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not quite straight in its direction, but has three slight curvatures. One of these is
an antero-posterior flexure, corresponding with that of the vertebral column in the
neck and thorax. The other two are slight lateral curves ; for the oesophagus,
commencing in the median line, inclines to the left side as it descends to the root
of the neck ; thence to the fifth dorsal vertebra it gradually resumes the median
position ; and finally, it deviates again to the left, at the same time coming forward
towards the cesophageal opening of the diaphragm. After piercing the diaphragm,
it turns abruptly towards the left side to join the stomach.

Relations. In the lower cervical and upper dorsal region the oesophagus is
applied to the anterior surface of the spine, being connected with it and with the
longus colli muscle by loose areolar tissue ; opposite the middle dorsal vertebra? the
thoracic duct passes obliquely upwards from right to left behind it, and then ascends
on its left side ; in its lower third the oesophagus is placed in front of the aorta. In
the neck the oesophagus lies close behind the trachea (projecting about a quarter of



THE (ESOPHAGUS.



65



an inch to the left of that tube), and the recurrent laryngeal nerve ascends on each
side in the angle between them (see fig. 81) ; on each side is the common carotid
artery and also a part of the thyroid body, but as the oesophagus incTTnes to the
left side, it is in more immediate connection with the left carotid. In the thorax
the oesophagus is successively covered in front by the lower part of the trachea, by
the commencement of the left bronchus, and by the pericardium and the diaphragm.
The aorta, except near the diaphragm, where the oesophagus is in front of the vessel,
lies to the left, and the vena azygos major to the right and behind ; the pneumo-
gastric nerves descend in close contact with its sides, and form a plexus around it,
the left nerve proceeding gradually to the front, and the right nerve retiring behind
it. In the superior mediastinum the left pleura lies close to its left side, while lower
down in the posterior mediastinum the right pleura is in relation with its right side,
and often extends inwards slightly behind it. Lastly, just before it pierces the
diaphragm the oesophagus is in contact with both pleurae.

STRUCTURE OP THE (ESOPHAGUS.

The walls of the gullet are composed of three coats ; viz., an external or
muscular, a middle or areolar, and an internal or mucous coat. Outside the

Fig. 83. SECTION OF THE HUMAN (ESOPHAGUS.
(P'rom a drawing by V. Horsley.) Moderately magnified.

The section is transverse, and from near the middle
of the gullet, a, fibrous covering ; b, divided fibres
of the longitudinal muscular coat ; c, transverse
muscular fibres ; d, sub-mucous or areolar layer ; e,
muscularis inucosse ; /, mucous membrane, with vessels
and part of a lymphoid nodule ; g, laminated epithelial
lining ; k, mucous gland ; i, gland duct ; TO', striated
muscular fibres cut across.

muscular coat there is a layer of areolar
tissue, with well marked clastic fibres.

The muscular coat consists of an
external longitudinal layer (seen in section in
fig. 83, &) and an internal circular layer (c).
This twofold arraugement of the muscular
fibres prevails throughout the whole length
of the alimentary canal ; but the two layers
are here much thicker, more uniformly dis-
posed, and more evident than in any other
part, except quite at the lower end of the
intestine. The external or longitudinal fibres
are disposed at the commencement of the tube

in three bands, one in front and one on each side. The lateral bands are con-
tinuous above with the inferior constrictor of the pharynx ; the anterior arises from
the back of the cricoid cartilage at the prominent ridge between the posterior
crico-arytei.oid muscles, and its fibres spread out on each side of the gullet as they
descend, soon blending with those of the lateral bundles to form a continuous
layer around the tube. The direction of many of the fibres is at first slightly
oblique, but towards the lower end it is more directly longitudinal. The internal
or circular fibres are separated above by the fibres of the lateral longitudinal bands
from those, of the inferior constrictor of the pharynx. The rings which they form
around the tube have a horizontal direction at its upper and lower part, but in the
intervening space are slightly oblique. At the lower end both layers of fibres
become continuous with those of the stomach.

