STOMACH. 663 



transverse mesocolon ; its lower border, with the peritoneum covering the caecum 

 and ascending colon. It serves to retain the small intestines in their position, 

 and contains between its layers the mesenteric vessels and nerves, the lacteal 

 vessels, and mesenteric glands. 



The mesocsecum, when it exists, serves to connect the back part of the caecum 

 with the right iliac fossa ; more frequently, the peritoneum passes merely in front 

 of this portion of the large intestine. 



The ascending mesocolon is the fold which connects the back part of the ascend- 

 ing colon with the posterior wall of the abdomen. 



The descending mesocolon retains the descending colon in connection with the 

 posterior abdominal wall; more frequently, the peritoneum merely covers the 

 anterior surface and sides of these two portions of the intestine. 



The transverse mesocolon is a broad fold, which connects the transverse colon 

 with the posterior wall of the abdomen. It is formed of the two ascending layers 

 of the great omentum, which, after separating to surround the transverse colon, 

 join behind it, and are continued backwards to the spine, where they diverge in 

 front of the duodenum, as already mentioned. This fold contains between its 

 layers the vessels which supply the transverse colon. 



The sigmoid mesocolon is the fold of peritoneum which retains the sigmoid 

 flexure in connection with the left iliac fossa. 



The mesorectum is the narrow fold which connects the upper part of the rectum 

 with the front of the sacrum. It contains the hemorrhoidal vessels. 



The appendices epiploicse are small pouches of the peritoneum filled with fat, 

 and situated along the colon and upper part of the rectum. They are chiefly 

 appended to the transverse colon. 



THE STOMACH. 



The Stomach is the principal organ of digestion. It is the most dilated part 

 of the alimentary canal, serving for the solution and reduction of the food, which 

 constitutes the process of chymification. It is situated in the left hypochondriac, 

 the epigastric, and part of the right hypochondriac regions. Its form is irregularly 

 conical, curved upon itself, and presenting a rounded base, turned to the left side. 

 It is placed immediately behind the anterior wall of the abdomen, above the 

 transverse colon, below the liver and Diaphragm. Its size varies considerably in 

 different subjects, and also according to its state of distension. When moderately 

 full, its transverse diameter is about twelve inches, its vertical diameter about 

 four. Its weight, according to Clendenning, is about four ounces and a half. It 

 presents for examination two extremities, two orifices, two borders, and two 

 surfaces. 



Its left extremity \s, called the greater or splenic end. It is the largest part of the 

 stomach, and expands for two or three inches to the left of the point of entrance 

 of the oesophagus. This expansion is called the great cul-de-sac or fundus. It 

 lies beneath the ribs, in contact with the spleen, to which it is connected by the 

 gastro-splenic omentum. 



The lesser or pyloric end is much smaller than the preceding, and situated on a 

 plane anterior and inferior to it. It lies in contact with the wall of the abdomen, 

 the under surface of the liver, and the neck of the gall-bladder. 



The cesophageal or cardiac orifice communicates with the oesophagus ; it is the 

 highest part of the stomach, and somewhat funnel-shaped in form. 



The pyloric orifice communicates with the duodenum, the aperture being guarded 

 by a valve. 



The lesser curvature extends between the cesophageal and cardiac orifices, along 

 the upper border of the organ, and is connected to the under surface of the liver 

 by the lesser omentum. 



The greater curvature extends between the same points, along the lower border, 



