front and inner side of thigh, leg, and foot.
Describe the sacral plexus.
It is formed by the lumbo-sacral cord (the anterior division of
fifth nerve with a branch of the fourth), and anterior divisions of
three upper sacral nerves and part of that of fourth : it rests upon
the anterior surface of the pyriformis muscle, giving off the
Superior gluteal, from lumbo-sacral cord passing out through great
sacro-sciatic foramen, to gluteus medius and minimus and tensor
vaginse femoris muscles.
Muscular branches, to pyriformis, obturator internus, gemelli, and
quadratus femoris.
Pudic passes out of pelvis by greater saero-sciatic foramen to
reënter it by lesser sacro-sciatic foramen : its branches are.
Inferior hemorrhoidal. Perineal, Dorsal of penis.
Muscular, to transversos peronei, accelerator urinse, erector penis
and compressor urethras muscles : the preceding branches supply
analogous muscles and parts in female.
Small sciatic, escapes by greater sacro-sciatic foramen, to skin of
scrotum, back of leg and thigh, and gluteus maximus muscle.
Great sciatic, is a eontinuation of lower part of sacral plexus,
14
210
ESSENTIALS OF HUMAN ANATOMY.
forming the largest nerve in the body. Escaping by the greater
sacro-sciatic foramen below pyriformis muscle, it gives off these
branches,
Articular (to hip).
Muscular, to biceps, semi-tendinous, semi-membranous and
adductor magnus, and divides into the internal and external pop¬
liteal nerves.
Give the branches of the internal popliteal nerve.
Articular (to knee).
Muscular to gastrocnemius, plantaris, soleus, and popliteus.
External or short saphenous, a cutaneous branch communicating
with external popliteal, musculo-cutaneous, and small sciatic
nerves.
Describe the posterior tibial nerve.
It is a continuation of former, runs down middle of back of leg
beneath the calf muscles to divide between the inner malleolus and
the heel into the internal and external plantar : its branches are.
Muscular, to tibialis posticus, flexor longus digitorum and pollicis
muscles.
Plantar cutaneous, to skiu of heel and inner side of sole of foot.
Internal plantar, supplying skin of sole, tarsal, and metatarsal
articulations, the two inner lumbricals, abductor pollicis, and
flexor brevis digitorum, with four digital branches which supply
both sides of first, second, and third toes and inner half of fourth.
External plantar, smaller than preceding, supplying flexor acces-
sorius, abductor minimi digiti, flexor brevis minimi digiti, all the
interossei, two outer lumbricales, adductor pollicis, transversos
pedis muscles, and skin of little toe and adjoining side of fourth
toe.
Describe the external popliteal nerve.
It descends obliquely along outer side of popliteal space close to
tendon of biceps, giving off.
Two articular branches to knee ; cutaneous branches to skin of
postero-external surface of leg, and a branch, the communicans
peronei, joining external saphenous nerve : it divides into the
Anterior tibial, about one inch below head of fibula, giving nms-
THE SYMPATHETIC NEEVE.
211
cular branches to tibialis anticua, extensor longus digitorum, pero-
neous tertius, extensor proprius pollicis, and extensor brevis
digitorum, articular to tarsal and metatarsal joints, and cutaneous
to skin of adjacent sides of great and second toes ;
Mmculo-cutaneous, giving oif muscular branches, to peroneus
longus and brevis, and cutaneous, to skin of lower part of leg, and
dorsum of foot and toes, except outer side of little and adjoining
sides of great and second toes.
Describe the sacral and coccygeal nerves.
They are five in number, their long roots forming the cauda
equina in the spinal canal ; each divides into an anterior (see page
209) and posterior division, the latter escaping by the posterior
sacral foramina, except the fifth, which emerges between sacrum
and coccyx, and supplies multifidus spinse muscle and skin of
posterior gluteal region; a branch goes from third nerve to bladder;
the two lower nerves join with coccygeal, forming loops, which
supply skin over coccygeal region and coccygeus, levator, and
sphincter ani muscles.
The Sympathetic Nerve.
What is the sympathetic nerve or system ?
It consists of a series of ganglia with intervening commissural
bands, forming two cords on either side of spinal column connected
above by ganglion of Ribes on the anterior cerebral communicating
artery, and below by ganglion impar, in front of coccyx ; they also
communicate with the spinal system of nerves.
Locate and briefly describe the connections of the cranial
and facial ganglia.
Ganglion of Ribes, on anterior communicating artery, connected
with cavernous and carotid plexuses.
Carotid ganglion (Laumonier's) on under surface of vessel.
Gasserian, on fifth nerve (infra).
Ciliary or ophthalmic, in orbit (infra).
Spheno-palatine (Meckel's), in spheno-maxillary fossa (infra).
Otic (Arnold's), on inner side of inferior maxillary nerve below
foramen ovale (infra).
Ganglia are occasionally found on middle meningeal, lingual.
212
ESSENTIALS OF HUMAN ANATOMY.
temporal, and pharyngeal arteries, receiving the name of their dis¬
coverer,- as Bidder, Cloquet, etc.
Ganglion of Bochdalek is situated at point of junction of one of
the nasal branches of Meckel's ganglion and anterior dental nerve.
Submaxillary lies above deep portion of submaxillary gland
(infra).
Describe the ciliary ganglion.
Situated iu the orbit between the optic nerve and external rectus
muscle, its roots are, sensory, from nasal branch of ophthalmic (fifth
pair) ; motor, third nerve ; sympathetic, cavernous plexus ; its
branches are.
Short (Aliary to ciliary muscle and iris.
Describe the spheno-palatine ganglion.
Deeply placed in spheno-maxillary fossa, its roots are, sensory,
from superior maxillary ; motor, facial, through Vidian ; sympa¬
thetic, from carotid plexus; its branches are.
Ascending, Middle palatine. Vidian,
Anterior palatine, Superior nasal. Pharyngeal, or
Posterior palatine, Naso-palatine, Pterygo-palatine.
Describe the otic ganglion.
It lies immediately beneath foramen ovale on the inner surface
of inferior maxillary nerve; its roots are, sensory, from auriculo¬
temporal ; motor, internal pterygoid branch of inferior maxillary,
also facial and glosso-pharyngeal through continuation of small
"petrosal nerve; sympathetic, from middle meningeal plexus; its
branches supply tensor tympani and tensor palati muscles.
Describe the submaxillary ganglion.
Situated above deep portion of submaxillary gland, its roots are,
sensory, from gustatory branch of inferior maxillary; nwtor, facial,
through chorda tympani ; sympathetic, from facial plexus ; its
branches go to mucous membrane of mouth, to submaxillary gland
and to its duct.
Describe the petrosal nerves.
The great petrosal (large superficial petrosal) is usually described
as a branch of the spheno-palatine ganglion passing through the
THE SYMPATHETIC NERVE.
213
Vidian canal, distributing twigs to mucous membrane of back part
of nose, septum, and end of Eustachian tube, enteringskull through
foramen lacerum medium, where it divides into the large superficial
petrosal, which enters hiatus Fallopii, receives a twig from Jacob-
son's nerve, and terminates in the geniculate ganglion of facial
nerve, and the carotid {large deep petrosal) ioining the carotid plexus.
Small petrosal (small superficial petrosal) connects geniculate
ganglion of seventh nerve with otic ganglion.
External petrosal (external superficial petrosal) passes between
geniculate ganglion of seventh nerve to middle meningeal plexus.
More correctly, the great petrosal and carotid branches may be
said to form the Vidian nerve, which runs forward through the
same named canal to join the spheno-palatine ganglion, supplying
it with motor and sympathetic fibres. According to this descrip¬
tion, the twigs said to be given off by the Vidian nerve to the nasal
mucous membrane must be considered branches of the ganglion
running back in the same sheath.
Describe the cervical ganglia.
There are three on either side, viz., the
Superior cervical ganglion. It is placed opposite second and
third cervical vertebrae behind carotid sheath, and gives off a
Superior branch, to internal carotid artery, forming by its division
the cavernous plexuses and carotid plexus (with its subdivisions) ;
Descending branch, connecting superior with middle ganglion ;
External branches to cranial and spinal nerves, and anterior
branches forming plexuses on external carotid and its branches ;
Pharyngeal, forming with branches from pneumogastric, glosso¬
pharyngeal, and external laryngeal nerves, ihß pharyngeal plexus-,
Laryngeal, uniting with superior laryngeal nerve and its
branches ;
Superior cardiac, connected with other branches of sympathetic,
and with some of pneumogastric, passes to back of aorta, the right
joining the deep, and the left (usually) the superficial cardiac plexus.
Middle cervical ganglion is placed opposite fifth cervical vertebra ;
by its
Superior and inferior branches it communicates respectively with
superior and inferior cervical ganglia; the filaments join
214
ESSENTIALS OF HUMAN ANATOMY.
fifth and sixth spinal nerves, the internal are the thyroid to inferior
thyroid artery and gland, and the middle or great cardiac nerve,
communicating with other sympathetic branches and recurrent
laryngeal, to terminate in the deep cardiac plexus.
Inferior cervical ganglion is placed between base of transverse
process of seventh cervical vertebra and neck of first rib on inner
side of superior intercostal artery ; its superior and inferior branches
connect it respectively with middle cervical, and first thoracic
ganglia; the branches join the spinal nerves, others form
a ]>lexus or vertebral artery ; its chief branch is the
Inferior cardiac nerve, communicating with recurrent laryngeal
and middle cardiac nerves, terminating in the deep cardiac plexus.
What is the carotid plexus ?
It is a plexus situated on the outer side of the internal carotid
artery communicating with the Gasserian and spheno palatine
ganglia, the sixth nerve, and tympanic branch of glosso-pharyn-
geal ; it supplies the carotid artery and dura mater
What is the cavernous plexus ?
It is one situated below and internal to that part of the internal
carotid artery running alongside of the sella turcica, in the
cavernous sinus; it communicates with third, fourth, fifth, and
sixth nerves, and ophthalmic ganglion, and supplying carotid, it,
with the carotid plexus, forms plexuses embracing the cerebral
and ophthalmic arteries.
What are the other ganglia of the sympathetic system ?
Usually twelve thoracic, four lumbar, four or five sacral, one
coccygeal (ganglion impar), and numerous ganglia connected
with the various viscera, whence plexuses are formed named from
their locality, or the organ.
What are the branches of the thoracic portion ?
Communicating, with one another and the dorsal spinous nerves,
filaments to aorta and its divisions and to posterior pulmonary
plexus, and
The Great Splanchnic nerve, formed by internal branches from
thoracic ganglia between sixth and tenth, with filaments from
THE SYMPATHETIC NEEYE.
215
upper six; it perforates crus of diaphragm to terminate in semi¬
lunar ganglion, sending branches to renal plexus and suprarenal
capsule.
The Lesser Splanchnic, springing from tenth and eleventh ganglia
and cord between and communicating with great splanchnic, it
pierces diaphragm with preceding, to join the coeliac plexus.
Smallest, or Renal Splanchnic, arises from last ganglion, occasion¬
ally communicates with preceding, pierces diaphragm, and termi¬
nates in renal and lower part of cœliac plexus.
Describe the solar plexus.
It supplies all the abdominal viscera, consisting of a network of
nerves and ganglia lying in front of the aorta and crura of dia¬
phragm, surrounding the cœliac axis and root of the superior
mesenteric artery, extending below to the pancreas, laterally to the
suprarenal capsules. The great and part of lesser splanchnic
nerves of both sides and termination of the right piieumogastric
form this plexus, in conjunction with the two semilunar ganglia,
these latter being large, irregular gangliform masses, composed of
■smaller ganglia with interspaces between, placed by side of cœliac
axis and superior mesenteric artery, close to suprarenal capsules,
that on the right lying beneath the vena cava. From this are
derived the following plexuses accompanying the same-named
arteries to the various organs :
Phrenic, or diaphragmatic,
Cœliac,
Gastric,
Hepatic,
Splenic, Aortic,
Name some of the more important.
Tympanic (see p. 316).
Great, or deep, cardiac is placed in front of bifurcation of trachea,
and above that of pulmonary artery, behind aortic arch, and is
formed by all sympathetic cardiac nerves (except left superior), and
cardiac branches of recurrent laryngeal and pneumogastric (except
left superior cardiac and left inferior cardiac of pneumogastric).
Superficial cardiac lies beneath aortic arch in front of right pul-
Suprrarenal,
Renal,
Superior mesenteric.
Spermatic,
Inferior mesenteric.
216 ESSENTIALS OF HUMAN ANATOMY.
monary artery, and is formed by left superior cardiac, left inferior
cardiac of pneumogastric, and branches from deep cardiac plexus.
Coronary, the posterior, ehiefly from deep, the anterior from
superficial cardiac plexus.
Aortic, on sides and front of vessel between roots of superior
and inferior mesenteric arteries.
Hypogastric, lying in front of sacrum, between eommon iliac
arteries, it supplies the pelvic viscera, and is formed by filaments
from aortic plexus, and from lumbar and first two sacral ganglia,
contains no ganglia, and divides into two lateral portions, forming
the inferior hypogastric or pelvic plexuses.
Inferior hypogastric plexuses. These lie upon each side of rect um
and bladder (rectum, vagina, and bladder, in females), and each is
formed by a continuation of the hypogastric plexus and branches
from second, third, and fourth sacral nerves, and a few filaments
from sacral ganglia; the branches accompany those of internal
iliac artery, and are distributed to all the pelvic viscera; their
branches are
Inferior hemorrhoidal plexus.
Vesical plexus. Vaginal plexus.
What is a viscus ?
Any of the internal organs with their appendages, contained
within the cranial, thoracic, or abdominal cavities.
Of what does the digestive apparatus consist?
Of the alimentary canal, a musculo-membranous tube, lined
witb mucous membrane, about thirty feet long, and extending
from the mouth to the anus, and certain accessory organs.
VISCERAL ANATOMY.
The Digestive Organs.
THE TEETH.
217
Name the subdivisions of the alimentary canal.
Mouth, pharynx, oesophagus, stomach, small intestine (duode¬
num, jejunum, ilium), large intestine (caecum, colon, rectum).
What are the accessory organs ?
The teeth, salivary glands (parotid, submaxillary, sublingual),
liver, pancreas, and spleen.
The Teeth.
What is their function ?
To reduce the food to fragments, thus enabling the digestive
fluids to act to best advantage.
Into what classes are they divided ?
Into
Temporary, or milk teeth, ten in each jaw, viz., four incisors, two
canines, and four molars ;
Permanent teeth, sixteen in each jaw, viz., four incisors, two
canines, four bicuspids or premolars, six molar's.
Of what parts does every tooth consist ?
Of a
Crown or body (Fig. 82), that part projecting above the gum.
Neck, the constricted portion between crown and fang.
^Fang, or root, that part occupying the alveolus, held there by
the periodontium (periosteum), lining the socket; in addition, the
teeth are steadied by the gums, composed of dense fibrous tissue
covered with mucous membrane.
^Pulp-cavity, an interior cavity filled with the tooth-pulp, a
vascular connective tissue with numerous nerves, both arteries and
nerves reaching the pulp by a canal opening at apex of fang.
Describe the characteristics of each of the four varieties of
teeth.
Incisor or cutting teeth. The crown is wedge-shaped, convex in
front, bevelled and slightly concave behind; the fang is single,
long, conical, and transversely flattened.
218
ESSENTIALS OF HUMAN ANATOMY.
Fig. 82.
CaniaeH. Crown is large, conical, convex in front, rises above
level of other teeth; fang long, conical, compressed laterally;
upper pair are called in common parlance " eye-teeth," the lower
"stomach-teeth."
Bicuspid^. Crown has two projecting cusps, fang generally is
single, laterally grooved with bifid apex; they are also called/>re-
mo/ars.
Jlolar (grinders). Crown nearly cubical, with four cusps in
upper, and five in lower molars; fangs, usually three for first two
upper, and two for first two lower molars ; the third molar is called
the " wisdom tooth " {deiis sapientiœ), from
its late appearance, and usually has hut one
fang with grooves indicating a tendency to
formation of three fangs in upper, two in
lower jaw.
The second temporary molar is the largest
milk tooth, and is succeeded by the second
permanent bicuspid.
Describe the structure of a tooth.
Each is formed chiefly of
Dentine, or iron/, composed of minute,
wavy, branching tubes, called dental tubuli,
embedded in a hard, homogeneous substance,
the intertubular tüsue. The tubules are
about j55¡;th of an inch in diameter, divid¬
ing dichotomously, giving the wavy appear¬
ance of the cut surface, and open into the pulp cavity. Chemically
dentine consists of twenty-eight parts of animal, and seventy-two
of earthy matter.
EnameD forms a thin crust over crown, is the densest of all
animal tissues, containing only 3.5 per cent, of animal matter, and
is composed of minute parallel hexagonal rods, about of an
inch in diameter, pursuing a wavy course.
Cement, or crustapetrosa*, is a layer of true bone commencing at
the neck and becoming thicker toward apex of fang.
Pulp, filling the pulp-cavity consisting of soft, very vascular
connective tissue, with numerous nerves and cells, the latter being
THE TEETH.
219
of two kinds, columnar, called odontoblasts—arranged in a layer
lining pulp-cavity—and fusiform cells wedged in between these
or permeating the pulp, both having fine processes, said to be pro¬
longed into the dentinal tubules.
Whence do the teeth obtain their blood and nerve supply?
From the alveolar and infraorbital branches of internal maxil¬
lary, and from inferior dental artery ; the nerves come from the
anterior and posterior dental branches of the superior maxillary,
and from the inferior maxillary division of the fifth nerve
When do the temporary teeth appear ?
The time is variable, but, according to the latest authority, they
erupt as follows, expressed in months :
m
a
S
a
"o
a
p
S
a
Ü
a
M
a
a
0.
M
Ü
Upper. . . .
20-30
12-15
18-24
8-10
8-10
8-10
8-10
18-24
12-15
Lower
20-30
12-15
18-24
12-15
■4-7
4-7
12-15
18-24
12-15
The order of their appearance is first, lower central incisors;
then upper central incisors, closely followed by laterals; then
lower laterals ; next upper anterior molars followed by lower ; then
upper canines followed by lower; finally, lower back molars, fol¬
lowed by upper.
Describe the order of appearance of the permanent teeth.
The first to appear are first molars at end of sixth year, the
lower teeth usually preceding the upper; thus, expressed in years,
these teeth erupt as follows :
Upper n-21
Lower 17-21
12-1.5 10
12-13 01/ 10
9 11-12 8 7 7 8 11-12! 9 10 0'12-13 17-21
11 I i ■ ■
9 |11-12, 8 7 7 8 11-12! 9 10 0^ . 12-13 17-21
220
ESSENTIALS OP HUMAN ANATOMY.
Describe the development of the teeth.
About the seventh foetal week appears a depression in each jaw,
the primitive dental groove, from the bottom of which is developed
a ridge which, atrophying at intervals, leaves a row of projecting
papillae, containing odontoblasts, which become capped with epithe¬
lial masses developed from the margins and sides of the groove,
the enamel organ. Now the groove becomes converted into folli¬
cles, each containing a papilla, hy contraction and projection of its
margins and the ingrowth of membranous septae.
About the thirteenth week the papillae grow rapidly, the follicles
deepen and become closed in hy the coalescence of from two to
five small membranous outgrowths springing from their margins,
called opercula. The lips of the dental groove advance and fuse,
completing the saccular stage about the end of the fifteenth week.
The more superficial portion of the groove remains open, leaving
the secondary dental groove, in which ten lunated depressions appear
behind each of the sacs of the milk teeth, for the ten anterior
permanent teeth; the secondary groove closes in like the primary
one, the follicles becoming cavities of reserve, into which papillae
grow to he closed in as for the temporary teeth ; the remaining
teeth arise from successive expansions backward of the primitive
dental groove. The dentine forms from without inward capped
with enamel, and by the gradual growth of the fang the crown
produces absorption hy pressure upon the overlying hone and
mucous membrane, when eruption occurs ; the cementum is formed
by the periodontal membrane last of all, increasing up to old aige.
The Mouth.
What is the mouth?
It is an ovoid cavity in which food is masticated, hounded hy
lips in front, by cheeks and alveolar processes of both jaws with
their contained teeth at sides, hy hard and soft palate above, hy
tongue and floor of mouth below, and terminates at the anterior
pillars of the fauces where it opens into pharynx hy fauces, and is
lined hy mucous membrane covered by scaly stratified epithelium
containing numerous racemose glands, continuous with external
skin ; it presents for examination
THE MOUTH.
221
The hard palate, formed by palatal processes of superior maxil¬
lary and palate bones covered by the intimately adherent peri¬
osteum and mucous membrane.
Soft palate, consisting of a fold of mucous membrane depending
from posterior border of hard palate, enclosing muscular tissue,
an aponeurosis, adenoid tissue, mucous glands, etc. ; the muscles
on each side heing the levator and tensor palati, palato-glossus,
palato-pharyngeus, and azygos uvulae—the latter with fellow
forming the median projecting conical uvula.
Anterior and posterior pillars of the fauces, the former contain¬
ing within a fold of mucous membrane the palato-glossus muscle
on each side, arching downward and forward from palate to base
of tongue; the latter, the palato-pharyngei muscles, passing back¬
ward and downward to sides of pharynx.
Isthmus faucium, bounded by pillars of fauces, base of tongue,
and free margin of soft palate.
Tonsils' (Fig. 83), situated between anterior and posterior pillars
on each side, consisting of glandular tissue containing twelve to
fifteen openings leading into crypts lined with mucous membrane,
external to which is a layer of closed capsules analogous to those
of Peyer's glands ; the tonsil is only separated from the internal
carotid artery hy superior constrictor muscle.
Openings of ducts of Steno, opposite second upper molar tooth on
each side, delivering the secretion of parotid glands.
Openings of ducts of Wharton, one on either side of fraenum of
tongue, delivering secretion of submaxillary glands.
Openings of ducts of sublingual gland [ducts of Ririnus), from
eight to twenty in number, they open on an elevated crest of mucous
membrane on each side of fraenum linguae, one or more joining in
a tube opening into Wharton's duct called the duct of Bartholine.
What are the salivary glands ?
Three compound racemose glands on each side. The parotid,
the largest, lies below and in front of ear between zygoma above,
mastoid behind, and ramus of jaw in front—its duct is Stenson's-,
the submaxillary lies below jaw in anterior part of submaxillary
triangle—its duct is Wharton's ; the sublingual lies beneath mucous
222 ESSENTIALS OF HUMAN ANATOMY.
membrane of floor of mouth against jaw, close to symphysis—its
ducts are those of Rivinua.
Describe the tongue.
Its base is attached to hyoid bone by muscles, to epiglottis by
the two lateral and one median' glosso epiglottidean fold of
Fto 83.
mucous membrane, and to soft palate by anterior pillars ; its tip,
sides, dorsum, and part of under surface are free ; a median raphé
THE MOUTH.
223
and fibrous septum divide tbe organ into halves ; its mucous mem¬
brane reflected over floor of mouth to gums forms in front an an-
tero-posterior fold, the frœnum linguœ ; the tongue is formed by
certain intrinsic muscular fibres, viz., those of lingualis, and by ex¬
trinsic muscles, the stylo-glossus, hyo-glossus, genio-hyo-glossus,
and palato-glossus (see p. 121). The mucous membrane of tongue
presents the
Oircumvallate papillce, numbering eight to ten, arranged on back
part of dorsum in two lines converging behind like a letter V,
presenting at their junction a deep mucous follicle, the foramen
cceeum^.
Fungiform papillcF, scattered over dorsum, but chiefly found at
sides and apex.
FiliformpapillcF, with secondary papillae projecting from apices,
arranged in lines, cover the anterior two-thirds of dorsum of
tongue.
Racemose glands^, situated along sides beneath tip, but chiefly
over posterior third of dorsum.
Lymphoid tissue, collected into masses or follicles, some resem¬
bling crypts of tonsil.
Describe the blood supply.
This is from,
ÍDorsalis linguœ. Facial, by submental branch anas-
Sublinguul, tomosing with sublingual.
Ranine,
Ascending pharyngeal.
Describe the nerve supply.
The gustatory branch of fifth is distributed to papillae at front
and sides, which endows these parts with general sensibility ; and
also by its connection with the chorda tympani becomes the nerve
of taste.
Lingual branch of the glosso-pharyngeal, supplying mucous mem¬
brane of base and sides and circumvallate papillae ; it is the nerve
of taste for these parts.
Hypoglossal, to muscles ; the motor nerve.
Superior laryngeal, sends a few filaments to base from its internal
branch.
224 ESSENTIALS OF HUMAN ANATOMY.
What two anatomical points of surgical interest does the
palate present in the neighborhood of the last molar
tooth ?
Just behind this tooth the hamular process and internal pterygoid
plate can be felt, the point .for division of tensor palati aponeurosis
in the operation for cleft palate, and in front of this to inner side
of last molar tooth is ihQ posterior palatine artery as it emerges from
the canal, sometimes requiring plugging after a cleft-palate
operation.
The Pharynx.
What is the pharynx ?
A conical musculo-membranous sac, about four and a half inches
long, extending from under surface of base of skull to a point cor¬
responding to the cricoid cartilage in front, and the fifth cervical
vertebra behind. It is widest opposite cornua of hyoid bone,
narrowest below, where it terminates in the oesophagus; it is
bounded above by basilar process of occiput, is connected posteri¬
orly with the cervical vertebrae and longus colli and recti capitis
antici muscles ; anteriorly it is incomplete, opening into the mouth,
being attached to internal pterygoid process, pterygo-maxillary
ligament, lower jaw, tongue, hyoid bone and larynx ; laterally, it is
attached to styloid processes and muscles arising from them, while
the common and internal carotid arteries, the internal jugular veins,
and eighth, ninth, and sympathetic nerves here lie in contact
with it.
How many openings communicate with it ?
Seven : the two posterior nares, two Eustachian tubes, mouth,
larynx, and oesophagus.
Of how many coats does it consist ?
Three : an internal mucous, continuous with lining of mouth, etc.,
covered with ciliated epithelium down to the level of floor of
nares, below by squamous epithelium, containing racemose glands
most plentiful around orifices of Eustachian tubes, and much
lymphoid tissue surrounding crypts like those of tonsil ; a middle
THE PHARYNX. 225
fibrous coat {pharyngeal aponeurosis), thick above, where the mus¬
cular fibres are wanting ; and an external muscular coat composed
of the superior, middle, and inferior constrictors, stylo-pharyngeus,
and palato-pharyngeus muscles.
Describe the pharyngeal muscles.
Inferior constrictor'^ : origin, side of cricoid and thyroid cartilages ;
insertion, posterior median raphé ; action, constricts pharynx during
swallowing; nerves, pharyngeal plexus,
glosso-pharyngeal, external laryngeal,
recurrent laryngeal.
Middle constrictor^ : origin, greater and
lesser cornua of hyoid bone and stylo¬
hyoid ligament; insertion, posterior
median raphé ; action, same as superior
constrictor ; nerves, glosso-pharyngeal,
pharyngeal plexus.
Superior constrictor'" : origin, lower third
of margin of internal pterygoid plate
and hamular process, contiguous surface
of palate bone, reflected tendon of tensor
palati muscle, pterygo-maxillary liga¬
ment, alveolar process above posterior
end of mylo-hyoid ridge and side of
tongue ; insertion, posterior median raphé
and pharyngeal spine of occipital bone; action, same as other
constrictors; nerves, glosso-pharyngeal plexus.
Stylo-pharyngeus": origin, inner side of base of styloid process;
insertion, blends with constrictor muscles, and is also inserted into
the posterior border of thyroid cartilage; action, draws sides of
pharynx upward and outward; nerves, glosso-pharyngeal, pharyn¬
geal plexus, the former running on outer side, and crossing muscle
to reach tongue.
What is the pharyngeal tonsil ?
A considerable mass of lymphoid tissue extending across back
of pharynx, between the orifices of the Eustachian tubes.
15
Fig. 84.
226 ESSENTIALS OF HUMAN ANATOMY.
What arteries supply the pharynx ?
Superior thyroid, Pierygo-palatine,
Ascending pharyngeal. Descending palatine, to
epiglottis, etc.
What are its nerves ?
Branches from pharyngeal plexus, formed by pharyngeal
branches of glosso-pharyngeal, pneumogastric, superior laryngeal,
and sympathetic nerves.
The Œsophagus.
Describe it.
It is a muscular canal, about nine inches long, joining the
pharynx and the stomach, commencing at lower border of cricoid
cartilage, passing through the œsophageal opening of the dia¬
phragm, to terminate at cardiac orifice of the stomach, opposite
the ninth dorsal vertebra ; in the neck it lies between trachea and
spinal column and longus colli muscle, at lower part inclining to
the left, having on either side the common carotid artery, with
lateral lobes of thyroid gland—the recurrent laryngeal nerves
ascend between it and trachea ; in the thorax, while a little to the
left at first, after passing behind aortic arch, it runs to right of the
vessel, to pass in front and to the left again before piercing the
diaphragm.
What coats has it ?
It has three : an internal mucous, when empty thrown into longi¬
tudinal folds, containing numerous racemose glands, its surface is
studded with small papillae, and it is covered by a thick layer of
squamous epithelium ; a middle cellular, loosely connecting the
mucous and the succeeding' coat ; a muscular, composed of an ex¬
ternal longitudinal and internal circular layer, the fibres above con¬
sisting chiefly of the striated, but helow almost entirely of the
unstriped involuntary variety.
Name its arteries and nerves.
Arteries, chiefly from thoracic aorta.
Veins, are drained by vena a^ygos minor.
THE STOMACH.
227
Nerves, from oesophageal plexus, formed by pneumogastrics with
some sympathetic filaments.
The Stomach.
Describe it.
The stomach is irregularly conical, curved upon itself, present¬
ing a round base turned to left side. Moderately distended, it
measures about twelve inches in its longest, and four inches in its
vertical diameter. It lies in left hypochondriac, epigastric, and
part of right hypochondriac regions, immediately behind anterior
wall of abdomen below the liver and diaphragm, and above the
colon ; it presents for examination the
Greater or splenic end, or fundus, situated to the left, being
attached to the spleen by gastro-splenic omentum, and to dia¬
phragm by gastro-phrenic ligament.
The lesser, or pyloric end, is in contact with abdominal wall and
under surface of liver near end of cartilage of eighth rib.
The oesophageal, or cardiac orifice, is the highest point of the
stomach, is funnel-shaped, and communicates with œsophagus.
The pyloric orifice communicates with duodenum, the opening
being guarded by a reduplication of the mucous lining containing
numerous circular muscular fibres, forming a thick ring—this is
called the pyloric valve.
The lesser curvature extends along the upper border of organ
between the cardiac and pyloric orifices, is concave, and is con¬
nected with under surface of liver by the lesser omentum.
The greater curvature is convex, extends along lower border be¬
tween the two orifices, and gives attachment to great omentum.
How many coats has the stomach ?
Four, as follows : a
Serous, derived from peritoneum covering all parts except along
greater and lesser curvatures, where the omenta leave a triangular
space, along which pass the vessels and nerves; a
Muscular, consisting of three sets of fibres: longitudinal, con¬
tinuous with the longitudinal coat of œsophagus and small intes¬
tine, more distinct along the curvatures ; the circular fibres form a
continuous layer beneath the former set, most abundant at pyloric
228
ESSENTIALS OF HUMAN ANATOMY,
end, forming valve (supra) ; the oblique fibres, some passing obliquely
from left to right, others vice versá, around the cardiac orifice, to
which part they are chiefly limited; a
Mucous, covered with columnar epithelium, and thrown into
longitudinal folds or rugce when stomach is empty, covered by
small shallow polygonal-shaped alveoli from yj^th to yj^th of an
inch in diameter, into which the gastric follicles open.
Describe the gastric glands.
They are of three kinds, the
Peptic follicles, lined throughout with columnar epithelium, con¬
sisting of a duct into which open several caecal tubes, in which,
beneath the epithelium, lie large spheroidal, coarsely granular
peptic cells ; these glands are found in all parts of the stomach.