VOL. in., PT. 4. y




66 ORGANS OF DIGESTION.

The muscular coat of the upper end of the oesophagus is of a well marked red
colour, and consists wholly of striped muscular fibres ; these are gradually replaced
by plain muscular fibres, so that these are almost the only ones found in the lower
half of the tube. A few striped fibres may, however, be found even at the lower
end, and in some animals they preponderate throughout the whole length of the tube.

The longitudinal fibres of the oesophagus are sometimes joined by a broad band of smooth
muscle, passing from the left pleura, and sometimes also by another from the left bronchus.
According- to Cunning-ham, the former is almost constantly present, and the latter very
frequently.

The areolar or submucous coat is placed between the muscular and mucous
coats, and connects them loosely together. It exceeds the mucous membrane con-
siderably in thickness, and in it are contained the mucous glands (fig. 83, A), which
open on the mucous membrane.

The mucous membrane is of .firm texture, and is paler in colour than that of
the pharynx or stomach. From its loose connections its outer surface is freely
movable on the muscular tunic ; and under ordinary circumstances the mucous
lining is thrown into longitudinal folds or rugae, which are in mutual contact. These
folds disappear on distension of the canal.

Minute papillae (/) are seen upon the mucous membrane, and the whole is covered
with a thick stratified scaly epithelium. In the embryo for a certain period the
oesophagus is lined by columnar ciliated epithelium (Neumann), patches of which
may persist even to the time of birth (Klein).

The small compound racemose or tubulo-racemose glands, named cesophageal
glands, which are for the most part seated in the submucous tissue are specially
numerous at the lower end of the tube. A few of the smallest are situated in the
substance of the mucous membrane. The cells of these glands are columnar. Their
ducts are usually surrounded by collections of lymphoid tissue as they pass through
the mucous membrane.

The mucous membrane is bounded next to the submucous coat by longitudinally
disposed plain muscular fibres, which, imperfect above, form a continuous layer
towards the lower end of the tube (muscularis mucosce, e).

Duplicity of the oesophagus in part of its extent, without other abnormality, has been
recorded (Blaes, quoted by Meckel).

Vessels and nerves. The arteries of the oesophagus consist of a series of
small vessels derived from the inferior thyroid, descending thoracic aorta, left
inferior phrenic, and coronari/ of the stomach ; these branches anastomose together.
The veins pass to the 'inferior thyroid, azygos, and coronari/ of stomach ; the
submucous veins at the lower part of the oesophagus form a free communication
between the portal and systemic veins, and become dilated iu cases of obstruction
to the circulation through the liver. The lymphatics go to the inferior deep
cervical and posterior mediastinal glands. The nerves are derived from the
recurrent laryngeals, vagi, and sympathetic. The blood-vessels have for the most
part a longitudinal arrangement. There are separate networks for the mucous
membrane, the muscularis mucosae and the muscular coat, and the glands and fat
lobules which arc met with in the submucosa have each their capillary plexus.
Lymphatics are found in both the submucous and mucous coats, those of the latter
commencing as in the mouth and pharynx within the papilke. A small amount of
lymphoid tissue is also present, and may be accumulated into lymphoid nodules,
especially in the neighbourhood of the ducts of the mucous glands. Both here and
in the pharynx the alveoli of the mucous glands arc invested by sinus-like lymphatic



THE CESOPHAGUS. 67

vessels (Kidd.) The nerves form a gaugliated plexus between the two layers of the
muscular coat, as in other parts of the alimentary canal, but it is characterised by
the comparatively large size of the groups of ganglion-cells and~of~the cells
themselves, and also by the fact that it contains, besides non-medullated fibres, a
large number of medullated nerve-fibres (derived from the pneumo-gastric nerves).
Each of these fibres in passing a ganglion is joined by a non-medullated fibre
derived from one of the cells of the ganglion, a T-shaped junction being formed, as
in the case of the nerve-fibres passing through the posterior-root ganglia. The
medullated fibre then passes on and branches, and is finally distributed in terminal
arborisations (motor end-organs) in the striped muscular fibres (Ranvier). The non-
medullated fibres are distributed chiefly to the plain muscular tissue. There is also
a gangliated plexus in the subrnucous tissue, from which fibres pass to the glands
and to the rnuscularis mucosas, whilst others penetrate between the deeper layers of
the stratified epithelium and end in an open arborisation of varicose fibrils between
the cells (G. Eetzius).



