830 THE PERITONEUM. 



the fold by which the spleeu is attached to the stomach. The splenic 

 artery lies behind the sac of the omentum in its course to the spleen, but 

 its gastric branches turn round the splenic margin of the sac and reach the 

 stomach by that means. The coronary artery of the stomach reaches the 

 front of the sac by turning round its upper margin ; and the hepatic artery 

 passes round from below, close to the foramen of Winslow. 



The disposition of the peritoneum below the level of the transverse meso- 

 colon is comparatively simple. The mesentery of the small intestine, 

 although greatly frilled out in front to correspond in length with the 

 jejunum and ileum to which it affords support, is attached posteriorly by a 

 very short border which extends from the level of attachment of the trans- 

 verse colon immediately to the left of the middle line, directly down to the 

 right iliac fossa, where the ileum falls into the caecum. At its widest part 

 the length of the mesentery is from four to six inches between its vertebral 

 and its intestinal border. Between the two layers of serous membrane of 

 which it consists are placed, beside some fat, numerous branches of the 

 superior mesenteric artery and vein, together with nerves, lacteal vessels, 

 and mesenteric glands. In the right and left lumbar region the peritoneum 

 invests the ascending and descending colon usually in less than their whole 

 circumference, and thus binds them closely down to the abdominal parietes, 

 without the intervention of a meso- colon. In some cases the caecum is 

 suspended at a short distance from the right iliac fossa, by a distinct dupli- 

 cature of the peritoneum, which is termed the mcso-ccecum ; but, more 

 commonly, the peritoneum merely binds down this part of the large intes- 

 tine, and forms a distinct but small mesentery for the vermiform appendix 

 only. The sigmoid flexure is attached to the left iliac fossa by a consider- 

 able mesentery, the sigmoid meso-colon ; and in the pelvis the rectum is 

 attached by a fold named meso-rectum. The other peritoneal folds within 

 the pelvis will be mentioned elsewhere. 



Along the colon, and upper part of the rectum, the peritoneum is de- 

 veloped into numerous little projections filled with adipose tissue. These 

 fatty processes are named appendices epiploicce. 



At the upper end of the attachment of the mesentery, on its left side, 

 there is always visible a small portion of the terminal part of the duode- 

 num appearing from underneath in about half its breadth ; and on the 

 right side of the mesentery there is often another little angle of duodenum 

 visible between the mesentery and meso-colon. Thus it will be observed 

 that, while the commencement of the duodenum is invested, like the sto- 

 mach, in front by the general peritoneum and behind by the sac of the 

 omentum, and a succeeding portion is invested only in front, the remainder 

 is crossed by the colon and mesentery, and is only to a small extent in 

 contact with peritoneum. 



THE STOMACH. 



The stomach is that dilated portion of the alimentary canal which inter- 

 venes between the oesophagus and the duodenum, and within which the 

 food is retained for a time to be acted on by the gastric juice, and to be 

 converted into chyme. 



This organ is seated in the left hypochondriac and the epigastric regions, 

 extending also into the right hypochondrium. It lies in part against the 

 anterior wall of the abdomen, and in part beneath the liver and diaphragm, 

 and above the transverse colon. 