Mucous glands, found in greatest numbers at pyloric end, and
resemble the preceding, but are without the large peptic cells, and
the caecal tubes are longer.
Lenticular, or simple solitary, found especially in early life, consist¬
ing of masses of lymphoid tissue.
Give the blood and nerve supply.
The arteries are, gastric^^, pyloric and right gastro-epiphic^''
branches of the hepatic artery^*.
Fig. 85.
THE SMALL INTESTINE.
229
The veins empty into splenic and portal veins.
The nerves are terminal branches of both pneumogastrics and
numerous branches from sympathetic.
The Small Intestine.
Describe it.
It is the narrowest part of the digestive tract, is a convoluted
tube some twenty feet long, occupying the central and lower parts
of the abdominal and pelvic cavi¬
ties, and is suspended from the Fio. 86.
spine by a fold of peritoneum fl
called the mesentery, its three di- í
visions are the V\\
Z>ModenM?n^ (Fig. 86), as long as
the breadth of twelve fingers, i.e.,
eight to ten inches, passing up- .ryaTiT'
ward and backward to the right
to under surface of liver, near
gall-bladder—ascending portion— FO
then descending in front of
right kidney—descending portion
—thence running transversely
across spine to end in thejejunum
on left side of second lumbar
vertebra—transverse portion—the
junction being crossed by superior
mesenteric artery; it is only
partially covered by peritoneum, f f
has no mesentery, and surrounds Ê /
the head of the pancreas; into ■"|
the descending portion, to the ^ f
innerside, pass obliquely the com- ^3
mon bile and pancreatic ducts.
Jejunum?, so-called because usually empty after death, includes
upper two-fifths of remainder of small intestine, and lies chiefly
in the umbilical region.
230
ESSENTIALS OF HUMAN ANATOMY.
Ileum*', includes remainder (three-fifths) of small intestine, is
named from its numerous coils, occupies chiefiy umbilical, hypo¬
gastric, right iliac, and occasionally pelvic regions, and opens into
the inner side of the commencement of the large intestine in the
right iliac fossa ; the orifice is guarded by a two-leaved valve (see
page 231).
What coats has the small intestine ?
The same as stomach.
The mucous membrane is covered with columnar epithelium,
and forms transverse folds encircling the tube for one-half to two-
thirds its circumference, forming the
Valvulœ conniventes-, they are absent in first two inches of duode¬
num and almost disappear in lower part of ileum ; villi cover the
surface, formed of a central lacteal vessel accompanied by un-
striped muscular tissue, an encircling plexus of capillaries, lym¬
phoid tissue and granular corpuscles, all enclosed by a basement
membrane supporting columnar epithelium: their number is esti¬
mated at four million ; the
Cellular coat connects mucous with muscular coat, and contains
the intestinal vessels ; the
Muscular coat, externally is composed of longitudinal and in¬
ternally of circular fibres, these not forming complete rings.
Describe the glands of the small intestine.
They are,
Bru/iiier's glands, resembling pancreas in structure, and are
limited to duodenum and commencement of jejunum.
Simple follicles or glands of Lieberkiihn, are minute tubular de¬
pressions lined with columnar epithelium.
Solitary glands, most numerous in lower part of ileum, but
found in all parts, and consist of masses of lymphoid tissue about
half a line to a line in diameter.
Peyer's glands or patches are twenty to thirty ovoidal patches
composed of numerous solitary glands (hence named agminaled
glands), situated opposite to mesenteric attachment, their long
axis lengthwise, and are largest and most numerous in ileum,
although occasionally seen in duodenum ; the valvulae conniventes
cease at their margins.
THE LARGE INTESTINE.
231
Name bloodvessels and nerves.
The arteries are from gastro-duodenal of hepatic and superior
mesenteric arteries; the veira-« chiefly empty into portal vein; nerves
are, from superior mesenteric plexus of sympathetic.
The Laxge Intestine.
Describe
It extends from ileum to anus, is about five feet long, is large
and sacculated, has the same coats as small intestine, the mucus
destitute of villi, but thrown into crescentic folds by the longi¬
tudinal muscular fibres which are disposed in three bands, shorter
than the other coats, so forming them into pouches.
Describe the subdivisions of tbe colon.
They are.
The cœcunv' or caput coli, the dilated commencement of the large
bowel situated in the right iliac fossa, and usually wholly covered
by peritoneum.
The appendix vermiformis, a narrow, blind-ended, worm-like
tube, from three to six inches long, springing from lower back
part of caecum, held, coiled upon itself, by a peritoneal fold.
The ileo-ccecal valve (or Bauhin's) is formed by two horizontal
semilunar folds of mucous membrane at the termination of ileum in
caecum, opening toward large intestine and guarding against re-
fiux from large into small bowel ; the mucous folds are reinforced
by circular muscular fibres, and the surfaces toward the ileum are
covered with villi, while these are absent on the caecal side.
The ascending colon' extends up from caecum in front of right
kidney, to under surface of liver to right of gall-bladder, where
abruptly bending to the left, it forms the hepatic flexure-, it is
almost—sometimes entirely—enveloped in peritoneum, in which
latter event it has an ascending meso-colon.
The transverse colorS traverses the abdomen from right to left,
just below liver, stomach, and spleen, to left hypochondriac region,
where it curves downward beneath lower end of spleen, forming
ihe splenic flexure-, it has a wide transverse meso-colon, attaching
it to the spine.
232 ESSENTIALS OF HUMAN ANATOMY.
The descending colon? passes down in front of left kidney to left
iliac fossa and is only partially covered with peritoneum, its pos¬
terior surface usually being free.
The sigmoid flexure^", the narrowest part, lies in left iliac fossa
extending from descending colon at crest of ilium to left sacro¬
iliac symphysis ; it is curved like an S, and is held in place by a
loose peritoneal fold, the sigmoid meso-colon.
The rectum}'^ extends from left sacro-iliac symphysis to anus, is
from six to eight inches long, curves slightly to right and then
adapts itself to sacral curve, and near top of coccyx inclines back¬
ward to anus; it is non sacculated, but just above anus presents a
considerable dilatation ; it is only covered with peritoneum at its
anterior portion—except above—while its lower inch and a half is
destitute of any such covering ; the longitudinal muscular fibres
form a continuous layer around the rectum.
What are the appendices epiploicae ?
They are little peritoneal pouches filled with fat placed along
colon and upper part of rectum.
What guards the anal orifice ?
The sphincter ani and internal sphincter; a third has been
described as some three inches up the bowel (see page 331
What are the folds of Houston?
Three semilunar folds of mucous membrane, one at upper right
side of rectum, one at left middle portion, and one projecting from
front of rectum opposite bladder.
Name the glands of the large intestine.
Follicles of Lieberkuhn and solitarxj glands.
Give the blood- and nerve-supply of the large intestine
and rectum.
The arteries are branches of the superior and inferior mesenteric,
the middle hemorrhoidal from the internal iliac, and the inferior
hemorrhoidal from internal pudic.
The nerves come from sympathetic plexuses around mesenteric
arteries, and, in case of rectum, the fourth anterior sacral nerve
supplies the sphincter muscle.
THE LIVER.
233
The Liver.
Describe it.
It occupies the right hypochondriac region extending across the
epigastrium into the left hypochondriac. It is the largest gland in
the body, weighing from three to four pounds, its transverse diam¬
eter is from ten to twelve inches, its antero-posterior six to seven,
its thickest part behind three inches. Covered by peritoneum,
except at attachments of ligaments and bottom of fissures, it
possesses a fibrous coat, covering the whole organ continuous with
the capsule of Glisson at transverse fissure ; there are five fissures,
five lobes, five ligaments, and five sets of vessels; the
Upper surface is convex, smooth, lying in contact with dia¬
phragm above, and below with a small portion of abdominal
wall ; it is divided into two unequal lobes by a peritoneal fold, the
suspensory ligament ; the
Under surface is concave, is in relation with stomach, duodenum.
Fig. 87.
hepatic flexure of colon, right kidney, and suprarenal capsule,
and is divided by a longitudinal fissure ®,') into a right and left
lobe; the
Anterior border* is thin, sharp, and deeply notched at site of
234
ESSENTIALS OF HUMAN ANATOMY.
round ligament; it corresponds usually with margins of ribs in
males, projecting a little lower in women and children ; the
Posterior border^ is rounded and grooved, or even perforated, by
inferior vena cava.
Describe the ligaments.
They are five in number, four being composed of folds of peri¬
toneum, the fifth is the obliterated umbilical vein ; the
Suspensory or broad ligament^^ (falciform) is a falciform antero¬
posterior peritoneal fold, with apex backward, attached to liver
from notch on ánterior border to posterior border,—its anterior
free edge enveloping the round ligament—and to diaphragm and
sheath of right rectus muscle as low as umbilicus ; the
Coronary ligaments consist of two layers reflected from diaphragm
on upper and lower margins of posterior border of organ, between
which firm areolar tissue binds the liver to diaphragm ; the
Lateral ligaments, right and left, triangular, are formed of two
layers of peritoneum extending from sides of diaphragm to ad¬
jacent margins of posterior border of liver ; the
Bound ligamenfP, a fibrous cord, ascends from umbilicus in an¬
terior free margin of broad ligament to longitudinal fissure, trace¬
able back to vena cava, the back portion, the remains of ductus
venosus, the anterior of umbilical vein.
Describe the fissures.
They are five in number, dividing the under surface of the
organ into five lobes; the
Longitudinal fissurà,^, extends from notch on anterior border to
posterior border, separating right and left lobes, and is joined by the
transverse fissure^" at posterior third ; the anterior two-thirds of the
longitudinal fissure is called the umbilical fissure from lodging fœtal
umbilical vein, the posterior third the fissure of the ductus venosus
lodging the obliterated fœtal vessel ; the anterior part of the former
is often partially bridged over by the pons hepaticus ; the
Transverse fissurd" is about two inches long, passing transversely
across under surface of right lobe from junction of posterior and
middle thirds of longitudinal fissure ; here enter the portal vein,
hepatic artery, and nerves, and the bile ducts and lymphatics
emerge; the
THE LIVER.
235
Fissure of the gall-bladder^*' lies parallel and to right of longi¬
tudinal fissure reaching back nearly to transverse fissure ; the
Fissure for vena cava is short and deep, sometimes converted
into a canal, extending obliquely upward from a little behind
right extremity of transverse fissure to posterior border of liver,
there joining the fissure of ductus venosus ; the hepatic veins here
empty into vena cava.
Describe the lobes of the liver.
They are five in number ; the
Right lobe^, the largest, of a quadrilateral form, its under surface
marked by three fissures : viz., transverse, for gall-bladder, and
for inferior cava, and by an anterior depression for colon, a pos¬
terior one for right kidney; the longitudinal fissure forms the
division between this and the
Left lobe*, smaller and flattened, resting by its anterior concave
surface on stomach ; the
Lobus quadratus^ is marked off from under surface of right
lobe by transverse fissure behind, by that for the gall bladder on
the right, and anterior part of longitudinal fissure on left; the
Lobus Spigeli^ projects from back under surface of right lobe,
bounded in front by transverse fissure, on right by that for cava,
and on left by posterior third of longitudinal fissure ; the
Lobus caudatus' is a small elevation running obliquely outward
from base of lobus Spigelii to under surface of right lobe ; it inter¬
venes between rigbt end of transverse fissure and commencement
of that for vena cava.
Describe tbe vessels of the liver.
They number five, viz., hepatic artery, portal vein, hepatic vein,
hepatic duct, and the lymphatics ; the first three are enveloped in
loose areolar tissue called capsule of Glisson, which accompanies
the vessels through ihQportal canals in the interior of the organ;
the
Portal vein**, about four inches long, is formed by the junction of
superior mesenteric and splenic veins, the latter receiving the
blood returned by inferior mesenteric vein, while the gastric veins
empty into the portal vein itself. Entering the transverse fissure it
divides into branches for right and left lobe, which receive the
236 ESSEXTIALS OF HUMAN ANATOMY.
vaginal and capsular veins, and subdividing form interlobular veins^
(Fig. 88), which send branches to interior of each lobule forming
a plexus converging to empty into the central intra-lobnlar vein^
running at right angles to other vessels; the intra-lobular vein
empties into a sublobular vein, a radicle of hepatic vein ; the
Hepatic veim^^ (Fig. 87) commence in sublobular veins as just
described, which unite to form three large and several smaller
branches terminating in inferior vena cava in fissure for that
vessel; the
Fio. 88.
Hepatic arterif^ springs from cceliac axis, enters transverse
fissure, and divides into branches which ramify in the capsule of
THE LIVER.
237
Glisson—vaginal, supplying nutriment to vessels, ducts, etc., cap-
miar to terminate in external fibrous coat—and ends in a plexus
on outer surface of each lobule formed by ultimate branches of
portal vein, the interlobular plexus above described ; the
Hepatic ¿Mcí ®bove 13 ¡g formed by the union of two trunks of
nearly equal size which emerge from the transverse fissure, one
from the right and other from left lobe ; it passes downward to the
right for one inch and a half to be joined by the cystic duct from
the gall-bladder, to form the ductus communis choledochus (see
p. 238) ; the
Lymphatics accompany bloodvessels, and consist of a deep and
superficial set.
Whence do the nerves of the liver come ?
From the hepatic plexus of the sympathetic, from the pneumo-
gastric nerves, especially the left, and right phrenic.
Describe the liver structure.
It is composed of numerous lobules from one-twentieth to one-
tenth of an inch in diameter, of irregular form in human liver,
polygonal in pigs, their bases clustered round the sublobular vein,
to which each is connected by its intralobular vein ; the lobules
are bound together by loose areolar tissue; each lobule is formed
of hepatic cells, spheroidal or many-sided nucleolo-nucleated cells,
measuring from one-one thousandth to one-two thousandths of an
inch, containing granular yellow coloring matter and globules,
which cells lie in the meshes of the dense capillary network
occupying its interior, spaces between the cells forming inter¬
cellular biliary passaged, the radicles of the bile ducts.
What is the capsule of Glissou ?
The areolar tissue entering the transverse fissure, surrounding
the hepatic vessels to their ultimate ramifications, and continuous
with fibrous coat of organ.
How may the portal he distinguished from the hepatic
veins in a liver section ?
The portal veins are collapsed, being surrounded by the capsule
of Glisson, while the hepatic are patulous, being closely connected
with liver substance.
238
ESSENTIALS OF HUMAN ANATOMY.
Describe the gall-bladder'*.
It is a pear-shaped, fibro-muscular receptacle for the bile ; its
fundus and under surface of body and neck covered by peritoneum,
while its interior is lined with a cylindrical-celled, epithelial-
coated mucous membrane, presenting a honeycombed appearance
from the confluence of numerous minute rugae; its length is from
three to four inches, its capacity from eight to twelve fluidrachms,
and it lies in a fissure on the under surface of liver, its fundus—
most dilated portion—projecting slightly beyond the anterior border,
touching abdominal wall just below ninth costal cartilage; the
narrow neck curves upon itself like an italic f, to terminate in the
cystic duct, which is about one inch long, and is lined by mucous
membrane so disposed in a series of crescentic folds as to present
the appearance of a spiral valve-, it joins the hepatic duct to form
the common bile-duct.
Describe the ductus communis choledochus'® (Fig. 87).
It is about three inches long, three-sixteenths of an inch in
diameter, and is formed by the junction of the hepatic and cystic
ducts ; it opens usually by a common orifice with the pancreatic
duct, a little below the middle of inner side of descending portion
of duodenum ; its walls are composed of fibrous with a little mus¬
cular tissue, its mucous membrane is covered with columnar epithe¬
lium, and it runs between the layers of gastro-hepatic process of
the peritoneum.
The Pancreas.
Describe the pancreas® (Fig. 85).
It is a compound racemose gland, from six to eight inches long,
by one and one-half inches at its widest, part, lying behind the
stomach and in front of the first lumbar vertebra. It is composed
of lobules connected by areolar tissue, each lobule consisting of
an ultimate branch of the duct lined with columnar epithelium,
terminating in caecal pouches or acini, also lined with cylindrical
epithelium, outside of which is a fine capillary network. -The
Fancreaiic duct {canal of Wirsung) extends the whole length of
THE SPLEEN.
239
gland and opens into middle of descending part of duodenum, to
the inner side, with common bile-duct ; its
Head or right extremity is embraced by the concavity of the
duodenum, the common bile-duct lying behind, the pancreatico¬
duodenal artery in front ; the
Tail or left extremity reaches spleen above left kidney and supra¬
renal body ; tbe
Body is covered by the ascending layer of transverse meso-colon
and posterior surface of stomach ; posteriorly, the superior mesen¬
teric artery and vein, the portal vein, the vena cava, and the aorta
separate it from the first lumbar vertebra.
The arteries'® (Fig. 85) are derived from the splenic, pan¬
creático duodenal branch of hepatic and superior mesenteric
arteries.
The veins empty into splenie and superior mesenteric veins.
The nerves come from the splenic plexus of the sympathetic.
What is the lesser pancreas ?
A lobular fold, passing transversely to the left behind the supe¬
rior mesenteric vessels, which is sometimes detached from the
glajid when it may open into duodenum by a separate duct an
inch or more above the pancreatic duct.
The Ductless Glands.
What are the ductless glands ?
The spleen, suprarenal capsules, thyroid and thymus glands,
bodies whose functions are uncertain and whieh have no ducts.
The spleen and suprarenal capsules lie in the abdominal cavity,
but the others will be for convenience described after them.
The Spleen'" (Fig. 85).
Describe it.
It is a soft, brittle, very vascular, oblong, fiattened organ em¬
bracing the cardiac end of the stomach, to which it is attached by
the gastro-splenic fold of peritoneum, which latter membrane
completely invests the spleen, except where the gastro-splenic
240
ESSENTIALS OF HUMAN ANATOMY.
omentum and suspensory ligament are attached; the organ lies
deeply in the left hypochondriac region; the
Outer surface is convex, smooth, lying in contact with diaphragm,
which separates it from the ninth, tenth, and eleventh rihs ; the
Inner surface is concave, lies in contact with stomach, and
presents the
Hilum, a vertical fissure pierced at various points hy bloodvessels,
lymphatics, and nerves ; the
Anterior border is often notched, and the
Posterior border is rounded and in relation with left kidney ; the
Suspensory ligament, a peritoneal fold, connects it with the under
surface of diaphragm ; the
Fibro-elastic coat, beneath the serous (see above) which inti¬
mately adheres to it, forms the framework of the spleen, passing
inward at the hilum with the vessels as sheaths, from which, and
the inner surface of capsule, numerous hands or trabeculœ pass,
uniting to form numerous small spaces or areolae filled with the
splenic pulp.
Describe the spleen-pulp.
It is of a dark reddish-brown color, and nnder the microscope is
seen to consist of a network of branched connective-tissue cells,
containing pigment granules (broken-down blood corpuscles),
granular matter, nucleated cells, free nuclei, and red blood-cells
in all stages of disintegration ; the
Splenic artery'"' (Fig. 85) is large, tortuous, and divides at
hilum into five or six branches which do not anastomose to any
extent, each branch breaking up again and again into smaller
ones, until they terminate in bundles of straight vessels which
open into the interstices of the reticulum formed by the branched
connective-tissue cells.
What are the Malpighian bodies ?
Small, rounded, expanded masses of the lymphoid tissue of the
external coat of the small splenic arteries, from one-one hundredth
to one twenty-fifth of an inch in diameter, usually surrounding
the vessel, hut sometimes projecting from one side ; they are com¬
posed of a delicate reticulum packed with lymph corpuscles and
pervaded hy capillaries ; the
THE THYROID GLAND.
241
ßSplenic vein arises from the lacunar spaces in the pulp, and
empties into the portal vein ; the
Nerves are derived from the right pneumogastric nerve and the
right and left semilunar ganglia.
The Thyroid Gland.
Describe it.
It consists of two lateral lobes situated at the sides of the upper
portion of the trachea, connected about their lower thirds by a
narrow transverse portion, the isthmus, which is occasionally
absent. A third lobe, the pyramid, sometimes springs from the
left upper side of isthmus, or the left lobe, and extends to hyoid
hone ; it is at times detached ; occasionally a slender muscular
band—the levator glanduhz thyroideœ—extends from hyoid bone to
isthmus or the pyramid. Structurally, the gland consists of a
connective-tissue capsule, sending in septa subdividing the organ
into lobes, each of which is formed of numerous closed vesicles
filled with a viscid yellowish fluid embedded in connective tissue
containing a dense vascular plexus surrounding the vesicles.
What arteries supply this gland ?
The superior and inferior thyroid branches respectively of ex¬
ternal carotid and thyroid axis, and at times the middle thyroid, or
thyroideœ ima, springing either from the innominate artery or
aortic arch, itself to pass up on the front of the trachea. These
vessels are remarkable for their size and frequent anastomoses.
(For description of those vessels, see pages 159 and 161.)
Describe the veins of the thyroid gland
They form a plexus on the surface of the gland, whence arise the
Snperwr thyroid vein, | tying into internal jugular vein.
Middle thyroid vein, J
Inferior thyroid vein opening into innominate vein.
Name the nerves.
Branches of the pneumogastric nerves and of middle and inferior
cervical ganglia.
16
242
ESSENTIALS OF HUMAN ANATOMY.
The Thymus Gland.
Describe it.
This is a temporary organ of unknown function, reaching its
full development at the end of the second year, after which it
gradually atrophies, having nearly disappeared at puberty. When
fully developed it extends from fourth costal cartilage to lower
border of thyroid gland, consisting of two lateral lobes in close
contact along the middle line, while sometimes an intermediate lobe
exists; the sternum and origins of the sterno-hyoid and sterno¬
thyroid muscles cover it, as it lies in the neck behind these muscles
upon front and sides of trachea; it rests, in the mediastinum, upon
the pericardium, the thoracic fascia separating it from the aortic
arch and great vessels. Its dimensions are : length, two inches,
breadth, one and a half inches, thickness, three to four lines ; at
birth it weighs about half an ounce.
Describe its structure.
It is formed of numerous lobules bound together by delicate
areolar tissue, all being inclosed by a fibrous capsule ; the lobules
are composed of a cortical lymphoid tissue, and a medullary portion
containing a few lymphoid cells, but toward the centre granular
cells and concentric corpuscles exist. Each follicle is surrounded
with a capillary plexus.
Describe the arterial and nerve supply.
The arteries are derived from internal mammary, and superior
and inferior thyroid.
The veins empty into thyroid and left innominate veins.
The lymphatics arise in the substance of the gland, and are said
to empty into internal jugular vein.
The nerves are very minute, coming from pneumogastric and
sympathetic.
The Suprarenal Capsules.
What are they ?
Two triangular or semilunar flattened bodies, situated behind
peritoneum, immediately in front of upper part of each kidney.
THE ABDOMINAL CAVITY.
243
They consist of a thin, closely adherent fibrom capsule, which sends
numerous communicating partitions inward, a cortical and medul¬
lary portion, the former containing groups of finely granular poly¬
hedral cells, with a channel between them and the fibrous portions,
believed to be a lymph sinus ; the medullary portion is formed of
stout connective-tissue bundles, between which lie coarsely granu¬
lar columnar and branched cells, which have been thought to com¬
municate with the nerve fibres of the very fine plexus found in the
medulla.
What parts do these organs lie in contact with ?
The lower concave border rests upon upper end of kidney ; their
anterior surfaces touch respectively the under surface of liver,
pancreas, and spleen; their posterior surfaces lie upon crura of
diaphragm, opposite tenth dorsal vertebra, and their inner margin
is related to the great splanchnic nerves and semilunar ganglia, on
the right side touching vena cava, on left aorta.
Name its vessels and nerves.
The arteries are the suprarenal and branches of inferior phrenic
and renal arteries forming a dense capillary network in its inte¬
rior; the
Veins return blood from the medullary venous plexus by supra¬
renal veins into inferior vena cava on right side, and on left into
renal vein ; the
Nerves are very numerous, chiefly distributed to medulla, and are
derived from solar and renal plexuses and phrenic and pneumo-
gastric nerves, having developed upon them numerous small
ganglia, whence the opinion held by some that these bodies belong
to the sympathetic nervous system.
The Abdominal Cavity.
What is the abdomen ?
An ovoidal cavity, limited above by the thorax, below by the
brim of pelvis ; in front and at sides, by lower ribs, abdominal
muscles, and venter ilii ; behind, by spine, psoas, and quadratus
lumborum muscles ; it is lined with peritoneum—a serous mem-
244
ESSENTIALS OF HUMAN ANATOMY.
brane—which is reflected to form partial or complete investments
for the contained organs or viscera.
Name the abdominal viscera.
Stomach,
Liver,
Spleen,
Kidneys,
Bladder (when full),
Uterus (during pregnancy),
Receptaculum chyli.
Describe the openings in its walls.
They are the
Umbilical, for fœtal umbilical vessels, obliterated after birth,
leaving a depression, the umbilicus.
Opening for inferior vena cava, in diaphragm.
Aortic opening, behind diaphragm between crura, for aorta, vena
azygos major, thoracic duct, and sometimes left sympathetic nerve.
(Esophageal opening, in diaphragm for oesophagus and pneumo-
gastric nerves.
Internal abdominal ring, on each side, for spermatic cord in male,
round ligament in female.
Femoral, or crural ring, on each side, below Poupart's ligament,
for femoral vessels.
Into what regions is the abdomen artificially divided ?
Into nine, by two imaginary parallel lines encircling the body
on a level with ninth costal cartilages and summits of iliac crests,
and two other parallel lines drawn from the cartilage of the eighth
rib on each side to the centre of Poupart's ligament.
What are these regions named, and what does each con¬
tain?
The right lateral are, from above downward (see cut), the
Right hypochondriac, which contains right lobe of liver, gall¬
bladder, hepatic flexure of colon, upper part of right kidney, and
part of right suprarenal capsule.
Intestines,
Gall-bladder,
Pancreas,
Suprarenal capsules.
Abdominal aorta.
Inferior vena cava.
Thoracic duct.
THE ABDOMINAL CAVITY.
245
Right lurnhar, contains ascending colon, lower part of right
kidney, and some coils of small intestine.
Fig. 89.
Right inguinal {iliac), contains caecum and appendix vermiformis,
ureter, spermatic vessels.
The median regions are, from above downward (see cut) ; the
Epigastric, contains middle and pyloric end of stomach, left lobe
of liver, lobulus Spigelii, pancreas, duodenum, parts of kidneys
and suprarenal capsules, aorta and branches, vena cava, semilunar
ganglia, thoracic duct.
Umbilical, contains transverse colon, part of great omentum and
mesentery, transverse portion of duodenum, and some coils of
jejunum and ileum, part of both kidneys, and the receptaculum
chyli.
246 ESSENTIALS OF HUMAN ANATOMY.
Hypogastric, contains coils of small intestine, the bladder in
children, or when distended in adults, and the uterus during
latter six months of pregnancy, often caecum, appendix vermi¬
formis, and sigmoid flexure of colon.
Left lateral regions from above downward (see cut) are,
Left hypochondriac, contains splenic end of stomach, spleen, and
tail of pancreas, splenic flexure of colon, upper half of left kidney,
and part of left suprarenal capsule.
Left lumbar, contains descending colon, part of omentum, lower
part of left kidney, and some coils of small intestine.
Left inguinal (iliac), contains sigmoid flexure of colon, ureter,
spermatic vessels.
The Peritoneum.
Describe it.
A serous membrane forming a closed sac (in male), the layer
covering the walls being called the parietal, that reflected over
the viscera, the visceral layer ; it is coated with a layer of flattened
endothelium, its attached surface heing connected with subjacent
parts by the subperitoneal areolar tissue or fascia.
Does the peritoneum always form a closed sac ?
No; in the female the Fallopian tubes open into its cavity.
How is the peritoneum divided for convenience of descrip¬
tion?
Into the greater sac^^, or that covering upper anterior portion of
liveF, the stomach® behind and above, descending to ileum forming
the anterior layer of great omentum'®, the under surface of meso¬
colon"®, the mesentery"', and reflections"® upon and between the
rectum", uterus in female"", and bladder", then lining the antero¬
lateral abdominal walls to reach, from the under surface of dia¬
phragm", the upper surface of liver, the starting-point of this
description (see Fig. 90).
The lesser sac, or cavity of the great omentum^*, starting from
diaphragm behind, this layer passes over back of liver'®, then
THE PERITONEUM.
247
covers back and under side of stomach®, forms the inner layer of
great omentum'®, passes over colon' completing meso-colon'°, and
thence passes over duodenum® and pancreas'® to line the posterior
abdominal wall, reaching the point
started from; the two cavities com¬
municate through the foramen of
Winslow.
Describe the foramen of Wins-
low" (Fig. 90).
It is an opening at the con¬
stricted portion of peritoneum
where it curves around the hepatic
vessels.
Does this foramen transmit
anything ?
No; it is merely the orifice of
communication between the two
sacs.
What are the omenta ?
Three folds of peritoneum, viz.,
the
Gastro-hepatic, or lesser omentum}^, extending between the trans¬
verse fissure of liver and lesser curvature of stomach, consisting of
two layers, the anterior pertaining to the greater, the posterior to
the lesser sac, which enfold at the right free border the hepatic
artery, common bile-duct, portal vein, lymphatics, and hepatic nerve
plexus.
The great, or gastro-colic omentum}^, is formed of four layers, two
descending, one from the anterior, the other from posterior wall of
stomach, and uniting below to pass as low as pelvis, when they
ascend to transverse colon, separate and embrace this part of
the bowel; the
Gastro-splenic omentum is the fold connecting spleen with
stomach, contains the splenic vessels and vasa brevia, and is con¬
tinuous below with the great omentum.
248
ESSENTIALS OF HUMAN ANATOMY.
What are the mesenteries ?
Double layers of peritoneum embracing various portions of in¬
testinal tube (except duodenum), which they suspend from poste¬
rior abdominal walls ; between the folds run the vessels of the
part suspended. They are called, the
Mesentery"^, meso-cœcum, meso-color^", meso-rectum.
What other name is given to suspensory folds of perito¬
neum?
Ligaments, such as,
The gastro-phrenic, slinging stomach from diaphragm.
The longitudinal, two lateral^'', and coronary ligaments of liver.
The vesical, five so-called false ligaments.
Two vesico-uterme'", two recto-uterine", two broad ligaments of
uterus.
Suspensory ligament of spleen connecting this organ with dia¬
phragm.
Mention the viscera wholly(') and partially(') covered with
peritoneum and those totally deficient(^) in such
investment.
(1) The spleen, small intestin^, caecum, transverse cohrd, sigmoid
flexure, ovaries, uterus, stomach" and liver^ practically, duodenum (first
part), rectumP^ (upper third).
(2) Duodenum" (descending Rectum (middle third"),
and transverse).
Ascending colon.
Descending colon.
Vagina" (upper part).
Bladder" (posterior surface).
(3) Rectum" (lower third).
Bladder" (base.
Pancreas",
Kidneys,
Suprarenal capsules.
anterior surface).
Vagina (lower portion).
THE LARYNX.
249
ORGANS OF VOICE AND RESPIRATION.
The Larynx.
What is the larynx^ (Fig. 92) ?
The voice-organ, formed of cartilages united by ligaments, the
segments enjoying movement upon one another, which is effected
by numerous muscles.
Mention the component cartilages.
They are nine in number, being the
Thyroid cartilage^, Two arytenoid cartilages,^
Oricoid cartilage'. Two cuneiform cartilages.
Epiglottis, Two cornicula laryngis.
Describe the thyroid (shield-like) cartilage.
It consists of two ake^, or lamellae, Tio. 91.
united at an acute angle in front, forming
a vertical ridge', whose more prominent
upper portion is called the pomum
Adami^, or Adam's apple ; the
Inner surfaces of the alae are smooth,
giving attachment in front, at the reced¬
ing angle formed by their junction, to
epiglottis, true and false vocal cords,
thyro-arytenoid and thyro-epiglottidean
muscles.