RECENT LITERATURE OF THE (ESOPHAGUS.

Bigg-s, G. P., Diverticulum of the oesophagus, Pioc. New York Path. Soc., 1891-92.

Brosset, J., DCS vices de conformation de VcKsophage, Lyon medical, 1889.

Chavasse. T. I\, On a case of pressure diverticulum of the oesophagus, Trans. Path. Soc.
London, xlii, 1891.

Coakley, C. S., The arrangement of the muscular fibres of the oesophagus, Kesearches from the
Loomis Labor., Univ. of the City of New York, 1892.

Dobrowolski, Z., Lymphknotchen in der Schleimhaut der fpeise-rohre, des Magens, d-c., Beitr.
zur pathol. Anatomic u. allg. Pathologic, Bd. xvi, 1894.

Flesch, Max, Ueber Bezichungen zwischen Lymphfollikeln und secernitrcnden Drilsen im
(Esophagus, Anatom. Anz., Jahrg. iii, 1888.

Juvara, E., Sur un muscle diaphraymatico-wsophagicn, Bull. soc. anat. , Paris, 1894.

Klaus, G., Der kindliche (Esophagus, <kc., Inaug. Diss., Muncben, 1890.

Laimer, E., Beitray zur Anatomic des (Esophagus, Wien. med. Jahrb., 1884.

Mayer, S., Die Membrana peri-oesophagealis, Aiiat. Anz., viii, 1892.

Kubeli, O., Ueber den (Esophagus des Menschen und der Haustiere, Archiv f. wissensch. u.
akt. Tierheilkunde, Bd. xvi, 1890.

Shattock, S. G., Congenital atrcsia of the cesophagus, Trans. Path. Soc., xli, 1890.

Strahl, H., Beitrdge zur Kentnniss des Baues des (Esopliagus, Arch. f. Anat. u. Physiol Anat
A th., 1889.

Tetens, J., Ein Beitrag zur Lehre -von dcm (Esophagus- Divcrticuium, Kiel, 1889.

Willett, E., Atresia of asopliagus, Trans. Path. Soc., 1893.



68



OEGANS OF DIGESTION.



THE ABDOMINAL VISCERA.

As that part of the digestive canal which is found beneath the diaphragm, and
consists of the stomach and intestines, is situated within the cavity of the abdomen,
and occupies, together with the liver and pancreas, by far the greater part of that
cavity, the general topographical relations of the abdominal viscera may here be
briefly explained.

THE ABDOMEN.

The abdomen is the largest cavity in the body, and is lined by an extensive and
complicated serous membrane, named the peritoneum. It is subdivided into two
parts : an upper or larger part, the abdomen, properly so called ; and a lower or
pelvic part. The limits between these portions of the cavity are marked by the brim
of the true pelvis.

The abdomen proper differs from the other large cavities of the body in being
bounded mainly by muscles and fascias (described in Vol. II. , pt. 2.) instead of
more or less rigid osseous walls, so that it can readily vary in its capacity according
to the condition of its contained viscera. Its walls are pierced by several apertures,
such as the several diaphragmatic openings for the aorta, vena cava and oesophagus,
and the femoral rings and inguinal canals. In the median fibrous substance of
the anterior wall lies the umbilical cicatrix. The cavity is of an irregularly oval
form with the long axis directed from above downwards and having its transverse
diameter usually greater than its antero-posterior. It extends under cover of the
lower ribs and costal cartilages as high as the vault of the diaphragm, and below it
is bounded laterally by the iliac fossae, between which at the pelvic inlet it becomes
continuous with the cavity of the pelvis. The posterior wall of the abdomen is
formed by the bodies of the lumbar vertebras with the psoas and quadratus
luniborum muscles on either side. In consequence of the forward projection of the
lumbar vertebrae there is a considerable hollow on either side of the spine ; so that in
a horizontal section the abdominal cavity appears somewhat kidney-shaped. The

Fig. 84. OUTLINE of THK FRONT OF THE ABUOMKN,

SHOWING THK DIVISION INTO REGIONS.

