1000 



THE ORGANS OF DIGESTION. 



an inverted funnel without visible external limit. On the inner surface a defi- 

 nite line is seen between the oesophagus and cardia. Above the line the mucous 

 membrane is whitish and made largely of pavement epithelium, while below the 

 color is red and the mucous membrane shows characteristic cylindrical epithe- 

 lium. Sometimes an external ring as well as an internal projection is found 

 between cardia and the rest of the stomach, forming a kind of antrum cardiacum. 

 Passing from the cardia to the left and above, we find the first great pouch, 

 the blind sac QY fundus, whose relative size varies with age. In early youth it is 

 slightly developed, in adult man it forms about one-fifth of the stomach. 



This continues on the right into the body of the stomach, which has two sur- 

 faces anterior and posterior and two borders. The anterior surface looks 

 upward and forward, the posterior backward and downward, and they are 

 included between the borders lesser curvature, concave and turned to the right 

 and above, and larger curvature, convex and three or four times as large as the 

 lesser, turned to the left and below (Figs. 623 and 624). 



At the right the body of the stomach gradually contracts toward its duodenal 

 end. Then follows a second smaller part of the stomach, the portio pylorica, which 

 includes the antrum pyloricum, whose form and size vary. Usually the antrum 

 appears as a double pouch ; the flatter one is higher and extends from the lesser 

 curvature to the beginning of the duodenum. It is not very distinctly marked 

 off from the body. The other lies laterally and is separated by a more or less 

 deep notch from the greater curvature (Fig. 627). 



Sometimes a third one is found under this last one. On the inner surface of 

 the stomach there is sometimes a mucous fold, plica prcepylorica, separating the 

 antrum from the body of the stomach. The pouches representing the antrum 

 pylori are caused by two flat ligamentous bands some millimeters wide, one run- 

 ning along the anterior wall, one on the posterior. They are called pyloric liga- 

 ments (lig. pyloricum) and lie between the muscular and serous coats and are 

 closely fused with the latter (Fig. 627). 



The division between the stomach and intestine is marked externally by a 

 circular constriction, sulcus pyloricus, and more deeply by a muscular ring, 



sphincter pyloricus, and internally 

 by a corresponding projection of 

 mucous membrane called valvula 

 pylorica or pylorus (Fig. 625). 



The valve usually presents a 

 round opening, bigger or smaller 

 orificium duodenale which may have 

 a central or eccentric position. It 

 may not be an enclosing ring but a 

 crescentic projection, and rarely con- 

 sists of two halves lying opposite 

 each other. 



The first part of the duodenum is often pouched, called antrum duodeni. 

 The size of the stomach varies according to age, sex, individual, and degree 

 of distention. 



A woman's stomach increases more in length, is more slender, and in general 

 smaller than that of a man. In moderate distention Sappey found the greatest 

 diameter of the stomach to be 24-26 cm. (10-12 inches), from the lesser to the 

 greater curvature 1012 cm. (4-5 inches), and from the anterior to the posterior 

 wall 89 cm. (3J inches). The distance between the two orifices is three to six 

 inches. Luschka, by blowing up the stomach, found its long axis to measure 34 

 cm., greatest vertical diameter 15 cm., greatest antero-posterior diameter 11.5 

 cm., and smallest antero-posterior diameter, at pylorus, 3.7 cm. 



In the empty condition, as in the dead subject, the greatest diameter is reduced 

 to 18-20 cm., the second diameter is 78 cm., and the third disappears as the two 

 walls touch. 



Gastric mucous membrane 

 Circular muscular fibres 

 Longitudinal muscular fibres 

 Peritoneum 



FIG. 625. Diagrammatic view of coats of the stom- 

 ach, duodenum, and pylorus. (Allan Thomson.) 