The outer surface affords attachment
along an oblique ridge to sterno-thyroid
and thyro-hyoid muscles, below and be¬
hind to inferior constrictor muscle.
The upper border presents a deep,
medium notch', and is slightly concave
on either side.
The lower border is connected medianly with cricoid cartilage
by crico-thyroid membrane, and on each side by crico-thyroid
muscle.
250 ESSENTIALS OF HUMAN ANATOMY.
The posterior borders are thick, rounded, and terminate above
and below on each side in cornua, the two superior^ having attached
to their apices the thyro-hyoid ligament, while the inferior^ articu¬
late internally by an oval facet with cricoid cartilage; to this
border are also attached the stylo-pharyngeus and palato-pharyn-
geus muscles.
Describe the cricoid (ring-like) cartilage.
It is placed with its narrow portion® in front, and has on each
side two articular facets, one on upper margin behind for arytenoid
cartilages, one externally, near lower margin for inferior cornu of
thyroid cartilage.
The upper border gives attachment in front and at sides to crico¬
thyroid membrane, at sides to lateral crico-arytenoid muscles.
The lower border is connected with first tracheal ring by a fibrous
membrane.
The posterior surface presents a median vertical ridge for attach¬
ment of longitudinal fibres of oesophagus, and on either side the
posterior crico-arytenoid muscles are attached.
Describe the two arytenoid (pitcher-like) cartilages'.
They are pyramidal in form, and are placed at the upper border
of cricoid cartilage at back of larynx ; the
Posterior surface of each affords attachment to arytenoideus
muscle; the
Anterior surface of each has attached the thyro-arytenoid muscle
and false vocal cord ; the
Internal surfaces face each other ; the
Base presents a concave, smooth, articular facet for cricoid carti¬
lage ; the
External angle has attached to it the posterior and lateral crico¬
arytenoid muscles ; the
Anterior angle has attached to it true vocal cord ; the
Apex articulates with a corniculum laryngis.
Describe the cornicula laryngis.
They are two small conical cartilaginous nodules surmounting
the apices of arytenoid cartilages afibrding attachment to aryteno-
epiglottidean folds.
THE LARYNX.
251
Describe the two cuneiform cartilages.
They are elongated cartilages contained in free borders of aryteno-
epiglottidean folds.
Describe the epiglottis.
It is a thin, leaf-shaped lamella of fibro-cartilage, attached by
apex to reëntering angle of thyroid cartilage just below median
notch; it lies at base of tongue, in front of upper opening of
larynx, and during deglutition shuts like a lid over laryngeal
orifice. Its
Base is free, rounded, curving forward toward base of tongue ;
the
Apex is attached to receding angle of thyroid by thyro-epiglottic
ligament; the
Anterior surface is covered with mucous membrane reflected on
to sides and base of tongue, forming the three glosso-epiglottidean
ligaments ; the
Posterior surface shuts down over laryngeal opening during deg¬
lutition; the
Lateral margins give attachment to aryteno-epiglottidean folds.
How are the ligaments of the larynx divided ?
Into extrinsic, or those connecting thyroid cartilage and epiglottis
with hyoid bone ; and intrinsic, those binding the various cartilages
together.
Name the extrinsic ligaments.
Thyro-hyoid membrane. Two lateral thyro-hyoid ligaments,
containing a small cartilaginous or bony nodule, the cartílago
tritícea ; Hyo-epiglottic.
Name the intrinsic ligaments.
Crico-thyroid membrane,
Two crico-thyroid capsular liga¬
ments,
Two crico-arijtenoid ligaments.
Two crico-arytenoid capsular
ligaments,
Two inferior thyro-arytenoid liga¬
ments,
Hyo-epiglottic ligament,
Thyro-epiglottic ligament.
Three glosso-epiglottic folds.
Two superior thyro-arytenoid
ligaments.
252
ESSENTIALS OF HUMAN ANATOMY.
What are the vocal cords ?
The superior or false vocal cords, on each side, are two folds of
mucous membrane enclosing the superior thyro-arytenoid ligaments
composed of elastic tissue, stretching between angle of thyroid
cartilage below epiglottis and anterior surfaces of arytenoid carti¬
lages; the lower margin forms the upper free crescentic margin of
ventricle of larynx.
The true, or inferior vocal cords, are two strong, yellow elastic
fibrous tissue bands, the inferior thyro-arytenoid ligaments, covered
by thin, tightly adherent mucous membrane, which pass from the
receding angle of the thyroid to anterior angles of arytenoid carti¬
lages, the upper border forming the lower margin of ventricle of
larynx, the lower continuous with lateral portion of crico-thyroid
membrane; each has the thyro-arytenoid muscle lying parallel
externally ; these cords or membranes produce sound by their vibra¬
tions, the false cords do not, although indirectly influencing vocali¬
zation.
What is the glottis (rima glottidis) ?
It is the narrow triangular interval between the true vocal cords;
it measures, in males, somewhat less than an inch, by from one-
third to one-half inch at its base behind, when dilated.
Describe the ventricle of the larynx.
It consists of an oval depression or sinus on each side, between
the true and false vocal cords leading upward, external to superior
cord, into a caecal pouch, the sacculus laryngis.
Describe the sacculus laryngis.
It is a slightly curved conical membranous sac, situated between
tbe inner surface of thyroid cartilage and false vocal cords on each
side ; internally lined with mucous membrane, perforated by orifices
of ducts of sixty to seventy follicular glands lying in the submu¬
cous tissue; it is strengthened externally by a fibrous capsule con¬
tinuous below with superior thyro-arytenoid ligament, and has its
inner (laryngeal) surface covered by the inferior thyro-arytenoi-
deus, and its external by thyro-epiglottideus muscles, which com¬
press the sacculus, discharging the mucus upon, and for the lubri¬
cation of the vocal cords.
THE LARYNX.
253
What kind of epithelium has the mucous membrane ?
Above the false vocal cords squamous epithelium is found, except
in front, which is covered by ciliated columnar cells as high as
middle of epiglottis ; below the false cords, only ciliated columnar
epithelium is found.
Describe the muscles of the larynx and epiglottis.
Crico-thyroid'^ (2) (Fig. 92) : origin, triangular from antero-lateral
surface of cricoid cartilage ; insertion, lower border of thyroid and
anterior border of lower cornu ; action, increases tension of vocal
cords by tilting thyroid cartilage forward; nerve, superior laryngeal.
Crico-arytenoideus posticus (2) ; origin, lateral half of posterior
surface of cricoid ; insertion, outer angle of base of arytenoid carti¬
lage ; action, by rotating arytenoid cartilages outward it opens
glottis and tightens cords ; nerve, recurrent laryngeal.
Crico-arytenoideus lateralis [2): origin, upper border of side of
cricoid; insertion, outer angle of base of arytenoid; action, by
rotating arytenoids inward closes glottis ; nerve, recurrent laryngeal.
Thyro-arytenoideus (2): origin, lower half of receding angle of
thyroid and crico-thyroid membrane ; insertion, base and front sur¬
face of arytenoid cartilage ; action, advances arytenoid and cricoid
cartilages thus relaxing vocal cords, also compresses sacculus laryn¬
gis; nerve, recurrent laryngeal.
Arytenoideus {1): origin, back surface and outer border of one
arytenoid to be inserted at same part of other cartilage ; action, ap¬
proximates arytenoids closing back of glottis ; nerves, superior
and recurrent laryngeal.
Kerato-cricoideus : a small .muscular bundle ; origin, from near
lower border of cricoid cartilage ; insertion, inferior cornu of thy¬
roid cartilage ; action, possibly steadies one cartilage upon the
other, only occasionally found, and usually on one side.
Triticeo-glossus : origin, cartilage of same name in lateral thyro¬
hyoid ligament; insertion, tongue with hyo-glossus muscle; occurs
on one or both sides; action, unknown.
Describe the muscles of the epiglottis.
Thyro-epiglottideus : origin, inner surface of thyroid cartilage;
insertion, ary teuo-epiglottidean fold, margin of epiglottis, outer sur-
254
ESSENTIALS OF HUMAN ANATOMY.
face of sacculus laryngis ; action, depresses epiglottis ; nerve, recur¬
rent laryngeal.
Aryteno-epiglottideus superior ; origin, apex of arytenoid cartilage;
insertion, aryteno-epiglottidean folds ; action, narrows upper laryn¬
geal orifice ; nerve, recurrent laryngeal.
Aryteno-epiglottideus inferior : origin, arytenoid cartilage above
superior vocal cord; insertion, inner upper part of epiglottis;
action, compresses sacculus laryngis ; nerve, recurrent laryngeal.
Mention the arteries and veins of the larynx.
The arteries, are laryngeal branches of superior and inferior
thyroid arteries, which inosculate freely ; the
Veins, empty into superior, middle, and inferior thyroid veins.
What nerves supply the larynx ?
The superior, and inferior or recurrent laryngeal, branches of
pneumogastric, the former receiving branches from spinal acces¬
sory and superior cardiac sympathetic nerves ; the
Superior laryngeal is chiefly a nerve of sensation, supplying laryn¬
geal mucous membrane and arytenoid muscles by its internal
laryngeal branch, after piercing the thyro-hyoid membrane; and
the crico-thyroid muscle by its external laryngeal branch ; the
Recurrent laryngeal is the motor nerve supplying all the laryn¬
geal muscles except crico-thyroid] the right nerve descends the
neck to pass from before backward around the subclavian artery,
the left winds in the same direction around the aortic arch, and
both nerves ascend in groove between trachea and oesophagus to
their distribution, giving off in their course cardiac, oesophageal,
tracheal, and pharyngeal branches, and anastomosing with superior
laryngeal nerves.
The Trachea and Bronchi.
What is the trachea' (Fig. 92)?
It is a membranous, cylindrical air-tube, flattened posteriorly,
of a transverse diameter of three-quarters to one inch, extending
from lower part of larynx (corresponding to sixth cervical vertebra),
to opposite fourth or fifth dorsal vertebra, where it bifurcates to
form the
THE TBACHEA AND BRONCHI.
255
Right and kft bronchui ; it is composed of sixteen to twenty imper¬
fect cartilaginous rings surrounding two-thirds of the cylinder,
enclosed in a double elastic fibrous membrane connecting the rings
with one another, while the space behind has, in addition to the
membrane—there forming a single layer—a layer of longitudinal
and another of transverse unstriped muscular fibres, the transverse
lying beneath the fibrous membrane called trachealis mwck-, the
last ring, by a triangular hooked-process curving backward between
the bronchi, forms two imperfect rings on either side for right and
left bronchus ; the lining mucous membrane contains much lym¬
phoid tissue and numerous glands, and is covered by several
layers of epithelium, the most superficial columnar ciliated.
Give the relations of the trachea in the neck.
It is covered in front from above downward by
Anastomosing branches Posteriorly, it lies upon
between jugular veins, Œsophagus,
Isthmus of thyroid gland Laterally, lie
Inferior thyroid veins. The common carotid
Arteria thyroidea ima arteries^',
(when present). Lobes of thyroid gland,
Sterno hyoid muscle. Inferior thyroid arteries,
Stero-thyroid muscle. Recurrent laryngeal nerves.
Describe its relations in the thorax.
It is covered from before backward by
Manubrium of sternum. Posteriorly, lies the
Remains of thymus gland, Œsophagus,
Left innominate vein. Laterally, on each side, the
Arch of aorta, Pneumogastric nerves.
Innominate artery.
Left carotid artery*',
Deep cardiac plexus.
What are the bronchi ?
Two tubes, structurally like trachea, extending from its bifurca¬
tion into the lungs, dividing and subdividing to form the bron¬
chial tubes, in whose walls only scattered cartilaginous plates
exist until the diameter of one-fourth of a line is reached, when
256
ESSENTIALS OF HUMAN ANATOMY.
they become wholly membranous, while the muscular coat and
elastrlc fibrous coat then form a continuous circular layer around
the smallest tubes ; the mucous membrane is covered with ciliated
columnar epithelium ; the
Right bronchus is wider, shorter (about one inch long), and
more horizontal than left ; the
Left bronchus is smaller, more oblique, and longer (nearly two
inches).
Describe the relations of each bronchus.
The right, beginning opposite fourth dorsal, enters lung opposite
fifth dorsal vertebra, lying behind superior vena cava and right
auricle of heart, having the right pulmonary artery at first below,
then anterior to it, and the vena azygos major arching over it
from behind.
The kft bronchus, commencing at samç point as right, passes in
front of oesophagus, thoracic duct, and descending aorta beneath
the aortic arch, the left pulmonary artery lying at first above,
then in front of it to enter lung opposite sixth dorsal vertebra.
What vessels and nerves supply trachea and bronchi ?
The arteries are tracheal branches of inferior thyroid arteries and
bronchials from aorta ; the
Veins empty into thyroid plexus and bronchial veins ; the
Lymphatics empty into mediastinal glands ; the
Nerves are branches from pneumogastric, recurrent laryngeal
branch of same, and sympathetic nerve.
The Lungs.
Describe them.
They are the two organs of respiration, occupying the greater
part of the thoracic cavity, separated by the heart and other contents
of the mediastinum, covered by the pleurse, of a specific gravity
of 0.345 to 0.746, weighing together about forty-two ounces, the
right being the heavier by two ounces. They are pinkish-white
at birth, but irregularly marked by slate-colored patches as age
advances from the deposit of carbonaceous matter, or perhaps
altered blood-pigment, in the lung tissue; they are divided into
THE LUNGS.
257
lobes, the right lung having three*,®,®, the left only two',® ; each
lung has an
Apex, extending into root of neck beneath and above first rib,
about one to one and a half inches, where it is in contact with
first and second part of subclavian artery ; the
Fig. 92.
Base is broad and concave, resting upon diaphragm, its thin
margins extending lower down externally and behind than in
front ; the
External surface is smooth, convex, marked by the interlobular
fissures, and conforms to the shape of the thorax; the
Inner surface is concave, and the left lung presents a depression
in front for heart; behind, each has a deep fissure, the hilum
pulmonis, the point of attachment of root of lung ; the
17
258
ESSENTIALS OP HUMAN ANATOMY.
Root^^ is the point of entrance of bronchus, pulmonary and
bronchial arteries, and of exit of the pulmonary and bronchial
veins and lymphatics ; in front of each lies the phrenic nerve and
anterior pulmonary plexus, behind, the pneumogastric and pos¬
terior pulmonary plexus.
In what order are these various structures arranged ?
From before backward.
Pulmonary veins, | ^ay be recalled by letters
Pulmonary artery, > V A B
Bronchus, etc. J > > •
From above downward ; right lung.
Bronchus, ] to be recalled by letters,
I "D
Pulmonary artery, |- '
Pulmonary veins, j '
V.
Left lung,
Pulmonary artery, )
Bronchus, etc., '
Pulmonary veins.
B,
V.
Describe the structure of the lung.
They have externally a serous coat, a subserous areolar tissue
penetrating between the lobules, and their bulk is composed of the
pulmonary substance or parenchyma, which is formed of an aggre¬
gation of lobules, each composed of a terminal bronchial tube with
its air cells, and ramifications of pulmonary and bronchial vessels,
lymphatics, and nerves, thus forming a miniature of lung ; they
are pyramidal and large upon the surface, smaller and irregular in
the interior; the alveoli, or air-cells, are small polyhedral alveolar
recesses measuring about one-two-hundredths to one-seventieth of
an inch, opening into the sides and ends of the intercellular passages
—i.e., the irregular terminations of the bronchioles—separated
from one another by delicate membranous septa, between the layers
of which lies the plexus formed by the pulmonary artery, thus ex¬
posing the blood to air on two surfaces ; they are lined with a layer
of squamous epithelium.
THE PLEUEL.
259
What are the vessels and nerves of the lungs ?
They receive blood by bronchial arteries for their own nutrition,
and venous blood by pulmonary artery for aération, i. e , absorption
of oxygen and emission of carbonic dioxide ; the vessels are
Bronchial arteries, branches of aorta. Pulmonary arteries, from
right side of heart. The bronchial veins empty on right side into
the vena azygos, on the left, into superior intercostal vein ; the
Lymphatics empty into bronchial glands ; the
Nerves are derived from the anterior and posterior pulmonary
plexuses, formed chiefly by branches from the sympathetic and
pneumogastric nerves.
The Pleurae.
What are the pleurae ?
Two closed delicate serous sacs, consisting of a portion investing
each lung and another lining, respectively, the right and left halves
of thorax.
Are the pleurae in contact internally ?
No, except at one point in front, leaving a space between them
elsewhere.
What is the visceral layer (that covering lung) of each
pleura called ?
The pleura pulmonalis, investing the lung as far as its root.
What is that called which lines the thorax ?
Pinera costalis. or parietal layer.
What is the ligamentum latum pulmonis ?
This broad ligament of the lung is a triangular fold of the pleura
passing downward from lower border of root of lung to diaphragm,
retaining lower part of lung in position.
Do the pleural cavities differ from each other 1
Yes, the right is shorter, wider, and extends higher in neck.
260 ESSENTIALS OF HUMAN ANATOMY.
What is the mediastinum ?
The median space left between the two pleural sacs, extending
from sternum to vertebral column, containing all the thoracic vis¬
cera but lungs.
Mention its subdivision, and the contents of each.
The anterior mediastinum, bounded in front by sternum, on each
side by pleurae, and behind by pericardium ; its contents are
Origins of sterno-hyoid and sterno-thyroid muscles,
Origin of triangularis sterni muscle.
Left internal mammary vessels,
Remains of thijmus gland.
Loose areolar tissue containing lymphatics.
The middle mediastinum is the broadest portion of interpleural
space ; its contents are the '
Heart enclosed in the pericardium. Pulmonary artery.
Ascending aorta. Pulmonary vein,
Superior vena cava. Phrenic nerves.
Bifurcation of trachea.
The posterior mediastinum, bounded in front by pericardium and
roots of lungs, behind by spinal column, and laterally by the
pleurae ; its contents are the
Descending aorta, Pneumogastric nerves.
The greater azygos vein. Splanchnic nerves.
The lesser azygos vein, Œsophagus,
Left superior intercostal vein. Thoracic duct,
Lymphatic glands.
The Urinary Organs.
Where are the kidneys situated 1
In the lumbar regions, one on each side of the vertebral column
each kidney reaching from the eleventh rib nearly to the iliac crest,
but the right a little lower than the left; they lie embedded in a
mass of fat behind the peritoneum, which retains them in place
with the aid of their bloodvessels.
THE UEIN-ARY ORGANS.
261
What are their size and weight ?
Each measures about four inches in length, two in breadth, and
one inch in thickness ; they weigh, in the male, from four and a
half to six ounces ; in the female, four to five and a half ounces.
Describe their relations.
The Anterior surface of right kidney is in relation with the right
lobe of liver, descending portion of duodenum, and ascending colon.
The Anterior surface of left kidney, with great end of stomach,
lower end of spleen, tail of pancreas, and descending colon.
The Posterior surface of each rests upon crus of diaphragm, the
anterior lamellae of transversalis aponeurosis separating it from
quadratus lumborum and psoas magnus.
The Superior extremity is embraced by the suprarenal capsule.
What is the hilum of the kidney ?
A notch or fissure one inch long at central portion of internal
border, opening into a cavity, the sinus ; through it pass the
lymphatics ; the renal vein is in front ; the renal artery^ next, and
ureter^, or excretory duct, behind and below.
Describe the naked-eye appearances of a vertical section
of a kidney.
The kidney proper consists of a
Cortical structuré-, composed of convoluted and straight urinifer-
ous tubules, bloodvessels, nerves, lymphatics, connective tissue,
and Malpighian bodies, and is prolonged down between the pyra¬
mids, forming the columns of Berlin-, a fibrous capsule envelops
the organ, passes into the sinus which it lines, blending with the
sheaths of vessels, nerves, and the calices ; the
Medidlanj substance''' consists chiefly of straight tubuli uriniferi,
" looped tubes of Henle ", bloodvessels, etc., arranged in eight to
eighteen
Pyramids of MidpighP, whose apices are embraced by the calices
of the pelvis; the
Pelvis consists of from seven to eighteen caliced', cup-like tubes,
embracing the apices of one or more Malpighian pyramids, con¬
verging to form three infundibula, these again joining to form the
pelvis^, which gradually contracts into the ureterU or excretory duct.
262
ESSENTIALS OF HUMAN ANATOMY.
Describe the tubuli uriniferi" (Fig. 94).
They commence in a dilated cœcal extremity, the MidpUjhian^
capsule and terminate by opening on the free surface of the
papillae'^ They are called, in various portions of their course, the
Fig. 93.
Proximal convoluted tuhê, the much convoluted portion after
leaving the Malpighian capsule and situated in the cortical portion.
The spiral tube of Schachowa*, ^next succeeding, where the tube
approaches the medullary portion in a spiral manner ; now enter¬
ing the medullary portion, the tubes suddenly become smaller,
THE URINARY ORGANS.
263
quite straight, dipping down into the pyramids to ascend, suddenly
enlarge, and again become spiral, and reënter the cortical structure,
constituting the descending
Loop of Henlâ, this ascends',® in an irregular angular manner
through the cortex, and terminates in the
Distal convoluted which terminates in a narrow
Curved tvhê^, continuous with a
Straight, or collecting tubd^^*, terminating on summit of one of
the papillae.
Describe these straight tubes'^"•
Traced into pyramids from the papillae, they run from apex to
base, dividing dichotomously, receiving the curved tubes, to enter
the cortex much increased in number, where they form conical
masses with their bases toward the medullary portion.
What are these conical masses called ?
The pyramids of Ferrein.
Describe the epithelium of the uriniferous tubules.
It varies in different portions, being flattened polyhedral, angular,
and columnar.
Describe the Malpighian bodies (tufts, or vascular
glomeruli).
Each is formed by a renal afferent»' (Fig. 95) arteriole, which, after
piercing the capsule—a pouch-like commencement of a tubulus
uriniferus lined with flattened epithelium''—breaks up into a tuft
of vessels forming a plexusc, from which arises the efferent» vessel
emerging from capsule near point of entrance of aflerent arteriole.
Describe the renal circulation.
The
Renal artery, from aorta, divides just external to hilum, into
four or five
Primary branches, which divide and subdivide to form
Arterias, propria renales, two of which run along the sides of each
Malpighian pyramid, giving ofi" aflerent branches to Malpighian
bodies in columns, and, bending between bases of pyramids and
cortex, send ofl" the (1) interlobular, and (2) arteriolse rectae ;
264
ESSENTIALS OF HUMAN ANATOMY.
(1) Ii(terlol>)iliir arteries, passing outward between the pyramids
of Ferrein to capsule, terminating in stellate plexuses beneath it
(stars of Verhryen), and also supplying afferent arterioles to Mal-
pighian bodies of cortex, whence issue efferent vessels forming a
ámae venouspkxm axoxxnà adjacent uriniferous tubules; and the
(2) Arteriolœ rectœ, or descendímj branches, passing from bases to
apices, of pyramids, there to terminate in the venous plexuses.
The blood is collected by the stellate venous plexuses beneath the
capsule, forming vente interlobulares, which pass between pyramids
of Ferrein, are joined by branches emptying the plexuses around
convoluted tubes of cortex , and join the venae rectae at bases of
Malpighian bodies; these tience recfce being branches from
at apices of medullary pyramids formed by arteriolae rectae. The
Fig. 94.
'N Subcapsular layer
< without Malpighian
corpuscles.
A) Cortex,
( h '))
f f 1 (l
Inner stratum of cortex, without WjM (r
Malpighian corpuscles. ' "jV " ' | ~
THE URETERS.
265
junction of the venœ rectœ and venœ interlobulare« form the venœ
propriœ renales, accompanying the arteries of the same name,
which receive venous twigs from Malpighian bodies of medulla
and unite in the sinus to form the
Renal, or emulgent vein, which passes out of hilum to empty into
inferior vena cava, the right vein being the shorter.
Describe the nerves of the kidney.
They are small, fifteen in number, have ganglia developed upon
them, and come from the solar plexus, lower and outer part of
semilunar ganglia, and from lesser and smallest splanchnic nerves
forming the renal plexus, communicating with spermatic plexus.
What is the ureter ?
It is the tubular, cylindrical, excretory duct of the kidney, of
the size of a goose-quill, sixteen to eighteen inches long, extend¬
ing from the pelvis of kidney to base of bladder, into which it
opens by a constricted orifice, after having passed obliquely for
nearly an inch between its muscular and mucous coats : it has a
fibrous coat continuous with capsule of kidney and fibrous tissue
Fig. 95.
The Ureters.
266
ESSENTIALS OF HUMAN ANATOMY.
of bladder, a muscular composed of longitudinal and circular
fibres, a mucous covered with several layers of many shaped epithe¬
lial cells.
Describe its course and relations.
It passes obliquely downward along posterior abdominal wall
beneath the peritoneum, over the iliac arteries, behind ilium on
right side, and sigmoid flexure on left, enters the posterior false
ligament of bladder in male, with vas deferens between it and
bladder, and enters bladder obliquely (see supra) about one and
one-half inches behind prostate, and two inches from its fellow,
at posterior angle of trigone ; in female it passes along sides of
cervix uteri and upper part of vagina; the right ureter lies close
to outer side of vena cava.
The Bladder.
What is the bladder' ?
The musculo-membranous reservoir for the urine, situated be¬
hind the pubes, between it and rectum in male, between the pubes
and uterus in female; wheç moderately distended its dimensions
are, length five inches, breadth three inches, capacity about one
pint; in the child it is an abdominal organ, and also in adults
when distended. It presents for examination, the
Summit^" (Fig. 98), connected with umbilicus by a fibro-mus-
cular cord, the urachus, and by two fibrous cords placed on either
side, the obliterated foetal hypogastric arteries ; the
Body lies against posterior surface of pubes, triangular liga¬
ment, internal obturator muscles, and—when distended—abdom¬
inal walls, its posterior surface being covered by peritoneum,
having some coils of small intestine interposed between it and
rectum, and uterus in female ; the obliterated hypogastric arteries
cross its sides obliquely from below, upward and forward, all
below them being uncovered with peritoneum; the vas deferens
curves from before backward along each side to reach the base of
bladder passing across the obliterated hypogastric vessels and
along inner side of ureter ; the
THE BLADDER.
267
Fundus, or ôase" (Fig. 98), is directed downward and back¬
ward, resting in the male upon the second portion of rectum, in
the female upon lower part of cervix uteri, being adherent to
upper part of vagina, hut separated
from cervix by a fold of peritoneum _
which is reflected so as to cover a
small portion of base; in male the
peritoneum passes from rectum to same ^
portion of base ; the
Neck, or cervix^^ (Fig. 98), is the
constricted portion continuous with
urethra, surrounded in male by pros¬
tate gland, and is directed downward
and forward.
How is the bladder held in place ?
By true and fake ligaments ; the true,
being the
Anterior, or pubo-prostatic, formed by two folds of the recto¬
vesical fascia extending from either side of pubic symphysis to
front of cervix over upper surface of prostate gland ; the
Lateral, of same tissue, passing between lateral surfaces of
prostate gland on each side, and sides of base of bladder; the
Urachu^'^ (Fig. 98), a fibro-muscular cord covered with perito¬
neum, stretching between apex of bladder and umbilicus.
The false ligaments are.
Two Posterior, folds of peritoneum passing, in male from sides
of rectum, in female from sides of uterus, to postero-lateral aspect
of bladder, and contain the obliterated hypogastric arteries, the
ureters, vessels, and nerves.
Two laieral, peritoneal folds passing from iliac fossa to sides of
bladder.
Superior^ (Fig. 98), a peritoneal fold passing over urachus and
obliterated hypogastric arteries from apex of bladder to umbilicus.
What is the urachus^ (Fig. 98) ?
The remains of a tubular canal connecting bladder with allan¬
téis in fœtus.
268
ESSENTIALS OF HUMAN ANATOMY.
Describe the structure of the bladder.
It has four coats, viz., a
PeriioiiaiF^,''* (Fig. 98), covering posterior surface from entrance
of ureters at base to its summit, passing on to sides whence it is
reflected to abdominal and pelvic walls: a
Muscular, consisting of fibres spirally arranged forming figure-
of eight loops, the more superficial being nearly longitudinal, the
deeper nearly circular, corresponding to same-named layers of
older authors; these form seven more or less distinctly marked
layers, the loops directed toward, and embracing the urachus and
urethra respectively, the aggregation of these loops around the
neck forming the sphincter and the fibres passing in all directions
are continued into prostatic urethra (Pettigrew) : a
Cellular, which is a layer of areolar tissue intimately blended
with mucous membranes binding it to the muscular coat; a
Mucous coat, covered by transitional epithelium, the superficial
layer of polyhedral cells, below club-shaped and smaller spindle-
celled : it contains a few mucous follicles
and numerous racemose glands lined with
columnar epithelium near the neck; it
is thrown into folds or rugœ when blad¬
der is empty.
What are the muscles of the ure¬
ters?
Two oblique bands rising behind the
orifices of the ureters which converge, to
be inserted by a fibrous process into the
middle lobe of prostate gland.
What is the trigonum vesicae or
trigone vesicaP (Fig. 97)?
A triangular smooth surface at base of
bladder, with apex forward, of a paler
color than remainder of mucous mem¬
brane, which is intimately adherent to
subjacent tissues : the
Lateral boundaries are two slightly
marked ridges on each side passing backward and outward from
THE MALE ÜEETHRA.
269
the apex formed by urethral opening to orifices of ureters', cor¬
responding to the muscles of these ducts, the openings being placed
about two inches from one another and one and a half inches
behind urethral opening, a line connecting the two forming the
base of the trigone.
What is the uvula vesicae* (Fig. 97) ?
A slight elevation of the mucous membrane projecting from
lower anterior portion of floor of bladder into orifice of urethra.
Mention the arteries supplying the bladder.
Superior, middle and inferior vesical, and small twigs from obturator
and sciatic arteries in male, with additional branches from uterine
and vaginal, in female : the veins form intricate plexuses around
neck, sides, and base, emptying into internal iliac vein ; the
lymphatics accompany the vessels.
Give the nerve-supply of the bladder.
Branches from hypogastric plexus of sympathetic supply upper
part, and the third and fourth sacral nerves the base and neck.
The Male Urethra.
Describe this canal.
It extends from neck of bladder* to meatus urinarius, measuring
from eight to nine inches, presenting a double curve when penis is
flaccid, but a single one with convexity downward during erection.
Name and describe each of its divisions.
They are the prostatic',', membranous, and spongy.
The prostatic portion}^ {F'g- 9") is that portion passing from base
to apex of prostate gland, running nearer the upper surface, measur¬
ing one and a quarter inches long, is the widest and most dilatable
section of urethra and is sjjindle-shaped ; upon the median aspect
of the floor is a narrow longitudinal ridge eight to nine lines long,
the verumontanum or capmt gallinaginiê (Fig. 97) containing mus¬
cular and erectile tissue: on either side is a slight fossa, its floor
presenting the numerous openings of the prostatic ducts, called the
prostatic sinus.
270
ESSENTIALS OF HUMAN ANATOMY.
The simispocularis, or uterus masculinu^ (Fig. 97), is a depression
extending about a quarter of an inch upward and backward be¬
neath middle lobe of prostate in the median line at fore part of
verumontanum, upon or within whose margins are the slit-like
orifices of the seminal or ejaculatory ductê (Fig. 97).
The membranous portion'^ (Fig. 97) is that portion, three-quarters
of an inch long, extending between apex of prostate and bulb of
corpus spongiosum, which is included between the layers of the
triangular ligament about one inch beneath the pubic arch ; it is
surrounded by the compressor urethrae muscle, and is the narrowest
portion of urethra, except meatus.
The spongy portion^>^ (Fig. 97) is the longest measuring about
six inches, is so called from being contained in the corpus spongio¬
sum, extends from membranous portion to meatus urinarius, and
presents a posterior dilatation, that of the bulb® (Fig. 98), and one
Fis. 98.