1, epigastric region ; '2, umbilical ; 3, hypoga.stric ;
4, 4, right and left hypochondriac ; 5, 5, right and left
lumbar ; 6, b', right and left iliac.

walls of the pelvic cavity are mainly osseous,
but its flcor is formed by the integument, fat,
fasciae, and muscles, and has certain apertures
which are usually closed, but can be opened for
the passage of the gen i to-urinary products and
the contents of the rectum.

For the purpose of enabling reference to be
made to the situation and condition of contained
organs, the abdomen proper has been artificially
subdivided into certain regions which are
separated from one another by imaginary hori-
zontal and sagittal planes passing through the
abdomen, the edges of these planes being indicated by lines drawn upon the surface
of the abdomen. By this plan the abdomen is divided into nine regions (fig. 84),
the boundaries and contents of which will be described in the chapter on Superficial
Anatomy.




THE ABDOMINAL VISCERA. 69

THE PERITONEUM.

The peritoneum or serous membrane of the abdominal cavity is by far the most
extensive and complicated of the serous membranes. Like the otherr it may be
considered to form a shut sac, but in the female the two Fallopian tubes open at
their free extremities into its cavity. The parietal layer is connected with the fascias
lining the abdomen and pelvis by means of areolar tissue (subperitoneal) ; it is more
firmly adherent along the middle line of the body in front, as well as to the under
surface of the diaphragm. The visceral layer, which is thinner than the other,
affords a more or less complete covering to mosfc of the abdominal and pelvic
organs. The folds of the peritoneum are of various kinds. Some of them
constituting the mesenteries connect certain portions of the intestinal canal with
the posterior wall of the abdomen ; they are, the mesentery properly so called for the
jejunum and ileum, the transverse and sigmoid m&so-colon, and the meso-rectum.
Other folds connected with the stomach are called omanta ; they are the great
amentum or epiploon, the small amentum, and the gastro-splenic amentum. Lastly,
certain reflexions of the peritoneum from the walls of the abdomen or pelvis to
viscera which are not portions of the intestinal canal are named ligaments ; such
are the ligaments of the liver, spleen, uterus, and bladder.

The further account of the peritoneum will be deferred until the abdominal
viscera have been described.



RECENT LITERATURE OF THE ABDOMINAL PORTION OP THE ALIMENTARY
CANAL IN GENERAL, AND OF THE PERITONEUM.

Anderson, R. J., The peritoneum in man and animals, Dublin Journ. of Med. Science, 1883.

Anderson, W. , A plea for uniformity in the delimitation of the regions of the abdomen, Journ.
Anat. and Phys. , vol. xxvi, 1892.

Anderson, W., and Makins, G-. H., The planes of .mbperitoneal and subpleural connective
tissue, Journ. Anat. and Phys., vol. xxv, 1890.

Bag-insky, Adolf, Untersuchungen uber den Darmkanal des menschlichen Kindes, Virchow's
Arch, fur pathol. Anat., Ed. Ixxxix.

Ballantyne, J. W., The relations of the abdominal viscera in the infant, Edinburgh Medical
Journal, July, 1891.

Born, Hermann, Ein seltener Fall von angeborener Atresie und Durchtrennuny des Darmrohres
mit entwickelungsgeschichtlich-intercssanten Verhaltnissen am Peritoneum, Archiv f. Anat. u. Physio!.,
Anatom. Abt., Jahrg. 1887.

Brossike, G-., Ueber intraabdominale (retroperitoneale) Hernien und Bauchfelltaschen, nebst
einer Darstellung dcr Entwickelumg peritonealer Formationen, Berlin, 1891.

Cunning-ham., D. J., Delimitation of the regions of the abdomen, Journ. of Anat. and Phys.,
1892, and Tr. of the R, Acad. of Medicine of Ireland, vol. xi, 1893.

