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r part of the pancreas to the first part of the duodenum. It encloses the hepatic

nd Capacity of the Stomach.— Probably no organ in the body varies more in the limits of health than the stomach. Moreover, as its tissues change so er death, measurements made on softened and relaxed organs are not only ut quite misleading. Consequently it is difficult, perhaps impossible, to arrive estimate of its size and capacity. ith of the stomach in the fully distended condition is about 10 to 11 inches cm.), and its greatest diameter not more than 4 to 41 inches (10 to 11.2 cm.); pacity in the average state rarely exceeds 40 ounces, or 1 quart.

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HE COURSE OF THE LARGE INTESTINE.

The jejunum and ileum have been removed.

as been estimated by different authorities at from 10 to 13} inches (26 to 34 r, from 3 to 6 inches (8 to 15 cm.); and its capacity from 11 to 5 pints. The the capacity given by Dr. Sidney Martin are probably the most accurate : he acity varies between 9 and 59 oz., with an average of from 35 to 40, or a little 1 a direct line from the cardiac to the pyloric orifice varies from 3 to 5 inches and that from the cardia to the summit of the fundus from 2 to 4 inches

weight, the average of twelve wet specimens freed from their omenta was 2. (135 grms.), with a maximum of 1 oz. (198.45 grms) and a minimum of .Glendinning gives the weight as 4} oz.

at birth the stomach is scarcely as large as a small hen's egg, and its 1 oz. (28.3 grms.). In shape it corresponds pretty closely to that of fundus is well developed. It is vertical in position. tomach (Fig. 918).- As a result of disease, or of constriction of the e abdomen, the stomach is occasionally displaced in position and distorted instead of running obliquely forwards, downwards, and to the right, vertically along the left side of the vertebral column, in which direction erable length. Its inferior part bends rather suddenly, and runs upwards and to the right to join the pylorus, which is often placed quite superficially below the liver. As a result of the displacement, the left extremity of the pancreas is pushed downwards from the horizontal until it almost assumes a vertical position. The narrowing and inversion of the inferior margin of the thoracic framework at the same time constricts the stomach about its middle, and may lead to a bilocular condition..

Hour-glass or Bilocular Stomach.—This is a condition of the organ, by no means rare, in which the stomach is more or less completely separated into two divisions—a cardiac and a pyloric—the normal arrangement in certain rodents and other animals. As a rule the former division is the larger, but occasionally the two are nearly equal, or the pyloric portion may exceed the cardiac in size. Sometimes the condition is temporary, and the result of a vigorous contraction of the circular muscular fibres at the seat of constriction. In other cases it is

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A. Empty stomach in vertical position as defined by the X-rays.
B. Filled stomach in vertical position as seen with the X-rays.
C. Half-filled stomach in vertical position as seen with the X-rays.
D. Half-filled stomach in horizontal position as seen with the X-rays.

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permanent, and may be due to cicatricial contraction after gastric ulcer, or to some other pathological condition. The condition is more frequent in the female than the male, and is rarely found in the fætus or child.

Position of the Stomach.— When empty, or nearly so, the stomach lies in the left hypochondrium and left part of the epigastrium, with its fundus directed posteriorly towards the diaphragm, its long axis lying almost in a horizontal plane and its pyloric part running to the right to join the duodenum. In this state the whole organ is narrow and attenuated, particularly the pyloric part, which is contracted, and resembles a piece of thick-walled small intestine.

When distended, both the cardiac and pyloric parts become full and rounded (Fig. 923). It still lies within the hypochondriac and epigastric regions; but in exceptional cases, or in extreme distension, it may pass down below the subcostal lane and reach into the umbilical and left lumbar regions. As a result of the

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ncrease in length which takes place during distension, the pylorus is variable distance to the right beneath the quadrate lobe of the liver, he same time the long axis of the whole organ becomes much more "unning forwards, downwards, and to the right. Finally there is a special dilatation of the pyloric part, known as the antrum pyloricum, extreme distension is carried so far to the right that it may even reach bochondrium. and Position of the Stomach as seen by X-Ray Examination.—Examination mach by means of X-rays after a " bismuth meal" has given important n about the shape and position of the stomach in the living, and about es which occur as the stomach fills and empties. examinations corroborate, in great part, the conclusions which have been

by the study of formalin specimens so far as the shape of the stomach, ision into parts, is concerned. In regard, however, to the position and f the stomach, X-rays show that the stomach in the living, and especially et attitude, is more vertical than it is after death, and when the body d in the horizontal position. In the upright position, in fact, the long

organ appears to be nearly vertical. The general shape and position ach in the vertical position, moderately distended, is shown in Fig. 923. t will be seen that not only is the body of the stomach nearly vertical, e greater curvature reaches down to the umbilicus, and may descend i it. The pyloric part is directed upwards, as well as backwards, and is not usually the lowest point of the stomach. er anatomical features of the stomach described above are well brought the fundus is a hemispherical dome, lying to the left of the terminal he oesophagus, and continuous in outline with the body of the stomach. ontains gas, and appears translucent to X-rays. The body is of uniform the pyloric part is marked off from it by the incisura angularis, on rvature. Further, the pyloric part shows division into pyloric antrum canal. The incisura angularis and sulcus intermedius are distinct. tion of the stomach is greatly influenced by attitude and by the conabdominal muscles. Contraction of the abdominal muscles can elevate from 5 to 13 cm., or 2 to 5 inches, and the change from the horizontal attitude alters the height of the inferior border from 2 to 10 cm. This h occurs in the alteration from the horizontal to the erect attitude, ely for the differences found between the stomach seen in the post2 or on the operating table and the stomach displayed by means of is, if the stomach figured on p. 1167 be considered fixed at the cardiac newhat fixed at the pylorus, and the pyloric antrum and greater vuld sink downwards, the shape, as seen from the front, would closely X-ray appearances found often in the living. y stomach is a contracted tubular organ, except at the fundus, where