8
anterior, ihe fossa navicularis^^ (Fig. 98), the former having opening
into it the ducts of Cowper's glands, the latter fossa being situated
within the glans penis, having an opening directed forward in its
roof, the
Lacunus magnus, the orifice of a large mucous crypt ; there are also
here numerous other scattered openings of glands similarly directed.
What is the meatus urinarius ?
The anterior orifice of the urethra, a vertical slit about three
FEMALE URETHRA.
271
lines long bounded on each side by a small labium, and is the nar¬
rowest portion of the canal.
Describe the structure of the urethra.
It possesses three coats, viz., a mucous, forming a part of the
genito-urinary membrane internally and continuous with the skin
externally, having numerous mucous glands imbedded in its sub¬
mucous tissue, which open on its free surface, and is covered with
columnar epithelium except near meatus where it is squamous.
The muscular coat consists of longitudinal fibres externally,
circular within, the latter lying beneath urethral mucous mem¬
brane for its whole length, the former leaving the circular fibres at
the bulb to envelop the spongy body beneath its fibrous coat, again
rejoining the circular fibres at the meatus urinarios ; both mus¬
cular layers are in direct continuity with those of bladder. (For
voluntary urethral muscles see p. 331.)
Erectile, this is a thin layer of erectile tissue surround ing the mem¬
branous and prostatic portions, anteriorly becoming continuous
with that of corpus spongiosum.
Female Urethra.
Describe this canal.
It is about one and one-half inches long, extends from bladder to
meatus urinarius above anterior vaginal wall, pierces the triangular
ligament, and is embraced by compressor urethrae muscle as in
male : its structure is similar to that of male urethra, it is lined by
laminated squamous epithelium merging into spheroidal near blad¬
der, is a quarter of an inch in diameter, but is capable of much
greater dilatation; and its anterior opening (meatus) is situated
near anterior margin of vagina, about one inch below clitoris, sur¬
rounded by a prominence of mucous membrane.
The Male Generative Organs.
Where is the prostate gland situated' (Fig. 97)?
It surrounds neck of bladder and commencement of urethra,
lying in pelvic cavity posterior to deep perineal fascia, behind and
272 ESSENTIALS OF HUMAN ANATOMY.
below symphysis pubis upon the rectum: through it pass the
urethra and seminal ducts.
Describe its form and size.
It resembles a horse-chestnut in form, measures one and a half
inches transversely, one inch antero-posteriorly, three-quarters of an
inch in depth, and weighs about six drachms : the base is directed
backward toward bladder: it consists of two equal-sized lateral
lobes and a middle lobe, a small transverse band or rounded
triangular eminence placed between lateral lobes immediately
beneath neck of bladder behind commencement of urethra.
Describe its structure ?
It is composed of numerous follicular pouched glands opening
into elongated canals which join to form twelve to twenty excre¬
tory ducts imbedded in the interstices of a stroma formed of inter¬
lacing bundles of unstriped muscle, the whole being inclosed in a
fibrous capsule.
What retains the gland in place ?
The pubo-prostatic ligaments of bladder, posterior layer of deep
perineal fascia, and anterior portion of levator ani muscle.
Describe the situation and structure of Cowper's glands ?
They are two small lobulated glands of the size of peas, lying
between the two layers of the deep perineal fascia in front, close
behind bulb of urethra, surrounded by compressor urethrse muscle
and opening, by ducts one inch long which pass obliquely forward
beneath mucous membrane, on the floor of bulbous portion of
urethra.
The Penis.
Describe the penis ?
It has a root, body® (Fig. 98), and extremity or glans penis®, and
consists of three elongated cylindrical masses of erectile tissue,
composed of a fibrous sheath which sends inward numerous inter¬
lacing bands (trabeculae) forming numerous meshes in which lie
the bloodvessels. The upper two cylindrical bodies lying side by
THE PENIS.
273
side, like a double-barrel gun, are called the corpora cavernosa';
the third, much smaller, lying in median line beneath, like the
ramrod of a gun, is the corpus spongiosum'.
Describe the corpora cavernosa.
Situated as just described, they are intimately connected in their
anterior three fourths where they are in contact, presenting a
median dorsal groove for vessels and nerves, an inferior median
one for corpus spongiosum, while their posterior fourth diverges,
forming the crural, which are attached to the rami of pubes and
ischium anterior to the tuberosity; near their point of junction
with one another they become slightly enlarged, forming, on either
side, the hulb of the corpus cavernosum.
What other structure besides the crura secures the root of
the penis to symphysis pubis ?
The suspensory ligament, a fibrous membrane.
What is the septum pectiniforme® ?
The anterior portion of the vertical fibrous septum which is in¬
complete, the fibrous bands resembling in their arrangement the
teeth of a comb ; the septum and fibrous sheath contain numerous
elastic and muscular fibres in addition to the white fibrous tissue.
Describe the corpus spongiosum.
It incloses the urethra", lying medianly below at junction of
corpora cavernosa, commencing behind in front of deep perineal
fascia between the crura of the corpora cavernosa as a rounded
enlargement, the bulb^, which is surrounded by the accelerator
urinae muscle. Anteriorly it forms a conical enlargement, flatten¬
ing from above downward, which caps the blunted end formed by
the corpora cavernosa, the glans peni^, the margin of whose base
is called the corona glandis, the constriction behind the cervix.
What other parts of importance does the penis present ?
The meatus urinarius, the external orifice of urethra opening at
summit of glans penis.
The prepuce, a portion of skin of penis prolonged forward so as
either completely or partially to cover glans penis, lined internally
by a tissue resembling mucous membrane.
18
274
ESSENTIALS OF HUMAN ANATOMY.
The/r-flEWMWi prœputii, a fold of mucous membrane passing from
behind meatus to bottom of a depressed raphé to become con¬
tinuous with under margin of prepuce.
Oïanduke Tynonii odori/erœ, numerona small lenticular sebaceous
glands upon corona and cervix of glans, secreting sebaceous matter
with a peculiar odor.
What is meant by erectile tissue ?
An intricate venous plexus formed by the interspaces between
the fibrous trabeculae, the blood being delivered in the following
ways : (1) by arteries terminating in ordinary capillaries—this is
the arrangement in the corpus spongiosum and glans—(2) fine
convoluted arterial twigs opening direetly into venous network by
funnel-shaped extremities.
What are the helicene arteries ?
Convoluted, tendril-like arterial branches opening directly into
venous plexus (supra), as just explained, most abundant in back
parts of spongy and cavernous bodies.
Name the arteries, veins, and lymphatics of the penis.
The arteries are all branches of internal pudic, viz..
Artery of bulb, to corpus spongiosum.
Arteries of corpora cavernosa, to these bodies.
Dorsal arteries of penis, to corpora cavernosa, glans, prepuce, and
skin ; the
Veins return blood by dorsal vein, prostatic plexus, and pudental
veins.
Lymphatics, the superficial end in inguinal glands, the deep join
deep pelvic lymphatics ; the
Nerves are branches of internal pudic and hypogastric plexus
of sympathetic.
The Testes and their Coverings.
What are the testes or testicles (Fig. 99) ?
They are the procreating glands, those which secrete the seminal
fluid, are of ovoid form compressed laterally, and are each ob¬
liquely suspended in the scrotum by their own spermatic cord.
THE TESTES AND THEIE COVEEINGS. 275
They measure from one and a half to two inches long, one inch in
breadth, and one and a quarter inches antero-posteriorly, weighing
from six to eight drachms, the left being slightly larger.
What is the scrotum ?
A cutaneous pouch containing the testicles and part of sper¬
matic cords, formed of integument externally and beneath this of
a reddish contractile layer, the dartos, continuous with contiguous
superficial fascia and sending inward a partition, the septum scroti,
dividing the scrotum into two compartments.
Describe the coats of the testis.
They are, the
Tunica vaginalis testis, a serous coat originally derived from peri¬
toneum, consisting of a portion investing the testis, the visceral
layer, or tunica vaginalis propria, and a parietal layer, or tunica
vaginalis reflexa ; the
Tunica albugínea is formed of white fibrous tissue surrounding
the gland and reflected into its interior at its postero-superior
border to form an incomplete vertical partition, the mediastinum
testis, or corpus Highmorianum, from which fibrous septa pass, sepa¬
rating the glandular lobules ; the
Tunica vasculosa, or pia mater testis, consists of a plexus of blood¬
vessels bound together by areolar tissue, which invests the inner
surface of the tunica albuginea and sends ofi" processes between
the lobules.
What is meant by the coverings of the testis ?
The structures with which the testes become invested in their
passage, previous to birth, from the abdomen along the inguinal
canals into the scrotum.
Name these coverings.
Intercolumnar, or external spermatic fascia, derived from margins
of external abdominal ring.
Cremaster muscle, derived from lower border of internal oblique
muscle (some authors deny this).
scrotum, closely adhering to each other.
276 ESSENTIALS OF HUMAN ANATOMY,
Infundibuliform, or fascia propria, a downward continuation of
infundibuliform process of transversalis fascia.
Tunica vaginalis, derived from peritoneum (supra).
Describe the structure of the testis.
It consists of some hundreds of seminiferous tubules, one-one-
hundred and fiftieth to one-two-hundredths of an inch in diameter,
convoluted so as to form three hundred conical lobules, with apices
toward mediastinum ; the tubes then unite to form twenty or thirty
larger ducts, one-one-fiftieth of an inch in diameter, called vasa
recta", which, passing upward and into the mediastinum, form a
close network of anastomosing tubules, the rete testis ; these, at the
upper end of the mediastinum, terminate into twelve to twenty vasa
efferentid", perforate the tunica albuginea, and become enlarged
and convoluted, forming coni vasculosis, which aggregated compose
the globus major of epididymis ; the tubules consist of a mem¬
brana propria lined with a layer of polyhedral cells, with two or
more inner layers of spheroidal cells, which divide into epithelial
cells ultimately to become converted into spermatozoids ; the vasa
recta and tubes of rete testis have thin walls lined by one layer of
squamous cells ; the vasa efferentia and epididymis have thicker
walls, containing muscular tissue and are lined with columnar
epithelium.
What is the epididymis ?
A convoluted tube, some twenty feet long, lying along posterior
border of testis, commencing on testicle side by convergence of tubes
of coni vasculosi, and ending in the single vas deferens beyond.
Describe its various parts.
The globus major* is formed by the coni vasculosi, or efferent
ducts, which open at intervals into the single duct forming epi -
didymis; the
Bodys is the central portion formed by the convolutions of the
tube bound together by delicate areolar tissue ; the
Globus minor^ is the lower enlarged portion, composed as body
is, and connected to testis by fibrous bands and areolar tissue ; the
Vas aberrensi is a narrow tube extending up into cord for two
or three inches, ending in a blind extremity, occasionally con-
THE TESTES AND THEIR COVERINGS. 277
nected with lower part of tube of epididymis, or commencement
of vas deferens ; the
Hydatids of Morgagni are small bodies attached to epididymis or
upper portion of testicl^by pedicles ; one of these is probably the
remains of the duct of M'dlkr.
Describe the vas deferens'*.
It is the excretory duct of testis, and a continuation of epididy¬
mis, commencing at globus minors to ascend along posterior side
of testis and epididymis, back
of spermatic cord, through the
inguinal canal to internal ab¬
dominal ring, whence, passing
into pelvis, it crosses external
iliac, curves around epigastric
artery to reach side, then by a
curve downward and backward,
the base of bladder internal to
the ureter^ (F'g- 96) ! here it
lies between the bladder and
rectum, coursing along inner
border of seminal vesicle® (Fig-
96) on each side, becoming en¬
larged and sacculated, but nar¬
rowing at base of prostate where,
joined by duct of vesiculœ semi¬
nales® (Fig. 96), it forms the
ejaculatory duct' (Fig. 96). It
measures about two feet long,
is about one and a quarter lines in diameter, its lumen measuring
but one-third line, and has thick, rigid walls, presenting a hard,
cord-like sensation when rubbed between the fingers.
What are the arteries of the testis and its coverings ?
The gland itself is supplied by the spermatic arteryn^ (Fig. 99),
the coverings receive blood from superficial external pudic and deep
external pudic from femoral, superficial perineal from internal pudic,
cremasteric from epigastric, and artery of vas deferens from superior
vesical.
278
ESSENTIALS OF HUMAN ANATOMY.
The veins leave back of testicle formiiig the pampiniform plexus,
which ends in a single trunk emptying on right side into ascend¬
ing vena cava, on left into left renal vein.
Veins of the same name as arteries supplying coverings, return
blood to femoral, external and internal iliac veins.
What nerves go to each testicle and its coverings ?
Branches from spermatic plexus of sympathetic to testicle itself,
to coverings and cord the ilio-inguinal, ilio-hypogastric, superficial
perineal, inferior pudendal, and genital branch of genito-crural nerve.
What are the component parts of the spermatic cord, and
how are they disposed ?
Vas deferens, Spermatic nerve-plexus,
Spermatic artery, Branch of ilio-inguinal nerve,
Cremasteric artery. Branch of genito-crural nerve.
Artery of vas deferens, Vas aberreos (when present),
Spermatic veins, Lymphatics.
These form a cord bound together by connective tissue about four
inches long, extending from globus minor to internal abdominal
ring.
Describe the vesiculœ seminales.
They are two lobulated membranous receptacles for the semen,
which they dilute with their own secretion. They are pyramidal
in form, are about two and a half inches long by five lines broad,
by two to three lines thick, and lie in contact with base of bladder,
diverging from each other from base of prostate to near entrance
of ureters ; they join by their anterior pointed extremities with vas
deferens, forming on each side the ejaetdatory ducts' (Fig. 96),
terminating in prostatic urethra by slit-like orifices on each side of
the sinué' (Fig. 97) at front of verumontanum.
Describe the descent of the testes.
During early foetal life the testes lie at back part of abdomen,
behind the peritoneum, just below and in front of kidneys;
attached to lower end of epididymis, and attaining its full develop¬
ment from fifth to sixth foetal month is the gubernaculum testes, which
contains muscular tissue ; this divides below into three portions.
FEMALE OEGANS OP GENEEATION.
279
passing to Poupart's ligament, to os pubis and rectus muscle, and
to dartos at bottom of scrotum ; the gubernaculum is supposed to
contract and so cause descent of testicle, but this is a moot point.
Between the fifth and sixth month each testis reaches the iliac
'fossa, by seventh it enters internal abdominal ring, by eighth
month it has reached the scrotum, carrying before it the peritoneal
sac, the upper part of which usually becomes obliterated just
before birth, the lower portion then forming the tunica vaginalis
testis completely cut ofl" from abdominal cavity ; the other structures
in front of the testis are likewise carried onward, forming its cover¬
ing, as already described (see page 275).
Female Organs of Generation.
What is the vulva ?
The term includes the following organs :
Labia minord^. Vaginal orificê^.
Mous veneris*, Clitoris^,
Labia majorat. Meatus urinaríus^*.
These parts are also called the pudendum and external organs of
generation.
Describe the mens veneris*.
It is a rounded eminence surmounting vulva in front of pubes,
formed by a collection of fatty tissue, and at puberty becomes
covered with hair.
Describe the labia majora® and minora'®.
The Labia majorai' are two prominent longitudinal cutaneous
folds passing downward from mons veneris to anterior part of
perineum enclosing the common urinosexual opening. Each labium
is formed externally of hair-covered skin, internally, of mucous
membrane enclosing between these layers fatty areolar tissue and a
structure resembling the dartos ; the junction of the labia in front
constitutes the anterior commissure, that behind, the posterior com¬
missure ; the
Labia minora, or Nymphœ^', are two thin folds of mucous mem-
280
ESSENTIALS OF HUMAN ANATOMY.
brane, containing numerous sebaceous glands, inside the labia
majora, running from clitoris®,—above which they form a hood-like
prepuce,—obliquely downward for about one and a half inches on
each side of vaginal orifice, to be lost in the labia majora.
Describe the remaining structures forming the vulva.
The clitoris is a small penis with root, body, and glans, composed
of two corpora cavernosa formed of erectile tissue attached to rami
of pubes and ischium by two crura' ; it
has a suspensory ligament and two erec-
torcs clitoridis muscles ; the
Vestibule is the triangular smooth sur¬
place below clitoris, bounded on each side
by labia minora; the
Meatus urinarius^* is placed at back
part of vestibule, about one inch helow
clitoris, near vaginal margin, surrounded
by a prominence of mucous membrane ;
the
Vaginal orifice^'" is of an elliptical form,
usually more or less closed in the virgin by
hymen, and is surrounded by sphincter
vaginae muscle, the anologue of male
accelerator urinae muscle ; the
Hymen is a thin fold of mucous membrane, variously shaped, but
usually semilunar, with concavity upward, stretched across lower
part of vaginal orifice ; it may occasionally form a complete occlud¬
ing membrane, the condition being then known as imperforate
hymen; it may be practically absent in the virgin, and again, may
persist after copulation, but at that time is usually ruptured, giving
rise to small, rounded elevations surrounding vaginal outlet, called
carunculce myrtiformes ; the
Glands of Bartholinê-^ are small, oblong, reddish-yellow bodies,
lying on each side of commencement of vagina, each opening by
a long single duct external to hymen on inner side of each labium
majorum; the
Bulhi vestibulP are two oblong masses—a venous plexus enclosed
THE VAGINA.
281
in a fibrous envelope—extending from clitoris along each side of
vestibule, a little behind labia majora; the
Pars intermediaP is another small venous plexus immediately in
front of preceding, with which it is continuous as well as with
glans clitoridis ; the
Fourchette'is SusmaW transverse mucous fold, just within posterior
commissure ; the
Fossa navicularii is the space between fourchette and posterior
commissure.
The Vagina.
Describe it.
It is a cylindrical membranous canal flattened from before back¬
ward, lying between rectum and bladder, extending from vulva to
uterus, curved forward and downward conforming to axis of pelvis
and of outlet. Narrow at its orifice it is larger above, its an¬
terior wall measuring about four inches, its posterior six, being
attached higher up on os uteri behind than in front.
Describe its structure.
It is formed of an external layer of erectile tissue, a muscular
coat, and a lining mucous membrane with a median anterior
and posterior raphe or columns of the vagina] it contains mucous
glands ; the epithelium is of the squamous variety.
Give the relations of the vagina.
Its anterior surface is in relation with base of bladder and
urethra ;
The posterior surface is connected with lower three-fourths of
rectum, the upper fourth being separated from bowel by recto¬
uterine fold of peritoneum forming Douglas's cul-de-sac or pouch]
Laterally, above it gives attachment to broad ligaments of uterus,
below to levatores an i muscles and recto-vesical fascia.
The Uterus and its Appendages.
Describe the position and parts of uterus.
It is the organ of gestation, situated in pelvic cavity between
rectum and bladder, opening below into vagina, which is attached
282
ESSENTIALS OF HUMAN ANATOMY.
around its cervix. It is pear-shaped, flattened from before back¬
ward, is about three inches long, two inches in breadth at upper
part, and one inch thick, weighing from one to one and a half
ounces ; it presents for examination the
Fundus^, which is convex, covered with peritoneum, and placed
below level of brim of pelvis ; the
Body^ gradually narrows from fundus to neck, with anterior
flattened surface covered with peritoneum for its uppfer three-
fourths, and a posterior peritoneum-covered convex surface, while
each lateral margin is concave, aflbrding attachment to Fallopian'
tube above, to round ligament in front and below this, and to
ovarian ligament below and behind both ; the
Cervia? is the lower, rounded, constricted portion of uterus pro¬
jecting into upper portion of vagina, which is attached further up
behind than in front; the
Cavity of the Body is small, triangular, flattened from before back¬
ward, its upper extended lateral angles forming funnel-shaped cavi¬
ties at the bottom of each of which opens, by a minute orifice, the
Fallopian tube ; at the inferior angle is the small opening into the
cavity of the cervix called os internum or internal os uteri", the
Fig. 101.
Cavity of the cervix is spindle-shaped, flattened antero-pos-
teriorly, and opens into cavity of uterus above by internal os uteri,
and below into vagina by the external os uteri ; a median longi¬
tudinal crest of mucous membrane on back and front walls from
which proceed obliquely other smaller ones, forms the arbor vitce,
hardly noticeable after the first labor ; the
Os externum or external os uteri (also os tinctse)* is a transversely
ovoidal opening firom cervix into vagina which presents an anterior
and posterior lip.
THE UTERUS AND ITS APPENDAGES. 283
Describe ligaments of uterus.
Six are peritoneal folds, viz..
Anterior or vesico-uterine, two crescentic folds passing between
uterine neck and back of bladder ; the
Posterior or recto-uterine, passing between sides of uterus and
rectum ; the peritoneal pouch thus formed between rectum and
uterus being called Douglas's cul-de-sac or recto-vaginal pouch ; the
Two lateral or broad ligaments' (Fig. 101), stretched between sides
of uterus and lateral walls of pelvis, dividing this cavity into two
portions, and containing between their folds the Fallopian" tubes
and the round ligaments".
Describe the round ligaments of the uterus".
They are two rounded cords, four or five inches long, commenc¬
ing at superior angles of uterus to pass forward and outward
through internal abdominal ring into inguinal canal to become
lost, after dividing into three fasciculi, in the fatty tissue of mons
veneris ; they consist of dense fibrous tissue and unstriped muscle,
enclosed, in the foetal state, by a process of peritoneum extending a
short distance into inguinal canal, the so-called canal of Nuck,
usually obliterated in adult, but sometimes pervious throughout
life.
Describe the structure of uterus.
The womb has three coats, viz., a
Serous, derived from peritoneum covering fundus of organ and
its posterior surface, but only the superior three-fourths of its
anterior surface ; a
Muscular, forming bulk of uterus, composed of bundles of un¬
striped muscular tissue interspersed with areolar tissue, blood¬
vessels, lymphatics, and nerves. The fibres are disposed in three
layers, viz., transverse, in front and behind fundus ; middle layers,
passing longitudinally, obliquely, and transversely ; and circular,
arranged in two hollow cones whose apices surround the orifices of
the Fallopian tubes, whose bases fuse in middle of uterine body ;
at cervix these fibres pass transversely ; a
M^u^ous, thin, smooth, and closely adherent to subjacent parts.
284
ESSENTIALS OF HUMAN ANATOMY.
covered with columnar ciliated epithelium, and containing num¬
erous tubular follicles, most numerous in the cervix ; when their
ducts become obliterated their secretion is retained, forming small
vesicular elevations within os and cervix uteri called Ovula of
Naboth.
Name the uterine vessels and nerves.
The
Arteries are the uterine, from internal iliac, and ovarian, from
aorta, which pursue a very torturous course and freely anastomose.
The veins accompany arteries and terminate in uterine plexuses;
during pregnancy they are called uterine sinuses, consisting of the
lining membrane of the vein adhering to the walls of canals chan¬
nelled through uterine substance ; the
Lymphatics, terminate in pelvic and lumbar glands ; the
Nerves, are branches of inferior hypogastric, and spermatic
plexuses, and of third and fourth sacral nerves.
What are the Eallopiau tubes ?
They are the oviducts, two tubes about four inches long, ex¬
tending between layers of broad ligament on each side from supe¬
rior angle of uterus to sides of pelvis ; the canal of each tube is
very minute at its commencement the ostium internum at the
superior angle of the uterine cavity, continuing so for inner half,
when it gradually widens into the trumpet-shaped ostium abdomi-
naW, called from the fringe-like fimbriœ^'' which surround the
opening—one of which is attached to ovary—the fimbriated ex¬
tremity^''. Their walls are formed of a serous or peritoneal coat, a
muscular, formed of longitudinal and circular fibres, and a mucous
coat covered with ciliated columnar epithelium, continuous on
one side with uterine lining, on other with peritoneum.
Describe the ovaries".
They are two fiattened, ovoid bodies suspended by their anterior
margins from back of broad ligaments', behind and below Fallo¬
pian tubes, upon either side of uterus ; they are attached by their
inner extremities to uterus by the ovarian ligaments and by their
outer ends to one of fimbriae of Fallopian tube; their dimensions
are, length, one and one-half inches; width, three-quarters of an
inch ; thickness, one-third of an inch.
THE UTERUS AND ITS APPENDAGES. 285
Describe the structure of the ovaries.
They consist of numerous Graafian vesicles imbedded in a fibrous
stroma, covered externally by modified peritoneum, having col¬
umnar instead of squamous cells.
The stroma consists of numerous spindle-cells with connective
tissue and abundant bloodvessels ; the condensed peripheral layer
surrounding the organ was formerly described as the tunica albu¬
gínea.
What are the Graafian vesicles ?
Ovisacs, minute vesicles from one-one-hundredth of an inch in
diameter, to even one-one-twentieth of an inch after puberty;
microscopically, they are seen to consist of an external fibro-vascular
coat connected with stroma by a vascular network, an internal coat,
or ovicapsule lined by a layer of nucleated cells, the membrana
granulosa, which are heaped up around ovum at that part of
Graafian vesicle nearest the ovarian surface, forming the discus
proligerus-, it contains also a transparent, albuminous fluid, sus¬
pending the ovum in the immature vesicles.
Describe the human ovum.
It is a spherical mass of protoplasm, one-one-hundred and
twenty-fifth of an inch in diameter, and consists of the
Vitelline membrane, or zona pelludda, a transparent sac surround¬
ing the
Vdellus, or yelk, a fluid containing granules, among which is
found the
Germinal vesicle, containing a smaller body, the
Germinal spot, one-thirty-six hundredths of an inch in diameter.
What is the corpus luteum ?
An irregular yellow spot in ovary at site of a ruptured Graafian
vesicle, which differs in appearance according as it is a true or
false corpus luteum.
Describe the differences between these two kinds of corpora
lutea.
The true corpus luteum is that of pregnancy which increases up
to a certain point, reaching sometimes the size of a mulberry, and
usually does not entirely disappear until full term.
286
ESSENTIALS OF HUMAN ANATOMY.
The false corpus luteum is that following ordinary menstruation,
is much smaller, and disappears in about three months.
Name the ovarian arteries, veins, and nerves.
The arteries are the ovarian, from aorta, anastomosing with
uterine artery ; these vessels also supply Fallopian tubes ; the
Veins follow arteries and form a plexus near ovary, called the
Pampiniform plexus ; the nerves are derived from inferior hypo¬
gastric or pelvic plexus, from ovarian plexus, and the Fallopian
tubes receive branches from one of the uterine nerves.
What is the parovarium ?
It is also called the organ of Rosenmüller, is the remains of a
fœtal structure, and in the adult consists of a few closed epithelial-
lined, convoluted tubes, one commonly ending in a bulbous
hydatid-like swelling ; at its uterine end the parovarium is con¬
nected with the remains of the Wolffian duct—the duct of Gaertner.
The Mammary Glands.
Describe the mammae.
They exist in both sexes, being in male only rudimentary, but in
female are two large hemispherical eminences situated toward
lateral aspect of pectoral region on each side, reaching from axilla
to sternum, and from third to sixth or seventh ribs; just below
the centre projects a small, dark-colored conical prominence, the
nipple, surrounded by a lighter colored areola, in which are
numerous prominent sebaceous glands, which enlarge during
pregnancy ; the color of both nipple and areola darken during
pregnancy, and the latter also extends its area.
Describe the structure of the mammary glands.
They are composed of gland-tissue, of fibrous tissue connecting
the lobes, and fatty tissue in intervals between lobules ; the lobes
consist of lobules formed of a number of rounded vesicles grouped
about a small lactiferous tube into which their ducts open, which,
by tbeir union, finally form fifteen or twenty excretory ducts, or
tvhuli lactiferi, which converge toward the areolae, dilating beneath
it into the ampullce at base of nipple, when they contract into
THE SKIN AND ITS APPENDAGES.
287
straight tubes perforating the summit of the nipple; the lobules
are surrounded by a dense capillary network during lactation, as
is also the nipple, which becomes erected when irritated, partly
from fulness of blood, partly from contraction of its muscular
tissue.
Name the vessels and nerves of the mammae.
The arteries are derived from thoracic branches of axillary, in¬
tercostal, and internal mammary arteries ; the
Veins form an anastomotic circle around the base of the nipple,
called the circuius venosus, from which large vessels radiate to
terminate in axillary and internal mammary veins ; the
Lymphatics chiefly run along lower border of pectoralis major to
axillary glands, a few pass through intercostal spaces to anterior
mediastinal glands; the nerves come from anterior and lateral
thoracic cutaneous.
THE ORGANS OF SENSE.
The Skin and its Appendages.
Of what parts does the skin consist ?
Epidermis, or cuticle, | epithelial layers and the rete
formed of mucosum, or deep epithelial layers,
) which contain the pigment.
papillary layer, upon which lies rete
with an interposed basement mem¬
brane ;
corium.
Derma, cutis vera, or
true skin, formed of
Enumerate the accessory structures contained in the skin.
The tactile corpuscles, in papillae of sensitive parts.
Ducts of svoeat-glands, )
Hair.follicles, into which open
sebaceous glands, 1 ® skin.
Where do sweat- and sebaceous-glands with the hair
follicles lie ?
Chiefly in the subcutaneous fatty tissue, but sometimes in the
deepest layers of the corium.
288
ESSENTIALS OF HUMAN ANATOMY.
Describe the epidermis.
It is composed solely of epithelial cells, the deepest layer being
columnar, more rounded in the middle portions, and flat, scaly,
and horny on free surface; the deepest, softest layer is accurately
moulded upon the papillary layer of the derma, and contains the
skin pigment; it is called the rete mucosum.
Describe the derma.
Is a tough, flexible, and highly elastic tissue, protecting sub¬
jacent parts, and is the chief organ of the sense of touch ; excre¬
tion is effected by its various glands, and absorption also takes
place from its surface. The derma consists of the
Papillary layer, situated upon its free surface, presenting innu¬
merable, minute, vascular conical eminences, averaging in length
one-one-hundredth of an inch by one-two-hundred and fiftieth of
an inch in diameter at their bases, scattered irregularly in slightly
sensitive parts, but arranged in parallel curved lines, forming ridges,
in highly sensitive regions; each papilla contains one or more
capillary loops, and one or more nerve fibres, some terminating in
oval-shaped bodies, the
Tactile corpiLScles, where touch is most highly developed.
The corium is composed of interlacing bands of white fibrous
tissue, with some yellow elastic fibres, unstriped muscular fibres
wherever hair exists, lymphatics, bloodvessels, and nerve-plexuses.
What are the nails ?
Flattened, horny structures of modified epithelium, covering the
dorsal aspects of derma of distal phal.mges of fingers and toes.
They are convex externally, and have a root, imbedded in a groove
of skin, whence the growth in length comes ; a mairix, that por¬
tion of derma beneath, by which the nail grows in thickness; the
lunula, the white crescentic portion next to root, its color owing to
diminution in size, number, and vascularity of the papillae, which
are disposed in longitudinal rows elsewhere in the matrix.
What are the hairs ?
They are also modified epidermis, found everywhere in skin,
except palms of hands and soles of feet, but varying in size. They
each have a
ORGANS OF TASTE.
289
Root, bulbous in form, springing from a vascular papilla at the
bottom of an involution of the epidermis and corium, called a
hair-follicle, which sometimes extends into subcutaneous cellular
tissue; into the hair-follicle open one or more sebaceous glands ;
the
Shaft consists of a central or medullary portion, a fibrous portion,
and a cortical of thin flattened scales ; the medulla is commonly
absent in fine hairs ; the
Point is formed only of the flbrous and cortical portions.
Describe the sebaceous glands.
Most abundant in scalp, face, arm-pits, around nasal and oral
apertures, and in external auditory canal ; the largest are the Meibo¬
mian glands of eyelids; they are small sacculated glands, lodged
in the corium or subcutaneous tissue of nearly every part, except
palmar and plantar surfaces; the ducts usually open into hair
follicles, but sometimes on general surface of skin.
Describe the sweat glands.