Dexter, S., The anatomy of the peritoneum, New York, 1892.

Farabeuf, Arret d' evolution de I 'intestine, Progres medical, 1885, and Bull. soc. anat. , Paris, 1885.

Flesch, Max, Bemerkungen uber die Beziehungen des Bauchfells zur vorderen Wand der Harn-
blase, Anat. Anzeiger, Jahrg. iii. 1888.

Eraser, A., A case of complete transposition of the thoracic and abdominal viscera, Trans, of the
Roy. Acad. of Med. of Ireland, vol. v, 1895.

Fromont, Henri P., Contributions d I' anatomic topographique de la portion sous-diaphrag-
matiquf du tube digestif, Lille, Ib90.

Griffith, J. Wardrop, A case of transposition of the thoracic and abdominal viscera, Journal
Anat. and Phys., vol. xxvi, 1891.

Hasse, C., Ueber die Bewegungen der ZwerchfeU.es und ueber den Einfluss derselben auf die
Unterlelbsorgane, Arch. f. Anat. und Phys., Anat. Abth., Jahrg. 1886.

Henke, W., Der Raum der Bauchhohle des Menschen und die Verteilung der Einjeweide in
demselben, Archiv f. Anat. u. Physiol., Anatom. Abt., Jahrg. 1891.

Jones, C. H., Observations on the amentum, especially its blood-vessels, Illustr. Med. News,
London, vol. i, 1888.

Jonnesco. Organs de digestion, in Poirier, Anatomic, Paris, 1895.

Jonnesco et Juvara, Anatomic des ligaments de Vappendice vermiculaire et de la fossette ileo-
appendiculaire, Progres mid., 1894.

Klaatsch, H., Zur Morphologic der Mesenterialbildungen am Darmkanal der Wirbelthiere,
Morph. Jahrb., Bd. xviii, 1892.

Iiesshaft, P., Ueber die Bedeutung der Bauchpresse fur die Erhaltung der Baucheingeweide in
ihrer Lage, Anat. Anzeiger. 1888.



70 ORGANS OF DIGESTION.

Lock-wood, C. B., On the development of the great amentum and transverse colon, Proe. Royal
Society of London, vol. xxxv. 1883 ; ffunterian lectures on hernia, London, 1889.

Mettenlieimer, H., Ein Beitrag zur topographischen Anatomic der Brust- Bauch- und Becken-
hohle des neugeborenen Kindes, Morpa. Arbeiten, iii. 1893.

Perig-non, L., Etude sur le ddveloppement du peritoine dans ses rapports avec revolution du tube
digestif et de ses annexes, Paris, 1893.

Bolleston, H. D., The fossae, round the ccecum, and the position of the vermiform appendix,
with special reference to retro-peritoneal hernia, Proc. of the Anatom. Soc. of GrL Brit, and Ireland,
Journ. of Anat. and Physiol., vol. xxvi, 1891.

Smith, "W. Wilberforce, Delimitation of the regions of the abdomen, Journ. of Anat. and
Phys., vol. xxvii, 1892.

Symington, J., The topographical anatomy of the child, 1887 ; The relations of the peritoneum
to the descending colon in the human subject, Journ. of Anat. and Physiol., vol. xxvi, 1892.

Toldt, C., Ban und Wachstkumsverdnderungen der Gekrose des menschlichen Darmkanales,
Denksch. d. k. Akad. der Wissensch., Wien, Bd. Ivi, 1889 ; Die Darmgekrose und Netze im gesetz-
mdssigen und im gesetzwidrigen Zustand. Ibid. ; Ueber die Geschichte der Mescntericn, Vhdlgn. d.
Anat. Gres., Anat. Anzeiger, 1893 ; Utber die massgebendcn Gesichtspunkte in der Anatomic des
Bauchfells und der Gekrose, Denkschr. d. Akad. d. Wiss., Wien, 1893.

Treves, F., The anatomy of the intestinal canal and peritoneum in man, Hunterian lectures, 1875.

"Wartlin, A., A case of situs viscerum inversus, New York Med. Journ., vol. lix.



THE STOMACH.