be always dilated. When food is taken, when the individual is tting, it runs down to the point where the gastric walls are in contact her. The distal portion of the stomach dilates for some distance, or

as the pyloric canal. omach becomes filled the whole of the body of the organ becomes e fundus and cardiac portion more particularly so, and these two latter a storehouse. o definite division of this portion from the remainder of the stomach at sphincter, but the peristaltic waves of contraction begin about the organ, and form a fleeting constriction between the two parts. Isis goes on, the tubular pyloric part relaxes somewhat. The waves here become so deep as to divide this portion into chambers. The s are forced through the pylorus by successive waves of peristalsi rm, usually, of jets which impinge against the posterior aspect of vall. ce be undigested masses, the pyloric valve relaxes to allow them also e duodenum.

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STRUCTURE OF THE STOMACH.
The stomach wall is composed of four coatsnamely, from without inwards : (1)
Tunica serosa, (2) tunica muscularis, (3) tela submucosa, and (4) tunica mucosa (Fig. 924).
Tunica Serosa.—The serous coat is formed of the peritoneum, the relations of which

to the stomach have already been described. It is
closely attached to the subjacent muscular coat,
except near the curvatures, where the connexion
is more lax; and it confers on the stomach its
smooth and glistening appearance.

Tunica Muscularis. —The muscular coat, which
is composed of unstriped muscle, is thinnest in the
fundus and body, much thicker in the pyloric
portion, and very highly developed at the pylorus.
It is made up of three incomplete layers-an
external, stratum longitudinale; a middle, stratum
circulare; and an internal of oblique muscular fibres,
fibræ obliquc.

The stratum longitudinale consists of longitudinal fibres, continuous with those of the esophagus on the one hand, and those of the duodenum on the other (Fig. 926, A). They are most easily

demonstrated on the lesser curvature, where they
Stratum
longitudinale

can be traced down from the right side of the
@sophagus. Over the greater curvature and on the
two surfaces they are present as an extremely thin
and irregular sheet. Towards the pylorus the longi-
tudinal fibres grow much thicker, and also much

tougher and more closely united, and they take part
Fig. 924.— TRANSVERSE SECTION THROUGH in the formation of the pyloric valve.
THE WALL OF A HUMAN STOMACH.

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A specially condensed band of these can be often made out both on the front and back at the antrum pyloricum, the form of which is said to be due to their presence. These bands are known as the ligamenta pylori (pyloric ligaments).

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Fig. 925. – MUSCULAR COAT OF THE STOMACH, seen from within after removal of the mucous and submucous

layers. The anterior half of the stomach is shown, viewed from behind (Cunningham).

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The stratum circulare is composed mainly of circular fibres, continuous with the more superficial of the circular fibres at the lower end of the wesophagus (Fig. 925). They begin as a set of U-shaped bundles which loop over the lesser curvature at the right of

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2, and pass downwards and to the left on both surfaces. Further to the right

ed fibres are succeeded by circles which surround the organ completely. Traced he narrow end of the stomach, the circular bundles grow thicker, and at the hey undergo a further inving rise to the pyloric which surrounds the orifice muscular ring. bree oblique, forming the r, consist of fibres which ed on the fundus and adcs of the stomach, in much manner as those of the er are on the body and t of the organ (Fig. 926, are continuous above with

circular fibres of the inf the æsophagus, and form bundles which loop over a immediately to the left a, and run very obliquely and to the right for a distance on both surfaces n. These looped fibres, s to the left, gradually oblique, and finally form

surround the wide end ach completely, even as summit of the fundus. abres can be most readily moving the circular fibres rface below the cardia. towards the right, they to terminate by turning ining the fibres of the

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bmucosa. · The subs a layer of strong but cive tissue, which lies unites the muscular and (Fig. 924).

It is more ed to the muscular and o the mucous coat, and 1 in which the vessels ak up before entering embrane. cosa.—If examined in

soon after death, the is of a reddish-gray

FIG. 926.—THE THREE LAYERS OF THE MUSCULAR COAT OP moderate consistence.

THE STOMACH. A, External or longitudinal layer ; B, ed some time after

Middle or circular layer ; C, Internal or oblique layer. ur turns to a darker a, Longitudinal fibres of oesophagus ; b, Superficial circular whole membrane be- fibres of oesophagus passing into circular fibres of stomach d more pulpy. It is

in B ; C, Deep circular fibres of oesophagus passing into

oblique fibres of stomach in C; d, Oblique fibres forming mm.) and firmer in

rings at the fundus ; e, Submucosa. in the cardiac part, at the fundus, where it often shows signs of post-mortem digestion. ach is empty all three outer coats, which are extensile, contract; whilst

mucous coat, as a result of its want of elasticity, is thrown into nent folds or ruge, which project into the interior and, as it were, occupy ne contracted organ. These are, in general, longitudinal in direction,

cross branches, and they are largest and most numerous along the e. They disappear when the stomach is distended. urface of the mucous coat is examined in a fresh stomach, it is seen to

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