They are each formed of a single convoluted tube, situated either
in deepest portion of corium, or more usually in subcutaneous
cellular tissue, and opening on free surface by a spiral duct ; the
tubes are formed of an external fibro-cellular coat, continuous
with superficial layer of corium, and a lining of epithelial cells
continuous with epidermis.
What is their estimated number and area ?
Nearly two and a half millions, forming an evaporating area of
about eight square inches.
Organs of Taste.
Where does the sense of taste reside ?
In the mucous membrane of dorsum of tongue, upper portion of
pharynx, soft palate, and fauces.
Are there any special taste-organs ?
Yes, the taste-goblets, flask-like bodies with their bases resting on
corium, and a neck opening between epithelial cells. They consist
19
290
ESSENTIALS OF HUMAN ANATOMY.
of spindle-shaped, flattened cells externally, with central spindle-
eells, whose inner flne terminations are continuous with a terminal
nerve fibril ; these bodies are found in the circumvallate and some
of the fungiform papillae, and at the side of base of tongue.
What are the special nerves of taste ?
For its anterior two-thirds, chorda tympani of facial, recognizing
acid, saline, and styptic qualities (according to Flint).
For posterior third, lingual branch of the glosso-pharyngeal, for
perception of alkaline, metallic, sweet, and bitter tastes (Flint).
Organs of Smell.
Where does the sense of smell reside ?
In the mucous membrane lining upper portion of nasal fossae,
where the olfactory nerve filaments are distributed.
Describe the nasal mucous membrane.
It is also called the Schncidcrinn, or pituitary membrane, and is
continuous with that of pharynx. Eustachian tube, tympanum.
Fir.. 102.
OEGANS OF SMELL.
291
and mastoid cells, and with that of the accessory nasal cavities, the
frontal, ethmoidal, and sphenoidal sinuses and antrum, also through
lachrymo-nasal duct, wdth conjunctiva. Its epithelium is ciliated
columnar helow, and simple columnar above ; it contains numerous
mucous glands, and in the deeper portions of epithelial layer certain
nucleated bodies are found, the olfactory cells of Schultze with
two processes, one running between epithelial cells to free surface,
the other inward, to connect with a terminal nerve fibre.
What vessels supply the exterior of the nose ?
Lateralis nasi, from facial to alae of nose ; the
Artery of septum, from superior coronary to septum ; the
Nasal branches of ophthalmic and infraorbital to dorsum and
sides of nose; the veins terminate in the facial and ophthalmic.
What are the vessels of the nasal fossae ?
Anterior and posterior ethmoidal from ophthalmic to ethmoidal
cells, frontal sinuses, and roof ; the
Spheno-palatineaxidtviig iiomsmallmeningeal, from internal maxil¬
lary to membrane over spongy hones, meatuses, and septum ; the
Alveolar, from internal maxillary to antrum ; the
Veins usually accompany the arteries, terminating in facial,
ophthalmic, and other trunks.
What are the nerves of the nose ?
Branches of facial, infraorbital, infratrochlear, and nasal branch
of ophthalmic.
Describe the nerve-supply to the nasal fossae.
The olfactory^ is distributed to mucous membrane over upper
third of septum, and superior and middle spongy bones ; the
Nasal branch of ophthalmic' supplies upper anterior part of sep¬
tum and outer wall ; the
Anterior dental branch of superior maxillary supplies inferior turbi¬
nated hone and inferior meatus ; the
Spheno-palatine^, by naso-palatine branch', supplies middle of
septum, by anterior palatine, middle and inferior spongy bones.
The Vidian'" supplies the upper back part of septum and superior
spongy bones, parts to which are also distributed the upper ante¬
rior nasal branches of spheno-palatine ganglion'.
(For bones forming nasal fossae, see p. 58.)
292
ESSENTIALS OF HUMAN ANATOMY.
The Eye.
Bescribe the eyeball.
It is a spherical organ, with the segment of a smaller transparent
sphere, the cornea, /orming its anterior portion, lying in the orbit
in a cushion of fat, and held in position by the ocular muscles, the
optic nerve, conjunctiva, and eyelids. The following points should
be studied, the
Diameters, antero-posterior in adult about ninety-five hun¬
dredths of an inch, transverse ninety-two hundredths of an inch,
vertical ninety hundredths of an inch.
Anterior and posterior poles, the centres respectively of the cornea
and fundus oculi.
Axes of eyeballs, or ocular axes which pass through the poles of
each eye and are nearly parallel, not corresponding to axes of orbits,
which diverge.
Visual axis passes from the yellow spot through the centre of
curvature of the refracting media, so that these axes converge.
Nodal point, the centre of curvature of refracting media.
Equutorinlplane, that passing through centre of eyeball at right
angles to the axis, dividing the globe into two segments, an ante¬
rior and a posterior hemisphere.
Equator, the line where the just-mentioned plane cuts the surface
of eyeball.
Meridional planes, planes coinciding with ocular axis.
Meridians, the lines where meridional planes cut surface of eye¬
ball.
What is the capsule of Tenon ?
The tunica vaginalis oculi, and consists of a thin membranous sac
isolating the eyeball and allowing free movement, arising from
optic foramen behind to become lost upon sclerotic in front, having
a visceral layer investing posterior portion of globe, and a parietal
layer lining the fatty cushion in which eye rests, both layers being
lined by flattened endothelial cells : the lymphatic vessels of the
sclerotic open into it, the cavity being a lymph space also com¬
municating with the lymph-spaces of the optic nerve sheath ; the
SCLEROTIC AND CORNEA.
293
ocular muscles pierce this capsule : that portion of the capsule be¬
hind the point of passage of the tendons is sometimes called the
Capsule of Bonnet, while to that in front the name of
Capsule of Tenon has been restricted; this is an unnecessary
refinement.
What are the ttinics or coats of the eye t
The sclerotic' and corned', the most external, protective tunic.
Choroid, iris, and ciliary processes, the middle or vascular tunic.
Retina, the innermost, nervous tunic.
What are the humors of the eye ?
The refracting media, three in number, viz., the
Aqueous^, filling anterior chamber.
CnjsiaUine*, or crystalline lens.
Vitreou^, filling posterior four-fifths of the globe.
Sclerotic and Comea.
Describe the sclerotic.
It is a firm, unyielding fibrous membrane maintaining the form of
the posterior five-sixths of the globe, thicker behind than in front,
with smooth white external surface except where tendons are
attached, covered in front by conjunctival membrane, and having
an inner brown-stained surface grooved for ciliary nerves. Pos¬
teriorly to the nasal side it is pierced by the optic nerve with whose
sheath it is continuous, the sclerotic at this point forming a thin
Lmnina crihrosa through whose openings the nerve filaments
pass, the most central orifice, called the porus opticus, transmitting
the arteria centralis retinae. Surrounding the cribriform lamella
are numerous small openings for the ciliary vessels and nerves;
the venae vorticosae emerge midway between margin of cornea and
entrance of optic nerve, and the anterior ciliary vessels around the
corneal border. The sclerotic is formed of white fibrous tissue,
mingled with.fine elastic fibres and fusiform nucleated cells. The
following points should be noted ; the
Thickness, about one-twenty-fifth of an inch posteriorly, one-six¬
tieth of an inch anteriorly ;
294
ESSKNTIALS OF HUMAN ANATOMY.
Lamina fusca, the fine cellular tissue connecting sclerotic with
choroid ; the
Subconjunctival tisme, loose areolar tissue binding conjunctiva to
sclerotic; the
Arteries are few, come from ciliary, and form a coarse network ; the
Anterior vascular zone, surrounding cornea, formed by subcon¬
junctival branches of anterior ciliary vessels; the
Nerves, whose existence is very doubtful.
Describe the cornea.
It is the transparent, projecting, anterior sixth of the external
tunic. It is not quite circular, being a little broader in the trans¬
verse than the vertical diameter, and is set in sclerotic somewhat
Fio. 103..
like a watch-crystal in its case : its thickness, one twenty-second of
an inch to one thirty-second of an inch, is nearly same throughout
except toward outer margin where it is thinner : it is non-vascular,
the capillary vessels forming loops at its circumference : the nerves
are numerous, estimated at from twenty-four to forty-five, and are
derived from the ciliary nerves.
SCLEROTIC AND CORNEA,
295
Describe the structure of the cornea.
It consists from without inward, of the following layers :
Layer of conjunctival epithelium, the deepest columnar, next poly¬
hedral, most superficial three or four layers of scaly cells ; the
Anterior elastic lamina or membrane of Bowman, one two-thousandth
to one-twelve-hundredths of an inch thick, forming a thin, firm,
elastic layer consisting of extremely closely interwoven fibrils
similar to those of corneal tissue proper, but with no corneal cor¬
puscles; the
True corneal tissue is fibrous, tough, unyielding, continuous with
sclerotic and composed of sixty, superimposed, flattened lamellœ
made up of fibrillar connective-tissue continuous with fibres of
sclerotic : the layers are held together by a cement substance in
which are corneal spaces, stellate in-form, communicating with ad¬
jacent spaces by processes, each space containing a similarly shaped
but smaller corneal corpuscle which does not entirely fill it ; the
Posterior elastic lamina (membrane of Descemet or Demours) is
a structureless, elastic, brittle, extremely thin membrane, not ren¬
dered opaque by water, alcohol, or acids : it chief peculiarity is the
tendency to roll upon itself with the attached surface innermost,
when separated from cornea proper : at its circumference it breaks
up into bundles of fibres joining the ligamentum pectinatum iridis]
the
Posterm- epithelial layer is a single layer of polygonal transparent
nucleated cells.
Describe the choroid.
It is a thin, dark-brown, vascular membrane investing the pos¬
terior five-sixths of globe terminating in front at ciliary ligament,
there bending inward to form the ciliary processes : it is connected
externally with sclerotic by the lamina fusca, and consists of two
layers, the
External layer is formed of the larger branches of the ciliary arte¬
ries and the venae vorticosaef, interspersed with stellate pigment
cells by the union of whose processes a delicate network is formed;
externally the choroid is covered by a layer of elastic fibres, the
membrana suprachoroidea, coated externally with endothelial cells;
the
296
ESSENTIALS OF HUMAN ANATOMY.
Internal layer or membrana Ruyschiana consists of a fine capillary
plexus formed by the short ciliary vessels, which is separated from
pigmentary layers of retina by the
Vitreous membrane, a thin, structureless layer.
The arteries of the choroid are the short, posterior ciliary, and
recurrent branches from the long posterior and anterior ciliary ;
the
Veins, form four to five vence vorticosce^ {Vïg. 104), which pierce
the sclerotic midway between corneal margin and optic nerve; the
Nerves are the long and short ciliary nerves.
What are the ciliary processes ?
Sixty to eighty folds formed by plaiting and folding inward of
choroid at its anterior margin, which are received between corre¬
sponding folds of the suspensory ligament of the lens ; they con¬
sist of large and small processes, irregularly alternating, the former
about one-tenth of an inch long.
What is the ciliary body ?
It is- that portion of the middle tunic between the choroid and
iris formed of the ciliary muscle and ciliary processes.
Describe the ciliary muscle^.
A grayish circular band of unstriped muscular fibre about one-
eighth of-an inch broad, thickest in front, thinnest behind, con¬
sisting of radiating and circular fibres, the former, the more
numerous, arising from junction of cornea and sclerotic to pass
backward to choroid opposite the ciliary processes ; the latter are
internal, and pursue a circular course around the insertion of the
iris; they are called the "ring-muscle" of Mnlkr and were for¬
merly described as the ciliary ligament.
Describe the circulus arteriosus major and minor.
The former is an anastomotic ring formed by long ciliary arte¬
ries in the ciliary muscle; the latter, a second anastomotic circle
formed by transverse offsets from the converging branches passing
forward from the circulus major.
Describe the iris® (Fig. 104).
It is a thin, circular, perforated contractile curtain, suspended
behind the cornea in the aqueous humor in front of the crystalline
SCLEROTIC AND CORNEA.
297
lens, forming the anterior portion of the middle ocular tunic, and
is formed of radiating and circular muscular fibres, and of a fibrous
stroma. Anteriorly it is covered hy a layer of polyhedral cells
resting on a fine basement membrane, being continuous with the
membrane of Descemet. It presents for examination the
Pupil, the nearly central opening in iris placed a little to nasal
side of centre ; the
Ligamentum pectinatum iridis, a reticular tissue, connecting iris
with cornea, derived from membrane of Descemet which sends
fibrous prolongations to iris and sclero-corneal j unction ; the
Spaces of Fontana, the intervals between the reticulated fibres of
the ligamentum pectinatum at outer angle of anterior chamber,
which communicate with a larger space in the sclerotic close to
sclero-corneal junction ; the
Canal of Schlemm or Sinus circularis iridis, lined with endothe¬
lium, a venous sinus, containing two or three plexiform veins re¬
ceiving blood from the sclerotic and ciliary plexuses and com¬
municating with anterior ciliary veins ; the
Uvea, a layer of purplish-hued pigment-cells on posterior surface
of iris continuous with pigment layer of ciliary processes ; the
Sphincter pupillae, the narrow hand of circular muscular fibres
surrounding pupil on its posterior surface, about one-thirtieth of
Fig. 104.
298
ESSENTIALS OF HUMAN ANATOMY.
an inch wide, supplied by third nerve through ophthalmic gang¬
lion ; the
Dilator pupillœ, consisting of the radiating muscular fibres con¬
verging frotn circumference of iris toward pupillary margin, where
they blend with the circular fibres ; it is supplied by sympathetic
fibres from ophthalmic ganglion ; the
MembranapiijiUlarU, a delicate, transparent, vascular membrane
which occluded the pupil in the foetus, usually disappearing about
eighth foetal month, but occasionally persisting ; it is nourished
by many small vessels continued from margin of iris to those on
front part of lens capsule; the
Arteries, are branches of long and anterior ciliary forming the
circulis iridis major and minor (see p. 296); the
Veins, empty into those of ciliary processes and anterior ciliary
veins ; the
Nenes, are branches of third, fifth, and sympathetic, through
long and short ciliary nerves, the third going to sphincter pupillae
(circular fibres), the sympathetic to dilator pupillae (radiatipg
fibres), and the fifth supplying common sensation.
What is the retina ?
The innermost ocular tunic, forming a delicate, grayish, trans¬
parent nervous membrane, thicker behind than in front, terminat¬
ing nearly as far forward as the ciliary body by a ragged margin,
the ora serrata, but its fibrous stroma covered by the pigment layer
passes forward to iris as Üít pars ciliaris retinae. It presents the
Macula lutea or yellow spot of S'ômmering, a round elevated
spot exactly in centre of retina posteriorly, which corresponds to
axis of eye; here vision is most perfect, the retina being thin,
crowded with nerve elements, bnt destitute of rods and the nerve-
fibre layer ; the
Fovea centralis is a minute central depression at summit of yellow
spot; the
Optic papilla or disk is the point of entrance of optic nerve, cen¬
trally pierced by arteria centralis retinae, lying about one-tenth of
an inch to inner side of yellow spot; it is the only portion of retina
where the sense of vision is wanting, and is therefore called the
blind spot ; the
SCLEEOTIC AND COENEA,
299
Pars eiliaris retime consists of the fibrous and pigmented portions
of retina, destitute of nerve elements, continued over ciliary pro¬
cesses to iris ; the
Arteries of retina spring from arteria centralis retinae, a branch of
the ophthalmic, which after piercing the optic nerve divides into
four or five branches which soon
enter the nervous layer of retina
to form a fine capillary plexus not
extending beyond inner nuclear
layer ; no vessels exist in the fovea
centralis and very few in the mac¬
ula lutea.
Describe the structure of the
retina.
It is exceedingly complex, being
composed from within outward of
the following ten layers,
1. Membrana limitans interna, a
transparent membrane formed of
retinal connective tissue, lying in
contact with hyaloid membrane of
vitreous humor.
2. Fibrous layer, composed of
continuations of optic nerve fibres
deprived of their medullary sheaths,
forming radiating bundles or plex¬
uses.
3. Vesicular layer, a single layer
of large ganglion cells, except at
macula lutea where there are several layers ; they have one pro¬
cess prolonged into the fibrous layer becoming continuous with a
nerve fibril, and one or more extending into inner molecular layer
or, according to some, passing through it to terminate in inner
nuclear layer.
4. Inner molecular layer, made up of a dense reticulum of minute
fibrils, mingled with processes of ganglion cells and those of next
layer, containing in the interstices minute clear granules.
Fig. 105.
300
ESSENTIALS OF HUMAN ANATOMY
5. Inner nuclear layer, containing (1) oval nuclei with two pro¬
cesses, one passing inward to inner molecular layer, believed to
become continuous with processes of ganglion cells, and another
passing into outer molecular layer, these bifurcating and (accord¬
ing to some) communicating with rod and cone fibres ; (2) nucleated
cells without branches ; (3) cells connected with fibres of Müller.
6. Ok fer molecular layer, is thinner, resembles the inner molecular
layer, but contains branched stellate cells—probably ganglion
cells.
7. Outer nuclear layer, consists of (1) rod-granules, transversely
striated cells, with an external fine process connected with a single
rod of Jacobs's membrane, and an internal prolongation which
enlarges, then breaks up into minute fibrils entering the outer
molecular layer; and (2) cone-granules, closely connected with
cones of Jacobs's membrane, with a thick process passing inward,
1 ecoming bulbous and terminating by numerous fibrillse, which
enter outer molecular layer.
8. External limiting membrane, a membrane formed of retinal
connective tissue, perforated by numerous openings.
9. Jacobs's membrane or rods and cones, composed of rod-< arranged
perpendicularly to surface, each composed of an outer and inner
portion joined by cement substance ; and cones, with apices directed
toward choroid, formed of two portions and like rods their outer
segments are transversely striated ; this is probably the perceptive
layer of retina.
10. Pigmentary layer, formerly considered part of choroid, con¬
sisting of a single layer of hexagonal, pigmented epithelial cells.
The connective tissue is modified to form a fenestrated, sponge¬
like structure the membrane of Müller.
The Humors.
What is the aqueous humor ?
A small amount of clear alkaline fluid composed of water 96.7,
albumen 0.1, sodium chloride and extractive 8.2, filling anterior
and posterior chambers of the eye.
THE HUMORS.
301
What are the anterior and posterior chambers of the eye ?
The anterior chamber is a space filled with aqueous humor
bounded in front by cornea, behind by front of iris, and communi¬
cating through pupil with the
Posterior chamber, also filled with aqueous humor, which is now
thought to be only a narrow chink between peripheral portion of
iris, the suspensory ligament, and ciliary processes.
Describe the vitreous humor.
This forms about four-fifths of entire globe, is transparent, of the
consistence of thin jelly, and is composed of an albuminous saline
fluid enclosed, except where hollowed out for crystalline lens, in a
delicate hyoloid membrane, beneath which are small, granular,
nucleated cells; it possesses neither vessels nor nerves, and is
hollowed out in front where the crystalline lens reposes. Running
from entrance of optic nerve to posterior surface of crystalline
lens is the canal of Stilling or hyaloid canal, filled with fluid and
lined with a proce.ss of the hyaloid membrane.
Describe the crystalline lens with its ligaments, etc.
It is a transparent double convex body, more convex posteriorly
than in front, enclosed in a capsule, and is lodged in a depression
of the vitreous humor, where it is retained by its suspensory liga¬
ment. It lies immediately behind the pupil surrounded and
slightly overlapped by the ciliary processes, measuring about one-
third of an inch transversely by one-fourth of an inch antero-
posteriorly, and is composed of water 60, soluble albuminous
matter 35, insoluble albuminous matter 2.5, fat and Cholesterine 2
per cent. ; its
Capsule, is transparent, very elastic, and brittle, measuring one-
two thousandth of inch in front, one-six thousandth of an inch be¬
hind, and is attached anteriorly to lens by a .single layer of
polygonal nucleated cells, which absorb fluid post-mortem, and
breaking down from the liquor Morgagni ; the
Suspensory ligament or zonula of Zinn, is a thin transparent
membrane, containing longitudinal elastic fibres, connecting an¬
terior margin of vitreous with anterior surface of lens near its cir-
302
ESSENTIALS OF HUMAN ANATOMY.
cumference, presenting upon its outer surface a number of folds
between which fit the similar projections of the ciliary processes ;
the
Canal of Petit is about one-tenth of an inch wide, passing around
circumference of lens, bounded in front by suspensory ligament,
behind by vitreous humor, its base being formed by capsule of
lens ; when inflated it becomes sacculated.
What is the structure of the crystalline lens ?
It is formed of numerous laminae, composed of hexagonal fibres
one-five thousandth of an inch broad, with serrated margins, those
of contiguous fibres accurately fitting one another ; the lens is also
divisible after boiling or immersion in alcohol into three triangular
segments with their bases outward. The central harder portion is
called the nucleus, the peripheral portions the cortex ; it possesses
neither vessels nor nerves.
Describe the muscles of the eyeball.
Rectus superior^ : origin, upper margin of optic foramen and
sheatb of the optic nerve; insertion, sclerotic coat three to four lines
from cornea; ac¿íow, turns eyeball upward ; nerve, third cranial.
Rectus inferior' : origin, ligament of Zinn ; insertion, sclerotic
three to four lines from cornea; action, turns eye downward;
nerve, third cranial.
Rectus internus: origin, ligament of Zinn; insertion, sclerotic
three to four lines from cornea ; action, turns eye inward ; nerve,
third cranial.
Rectus externus^ : origin, by two heads, the upper' from the outer
margin of optic foramen, the lower' from ligament of Zinn, and a
pointed bony process at the lower margin of the sphenoidal fissure;
insertion, sclerotic, as other recti ; action, turns eye outward ; nerve,
sixth cranial (abducens): between the two heads pass the oph¬
thalmic vein, the third, nasal branch of the fifth, and the sixth
cranial nerves.
Obtiquus superior- : origin, one line above the inner margin of
the optic foramen, terminating in a rounded tendon which plays
through a fibro-cartilaginous ring or pulley' beneath the internal
angular process of the frontal bone, whence it passes beneath the
superior rectus ; insertion, sclerotic between superior and external
THE HUMORS.
303
recti, midway between the cornea and entrance of the optic nerve ;
action, rotates eye on its antero-posterior axis ; nerve, fourth cranial
(patheticus).
Obliquas inferior^": origin, orbital plate of superior maxillary;
insertion, sclerotic between superior and external recti; action,
rotates eyeball on antero-posterior axis ; nerve, third cranial.
(For muscles of lids see pp. 11'6, 117.)
Fig. 106.
Recapitulate the nerve supply of the ocular muscles.
Third cranial, or motor oculi, supplies superior, internal and in¬
ferior recti, and inferior oblique muscles.
Fourth cranial or patheticus, supplies superior oblique muscle.
Sixth cranial or abducens, supplies external rectus muscle.
Describe the vascular supply of the eyeball and its append¬
ages.
(All branches of the vessels not supplying these parts will be
omitted, having been already described on page 161.)
Ophthalmic, arising from cavernous portion of internal carotid,
entering orbit by optic foramen, giving olf the
304 ESSENTIALS OF HUMAN ANATOMY.
Lachrymal to lachrymal gland, conjunctiva, and upper eyelid,
inosculating with palpebral arteries.
Supra-orbital, supplies levator palpebrae and superior rectus
muscles.
Superior and inferior palpebral, supply eyelids.
Nasal, supplies lachrymal sac.
Short ciliary, twelve to fifteen' in number, penetrate sclerotic
around optic nerve entrance to supply choroid and ciliary processes.
Long ciliary, two in number, penetrate sclerotic, pass forward
between it and choroid to supply iris, forming circulas iridis major
near ciliary margin, and circulas iridis minor, near margin of pupil.
Anterior ciliary, spring from muscular branches, perforate scle¬
rotic, and join circulus iridis major.
Arteria centralis retinm, obliquely traverses optic nerve to be
distributed to retina.
Muscular branches, one superior, one inferior, to ocular muscles.
Anterior cerebral, from internal carotid, gives twigs to optic
nerve.
Lnfra-orbital, from internal maxillary, supplies inferior rectus
and inferior oblique muscles and lachrymal gland.
What are the chief lymph-spaces of the eyeball ?
The perichoroidal space, between choroid and sclerotic.
Cavity of capsule of Tenon, between eyeball and capsule.
Vaginal space, between optic nerve and sheath.
What veins rettirn the blood from the eye ?
The superior and inferior ophthalmic emptying into the cavernous
sinus ; they also freely anastomose with the facial veins.
Name the nerves of the eye.
Optic or second cranial, nerve of special sense : motor nerves, the
third, fourth, sixth, and sympathetic filaments.
The Ophthalmic division of fifth, supplies general sensation by
Lachrymal, to same-named gland, conjunctiva, and skin of upper
eyelid; also the following branches :
Frontal
THE HUMOES.
305
The sympathetic arises from cavernous and carotid plexus re¬
ceiving communicating filaments indirectly from spinal nerves,
and sending branches to third, fourth, fifth, and sixth nerves; the
dilator fibres (radiating) of iris, ciliary ganglion, muscles of orbit
and lids, with walls of arteries, receive their sympathetic nerve
supply from this source ; the
Short ciliary, numbering about ten, arise from ciliary (ophthal¬
mic) ganglion, and pierce the sclerotic posteriorly, to ramify in
sheath of optic nerve, choroid, ciliary muscle, iris, and cornea;
the
Ascending branches of the spheno-palatine {Meckel's) ganglion,
reaching orbit by spheno-maxillary fissure, usually considered to
supply only periosteum, are believed by some to go to optic and
sixth nerves and ciliary ganglion.
Give a brief description of optic tracts.
The deep origin of the nerve fibres of these tracts are the optic
thalami, corpora geniculata, and nates of corpora quadrigemina,
which, forming two flattened bands, wind around crus cerebri, to
which they are slightly attached, as well as to lamina cinerea and
tuber cinereum, and joining in front of latter they form the optic
commissure (see page 200 for illustration and more elaborate descrip¬
tion).
What course do the nerve fibres pursue in the optic com¬
missure or chiasm?
The most numerous, the decussating fibres, connect the right
hemisphere with the left retina, and the left hemisphere with the
right retina, occupying the centre of the commissure.
Other fibres {longitudinal, cerebro-retinal) connect each hemi¬
sphere with the retina of its own side.
Others {inter-cerehral) pass posteriorly, connecting the two optic
tracts.
Others {inter-retinal) pass anteriorly, connecting the two retinae.
What are the origin and course of the optic nerves ?
They arise on either side from the optic commissure, each passes
into the orbit through optic foramen with central artery of retina,
which pierces it, and enter eyeball through lamina cribrosa one-
20
306 ESSENTIALS OF HUMAN ANATOMY.
tenth inch to nasal side of globe, to aid in forming retina ; these
nerves are surrounded with a sheath derived from the dura mater
between which and nerve is a lymph space communicating with
subarachnoid space.
APPENDAGES OF EYE.
(Tutamina Oculi.)
Name these.
Eyebrows, or super cilia, Lachrymal gland ' and ducts'^,
Eyelids, or palpebrce, Lachrymal sac.
Conjunctiva''', a mucous Lachrymo-nasal duct.
membrane,
What are the eyebrows ?
The arched eminences of skin surmounting upper margins of
orbits on each side, from which grow several rows of short, ob¬
liquely placed hairs ; by the attached muscles the eyebrows can
partially shut off light from eyes.
What are the eyelids ?
Two movable curtains protecting by their closure the eyes from
injury ; the upper lid is the larger and more movable, having its
own elevator muscle ; the
Palpebral fissure is the elliptical space between the margins of
lids when opened, the internal and external angles being called,
respectively, the internal and external canthus, the former being
prolonged inward, leaving a triangular space between the lids, the
lacus lachrymalis, at the commencement of which is a small eleva¬
tion on each lid, the lachrymal papilla^, whose summit is pierced
by a minute opening, punctum lachrymalf?, the commencement
of the lachrymal canal.
What structures form the eyelids ?
Externally the skin, beneath which is much loose areolar tissue,
separating it from the fibres of the orbicularis palpebrarum muscle.
The lids retain their shape by means of the so-called tarsal carti-
APPENDAGES OF EYE.
307
läge»—in reality dense connective tissue without cartilage cells—
that for the upper lid heing semilunar and the larger, that for lower
lid elliptical ; these structures are connected at their orbital mar¬
gins with the circumference of the orbit by a fibrous membrane,
the tarsal ligaments, while in addition a rounded fibrous cord,
the tendo-oeuli, passes between the inner angle of each and the
nasal process of superior maxillary bone.
Imbedded in the cartilages are numerous sebaceous glands, the
Meibomian glands, discharging their secretion upon the free edge
of lids, preventing their adhesion ; they number thirty or forty in
the upper lid, fewer in the lower lid.
Attached to the free margins of lids is a double or triple row of stiff
hairs, curved in each lid so that their convexities meet, preventing
interlacing, these are the cilia, or eyelashes-, the inner surfaces of
lids are lined by a mucous membrane, the conjunctiva.
Their vascular supply is from the palpebral branches of ophthalmic
artery anastomosing with contiguous branches of facial.
The nerves are the third, seventh, and sympathetic to muscles,
the ophthalmic branch of fifth to skin and conjunctiva.
Describe the conjunctiva.
It is a mucous membrane lining the inner surfaces of the eyelids
and reflected thence upon anterior segment of sclerotic, its epithe¬
lial layer passing over cornea ; the
Palpebral conjunctiva is thick, opaque, vascular, and covered
with papillae, containing numerous glands ; at the inner angle of
the eye it forms a semilunar fold, plica semilunaris^ (Fig. 108).
The folds formed by the passage of the conjunctiva from lids to eye¬
ball are called the superior and inferior palpebral folds, the former
being the deeper; they contain numerous convoluted mucous
glands; the
Ocular conjunctiva is thin, transparent, possesses few vessels in
health, and is loosely attached to globe by the subconjunctival
areolar tissue.
What is the carúncula lachrymalis® (Fig. 108) ?
It is a small, conical, reddish body, at inner canthus, occupying
the space called the lacus lachrymalis, and is formed of a group of
follicles, resembling the Meibomian glands, covered with con¬
junctiva; from the caruncle project a few slender hairs.
308
ESSENTIALS OF HUMAN ANATOMY.
Describe the lachrymal apparatus.
It consists of the lachrymal gland with its ducts, the canaliculi,
the lachrymal sac, and the nasal duct. The
Lachrymal gland} (Fig. 107) is au oval, compound racemose
gland of the size and shape of an almond, lodged in a depression
at upper, outer portion of orbit, its concave under surface resting
upon the globe of eye, the conjunctiva, superior and external recti
muscles intervening ; it is held in contact with orbital periosteum
by a few fibrous hands. It has six or seven
Duct^ (Fig. 107), opening by minute orifices on upper outer
half of palpebral conjunctiva near superior retro-tarsal fold. The
secretion, or the
Tears, are taken up by the puncta, thence passing through canal¬
iculi into lachrymal sac and nasal duct, thus reaching inferior
meatus of nose.
Describe the canalieuli.
They are two minute canals^ about one-half a line in diameter,
commencing at the puncta, the superior passing upward, then
bending acutely to pass inward to lachrymal sac, the inferior
passing downward, then upward and inward ; they are lined with
mucous membrane continuous with conjunctiva, and are one-third
of an inch long.
Fig. 107.
Fig. 108.
THE BAR.
309
What is the lachrymal sac^ (Fig. 108) ?
It is the flattened, ovoidal, sacciform dilatation of upper part of
nasal duct, lodged iu the groove formed by lachrymal bone and
nasal process of superior maxillary ; its walls are formed of fibrous
elastic tissue covered in by tensor tarsi muscle and a fibrous ex¬
pansion from tendo-oculi attached to ridge of lachrymal bone,
while internally it is lined with mucous membrane.
Describe the nasal duct^.