71





THE STOMACH.

The stomach is a dilated portion of the alimentary canal situated^ between the
termination of the oesophagus and the commencement of the small intestine. In
shape it is somewhat pyriform, with the larger end QV fundus directed upwards and
backwards on the left side, and the smaller and lower end turned to the right. It
may be divided into a main or cardiac part, the long axis of which is directed
from above downwards, forwards, and a little to the right, and a much smaller
pyloric part, which passes nearly horizontally from left to right. Of its two open-
Fig. 85. DIAGRAMMATIC OUTLINES OP

THE EMPTY (A) AND DISTENDED (B)
STOMACH, SEEN FROM THE FRONT.

M dotted line represents the median
plane. The + indicates position on back
of organ of pyloric orifice.

ings the one, by which food

enters from the oesophagus, is

situated to the right of the fundus,

and is named the cardiac orifice

or cardia, the other, by which it passes into the duodenum, and which is placed on

a lower level and more forwards and to the right, is the pyloric orifice, which is

bounded internally by a circular constriction, sometimes also marked externally,

called the pylorus. The stomach has two surfaces, called anterior and posterior,

and two borders, termed the great and small (greater and lesser) curvatures.

Variations in position. The stomach varies greatly in size, position, direction,
and relations under normal physiological conditions, such as the condition of its
muscular wall, whether relaxed or contracted, the degree of its distension, and the
state of neighbouring organs.

When the stomach is empty it lies in the left hypochondrium and left half of
the epigastric region, its pyloric end being situated in or near the median plane

Fig. 86. DIAGRAMMATIC OUTLINE OF THE STOMACH, AS SEEN FROM

BEHIND. (His.) J

a, great curvature ; 5, small curvature ; c, left end, great cul-
de-sac, or fundus ; d, small cul-de-sac, or antrum pylori ; o,
cesophageal orifice or cardia ; p, pyloric extremity.

under cover of the liver at the level of the last dorsal
or first lumbar vertebra. The empty stomach is
often described as hanging vertically, with its sur-
faces anterior and posterior ; but it always presents
some degree of obliquity from above downwards

and forwards, and not unfrequently it is more nearly horizontal than vertical, this
direction being associated with a distended state of the small intestine, which pushes
the lower part of the stomach upwards and forwards. Although usually flattened so
as to present two surfaces and two borders, it is sometimes found contracted into a
cylindrical form. This is especially the case towards the region of the pylorus, where
its circular muscular fibres are best developed.

As the stomach is distended its fundus fills up the left cupola of the diaphragm,
pushing the left lobe of the liver towards the right side, and tilting up the apex of
the heart, while the lower part of the great curvature lies so as to come in contact
with the anterior abdominal wall below the left costal wall and the liver, and not
unfrequently to enter the left lumbar and umbilical regions. The distension of the
stomach is also accompanied by a movement of the pylorus towards the right side,




72 ORGANS OF DIGESTION.

so that this orifice of the stomach is often found under the liver close to the neck of
the gall bladder, and two or three inches to the right of the median plane. This
movement of the pylorus to the right side is accompanied by one of rotation, so
that , the orifice, which in the empty stomach is directed towards the right side,
looks backwards, and the pylorus is concealed from the front by the dilated pyloric
portion of the stomach. This part of the stomach moves more freely to the right




!



Fig. 87. HORIZONTAL SECTION OF ABDOMEN OF BOY AGED six YEARS, AT THE LEVEL OF THE CARDIAC

ORIFICE. (J. S.)

a, disc between tenth and eleventh dorsal vertebras ; 6, diaphragm divided at the level of its
oesophageal opening ; c, aorta ; d, cardiac orifice, behind this the stomach lies in direct contact with the
diaphragm. The spleen is normally more completely covered with peritoneum at this level.

than the pylorus itself, so that a blind recess is gradually formed to the right of a
sagittal plane passing through the pylorus. This is often called the antrum pylori
or small cul-de-sac.

Cardiac Orifice. The opening by which food enters the stomach from the
oesophagus is called the cardia, or cardiac orifice. Owing to its connections with the



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