It is a membranous canal about three-fourths of an inch long
extending from the termination of lachrymal sac through osseous
nasal duct to inferior meatus of nose, passing in a direction down¬
ward, backward, and slightly outward, its lumen being narrowest
about the midpoint; externally, it is composed of fibro-areolar
tissue ; internally, of mucous membrane continuous with that of
nose and lachrymal sac, the epithelial coating of both being of cili¬
ated epithelium, that of the canaliculi of scaly cells.
What is the valve of Hasner ?
An imperfect valve of mucous membrane guarding the some¬
what expanded terminal opening of the duct into the inferior
meatus of nose.
The Ear.
Where is the auditory apparatus lodged ?
In the petrous and mastoid portions of the temporal hone.
Enumerate the divisions.
Middle ear, or tympanum, comprising -
Internal ear, or labyrinth, comprising ■
The External ear, comprising the
Auricle, ot pinna.
External auditory canal.
Membrana tympani.
Cavity of tympanum.
Mastoid cells.
Eustachian tube.
Vestibule,
Semicircular canals.
Cochlea,
Auditory nerve.
810 ESSENTIALS OF HUMAN ANATOMY.
The External Ear.
What is the auricle ?
Its foundation is an expanded layer of fibro-cartilage, so disposed
in ridges as to concentrate and direct the waves of sound into the
external auditory canal, to which it is attached ; the cartilage is
deficient at certain points where it is connected by fibrous tissue;
it is covered with perichondrium, outside of which is thin, firmly
adherent skin, containing sweat and sebaceous glands, and provided
with short downy hairs. The various ridges and depressions are as
follows : the
Concha, the deep cavity leading into meatus ; the
Tragus, the pointed prominence in front of concha projecting
back over meatus, bearing on its under surface tufts of hairs; the
Antitragus, a small tubercle opposite tragus, separated by a deep
notch, the indsura intertragica ; the
Helix, the external prominent margin of auricle ; the
Antihelix, a parallel prominence anterior to former, bifurcating
above to form the
Fossa of the antihelix ; the
Fossa of helix, the narrow, curved depression between the helix
and antihelix.
What is the lobe or lobule of the ear ?
The inferior, soft pendulous portion, formed of fat and connective
tissue enclosed by integument.
Describe the muscles of the external ear.
The attolens aurem, attrahens aurem, and retrahens aurem, have
been described on page 116.
The muscles of the auricle, but slightly developed in man, are
the
He/icis major : a narrow, vertical band on anterior border of helix ;
Heiids minor: an oblique band at root of helix ;
Tragicus. a short, vertical band on outer surface of tragus ;
Anfitrag/cus : stretching from outer part of antitragus to lower
part of helix ;
THE MIDDLE EAR OR TYMPANUM.
311
Transirersus auriculce : radiating from posterior surface of con¬
vexity of concha to prominence caused by groove of helix ;
Obliquus auris: a few fibres passing from upper back part of
concha to convexity immediately above.
Give the vascular and nervous supply to the auricle.
The arteries are Posterior auricular, from external carotid.
Anterior auricular, branch of temporal.
Auricular, branch of occipital.
The veins accompany the corresponding arteries.
The nerves are, Auricularis magnus, from cervical plexus.
Posterior auricular, from facial.
Auricular branch (Arnold's) of pneumogastric.
Auriculo-temporal, from inferior maxillary divi¬
sion of fifth nerve.
Occipitalis major and minor.
What is the external auditory canal ?
It is an osseo-cartilaginous, oval, cylindrical canal, with greatest
diameter vertical at external orifice, but reversed at tympanic end;
it is narrowest at middle. About one and a quarter inches long, it
is directed obliquely forward and inward, and slightly curved with
convexity upward, and is lined by thin adherent skin, containing
hair follicles, sebaceous and ceruminous glands in its cartilaginous
portion. A narrow groove at the tympanic extremity, for insertion
of membrana tympani, is sometimes called the sulcus tympanicus,
interrupted above by the notch of Ricinus.
What are the arteries and nerves ?
The arteries are branches of posterior auricular, internal maxil¬
lary and temporal.
The nerves come chiefly from auriculo-temporal branch of supe¬
rior maxillary division of fifth nerve.
The Middle Ear or Tympanmn.
Describe the membrana tympani.
It forms the outer wall of the tympanum, and is an oval, trans¬
lucent membrane placed obliquely at the bottom of external audi-
312
ESSENTIALS OF HUMAN ANATOMY.
tory meatus, with its anterior, shallow funnel-shaped surface facing
downward, forward, and outward ; at its upper anterior border is a
white, pointed tubercle, formed by the short process of the malleus^
while a yellowish-white stripe passing from this downward and
backward toward the centre, indicates the handle of the malleus.
During life, when illuminated, the membrana tympani presents a
triangular light spot or " cone of light," having its apex at end of
malleus handle, whence it spreads downward and forward, and a
darker central portion, the umbo, or shadow. The upper anterior
part bridging a small notch in the bony ring to which the mem¬
brane is attached (the notch of Rivinus), is laxer, consisting of
loose connective tissue, vessels, and nerves, covered with skin and
mucous membrane, and has received the name of the membrana
flaccida, or Shrapnell's membrane.
Of what tissues is the membrana tympani composed ?
Of the skin, which is derived from the lining of the meatus; of
a fibrous layer, some of whose fibres radiate from near the centre
to the circumference, others form a dense ring around the attached
margin ; and of mucous membrane, derived from that lining the
tympanum. The handle of the malleus passes between the inner
and middle layers—according to von Tröltsch,it is received between
the circular and radiating fibres of the middle coat; an anterior
and a posterior pouch have also been described upon the posterior
surface by von Tröltsch, opening downward, formed by a " dupli-
cature of the membrana tympani extending from its border for¬
ward to the manubrium."
Describe the arterial supply of the membrana tympani.
The deep auricular branch of internal maxillary supplies the ex¬
ternal layers forming a plexus, which communicates at the
periphery with one in the mucous membrane formed from
Tympanic branches of internal maxillary and internal carotid
arteries, and by the
Vidian, from internal maxillary, and
Stylo-mastoid, from posterior auricular.
Mention the nerves supplying the membrana tympani.
To the external layer run filaments from the superficial temporal
branch of the fifth, while the mucous layer is supplied by the
tympanic plexus.
THE TYMPANUM. 313
The Tympanum.
Describe it.
It is aa irregular cavity, measuring about one-balf of an inch
antero-posteriorly, one-third of an inch vertically, and one-fifth of
an inch transversely, situated in the petrous bone, compressed
from without inward, being placed above the jugular fossa, having
the carotid canal in front, the mastoid cells behind, the external
meatus externally, and the labyrinth internally ; it communicates
with the pharynx by the Eustachian tube, and presents for exami¬
nation the following points ; the
Roof, a very thin plate of bone, indicated on cranial surface by
a depression on posterior surface of petrous portion of temporal
bone ; the
Floor, narrow, corresponding to jugular fossa, and presenting
near inner wall a small foramen for Jacobson's nerve-, the
Outer wall, the membrana tympani and bony ring to which it is
attached, presenting three small orifices, the
Iter chordœposterius, opening in angle of junction between pos¬
terior and external walls, just behind membrana tympani on a
level with its centre, for entrance of chorda tympani nerve ; the
Olaserian fissure, just above and in front of bony ring giving
origin to membrana tympani, for passage of laxator tympani muscle
and some tympanic vessels, and the lodgement of the long process
of malleus; the
Iter chordae anterius or canal of Huguier, opening just above pre¬
ceding, for escape of chorda tympani nerve; the
Inner wall is vertical, looking directly outward, and presents the
Fenestra ovalw or oval window, a kidney-shaped opening leading
into vestibule, closed by base of stapes with its ligament ; the
Fenestra rotunda or round window, below, at bottom of a funnel-
shaped depression, opening into scala tympani of cochlea, closed
by the membrana tympani secundaria ; the
Promontory, a rounded hollow eminence—the first turn of the
cochlea—situated between oval and round windows, and present¬
ing three grooves lodging branches of tympanic plexus; the
Eminence of the aqumductus Fallopii, passes above oval window,
314
ESSENTIALS OF HUMAN ANATOMY.
along inner tympanic wall, to curve behind that opening nearly
vertically downward along posterior wall ; the
Pyramid, a hollow conical projection, behind the oval window
and in front of vertical portion of aquseductus Fallopii, containing
the stapedius muscle whose tendon escapes from its summit ; a
minute canal communicates with the aquaeductus Fallopii trans¬
mitting the nerve to stapedius muscle ; the
Posterior wall, presenting the
Openings of the mastoid cells, one large and several smaller open¬
ings. The anterior wall, is wider above than below, corresponding
with carotid canal, the thin bony partition being perforated by
tympanic branch of carotid ; it presents the
Orifice of the canal for the tensor tympani muscle, which is situated
above, close to aquaeductus Fallopii, on the summit of a small
conical eminence, the anterior pyramid-, the
Opening of Eustachian tube, is immediately below preceding, sepa¬
rated by a thin horizontal bony plate, the processus cochleariformis.
What are the ossicles of the tympanum ?
Three bones forming a movable chain, passing between mem¬
brana tympani and oval window, called the
Malleus or hammer, consisting of
an oval head articulating with
incus, a neck, a manubrium or
handle, affording attachment near
its root to tensor tympani mus¬
cle, a short process coming in con¬
tact with membrana tympani, and
& processus gracilis or long process,
lodged in the Glaserian fissure, and
giving attachment to so-called
laxator tympani muscle ; the
Incus or anvil, having a body
articulating with malleus, a long
process terminating in a rounded end, the os orbiculare, which
articulates with head of stapes, and a short process attached to
margin of opening into mastoid cells; the
Fig. lOa.
THE TYMPANUM.
315
Stapes or stirrup, consists of a head articulating with os orbicu-
lare, a neck receiving insertion of stapedius muscle, two branches
or crura joining the oval base, which latter is connected with
margins of oval window by ligamentous fibres.
Describe the ligaments of the ossicles.
The suspensory ligament of the malleus, passing between tympanic
roof and head of malleus : the
Posterior ligament of malleus, or laxator tympani minor muscle of
Sömmering, passing from upper back part of external meatus to
handle of malleus and processus brevis ; tbe
Posterior ligament of the incus, passing between posterior tym¬
panic wall near margin of opening into mastoid cells and end of
short process of incus ; the
Suspensory ligament of the incus, descending from tympanic roof
to incus, near its articulation with malleus ; the
Annular ligament of stapes, connecting circumference of its base
to margins of oval window ; the
Capsular ligaments, around articulations between incus and
malleus, and incus and stapes, these joints having their surfaces
coated with cartilage, and being provided with a synovial mem¬
brane.
Other ligaments have been described under special names, as
the anterior and external ligaments of the malleus, and the obtu¬
rator ligament of the stapes, this latter being a membrane filling
up opening between crura of stapes.
Describe the muscles of the tympanum.
Tensor tympani: origin, under surface of petrous bone, cartilaginous
Eustachian tube, its own osseous canal ; insertion, handle of mal¬
leus near root ; action, draws membrana tympani inward—i. e.,
increases tension ; nerve, from otic ganglion.
Laxator tympani major: origin, spinous process sphenoid bone,
and cartilaginous Eustachian tube ; insertion, neck of malleus above
processss gracilis; action, relaxes membrana tympani; nerve, tym¬
panic branch of facial. (Now called ant. ligament of malleus.)
Laxator tympani minor : origin, upper back part external meatus ;
insertion, handle of malleus and processus brevis ; action, relaxes
membrana tympani. (Now caXleàposterior ligament of malleus.)
316
ESSENTIALS OF HUMAN ANATOMY.
Stapedius : oriyin, from interior of pyramid ; insertion, neck of
stapes; acíio», compresses contents of vestibule; filament of
facial.
Describe arterial supply of the tympanum.
The tijinpunic branch of the internal maxillary enters by Gla-
serian fissure and is distributed to membrana tympani (tympanic
branch of carotid also supplies this), anastomosing with Vidian
and
Stylo-mastoid, from posterior auricular to back part of tympanum
and mastoid cells.
Petrosal, from middle meningeal, entering through hiatus
Fallopii.
Tijinpanic, from internal carotid.
Vidian, from internal maxillary.
Branch, from ascending pharyngeal passing up Eustachian tube.
What nerves supply the tympanum ?
The Tympanic branchof the glosso-pharyngeal (Jacobson's nerve),
which pierces floor of tympanum to supply fenestrae and mucous
membrane, and aids in forming tympanic plexus-, the
Tympanic branch of facial, supplying stapedius muscle; the
Branch from otic ganglion, supplying tensor tympani muscle.
(The chorda tympani from facial, passing into tympanum by iter
chordae posterius, emerging by iter chordae anterius, arching across
cavity between handle of malleus and long process of incus ; it is
covered by mucous membrane and gives off no branches.)
Describe the formation of the tympanic plexus.
The tympanic branch of glosso-pharyngeal, or Jacobson's nerve,
divides into three branches, lying in grooves on the promontory,
one passes forward and downward to join carotid plexus, another
passes upward to join greater superficial petrosal nerve in hiatus
Fallopii, the third passes upward and forward through petrous
bone close to ganglionic enlargement of facial, from which it re¬
ceives a filament, and becomes ihQ lesser superficial petrosal nerve-,
the tympanic mucous membrane is supplied by branches from this
plexus.
THE TYMPANUM.
317
Describe the Eustachian tube.
It is about one and one-half inches long, passing downward,
forward, and inward, the passage hy which the air in the middle
ear freely communicates with that in the pharynx, thus permitting
free vibration, as the hole in the side of a drum does. It con¬
sists of about one-third hone, and two-thirds fihro-cartilage and
fibrous tissue ; the tympanic orifice measures about one and one-
half inch, the oval pharyngeal opening one-third inch.
The osseous portion, is one-half inch long, commencing at lower
part of anterior tympanic wall, gradually narrowing to terminate
at angle of junction of petrous and squamous portions of temporal
bone; the
Chrtilaginous portion is about one inch long, formed by a tri¬
angular plate of elastic fibro-cartilage curved upon itself into a
partial tube, but interiorly the margins are not in contact, the
defect being filled by fibrous tissue ; the
Mucoils membrane is continuous with that of pharynx, and is
covered by ciliated epithelium.
Where is the pharyngeal orifice situated ?
At upper lateral portion of pharynx behind posterior part of
inferior meatus, just above the level of nasal fioor.
Has this tube any special muscles ?
Yes, the following have been described:
Spfieno-salpingo-staphy/inis : origin, sphenoid bone and cartilag¬
inous tube ; insertion, convex external border of cartilage ; nerve,
internal pterygoid ; action, abductor or dilator of tube.
Salpingo-pharyngeus : a thin layer beneath mucous membrane,
probably really a fascia.
(The Levator paiati : origin, temporal bone and cartilaginous tube;
nerve, pneumogastric ; insertion, osseous tube, cartilage, and mucous
membrane ; action, dilates tube transversely.)
Give the arterial supply of the Eustachian tube ?
The ascending pharyngeal, from external carotid.
Branches of middle meningeal, from internal maxillary.
318
ESSENTIALS OF HUMAN ANATOMY.
Branch, from stylo-mastoid artery.
The nerves are, in addition to those supplying muscles of tube
(supra), from the fifth and seventh pairs and glosso-pharyngeal.
The osseous labyrinth, consisting of
Internal auditory canal, at bottom of which the auditory nerve
enters.
Auditory nerve (eighth cranial, or portio mollis of seventh),
with the
Organ of Corti, what the retina is to the eye, viz., the terminal
and receptive auditory apparatus.
Describe the internal ear.
Tt is formed by a series of cavities excavated in the petrous
bone, communicating externally with middle ear by the round
and oval windows, internally, with internal auditory meatus :
within the osseous labyrinth, surrounded by the
Perilymph, is the membranous labyrinth—filled with endolymph—
upon which the auditory nerve filaments are distributed.
Describe the various subdivisions of the osseous labyrinth.
The vestibule is the common central cavity with which all parts
of the internal ear communicate, placed behind cochlea in front of
semicircular canals, at inner side of tympanum ; it is ovoid,
measuring about one-fifth of an inch from before backward, as well
as from above downward, and presents the
Fenestra ovalis, or oval window, on its outer wall, closed in the
fresh state by base of stapes and its ligament ; the
The Internal Ear or Labyrinth.
Name its divisions.
1 Cochlea!^,
f Utricle,
j Membranous semicircular
Membranous labyrinth, consisting of canals,
Saccule,
Membranous cochlea.
THE INTERNAL EAR OR LABYRINTH. 319
Fovea hemispherical, a small, circular depression on its inner wall,
perforated antero-inferiorly by several minute foramina for branches
of auditory nerve, the perforated plate,
called ihñ maeula cribrosa-, the Fig. 110.
Pyramidal eminence, a vertical ridge
behind macula cribrosa; the
Aquœductm vestîbuli, at back of inner
wall, transmitting a small vein, and, ac¬
cording to some, containing a tubular
prolongation of lining membrane of ves¬
tibule, ending in a blind end in cranial
cavity between layers of dura mater ; the
Fovea semi-elliptica^, a transversely-
oval depression on roof, separated by
pyramidal eminence from fovea hemispherica ; the
Orifices of semicircular canals, these are five in number, opening
behind; the
Apertura scalœ vestibuli cochleae, a large oval opening, is situated
anteriorly.
Describe the semicircular canals',®,^.
They are three curved bony tubes, each describing the greater
part of a circle, of unequal length, of a diameter of about one-
twentieth of an inch, each lying at a right angle to the other two,
and presenting at one end a dilatation, or ampulla, more than
double the diameter of the tube ; the
Superior semicircular canaV" is vertical, describes about two-thirds
of a circle, passes at right angles tq posterior surface of petrous
bone, and forms a projection upon its anterior surface ; its outer
end is its ampulla, opening separately into vestibule ; its inner un-
dilated extremity joins with that of the
Posterior semicircular canaP, opening by a common orifice at back
of vestibule ; this canal is also vertical, is nearly parallel to pos¬
terior surface of petrous bone, is the longest, the dilated extremity
opening at lower back part of vestibule; the
External, or horizontal semicircular canaV, is the shortest, is di¬
rected outward and backward, is ampullated, and opens into vesti¬
bule just above oval window, its other extremity by a separate
orifice at upper back part of vestibule.
320
ESSENTIALS OF HUMAN ANATOMY.
The œohlea^ is conical, somewhat resembles a snail-shell, forms
the anterior part of the labyrinth, is placed almost horizontally in
front of the vestibule, its apex directed toward the upper front
part of tympanic wall, and its base corresponding to anterior perfo¬
rated depression at bottom of internal auditory meatus; it presents
for examination the
Modiolus, a central, conical axis, perforated by numerous canals
for filaments of cochlear branch of auditory nerve, its apex termi-
minating in a delicate expanded
lamella, like a funnel divided lon¬
gitudinally, called the infundihu-
lum\ extending from base to apex
is a canal, the canalis centralis modi¬
oli, for a small nerve and artery;
making two and one-half spiral
turns around the modiolus is the
Spiral canal^, about one-tenth of
an inch in diameter, and one and a
half inches long, narrowing from
base to apex, there forming the
cupola, where the scala tympani and scala vestibuli, formed by the
lamina spiralis, communicate by the helicotrema.
The cochlea presents three openings, viz., the round window,
communicating with tympanum, the oval one opening into vesti¬
bule, and that of the aquoeductus cochless'; projecting from the
modiolus is the
Lamina spiralis osseal », a process formed of two bony lamellae,
between which are numeroui canals for nerve fibres, defective in
last half turn of cochlea leaving an aperture, the helicotrema, and
terminating by the hook-like hamular process^; winding around
the modiolus at the point of attachment of the lamina spiralis is
the canalis spiralis modioli, lodging the enlargement of the cochlear
nerve containing ganglion cells, called the ganglion spirale, whence
come the nerve branches to the organ of Corti.
What is the scala vestibuli*- '• (Fig. Ill) ?
It is that portion of the canal of the cochlea above the lamina
spiralis and membrane of Reissner, communicating with vestibule
Fig. 111.
THE INTERNAL EAR OR LABYRINTH. 321
below and scala tympani above, by tbe helicotrema ; it is filled
with perilymph.
Describe the scala tympani»-
It is that portion of the spiral canal below the lamina spiralis^' »•
and membranous cochlea, terminating below interiorly at the round
window—which is closed by membrane, the mnnhntwt tympani
secundaria—and communicating above with scala vestibuli at heli¬
cotrema; it is filled with perilymph.
What is the aquaeductus cochleae''?
A small canal transmitting a vein from cochlea to jugular vein,
commencing at lower wall of scala tympani, and ending to inner
side of carotid canal close to posterior surface o.f petrous bone.
Describe and name the subdivisions of the membranous
labyrinth.
It consists of a'series of closed membranous sacs containing endo-
lymph ; its various parts are called
' 1. two membranous sacs.
Saccule, j
with the former of which communicate three
Membranous semicircular canals.
The utricle and saccule are separate, but are indirectly connected
by a minute canal passing from saccule to the similar one from
utricle, passing along aquaeductus vestibuli to end by a blind pouch
near posterior surface of petrous bone; the saccule communicates
with scala media (or membranous cochlea) by the canalis reuniens.
The endolymph in all parts is thus seen to communicate freely.
Describe tbe utricle.
It is an oblong, laterally compressed sac, filled with endolymph,
placed in upper back part of vestibule in fovea semielliptica, com¬
municating behind with semicircular canals by five openings, and
has distributed, chiefly at one part of its walls, numerous branches
of the auditory nerve, at which point is a round mass of minute
crystals of calcium carbonate, bound together by delicate fibrous
tissue forming the otoliths, otoconia, or ear-stones ; the thickening of
21
322 ESSENTIALS OF HUMAN ANATOMY.
the wall both of utricle and saccule, where the nerves penetrate,
is sometimes called the macula acoustica.
FIG. 112.
What are the membranous semicircular canals ?
They are three canals of the same shape but smaller than the
containing osseous canals, to which they are fastened by numerous
fibrous bands, conveying the auditory nerve filaments to the
ampullae; like the osseous canals they have five orifices which
open into the utricle.
Describe the saccule.
media by canalis reuniens, a small passage connecting the two
cavities.
What is the membranous cochlea'^" 113).
More usually called scala media or ductus cochlearis (Fig. 113)
Fig. 113.
It is a globular sac, smaller
than utricle, to which it is at¬
tached at one point, and lies in
fovea hemispherica ; it is sur¬
rounded with perilymph, and
indirectly communicates by a
short canal with utricle by
means of the blind canal pass¬
ing along aquseductus vestibuli
to terminate near posterior sur¬
face of petrous bone ; and with
membranous cochlea or scala
THE INTERNAL EAR OR LABYRINTH. 323
it begins by a blind extremity at lower anterior portion of vesti¬
bule, enters cochlea, where it forms in cross section a triangular
canal, its base being outer bony walls of cochlea, its lower wall
the membrana badlaris^, its upper the membrane of Rehmer^ ; it is
filled with endolymph and contains the organ of CortíP°, covered by
the delicate membrana tectorial parallel with basilar membrane^.
The periosteum on upper surface of osseous spiral lamina forms
an elevation, the
Limhm laminae spiralis^^, which presents an upper and lower
margin called respectively the labium vestibuläre and labium
tympanicum, the groove formed between these being termed the
sulcus spiralis'.
What is the membrane of Reissner''?
A delicate membrane stretched between outer wall of cochlea
and periosteum of vestibular surface of osseous spiral lamina near
commencement of limbus laminae spiralis"®, forming the upper
wall of membranous cochlea.
What is the membrana basilaris" ?
A thin membrane passing from labium tympanicum to bony
wall of cochlea, where it expands into the triangular ligamenium
spirale^. It forms the lower wall of membranous cochlea, sup¬
porting on its upper surface the organ of Corti™.
Describe the membrana tectoria or membrane of Cortib
A delicate membrane passing from between labium vestibuläre
and attachment of the membrane of Reissnerr to outer wall of
cochlea, running nearly parallel with basilar membrane" ; some
contend that it is free, resting upon the organ of Corti™, and in
its fresh pulpy condition serves as a damper of vibrations.
Describe the organ of Corti™.
It consists of a complex body formed by a series of some three
thousand arches roofing over a space called the zona arcuata,
formed of rods and epithelial hair eells, lying upon the membrana
basilaris'' and covered by the membrana tectoriat ; the
Rods of Corti are disposed in two rows, the inner^ and outer^^
rods, each rod with its swollen base resting upon the basilar
membrane"", and its expanded upper end inclined toward and
in contact with the opposite one, forming an arched canal filled with
324
ESSENTIALS OF HUMAN ANATOMY.
endolymph ; according to Waldeyer there are about six thousand
rods in the inner row, and four thousand five hundred in the outer;
a nucleated mass of protoplasm occupies the angle between the
base of each rod and the basilar membrane ; the
FIG. 111.
Hair cells'^ (Fig. 115J are epithelial cells with stiff hair-like
cilia^ disposed in three or four rows upon the superior surfaces
of the outer rods™ to the number of about eighteen thousand, and
in a single row upon inner rods®"! numbering about thirty-three
hundred ; the
Lamina reticularis (Fig. 115) is formed of several rows of small
fiddle-shaped cuticular structures called phalanges, connected
together and to heads of outer rods, forming
rings™"", through which project the hairs of
the outer hair cells.
Where does the auditory nerve arise
and to what parts of the ear is it
distributed ?
Its superficial origin is from groove between
olivary and restiform bodies at lower border
of pons ; its deep origin is threefold (1) from
superior vermiformis process of cerebellum,
and from (2) inner and (3) outer auditory
nuclei formed chiefly by gray substance of
posterior pyramid and restiform body, from
which latter it receives fibres as it winds
around it. Entering with facial nerve the
internal "auditory canal, at its bottom it di¬
vides into the cochlear and vestibular branches,
both of which contain numerous ganglion cells ; the
Vestibular division divides into three branches, the superior
Fig. 115.
ANATOMY OF INGUINAL HERNIA.
325
splitting into many filaments which pass through upper hack part
of bottom of meatus, enter the vestibule through macula cribrosa
to be distributed to utricle and ampulla of external and superior
semicircular canals ; the middle branch passes through the open¬
ings of the fovea hemispherica to supply the saccule ; the inferior
passes to ampulla of posterior semicircular canal ; the
Cochlear nerve divides into numerous filaments at base of
modiolus which enter its canals, pass between the two plates form¬
ing the lamina spiralis, forming a plexus which contains gan¬
glion cells, and sends branches, it is thought, to communicate with
the hair cells ; the
häumescentia ganglioniformis Scarpce is the gangliform swelling
on the vestibular branch in the internal auditory canal ; the
Ganglion spirale is the gangliform enlargement on the cochlear
nerve as it occupies the canalis spiralis modioli.
Give the arterial supply of the labyrinth ?
The internal auditory, a branch of basilar artery, enters with
nerve the internal auditory canal, there to divide into a vestibular
and cochlear branch ; the
Stylo-mastoid, from posterior auricular ; occasionally
Branches from occipital.
What is the internal auditory canal
A canal about one-third of an inch long, passing outward from
posterior surface of petrous portion of temporal hone to end in a
cribriform partition perforated with numerous foramina, some of
them arranged in a spiral-shaped depression, the
Tractus spiralis foraminulentus, others in three groups in as many
depressions ; at the upper part is the commencement of the aquae-
ductus Fallopii for the seventh or portio dura nerve.
Anatomy of Inguinal Hernia.
What is the inguinal canal?
The canal passing downward and inward for one and a half
inches which lodges the spermatic cord in the male, the round
ligament in the female, pursuing a course parallel to Poupart's
326 ESSENTIALS OF HUMAN ANATOMY.
ligament through or between the abdominal muscles, commencinf
at internal abdominal ring and terminating at the external ab¬
dominal ring.®
Describe the internal abdominal ring.
It is an ovoidal opening in the transversalis fascia" midwaj
between anterior superior iliac spine and spine of pubes, and about
half an inch above Poupart's ligament®. It is bounded above and
externally by arched fibres of transversalis muscle", below and
internally by epigastric vessels" ; from its circumference passes the
infundibuliform fascia on to the spermatic cord or round ligament.
What is the external abdominal ring® ?
An obliquely triangular opening in the aponeurosis' of external
oblique muscle', just above and to outer side of crest of pubes;
from base to apex it averages one inch by half an inch transversely.
It is bounded below by the crest of pubes, above by the curved
aponeurotic intercolumnar fibres', and on each side by the free
borders of the aponeurosis called the internal^ and external columns^
of the ring; from the margins of the ring passes on to the cord or
round ligament, the intercolumnar fascia.
Give the boundaries of the inguinal canal.
Anteriorly, the skin, superficial fascia, aponeurosis of external
oblique, and outer third of internal oblique muscles.
Posteriorly, the triangular ligament, conjoined tendon" of inter¬
nal oblique and transversalis muscles, transversalis fascia", sub¬
peritoneal fat, and peritoneum.
Superiorly, the arched fibres of internal oblique" and trans¬
versalis muscles.
Inferiorly, the union of the transversalis fascia" and Poupart's
ligament®.
What is Poupart's ligament® ?
The infolded, thickened margin of aponeurosis of external oblique
muscle, extending from anterior iliac space® to spine of pubes, from
which it is reflected a short distance along the pectineal line,
forming Gimbemat's ligament, while a triangular band of tendinous
fibres attached by its apex to the reflected portion of Poupart's
ANATOMY" OF INGUINAL HERNIA.
827
ligament along the pectineal line, passing inward beneath sper¬
matic cord behind the inner pillar in front of the conjoined ten¬
don, and interlacing with its fellow at the linea alba, is called the
triangular ligament-, the lower part of Poupart's ligament forms
the external pillar of the external abdominal ring®.
Fig. 116.
Describe the relations of the epigastric artery and the in¬
ternal abdominal ring.
It passes between the transversalis fascia and the peritoneum
along the lower inner margin of internal ring beneath the sper¬
matic cord.
What is the cremasteric fascia ?
A series of muscular loops connected by areolar tissue investing
the spermatic cord, supposed to have been derived from the in¬
ternal oblique muscle during the descent of the testicle, and, of
course, absent in the female.
What is Hesselbach's triangle ?
A triangular space at lower part of inner surface of abdominal
wall, bounded externally by the epigastric artery, internally by
margin of rectus muscle, and below by Poupart's ligament: the
conjoined tendon stretches across the inner two-thirds of this space,
the remainder being filled in by the transversalis fascia.
328 ESSENTIALS OF HUMAN ANATOMY.
What is an oblique inguinal hernia ?
A protrusion of bowel, omentum, or both, following the course
of the spermatic cord in the inguinal canal through both internal
and external rings {when complete), the neck of the sac being to
outer side of epigastric artery.
What are the coverings of an oblique inguinal hernia ?
Skin ; mperfidal fascia ; intercolumnar fascia ; cremaster muscle^'^ ;
infundibuliform fascia] subserous cellular tissue; and peritoneum
forming sac.
Where is the seat of stricture most apt to be?
(1) At internal ring, (2) inguinal canal by fibres of internal
oblique or transversalis muscles, (3) at external ring, provided it
is not at thickened neck of sac, the most usual site in old herniœ.
What is a direct inguinal hernia ?
One where the protrusion passes through some part of Hessel-
bach's triangle, passing directly through the external abdominal
ring, the neck of the sac being internal to the epigastric vessels.
What coverings has a direct hernia ?
The same as an oblique, except that the trnnsversalis fascia take
the place of the infundibuliform fascia, and the conjoined tendon is
substituted for the cremasteric fascia, hut this latter covering is
probably a theoretical, not an actual one.
Femoral Hernia.
Describe the femoral or crural canal.
It lies beneath Poupart's ligament®, to inner side of femoral vein^®,
extending from femoral ring above to saphenous ope« inp" below :
it is about half an inch long, closed above by the septum crurale,
formed of condensed areolar tissue, and below by the cribriform
fascia, a portion of the deep layer of the superficial fascia covering
the saphenous opening : the
Femoral or crural ring is an oval space between femoral vein and
Gimbernat's ligament, half an inch in diameter, larger in female
FEMORAL HERNIA.
329
than in male, situated below and external to internal abdominal
ring : it is closed by the septum crurale and a lymphatic gland ; the
Sapherwm opening^'' is an ovoidal opening one and a half inches
long by half an inch wide, below inner portion of Poupart's liga¬
ment®, formed by the pubic portion" of fascia lata passing behind
the saphenous vein leaving a margin concave outward, while con¬
tinuous with it is a strong falciform process, the iliac portion of
the fascia lata, the falciform procen^ of Burnè^, passing in front of
the vein, its narrow pubic portion blending with the attachment
of Poupart's and Gimbernat's ligaments ; this is called Hefs liga¬
ment'® : the opening is covered in by the cribriform fascia.
Bound the femoral canal.
Anteriorly, lie the transversalis fascia", Poupart's ligament®, and
falciform process of fascia lata'® ;
Posteriorly, iliac fascia, covering pubic portion of fascia lata ;
Externally, the fibrous septum separating it from femoral vein ;
Internally, the junction of the processes of the transversalis and
iliac fasciae forming femoral sheath lying against outer edge of
Gimbernat's ligament.
Describe the position of parts around the ring.
The Spermatic cord in male, the round ligament in female, lie just
above anterior margin ; the
Femoral veiriP lies upon its outer side ; the
Epigastric artery crosses upper outer angle of ring ; the
Obturator artery once in three and a half cases arises in common
with epigastric, when it closely skirts around the upper and inner
margins of the ring.
Describe the septum crurale.
It is a layer of condensed cellular tissue upon which lies a small
lymphatic gland, closing the femoral ring.
What is the crural sheath ?
It is a continuation downward of the fascia transversalis in
front, and of the iliac fascia behind the femoral vessels forming
their sheath, divided by septa into separate compartments for
femoral artery externally, femoral vein next, and leaving a third
internally, the femoral canal.
330 ESSENTIALS OF HUMAN ANATOMY.
Describe the deep crural arch.
When present, for it is not infrequently absent, it is a band of
fibres derived from transversalis fascia, crossing the front of, and
adherent to the crural sheath, passing from the centre of Poupart's
ligament to the pectineal line behind the conjoined tendon.
Where is the seat of stricture most apt to be ?
At (1) junction of Hey's and Gimbernat's ligaments, (2) margin
of saphenous opening, (3) neck of hernial sac.
What are the coverings of a femoral hernia?
They are SMn, Superficial fascia, Cribriform, fascia, Crural sheath,
Septum crurale, Subserous areolar tissue, Peritoneum forming «oc.
Ferineum and Ischio-rectal Regions.
What is the ischio-rectal region ?
That portion of the outlet of the pelvis immediately behind the
perineum containing the rectum, upon either side of which is a
deep fossa filled with fat, the
Ischio-rectal fossa!', of a triangular shape, between the end of
rectum'^ and tuberosity of the ischiumc on each side ; its base
corresponds to the skin, and apex to point of division of obturator
fascia and origin of anal fascia; its base measures about one
inch, its depth two inches, being deepest behind, and is bounded
internally, by sphincter ani^^, levator ani^, and coccygeus® muscles ;
externally, by tuberosity of ischiumc and obturator fascia ; in front,
by line of junction of superficial and deep perineal fascia ; and
behind, by margin of gluteus maximus muscle'^ and great sacro-
sciatic ligament ; the
Internalpudic artery and nerve run about one and a half inches
above margin of ischiatic tuberosity, becoming more superficial
as they pass forward along inner margin of pubic arch ; the
Inferior hemorrhoidal vesfe/s, occasionally large enough to give
trouble after lithotomy, traverse the centre of each fossa.
PERINEUM AND ISCHIO-RECTAL REGIONS, 'ó'ól
What is the perineum ?
It is the anterior portion of the pelvic outlet, in front of ischio¬
rectal fossae, is of a triangular form, bôunded, deeply, hy rami of
pubes and ischia, forming, superiorly, the pubic arch, and behind,
by an imaginary line drawn between ischiatic tuberosities; the
lateral boundaries, in adult, vary from three to three and one-half
inches.
Describe the muscles of the perineum.
Externa! sphincter ani'^: origin, tip of coccyxb and superficial
fascia in front of bone; insertion, tendinous centre of perineum®:
action, closes anus ; nerve, fourth sacral.
Internal sphincter ani : consists of an aggregation of the involun¬
tary circular fibres of intestine, forming a muscular ring two lines
thick and one inch broad.
Fig, 117.
Sphincter tertius (Hyrtl): origin, sacrum, encircling rectum four
inches above anus (not described by many anatomists).
Accelerator urinae^ : consists of two symmetrical halves with median
tendinous raphé ; origin, central tendon of perineum® and median
332 ESSENTIALS OF HUMAN ANATOMY.
raphé in front ; insertion, fibres spread over front of triangular
ligament, encircle the bulb and corpus spongiosum, spread over
sides of corpora cavernosa, to which they are partly attached
and partly terminate in a tendinous expansion covering dorsal
vessels of penis ; action, empties urethra after bladder ceases to
contract, perhaps aids in erection of penis ; nerve, perineal branch
of pudic.
Erector penis^: origin, inner surface of each tuberosity of
ischium, surface of crus penis and adjacent portion of pubic
ramus (-Erector ctitoridis in female arises from ischial tuberosity;
inserted on side of crus clitoridis) ; insertion, by an aponeurosis into
sides and under surface of each crus penis ; action, maintains
erection ; nerve, perineal.
Transrersus perinei* : origin, inner front side of tuberosity of
ischium ; insertion, tendinous centre of perineum (in female, side
of sphincter vaginae) ; action, steadies perineal centre ; nerve, peri¬
neal.
Levator ani^ : origin, body and ramus of pubes posteriorly, inner
surface of spine of ischium, from angle of division between ob¬
turator and recto-vesical layers of pelvic fascia; insertion, sides of
apex of coccyx*", opposite muscle by median fibrous raphé, ex¬
tending from coccyx to anal margin, side of rectum (and vagina
in female) blending with sphincter muscles, and side of prostate
gland, uniting beneath it with opposite muscle mingling with exter¬
nal sphincter and transversas peronei muscles at perineal centre^ ;
action, supports rectum, vagina, and pelvic viscera, with its fellow
helps form the fioor of the pelvis ; nerves, inferior hemorrhoidal
and fourth sacral.
Compressor urethrce : origin, aponeurotic, from three-fourths of
an inch of upper part of pubic ramus on each side ; insertion, each
muscle divides surrounding urethra from prostate gland to bulb of
urethra, uniting with the opposite muscle above and below this
tube by a tendinous raphé ; action, shut-off muscle ; nerves, peri¬
neal.
Coccygeus^: origin, by apex from spine of ischium and lesser
sacro-sciatic ligament ; insertion, by base into margin of coccyx
and side of lowest segment of sacrum ; action, raises coccyx ; com¬
pletes pelvic floor behind ; nerve, anterior division fifth sacral.
PERINEUM AND ISCHIO-RECTAL REGIONS. 333
Sphincter vagince : (in female) surrounds vaginal orifice, is homolo¬
gous with accelerator urinae in male—origin, central tendon of peri¬
neum ; insertion, corpora cavernosa of clitoris.
Erector clitoridis, in female replaces the erector penis muscle.
Describe the perineal fasciae.
The superficial layer of the superficial fascia, is thick, loose, loaded
with fat and continuous with the fasciae of ischio-rectal and crural
regions; the
Deep layer of the superficial fascia is a thin, moderately strong,
aponeurotic layer, continuous in front with dartos layer of scrotum,
is firmly attached to the margins of the rami of ischium and pubes
external to crura of penis as far back as ischial tuberosity, and
passes down behind the transversos perinei muscles to blend with
lower margin of the deep perineal fascia ; the
Anterior layer of the deep perineal fascia is attached above and
laterally to pubic arch, subpubic ligament and rami of ischium and
pubes beneath crura of penis, forming a dense membranous lamina,
extending and attached to tendinous perineal centre, becoming
continuous with deep layer of the superficial fascia behind trans¬
verse perineal muscles : it embraces and is continued forward on
anterior extremity of membranous urethra, which passes through
it one inch below symphysis pubis ; the
Posterior layer of the deep perineal fascia is attached like preceding,
but more posteriorly, embraces hack portion of membranous urethra
and is continued backward over outer surface of prostate gland,
the two layers forming the triangular ligament: the portion of
urethra embraced between these layers is the membranous urethra;
the
Obturator fascia is a continuation of transversalis and iliac fasciae
below a white hand at level of a line passing from lower part of
symphysis pubis to spine of ischium : it covers the internal obtu¬
rator muscle and is continuous with posterior layer of triangular
ligament; the
Recto-vesical fascia, or visceral layer of pelvic fascia, descends into
pelvis upon upper surface of levator ani muscle, investing prostate,
bladder, and rectum.
334
ESSENTIALS OF HUMAN ANATOMY.
Describe Buck's fascia.
It is a moderately dense fascia investing the penis as far as glans,
being a prolongation forward of deep layer of superficial fascia,
blending with dartos layer of scrotum : it directs the urine forward
into scrotum, penis, and upon abdomen when the urethra is rup¬
tured.
What layers of fascia form the triangular ligament ?
The superficial and deep layers of the deep perineal fascia accord¬
ing to the description of most authorities.
What structures lie between the layers of the deep perineal
What structures are exposed by the removal of the deep
layer of the superficial fascia ?
The erector penis muscles covering the crura of penis.
The accelerator urince muscle covering corpus spongiosum and bulb.
Transversus perinei muscles.
Transversus perinei arteries.
Superficial perineal vessels.
What parts are divided in lateral lithotomy?
Skin.
Superficial fascia.
Inferior hemorrhoidal vessels and nerves.
Posterior fibres of accelerator urince muscle.
Transversus perinei muscle and vessels.
Superficial perineal vessels and nerves, (probably) deep perineal
fascia.
Anterior fibres of levador ani.
Part of compressor urethras.
Membranous and prostatic portions of urethra.
Part of prostate gland (neck of bladder, according to Gross).
fascia ?
Membranous urethra,
Compressor urethra muscle.
Subpubic ligament.
Dorsal vein of penis.
Cowper's glands and ducts.
Pudic vessels,
Pudic nerves.
Arteries and nerves of bulb.
Venous plexus.
F ERINEÜM ARD ISCHIO-RECTAL REGIONS. 335
What structures must be avoided in this operation ?
In front, the bulb and its artery.
Exiemally, pudie artery.
Toward median line and posteriorly, the rectum.
At neck of bladder, the entire division of lateral lobe and, there¬
fore, the capsule of prostate gland and venous plexus.
Briefly describe the special points of interest connected
with the female perineum.
The perineal body is the point of junction of all the muscular
and aponeurotic structures of perineum, forming a pyramidal mass
of tissue extending for some distance up between rectum and
vagina, upon the integrity of which depends the proper support
afforded to the pelvic viscera by the floor of the pelvis
The length of the female perineum is only about one inch,
extending from posterior commissure to verge of anus : the accel¬
erator urince muscle is replaced by the sphincter vaginal encircling
the vaginal outlet: the triangular ligament, formed essentially as
in male, and perforated by the urethra, is much smaller.
INTRODUCTION
TO
PLATES ON OSTEOLOGY
The following illustrations, taken from GRAY, are added with the
idea of making this work a complete guide to the Student in his prac¬
tical work. In the majority of our schools a careful study of osteology
precedes dissection, the Student being given each bone for examination,
and being required to master its anatomical details before receiving
another one. The assistance offered by a complete set of plates needs
no comment. Supplemented, as these illustrations are, by an admirably
clear and condensed text, the Student has, in this work, a most effi¬
cient aid in that portion of his anatomical studies which is usually con¬
sidered most dull and uninteresting.
THE PUBLISHER.
INDEX OF OSTEOLOGICAL PLATES.
Kig. 118 Cervical Vertebra
l'ig. 119 l'irst Cervical Vele-
tra or Atlas
Fig. 120 Second Cervical Verte¬
bra or Axis
Fig. 121 Seventh Cervical Ver¬
tebra
Fig. 122 A Dorsal Vertebra
Fig. 123 Cunibar Vertebra
Fig. 121 Feculiar Dorsal Verte¬
bra
Fig. 125 Sacrum, anterior sur¬
face
Fig. 126 Saerum, posterior sur¬
face
Fig. 127 Occipital Done, outer
surface
Fig. 128 Occipital Done, inner
surface
Fig. 129 Left Parieial Done, ex¬
ternal surface
Fig. 130 Left Parietal Done, in¬
ternal surface
Fig. 131 Frontal Done, outer
surface
Fig. 132 Frontal Bone, inner
surface
Fig. 133 Left Temporal Bone,
outer suriace
Fig. 131 Left Temporal Bone,
inner surface
Fig. 135 Petrous Portion.»
Fig. 136 Sphenoid Dones,super-
ior surface
Fig. 137 Sphenoid Bones, an¬
terior surface
Fig. 138 Ethmoid Bone
Fig. 139 Perpendicular Piateof
Ethmoid(enlarged)
Fig. 140 Eight Masai Bone,
outer suiface
Fig. Ill Left NasalBone, inner
surface
Fig. 142 Left Superior Maxill¬
ary Bone, outer
surface
Fig. 143 Left Superior Maxill¬
ary Bone, inner
surface
Fig. 144 LeftMalar Bone,outer
surface
Fig. 145 Left Malar Bone,inner
surface
Fig. 146 Palate and Alveolar
Arch
Fig. 147 Left Palate Bone, in¬
ternal view
Fig. 148 Left Palate Bone, pos¬
terior view
Fig. 149 Left Lachrymal Bone,
external surface...
Fig. 150 Eight Inferior Tui;bu-
rated Done, inter¬
nal surface
Fig. 151 Eight InferiorTurbu-
rated Bone, outer
surface 352
Fig. 152 Vomer 3j2
I'ig. 153 Infei'ior Maxillary
Bone, outer sur¬
face, side view 353
Fig. 154 Inferior Maxillaiy
Bone, inner sur¬
face, side view 353
F^ig. 155 Base of the Skull, in¬
ner surface 354
Fig. 156 Base of Skull, external
surface 355
Fig. 157 Anterior Eegion of
the Skull 356
Fig. 158 Hyoid Bone, anterior
surface 356
Fig. 159 Eoof, Floor and Outer
Wallof Nasal Fossa 357
Fig. 160 Le It Clavicle, anterior
surface 357
Fig. 161 Left Clavicle, in¬
ferior surface 3.57
Fig. 162 Sternum and Costal
Cartilages 358
Fig. 162* Posterior Surface of
Sternum 358
Fig. 163 Peculiar Eibs 359
Fig. 164 Left Scapula, anterior
suriace or venter... 360
Fig. 165 Left Scapula, posterior
surface or dorsum 361
Fig. 166 Left numerus, anter¬
ior view 362
B'ig. 167 liCft Humerus, noster-
ior view 7. 362
Fig. 168 Bones of the Forearm,
anterior.surface 363
Fig. 169 Bones of the Forearm,
posterior surface... 364
Fig. 170 Bones of the Hand.
dorsal surface 365
Fig. 171 Bones of the Hand,
palmer surface 366
Fig. 172 Eight Os Innomina-
tum, external sur¬
face 367
Fig. 173 Eight Os Innomina-
tura, internal sur¬
face 368
Fig. 174 Eight Patella, anterior
and posterior sur¬
face 368
Fig. 175 Eight Femur, anter¬
ior surface 369
Fig. 176 Eight Femur, poster¬
ior surface 359
Eig. 177 Bones of fhe Leg,
anterior surface .370
Fig. 178 Bones of the Leg,
posterior surface 370
Fig. 179 Bones of the Foot,
dorsal surface 371
Fig. 180 Bones of fhe Foot,
plantar surface 372
338
338
338
339
339
339
310
341
311
312
342
313
343
344
314
345
345
346
317
347
318
348
319
349
349
350
350
350
351
351
332
352
352
338
Fig.118
knteriorTahrelt of Tram Proe,
Faramen VerttbraJ Art
Voftrv/rTulereh Trant. Proe.
\fFrectn.
Cervical Vertebra.
Cervical Vertebra.
fic4. 1j9.
/ ra.nii/$rte Proct»».
i
Artieular ProHt^
nferioTAjiUular Pnetat
Potafn-
\'e^£ebral
\
^ÍZ'ÍÍ^cTtvM^'^
Sjiin. Proc..
First Cervical Vertebra or Atlas.
fig. 120.
Odortotd Pt'Of .
Rngh Surf CJieeÂ
¿.Ttit.SarJ.frr Tram.LiJ'
Su rf. f»rÂil*9'
InfoT^ rtieProo,
Second Cervical Vertebra or Axis.
339
ëisua««« J'íKí/k
Seventh Cervical Vertebra or Vertebra Prominens.
FIG. 122.
Sn¡trier Artie. Aeeett 1^^
Demi faeei for hea3efRih
Taettjir Tulercleefltil-
DemiJijeetforfua.3 ofjii^
^ i'ror^
■ llf Infer. Artie.Troc.
A Dorsal Vertebra.
fig. 123.
Saper» Artie* Froc*
Lumbar Vertebra.
Íia »»tirtfafêt aiam
ADímt/atH htUt^
■Â Démi^êtt» âiov*
*» Trm nt ft,
\ ¡nftrAjUe pTPt i
■i t»»vtar*wirmTt^
tutntr4i
Peculiar Dorsal VertebríIí.
341
Sacrum, anterior surface.
Fia. 126.
Sacrum, postÈrÎÔ'r surface.
Fig. 127.
sur/rt'-' fo' Occif.
t t >
Occipital Bone, outer surface.
f IG. 128.
Occipital Bone, inner surface.
343
Left Tarietal Bone, external surface.
tvith
Frontal B
Fig. 130.
Groove foi-
^iM mem*
Left Parietal Boxe, internal surface,
ría. 131.
Frontal Bone, outer surface.
FrontaX Sinu»
, , , - , ,i U \KxjKtnii<.d iaaé f/Ji'tLsal Spmr,
ith fvt¡>ttjisuur^au^Mtkiiu>ui_ i J^mur^j jhitI ^ Nasa
Frontal Bone, inner surface.
Fio. 133.
345
kig. 134.
Left Temporal Bone, inner surface.
346
Fio. 135.
Petrous Portion, inferior surface.
ÎLaxtgh QimdrtlaUmlSurface
of M.roU'(i Mvol
Coyial/fii' Jacohtont nerv*
A^u/^uftrjis Corhlaa.
CaTUil/or Arnold'4 nerv«
Jugular
Vagi nal
Styloid
Styl<f*fnasroi/l foramen
Jngiilar Si'rfaco
AxíYÍCXiIaT fl4iU7C
rrvlo-pmaiirnecos)
Fia. 13G.
Fio. 137.
Sphenoid Bone, anterior surface.
348
Fio. 138.
Ethmoid Bone, outer surface of Right Lateral Mass,
(enlarged).
FIG. 139.
Perpendicular Plate of Ethmoid (enlarged), shown by
REMOVING THE RiGHT LATERAL MaSS.
349
Fio. 140.
urtÁ Frontal D.
with
—Opposite hone.
Right Nasal Bone,
outer surface.
fio. 141.
Fro nta Ï /^jnne-
cre.fñ
wt/A
a Tjícndíc'ola r
y^^Laic rfEOimoidt
groove for 3ia*ainervo
Left Nasal Bone,
inner surface.
fio, u2.
Left Superior Maxillary Bone, outer surface.
350
Bone* jtaftiÉiíLy olotln^ Ûi^yiee ^JÍTVtTarm
tna.rkfd in outlJji*
Injtriee Tiíriinatéd —
Afd. i^a*aX Spitt»
ßrittl*
paetíd xhrotißU
^ra.paîat. CaneA
Left Superior Maxillary Bone, inner surface.
Flo. 144.
fio. 14.5.
\ton±ei¿
Btadnpa^ rfnoyi
Left Malar Bone,
outer surface.
Left Malar Bone,
inner surface.
Fro. 14R.
Ani.jirtZctHrte
• Cctnrtl
í'oretmert- 'i
Poät.pulcilü^e
Ji/fáTá;ssoru
.^rcuncru
The Palate and Adveolar. Arch,
fig. 1-í7.
MORlZOHTAi ftATC
Left Palate Bone, internal view.
352
Fin. U8.
Lekt Palate Bone,
posterior view.
< Infer-
Left Lachrymal Bone,
external surface (enlarged).
Tig. HT.
Frontdl
Fro. 150.
Fig. 151.
Right Inferior Turbinated Right Inferior Turbinated
Bone, i.nternal surface. Bone, external surface.
Fig. 1.52.
Vomer.
353
rio. 153.
Inferior Maxillary Boxe, outer surface, side view.
rio. 154.
Inferior Maxillary Bone, inner surface, side view.
354
Fio. 1J)5.
Crtcvt fi>r Suj>er. tmglt/J.ffiHtlt
QroowÊ» far A.nt/'r. Msrun^talA''-
Tarairun l'éCnn*
C rt'^tn-
Sht for
Qro-ii't j»
^nUyioT
Oriftoit fre Clfa^lary
Íoitírior Eùimoidul
EiÀmatdai Sj>¿né
Olfattcmi
Guttut Auditor.
Slit far Durtf
Sup. Fétrodñl
For. laeevum
ru>r
A^iufduct.
EtSttriar Condjluid far..^
F o r a m
, _ - _ AI a d n u
Afattoid
Fott. MttiXnqoAl Grtovtt,
ÎASE OF THE SKULL, INNER OR CEREBRAL SURFACE.
Optio
Optio Oroo-
Olifury
ÀTiterlor Cllnoid
MiJ'/U Cliiioid
Fotltrior CliMid
Ctcovo far C'i
TowS l/ioeruni
Ooi/Ut af CuTfftCd'
Dop/ltoion tor CatMrian
O'-».)
fiq. lí>6.
Ifít ynto-yalaZ. n.
Ifl/ palat tfjt.
right Natopa¿M. n.
Faramtn
palatin»
Base of the Skult,, external surface.
356
fio. 157.
rinic ocult
Näial Sjftne
Jneitive fossa-
^ntùTipr
Kares
r- . :llt
1%/r X-'.i/íft,..;
OrpçvêfprTaci.al af
ANTJÍRIOR RKGION OF THE SKULL.
fio. 158.
TAyro'Ayoid^
sfy^o-hyoid.
\0«M-Ay9MÍ.
Sterno-hyoiH.
H void Bone, anterior surface.
357
Fig. 159.
itûûf
K(u(U ^
Kmtd vf TrontalÉen»
BtiviTiucX HAIÍ *f£tJtwuÁ¿
£Ioot
Ant.NíuaÍ Sj'iw
PalAít ^roc of 3up JHmjs.
¡hiato JProe. (fTalalo-
Post. Natal 3pint
JírU. PaltLUtu Carutl
Trola patted throuç!»
NatO'lnoArytnal Caa/ft
Mrstil» ptttttd tkroufk
¡ifuJtJiiuúim.
Outor Wall
"Wittai /V0.1 ofSup^Iix
l.tirKrymaí
— t'iuformJ'roa rf dUta
Infria TurbinaUd
Patata
Superu/r tíeatut
■Muidla Meatus
TnftJtar Mealut
Koof í'loor, and Outer Wali, of Left Nasal Fossa.
Fig. ico.
Afrutniul ZVCy
Left Clavicle, anterior surface.
Fio. igl.
w
\ o'sfes
.v> -»/W
s ii V « e ip^4
Left Clavicle, inferior surface.
358
Sternum and Costal Cartilaoes.
Fia te:.
ljrtiM>npto. HAcreo
flo. 162*.
Posterior Surface of Sternum.
859
F ra. 163.
Peculiar Ribs.
360
Left Scapula, anterior surface or venter.
361
Fia. 165.
Ce raceia
^ \Sinoiith Surface
ri ùt
I.eft Scapula, posterior surface or dorsum,
358
Sternum and Costal Cartilages.
Posterior Surface of Sternum.
359
Fro. 163.
Peculiar Ribs.
362
fig. ifl7.
fio. 166.
ßiiiyüa2
'•-sí
" : î ;
Ifl
y «printv«! ubd ioktut
m
1^:
? 'í-
f ?
^ h
n
Cemn^ ffnfi»
Left Humerus, anterior view.
Í'''w
••tâ\ ^rooÁ I
Left Humerus,
posieriok surl-ace.
363
rio. ics.
l m k
Bones of the Left Forearm, anterior surface.
3tí4
Fio. 1c9.
biNi
.SÄT.CAÄPI H O.ISNC,
KXT.CAJtPI &AO BtCflOft
Kir. «UwNfil ^NTCRNOOII poLLiei^
PLtsoR eioiTOii^
aVIUHl»
^ IXT. CARPI UL«At.
imeicii
OICITORWM C6MMUIIU
MiNtrni eiGiTi
Bükes of thf. Left Forearm, posterior surface.
365
fig. 170.
\Phatan>
Bones of the Left Hand, dorsal surface.
366
fio. 171.
"Mftaear/iu^
Bones of the Left Hand, palmer surface.
rwt*«*
o.cito««*
pro»
CaT^fis
»kuotlcmpl uknahi»
vloe* tkcvti mimimi eiciti
369
Fio. 175
FIO. 178.
'•"■.,(•...15'
Right Femur,
anterior surface.
MtUT»«»
Right Femur,
posterior surface.
370
Fio. 178.
f IIUtA
fH
Bones of the Right Leg,
.interior surface.
Bones of the Right Leg,
posterior surface.
371
Fio. 179.
V ^
Bones of the Right Foot, doesai. surface.
Bones of the Right Foot, pi.antar surface.
INDEX.
Abdomen, 243
muscles of, 129
Abdominal cavity, 243
regions, 245
Absorbents, 184
Acervulus cerebri, 196
Acetabulum, 68
Alveoli of lower jaw, 50
of upper jaw, 43
of the lungs, 258
Amphiarthrosis, 92
Anastomoses, 157,175
Anatomy, general, 17
descriptive, 17
Angle of the jaw, 51
of subscapular fossa, 76
Annulus ovalis, 154
Antihelix, 310
Antitragus, 310
Antrum of Highmore, 40
Anus, 232
Aorta, 158, 167,168
Appendices epiploicœ, 232
Appendix auriculae, 154, 155
ensiform, 65
vermiformis. 231
Aponeuroses, 115
pharyngeal, 225
Apophysis, 21
Aqueduct of Sylvius (iter e tertio,
etc.), 194, 195
Aquaeductus cochleae, 36
Fallopii, 36, 203
vestibuli, 319
Arachnoid membrane of brain, ISO
of spinal cord, 199
Arbor vitae, 198, 282
Arch, crural, deep, 330
palmar, 166
plantar, 175
Areola of mammae, 286
Arm, 78
Arnold's ganglion, 202
Arteriae propriae renales, 263
Arterial anastomoses, 175
Arteries, helicine, 274
hepatic, 168
lingual, 161
pharyngeal, 161
sublingual, 161
Arteries of the—
ankle-joint, 112
auditory canal, 311
auricle, 311
bone, 19
choroid, 298
elbow-joint, 104
Eustachian tube, 317
eye, 304
eye-lids, 304
hip-joint, 108
iris, 296
kidney, 263, 264
knee-joint, 110
labyrinth, 325
larynx, 254
lung, 259
mammae, 287
membrana tympani, 312
nasal fossae, 291
nose, 291
oesophagus, 226
ovaries, 286
pancreas, 239
penis, 274
pharynx, 226
retina, 299
shoulder-joint, 103
spleen, 240
stomach, 000
supra-renal capsules, 243
testicle, 277
thymus gland, 242
thyroid gland, 241
tympanum, 316
uterus, 284
wrist-joint, 105
Arteriolae rectae, 264
Artery—
anastomotica magna, 173
22 (373)
374
INDEX.
Artery—
aorta, 158, 167, 168
arteria receptaculi, 162
auricular, 161
axillary, 165
basilar, 164
brachial, 165
carotid (external), 161
(internal), 162
cerebral, anterior, 163
middle, 163
posterior, 163
choroid, anterior, 166
communicating, anterior, 163
posterior, 163
coronary, 159
digital, 167, 175
dorsalis hallucis, 174
pedis, 174
epigastric, deep, 171
superficial, 171
facial, 161
femoral, 171
gastric, 168
gluteal, 170
hemorrhoidal, 170
hepatic, 168
iliac, circumflex, 171
external, 171
internal, 169
ilio-lumhar, 170
infra-orbital, 162
innominate, 159
intercostal, 167
lingual, 161
lumbar, 169
mammary, internal, 164
maxillary, internal, 161
meningeal, anterior, 162
mesenteric, superior, 168
inferior, 168
obturator, 170
occipital, 161
ophthalmic. 162
palmar arches, 166
peroneal, 174
pharyngeal, ascending, 161
phrenic, 168
plantar, external, 174
internal, 174
popliteal, 173
profunda femoris, 173
inferior, 165
superior, 165
Artery—
pudic, deep external, 173
superficial external, 173
internal, 170
pulmonary, 175
radial, 166
renal, 169
sacral, lateral, 170
middle, 169
sciatic, 170
spermatic, 169
splenic, 168
subclavian, 163
subscapular, 165
suprarenal. 169
suprascapular, 164
temporal, 161, 102
thoracic, acromial, 165
superior, 165
thoracica alaris,'165
longa, 165
thyroid, superior, 161
inferior, 164
thyroidea ima, 159
tibial, anterior, 173
posterior, 174
transversalis colli, 164
tympanic, 162
ulnar, 166
uterine, 170
vaginal, 170
vertebral, 164
vesical, 109, 170
Arthrodial joints, 93
•Vrticulations, 92
atlo-axoidean, 95
carpal, 105
carpo-metacarpal, 106
costo-sternal, 98
costo-transverse, 98
costo-vertebral, 97
metacarpo-metacarpal, 106
metatarso-metatarsal, 113
occipito-atloid, 94
occipito-axoidean, 96
phalangeal, of foot, 114
of hand, 107
radio-ulnar, 104
sacro-coccygeal, 100
sacro-iliac. 99
sacro-ischiatic, 100
sacro-vertebral, 99
scapulo-clavicular, 101
scapulo-humeral, 102
INDEX.
375
Artery—
sterno-clavicular, 101
tarsal, 112
tarso-metatarsal, 113
temporo-maxillary, 96
tibio-fibular, 110
vertebra], 94
Arytenoid cartilages, 250
Atlas, 63
Auricle, 310
Axis, 63
cœliac, 168
optic, 292
thyroid, 164
visual, 292
Azygos veins, 180
uvulae, 122
IIAHTIIDLIX. duct of, 221
J) fihiii'U nr. L'Mi
iiaiilnii. valvi' (if. 231
Bull, cxti i ual lu i ve of, 206
internal nerve of, 205
Bladder, 266
Bodies, Malpighian, 263
Pacchionian, 186
Body, ciliary, 296
olivary, 196
perineal, 335
pituitary. 191
restiform, 197
Bone, astragalus, 90
calcaneum. 90
clavicle, 75
coccyx, 72
cuhoid, 90
cuneiform, 91
ethmoid, 38
femur, 85
fibula, 89
frontal, 23
humerus, 78
hyoid, 65
ilium, 69
incus, 314
innominate, 68
ischium, 70
lachrymal, 44
malar. 44
malleus, 314
maxillary, inferior, 49
superior, 40
nasal, 40
Bone—
occipital, 27
OS calcis, 90
OS magnum, 84
palate, 45
parietal, 25
pectineal, 70
peroneal, 89
phalanges of foot, 92
of hand, 85
pisiform, 84
pubic, 70
sacral, 71
scaphoid, 83
scapula, 76
semilunar, 83
sphenoid, 30
stapes, 315
sternum, 65
structure, microscopic, 18
temporal, 34
tihia, 88
trapezium, 84
trapezoid, 84
turbinated, inferior, 47
middle, 39
superior, 39
ulna, 80
unciform, 84
vomer, 48
Bones of the body, 20
of the carpus, 83
of the foot 90
of the hand, 82
of the leg. 88
of the lower extremity, 85
of the metacarpus, 84
of the metatarsus, 91
of the tarsus, 90
of the trunk. 61
of the upper extremity, 74
Wormian. 20
Bonnet, capsule of. 293
Bowman's membrane, 295
Brain, commissures of, 192
divisions of. 187
points on base. 190
on surface, 187-190
ventricles, 192
weights, average, 187
Bronchi. 255
Brunner's gland, 230
Bulb of corpus cavernosum, 273
of corpus spongiosum, 273
376
INDEX.
Buibi vestibuli, 280
Bulbs, olfactory, 191
Burns, ligament of, 329
Bursae of ankle, 149
of hip, 108
of knee, 110
of shoulder, 102
of wrist, 139
C^CUM, 231
Calamus scriptorius, 197
Calices of kidney, 2fil
Canal, alimentary, 224
auditory, external, 311
internal, 36
carotid, 36
central, of the cord, 200
crural. 329
dental, 41, 50
femoral, 328
Hunter's, 144, 171
hyaloid, 301
infraorbital, 41
inguinal, 326
of the modiolus, 320
nutrient, 19
palatine, 46
sacral. 72
spiral, of the cochlea, 320
for tensor tympani, 37
Vidian, 33
Canal of—
Huguier, 35
Nuck, 383
Petit, 302
Schlemm, 297
Stilling. 301
Canaliculi, 308
Canalis reuniens, 322
Canals, semicircular, 319
membranous, 322
Canthus, 306
Capillaries, 158
Capsule, internal, 194
of Bonnet, 293
of Glisson. 237
of the lens, 301
of Tenon, 293
Capsules, suprarenal, 242
Caput c,eci, 231
gallinaginis, 269
Carpus, 83
Cartilages of the larynx, 249
Cartilages of Santorini, 250
of tarsal, 306
of Wrisberg, 251
Cartílago tritícea, 251
Carúncula lachrymalis, 307
myrti formes, 280
Cauda equina, 211
Cavity, cotyloid, 68
glenoid, of scapula. 78
of the omentum, 246
orbital. 55
of reserve, 220
sigmoid, greater, 80
lesser, 80
of radius, 82
Cells, auditory, 324
ethmoid, 39
hepatic, 237
mastoid, 35, 314
olfactory, of Schultze, 291
Cement, 218
Cerebellum, 197
Cerebro-spinal system, 185
Cerebrum, 187
convolutions of, 189
fissures of, 187
lobes of, 188
Cervix of penis, 273
of uterus, 282
Chordae tendineae, 155
Choroid tunic, 295
plexus, 193
Cilia. 307
Circle of Willis, 163
Circulas arteriosus iridis major,
296
iridis minor, 296
venosus, 287
Clavicle, 75
Clinoid processes, 30, 33
Clitoris, 280
Coccyx, 72
Cochlea, membranous, 322
osseous. 320
Coeliac axis, 168
Collar-bone, 75
Colon, 231
flexures of, 231
Columme carneae. 155, 157
papilläres, 155
Columns of Berlin, 261
of spinal cord, 199
Commissure, optic, 200
Concha, 310
INDEX.
377
Condyles, of femur, 86
Condyles of humerus, 79
Coni-vasculosi, 276
Conjunctiva, 307
Conus arteriosus, 154
Convolutions of cerebrum, 189
Coracoid process, 77
Corium, 288
Cornea, 294
Cornicula laryngis, 250
Cornua of thyroid cartilage, 250
of the ventricles, 192
Corona glandis, 273
radiata, 195
Coronoid process, 49, 81
Corpora albicantia, 191
cavernosa, 273
quadrigemina, 192, 195
striata. 192
Corpus Arantii, 155
callosum, 193
dentatum of cerebellum,
198
of olivary body, 196
fimbriatum, 193
bigbmorianum, 275
luteum, 285
spongiosum, 273
Corpuscles, Malpigbian, 240
tactile, 288
Corti, organ of, 323
Cortical substance of kidney,
261
Cotyloid cavity, 68
Coverings of the testicle, 275
of hernia, 328, 330
Cowper's glands. 272
Crest of the ilium, 69
lachrymal, 44
nasal, 43 47
of the pubes. 71
of the tibia, 88
turbinated, 42. 46
Cricoid cartilage, 250
Crista galli, 38
Crura cerebri, 191
of clitoris, 280
of penis, 273
Crusta petrosa, 218
Crypts of Lieberkiibn, 230
Cuneiform cartilages, 251
Cuneus, 190
Cupola of cochlea, 320
Cuticle, 287, 288
Dartos, 276
Dentine, 218
Derma, 288
Descemet, membrane of, 295
Diaphragm, 133
Diartbrosis, 93
Digestion, organs of, 216
Disk, optic, 298
Discus proligerus. 285
Dorsum of scapula, 76
Douglas's cul-de-sac, 281, 283
Duct, cystic, 238
hepatic, 237
lymphatic, 184
nasal, 309
pancreatic, 238
of Bartholin, 221
of Gaertner, 286
of Millier, 277
of Rivinus, 221
of Steno. 221
of Wharton, 221
of Wirsung, 238
thoracic, 184
Ducts, biliary, 237
ejaculatory, 278
Ductus cochlearis, 322
communis choledochus, 238
Duodenum, 229
Dura mater of cerebrum, 186
of spinal cord, 199
Ear, 310
internal. 318
Earstones, 321
Eminence, hypothenar, 141
thenar, 141
Eminentia collateralis (pes accesso-
rius), 194
Enamel, 218
Enarthrosis, 93
Endocardium, 157
Endolymph, 318
Endosteum, 19
Epidermis, 288
Epididymis, 276
Epigastric region, 245
Epiglottis, 251
Epiphysis 22
Equator of eyeball. 292
Eustachian tube, 317
Eye, 292
its appendages, 306
378
INDEX.
Eyebrows, 306
Eyelashes, 307
Eyelids, 306
r.VLT.OPIAX tubes, 284
1 F;illoj)ius, aqueduct of, 313
hiatus ol, 36
Falx cerebelli, 186
cerebri, 186
Fascia, anal, 333
Buck's, 334
cremasteric, 327
cribriform, 329
den tata, 194
intercolumnar, 326
ischio-rectal, 333
lata. 142
lumbar, 131
obturator. 333
palmar, 138
perineal, 333
plantar, 150
recto-vesical, 333
Fasciae, 114
of the perineum, 334
Fauces, 221
Femur, 85
Fenestra ovalis, 313
rotunda, 313
Ferrein, pyramids of, 263
Fibro-cartilage, 94, 97, 102, 107, 110,
307. 310
Fibula. 89
Fimbriae, 284
Fimbriated extremity, 284
Fissure, auricular, 37
calcarine, 188
calloso-marginal, 188
collateral, 188
dentate. 189
Glaserian. 35
palpebral. 306
parieto-occipital, 187
pterygo-maxillary, 60
of Rolando, 187
of Sylvius, 187
precentral, 187
spheno-maxillary, 60
sphenoidal, 53
transverse, 189
Fissures of cerebellum, 198
of cerebrum, 187
of liver, 234
Fissures of spinal cord, 199
Folds, palpebral, 307
Fontana, spaces of, 297
Fontanelles, 52
Foot, 90
Foramen for Arnold's nerve, 37
caecum, 24
condyloid, 28
ethmoidal, 25
for Jacobson's nerve, 37
infra-orbital, 41
inter-vertebral, 62
lacerum anterius, 33, 53
magnum, 27, 54
mastoid, 35
medium, 54
mental, 49
nutrient, 19
obturator, (iS
of Monro, 193
of Scarpa, 43
of Stensen, 43
of Winslow, 247
olfactory, 38
ovale, 31
optic, 33
orbital, 32
palatine, 43
petrosal, 36
posterius, 54
pterygo palatine, 47
rotundum, 31
sacral, 71
spbeno-palatine, 46
spinal, 63
spinosum, 32
stylo-mastoid, 37
supra orbital, 24
supra-scapular, 77
thyroid, 68
"Vesalii, 32
Foramina at the base of the skull, 54
olfactory, 3,S
orbital, 32
spheno-maxillary, 60
Thebesii, 154
Forearm, 80
Fornix, 193
Fossa, canine, 40
coronoid, 80
digastric, 35
digital, 86
glenoid, 78
hyaloid, 301
INDEX.
Fossa, incisive, 40
infra-spinous, 77
ischio-rectal, 330
jugular, 29
lachrymal, 25
navicularis of vulva, 281
of penis, 270
olecranon, 80
ovalis, 154
pterygoid, 33
scaphoid, 33
spheno-maxillary, 61
sublingual, 50
submaxillary, 50
subscapular, 76
supraspinous, 77
temporal, 59
zygomatic, 60
Fossae, nasal, 58
of the skull, 53
Fourchette, 281
Fovea centralis, 298
bemispberica, 319
semi-elliptica, 319
Fraenulum, 196
Fraenum preputii, 274
G.a;RTNER, duct of, 286
Gall-bladder, 238
Ganglia, basic, 191
cervical, 213
of fifth nerve, 202
of the sympathetic, 211-214
Ganglion, Arnold's, 211, 212
Gasserian, 202
impar, 211
Meckel's, 212
of ribs, 211
spbeno-palatine, 212
spirale, 320, 325
Gasser, ganglion of, 202
Gimbernat's ligament, 326
Ginglymus, 93
Gladiolus, 65
Gland, lachrymal, 308
mammary, 286
pineal, 196
prostate, 271
thymus, 242
thyroid, 241
Glands, Brunner's, 230
Cowper's, 272
ductless, 239
Glands, gastric, 228
intestinal, 230
lachrymal, 308
lymphatic, 184
Meibomian, 307
of Bartholin, 280
of Tyson, 274
sebaceous, 289
solitary. 230
sweat, 289
Glans clitoridis, 280
penis, 273
Glenoid, 78
Glisson's capsule, 235
Globus major, 276
minor, 276
Glottis, 252
Gomphosis, 93
Graafian vesicle, 285
Groove, bicipital, 79
infraorbital, 41
musculo-spiral, 79
mylo-hyoid, 51
naso-palatine, 49
optic, 30
pterygo-palatine, 47
Gubernaculum testis, 278
Gums, 217
Gyrus, angular, 189
fornicatus, 189
Hairs, 288
Hamstrings, 146
Ilamular process, 33
Hand, 82
Haversian canals, 18
system, 18
Head of the humerus, 79
of the ulna, 81
Heart, 153
Helicotrema, 320
Helix, 310
Henle, tubes of, 261, 263
Hernia femoral. 328
inguinal, 325
Hey, ligament of, 329
Hiatus Fallopii, 36
Hilum of kidney. 261
Hippocampus major, 193
minor, 193
Horner's muscle. 117
Houston, folds of 232
Huguier, canal of, 35
380
INDEX.
Humerus, IS
Humor, aqueous, 300
vitreous, 301
Humors of the eyeball, 300
Hunter's canal, 144
Hydatids of Morgagni, 277
Hymen, 280
Hypochondrium, 244, 246
Hypogastriurm, 246
ILEUM, 69, 230
Ilium, 69
Ineisura intertragica, 310
Infundibula of kidney, 261
Infundibulum of brain, 191
Inguinal regions, 245, 246
Intestine, large, 231
small, 229
Internal capsule, 194
Intumescentia ganglioniformis Scar-
pae of seventh nerve, 325
Iris, 296
Ischium, 70
Iter ebordae anterius, 313
posterius, 313
e tertio ad quartum ventrlculum,
194
Ivory, 218
JACOB'S membrane, 299
Jacobson's nerve, 203
Jejunum, 229
Joint, ankle-. 111
elbow-, 103
bip-, 107
rotators of the, 144-146
knee-, 108
shoulder-, 102
wrist-, 105
Joints, motion in, 9.3
structures of, 93
I^IDNEYS, 260
IABIA majora, 279
J minora, 279
Labium tympanicum, 323
Labium vestibuläre, 323
Labyrinth, membranou.«, 321
osseous, 318
Lacteals, 184
Lacunus magnus, 27!)
Lacunae, 18
Lacus lacbrymalis, 306
Lamellae, 18
Lamina cinerea, 191
cribrosa (of sclerotic), 293
fusca, 294
reticularis, 324
spiralis, 320
Laminae of cornea, 295
Lancisi, nerves of, 193
Larynx, 249
Layer, dermoid, 288
ganglionic, 299
molecular, 299, 300
Leg, 88
Lens, crystalline, 301
Lieberkiibn, crypts or follicles of, 230
Ligament, annular, of foot, 149
annular of band, 139
conoid, 102
coronary, 110
costo-xipboid, 98
cotyloid, 107
crucial, of knee-joint, 110
deltoid, 112
falciform, 329
Girabernat's, 326
glenoid, 102
ilio-femoral or Y, 107
of Burns, 329
of Hey, 326
of Zinn, 301
orbicular, 104
I Poupart's, 129, 326
rhomboid, 101
' round, of tbe liver, 234
I round, of tbe uterus, 283
; sacro-sciatic, 100
stellate, 97
stylo-maxillary, 97
suspensory, of lens, 301
of liver, 234
of penis, 273
of spleen, 240
transverse, of hip-joint, 10 7
trapezoid, 102
triangular, of perineum, 334
Ligaments of tbe bladder, 267
broad, of uterus, 283
INDEX.
381
Ligaments, check. 96
of the knee-joint, 108
of the larynx, 251
of the liver, 234
of the ossicles, 315
of the ovaries, 284
of the scapula, 102
of the sternum, 99
of the uterus, 283
peritoneal, 248
tarsal, 307
Ligamentum latum pulmonis, 259
mucosum, llO
nuchse, 124
patellae, 108
pectinatum iridis, 297
Suspensorium, 96
teres, 107
Winslowii, 109
Limbus laminae spiralis, 323
Line, inter-trochanteric, 86
Linea aspera, 86
ilio-pectinea, 70
quadrati, 86
Liquor Morgagni. 301
Lithotomy, structures afíected,
334
Liver, fissures of, 234
lobes of, 235
structure of, 237
vessels of, 235
Lobe of the ear, 310
Lobes of the cerebellum, 197
of the cerebrum, 187
of the liver, 235
optic, 192
Lobule of the ear, 310
Lobules of the liver, 237
of the lung, 258
Lobulus caudatus, 235
quadratus, 235
Spigelii, 235
Lower, tubercle of, 154
Lumbar regions, 245, 246
Lung, broad ligament of, 259
Lungs, 256
Lunula, 288
Lymphatics, 184
hepatic, 237
of lung, 259
of penis, 274
of thymus gland, 242
of trachea and bronchi, 256
of uterus, 284
Lymph-spaces of eyeball, 304
Lyra, 193
YT ACÜLA acoustica, 322
111 lutea, 298
Maculae cribrosae, 325
Malleolus, 88, 89
Malpighi, bodies of, 240
pyramids of, 261
Malpighian corpuscles, 263
tuft, 263
Mammae, 286
Manubrium of the malleus, 314
of the sternum, 65
Marrow of bone, 19
Masses, lateral, of ethmoid, 39
Mastoid process, 85
Meatus auditorius extemus, 36
internus, 36
nasi, 59
urinarius, 273, 280
Meckel's ganglion, 212
Mediastinum, 260
testis, 275
Medulla oblongata, 196
Medullary substance, 261
Membrana basilaris, 323"
granulosa, 285
pupillaris, 298
Euyschiana, 296
sacciformis, 104
tectoria, 323
tympani, 311
secundaria, 321
Membrane, hyaloid, 301
interosseous, 104, 111
Jacob's, 300
limiting. 299, 300
of Bowman, 295
of Descemet, 295
of Reissner, 323
pituitary, 290
Sehneiderian, 290
Shrapnell's. 312
vitelline, 285
Membranes of brain, 186
of the spinal cord, 199
synovial, 93
tarsal synovial, 114
wrist synovial, 105
J Meridians of eyeball, 292
j Mesenteries, 248
I Meso-cephalon (pons Varolii), 195
382
INDEX.
Metacarpus, 84
Metalarsiis, 91
Modiolus, 1120
Monro, foramen of, 19.Î
Möns veneris, 279
Morgagni, hydatids of, 277
Moutli, 220
M.iller, <luct of, 277
muscle of, 296
Muscle of Bowman (ciliary), 296
ciliary, 296
cremaster, 327
dilator pupillte, 298
Horner's. 117
kerato-cricoideus, 253
levator glanduhc thyroidese, 241
of Müller, 296
sphincter pupilUe, 297
triticeo-glossus, 253
of the arm, 134
of the auricle, 310
of the back, 123
Muscles, double-bellied, 116
of the abdomen, 129
of the ear (external), 116
of the epiglottis, 253
of the Eustachian tube, 317
of the eyeball, 302
of the face, 117, 118, 119
of the forearm, 136
of the foot, 150
of the hand,140
of the head,111
of the hip, 144, 145
of the larynx, 253
of the leg, 147
of the neck,120
of the palate, 122
of the perineum, 331
of the pharynx, 225
of the shoulder, 134
of the stomach, 227
of the thigh, 142
of the thorax, 132
of the tympanum, 315
Muscular fibre, 114
Musculi pectinati, 154
^ ABOTH, ovules of, 2S4
11 Nails, 288
Nates of cerebrum, 196
Neck of humerus, 79
Nerve tissue, 185
Nerve, abducens, 202
Arnold's, 37, 204
auditory, 203
Bell's external respiratory,
206
internal respiratory, 205
chorda tympani, 202, 313, 316
circumflex, 206
cochlear, 203, 320
crural anterior, 209
facial, 202
genito-crural, 208
glosso-pharyngeal, 203
hypoglossal, 204
ilio-hypogastric, 208
ilio-inguinal, 268
intercosto-humeral, 206, 208
interosseous. 208
I Jacobson's, 37, 203, 316
laryngeal, 204, 254
maxillary, inferior, 202
superior, 202
median, 206
motor oculi, 201
musculo-spiral, 207
nonus or ninth pair, 204
obturator, 209
of Wrisberg, 206
olfactory, 200
ophthalmic division of fifth,
202
optic, 200
par vagum, 204
patheticus, 201
phrenic, 205
pneumogastric, 204
portio dura, 202
portio mollis, 203
pudic, 209
radial, 207
spinal accessory, 204
sympathetic, 211
thoracic, 206
trigeminus, 201
) tympanic, 203
I ulnar, 207
vestibular, 203, 324
Vidian, 213
Nerve-fibres, optic, 200, 305
I Nerves of ankle-joint, 112
of auditory canal, 311
of auricle, 311
of bladder, 269
of choroid, 296
IND
Nerves, cranial, 200
hepatic, 237
of Eustachian tube, 318
of elbow-joint, 104 .
of eye, 304
of eyelids, 304
of eye-muscles, 303
of hip-joint, 107
of iris, 298
of kidney, 265
of knee-joint, 110
of Lancisi, 193
of larynx, 204, 254
of lung, 259
of membrana tympani, 312
of nasal fossse, 291
of nose, 291
of oesophagus, 227
of ovaries, 286
of pancreas, 239
of penis, 274
of pharynx, 226
of shoulder-joint, 102
of spleen, 241
of stomach, 229
of supra-renal capsules, 243
of taste, 222, 290
of testicles, 278
of thymus gland, 242
of tongue, 222
of trachea and bronchi, 256
of tympanum, 316
of uterus, 284
of wrist-joint, 105
petrosal, 213
popliteal, 210
sciatic, 209
spinal, 205
splanchnics, 214
thyroid, 241
Nervous system, 185
Neurilemma, 185
Nipple, 286
Nose, 290
Notch, cotyloid, 68
inter-clavicular, 65
inter-condyloid, 87
popliteal, 88
sacro-sciatic, 70
sigmoid, 49
supra-orbital, 24
supra-scapular, 77
Nuck, canal of, 283
Nymph«, 279
383
Odontoblasts, 220
Odontoid ligaments, 95, 96
process, 63
(Esophagus, 226
Omentum, 247
Opening, saphenous, 329
Opercula, 220
Optic thalami, 192
Ora serrata, 298
Orbital cavities, 55
Organ of Corti, 323
of hearing, 310
of Rosenmüller, 286
of sight, 292
of smell, 290
Organs of generation, female, 279
male, 271
of sense, 287
of taste, 289
of voice and respiration, 249
urinary, 260
Os calcis, 90
orbiculare, 314
planum (orbital of ethmoid), 39
tincœ, 282
uteri, 282
Ossa innominata, 68
triquetra, 20
Osteology, 17
Ossification, 20
Ossicles of tympanum, 314
Otoliths, 321
Ovaries, 284
Oviducts, 284
Ovisacs, 285
Ovules of Naboth, 284
Ovum, 285
PACCHIONIAN bodies, 186
Palate, 221
Palpebrae, 306
Pampiniform plexus, 278, 286
Pancreas, 238
lesser, 239
Papilla, lachrymal, 306
optic, 298
PapilliB of skin, 288
Parovarium, 286
Pars ciliaris retinae, 299
intermedia, of vulva, 281
Peduncles of cerebellum, 195, 196,
197
Pelvis, 73
384
INDEX.
Pelvis of the kidney, 261
Penis, 272
Pericardium, 152
Perilymph, 318
Perineum, 331
female, 335
Periosteum, 19
Peritoneum, 246
Peronei muscles, 147, 149
Pes accessorius, 194
hippocampi, 194
Petit, canal of, 302
Peyer's patches, 230
Phalanges of ear, 324
of foot, 92
of hand, 85
Pharynx, 224
Pia mater of brain, 187
of spinal cord, 199
of the testes, 275
Pinna, or auricle, 310
Plane, equatorial, 292
meridional, 292
Plantar arch, 175
Plate, cribriform, 38
orbital, 39, 41, 44
perpendicular, 38
Pleurie, 259
Plexus, brachial, 206
carotid, 214
cavernous, 214
cervical, 205
choroid, 193
gastric, 215
lumbar, 208
pampiniform, 278, 286
sacral, 209
solar, 215
splenic, 215
tympanic, 316
Plexuses of the sympathetic, 214,
215, 216
Pli courbe (angular gyrus), 252
Plica semilunaris, 307
Point, nodal, 292
Poles of the eyeball, 292
Pomum Adami, 249
Pons Varolii, 195
Portal system, 178, 235
Porus opticus, 293
Pouches of membrana tympani, 312
Poupart's ligament, 129, 326
Prepuce of clitoris, 280
of penis, 273
Process, acromion, 77
alveolar, 43, 50
articular, 21
auditory, 36
basilar, 28
clinoid, 30, 33
condyloid, 28, 49, 79, 85, 86
coracoid, 77
coronoid, 50, 81
ethmoidal, 48
falciform, 329
hamular, of cochlea, 320
of pterygoid plate of sphe¬
noid, 33
lachrymal, 48
malar, 42
mastoid, 35
maxillary, 48
mental, 49
nasal, 42
odontoid, 63
olecranon, 80
olivary, 30
orbital, 39, 41, 45, 46
palatine, 43
pterygoid. 33
sphenoidal, 46
spinous, 32, 43, 47, 63, 70, 71
styloid, 37
transverse, 63
turbinated. 39
unciform, 39
vaginal, 37
vermiform, 197
zygomatic, 34
Processes, ciliary, 296
clinoid, 30, 33
of Ingrassias 32
Processus cochleariformis, 37
cerebello ad medullam (inferior
peduncles), 197
ad pontem (middle pedun¬
cles), 195
ad testes, 196
gracilis, 314
Promontory of sacrum, 71
of tympanum, 313
Prostate gland, 271
Prostatic urethra, 269
sinus, 269
Pterygoid processes, 33
Pubes. 70
Punctum lachrymale, 306
Pupil, 297
INDEX.
385
Pylorus, 227
Pyramid, anterior, 196
posterior, 197
of tympanum, 314
Pyramids of Ferrein, 263
of Malpighi, 261
Radius, si
Rami of inferior maxillary, 50
Ramus of ischium, 70
of the pubes, 70
Eeeeptaculum chyli, 184
Rectum, 232
Regions of abdomen, 244
Reil, island of, 188
Reissner, membrane of, 323
Renal vessels, 263
Rete mucosum, 288
Rete testis, 276
Retina, 298
Ribes, ganglion of, 211
Ribs, 66
Ridge, mylo-hyoid, 51
pterygoid, 32
Rima glottidis, 252
Ring, abdominal, 326
crural, 328
femoral, 328
Rings and phalanges, 324
Rivinus, duct of, 221, 222
notch of, 311
Rods and cones (Jacob's), 300
of Corti, 323
Rolando, fissure of, 187
Rosenmüller, organ of, 286
Rostrum of the sphenoid, 31
SAC, lachrymal, 309
Saccule, 322
Saccules laryngis, 252
Sacs of the peritoneum, 246
Sacrum, 71
Santorini, cartilages of (cornicula
laryngis), 250
Scala media, 322
tympani, 321
vestibuli, 320
Scapula, 76
Scarpa, foramen of, 43
intumescentia ganglioniformis,
325
Schindelysis, 93
Schlemm, canal of, 297
Schnitze, olfactory cells of, 291
Schwann, substance of, 185
Sclerotic, 293
Scrotum, 275
Sella turcica, 30
Septum crurale, 329
lucidum, 193
nasi, 58
pectiniforme, 273
Sheath, crural, 329
Shin, 88
Shoulder-joint, 102
-blade, 76
Shrapnell's membrane, 312
Sight, organs of, 292
Sigmoid flexure, 232
Sylvius, aqueduct of, 36, 203, 313
fissure of, 187
Sinus aortici or sinus of Valsalva,
156
circularis iridis, 297
of the kidney, 261
of Morgagni (sacculus laryngis),
252
pocularis, 270
Sinuses, 23
sphenoidal, 31
of Valsalva, 155,156
Skin, 287
Slit, nasal, 38, 58
Smell, organ of, 290
Space, anterior perforated, 191
posterior perforated, 191
Spaces, Foutana's, 297
Spermatic cord, 278
Sphincter vesicae, 268
Spinal cord, 198
Spine, ethmoidal, 30
of the ischium, 70
nasal anterior, 43, 58
posterior, 47
of the pubes, 71
of the scapula, 76
of the sphenoid, 32
of the tibia, 88
Spines of the ilium, 69
Spinous processes, 21
Spleen, 239
Spot, blind, 298
germinal, 285
light, 312
yellow, 298
Squamous, 22
386
INDEX.
Stars of Verheyen, 264
Steno's ducts, 221
Stenson's foramina, 43
Sternum, 65
Stilling, canal of, 301
Styloid, 22
Stomach, 227
Substance of Schwann, 185
Sulci, 189
Sulcus spiralis, 323
tympanicus, 311
Surface, auricular, 70
trochlear, 79
Sustentaculum tali, 90
Sutura, 92
Suture, baso-sphenoidal, 52
coronal, 52
lachrymo-ethmo-frontal, 52
lambdoidal, 52
masto-occipital, 52
masto-parietal, 52
petro-occipital, 52
petro-sphenoidal, 52
sagittal, 52
spheno-parietal, 52
squamo-parietal. 52
squamo-sphenoidal, 52
Sutures, facial, 52
of the orbit, 56, 57
of the skull, 51
Sympathetic system, 211
Symphysis, 92
of inferior maxillary, 49
Synarthrosis, 92
Synchondrosis, 92
Synovial membranes, 93
TAESDS, 90.
Taste, nerves of, 290
Taste-goblets. 289
Taenia hippocampi, 193
semicircularis, 193
Teeth, 217
Tendo-oculi, 307
Tendons, 115
Tenon, capsule of, 292
Tentorium cerebelli, 186
Testes, 274
of the cerebrum, 196
descent of, 278
Thebesius, foramina of, 154
Thigh, 85
Thorax, 64
Thyroid axis, 164
cartilage, 249
Tongue, 222
Tonsils, 221
Trachea, 254
Tract, lateral, 197
optic, 305
uveal, 297
Tracts, olfactory, 200
Tractus spiralis foraminulentus,
325
Tragus, 310
Trigonum vesicae, 268
Trochanters of femur, 85
Trochlea, 22
Tube, Eustachian, 317
Tuber annulare (pons Varolii),
195
cinereum, 191
Tubercle, 21
genial, 50
of Lower, 154
Tuberosities, 21
of femur, 87
of humerus, 79
of ischium, 70
maxillary, 40
Tubes of Henle (convoluted tubes),
j 261
spiral, of Schachowa, 262
Tubuli lactiferi, 286
seminiferi, 276
uriniferi, 262
Tuft, Malpighian, 263
Tunica albugínea, 275
vaginalis, 275
vasculosa, 275
Tunics of eyeball, 293
Tutamina oculi, 306
Tympanum, 313
Tyson, glands of, 274
ULNA, 80
Umbilical region, 245
Umbilicus, 244
Umbo, 312
Urachus, 267
Ureters, 265
Urethra, 271
bulb of, 270
Uterus, 281
masculinus, 270
Utricle, 321
INDEX.
387
Uvea, 297
Uvula, 221
vesicae, 269
VAGINA, 281
Vaginal, 22
Valley of cerebellum, 197
Valsalva, sinuses of, 15,i, 156
Valve, Eustachian, 154
ilio-csecal, 231
mitral, 156
tricuspid, 155
of Bauhin, 231
of Vieussens, 196
Valves of Kirkring (valvulae con¬
niventes), 230
semilunar, 155
Valvulae conniventes, 230
Vas aberreos, 276
deferens, 277
Vasa eíferentia, 276
recta, 276
vasorum, 158
Vein, axillary, 179
basilic, 179
cephalic, 179
jugular, 178
femoral, 182
iliac, 182
median, 179
popliteal, 182
portal, 183
radial, 179
splenic, 183
subclavian, 179
supra-renal, 183
ulnar, 179
vena cava, 180, 183
vertebral, 181
Veins, 177
azygos, 180
cardiac, 183 •
choroid, 296
hepatic, 183
iliac, 182
innominate, 180
interlobular, 2i)4
jugular, 178
of bone, 19
of head and neck, 178
of lower extremities, 182
of œsophagus, 226
of supra-renal capsules, 243
Veins of thymus, 242
of trachea and bronchi, 256
of the eye, 296, 298
of the kidney, 265
of the larynx, 254
of the lung, 259
of the pancreas, 239
of the penis, 274
of the stomach, 229
of the thorax, 181
pulmonary, 183
! saphenous, 182
spinal, 181
thyroid, 241
uterine, 284
without valves, 178
Velum interpositum, 187, 193,
194
1 Venœ comités, 177
proprias renales, 265
rectsB, 264
vorticosse, 296
Venter of the ilium, 70
of the scapula, 76
Ventricle of the cord, 200
fifth, 194
fourth, 195
of the larynx, 252
third, 194
Ventricles, lateral, 192
Verheyen, stars of, 264
Vertebra prominens, 64
Vertebrae, 61
Verumontanura, 269
Vesaluis, foramen of, 32
Vesicle, germinal, 285
Graafian, 285
Vesiculae seminales, 278
Vestibule, 280
of the ear, 318
Vidian canal, 33
nerve, 213
Vieussens, valve of, 196
Villi, 230
Viscus, 216
Viscera, covered bv peritoneum,
216
partially, 248
wholly, 248
Vitellus, 285
Vocal cords, 252
Vomer, 48
Vortex of heart, 157
Vulva, 279
388
IXDEX.
WALLS of the tympanum, 313
Wharton's ducts, 221
Whorl of heart, 157
Willis, circle of, 163
Wings of the sphenoid, 31, 32
Winslow, foramen of, 247
ligament of, 109
Wirsung, duct of, 238
Wormian bones, 20
Wrisherg, cartilages of, 201
nerve of 206
yELK, 28,i
ZINN, zonula of, 301
I Zona pellucida, 2hj
Zone, anterior vascular, 294
Zonula of Zinn, 301
Zygoma, 34, 60