120 HANDBOOK OF ANATOMY 



The Stomach Chamber. The roof is formed of the under 

 surface of the left lobe of the liver and the left cupola of the 

 diaphragm; this latter slopes down behind and forms the 

 posterior wall. The anterior wall is formed by the abdominal 

 wall between the ribs on the left and the liver on the right. 

 The floor on which the stomach rests is formed by the top of the 

 left kidney and suprarenal capsule, the gastric surface of 

 the spleen, upper surface of the pancreas, and coils of small 

 intestine. 



The Intestines are divided into three parts the duodenum; 

 the small intestine, consisting of jejunum and ileum ; and the 

 large intestine. The structure of the duodenum and small intes- 

 tine is alike ; they consist of two muscular coats an inner circular 

 layer and an outer longitudinal layer. The mucous membrane 

 is covered by a number of villi, small processes about ^ inch 

 long, and closely set all over the surface; they are for the 

 purposes of absorption. In order to increase the surface, the 

 mucous membrane is arranged in a series of circular folds 

 called valvulce conniventes. On the surface of the mucous 

 membrane are found also Peyer's patches, which are small aggre- 

 ' gations of lymphoid tissue about J inch long ; there are about 

 thirty-five to forty of them usually found, most marked in young 

 subjects. 



The Duodenum is really the first part of the small intestine, and 

 starts at the pyloric orifice of the stomach, on the left side of 

 the body of the first lumbar vertebra. It is a C-shaped organ,, 

 closely applied to the back wall of the abdomen. It starts at 

 the level of the first lumbar vertebra, passes downwards and to 

 the right as low down as the third lumbar vertebra and, turning 

 upwards, ends on the left side of the body of the second lumbar 

 vertebra at the duodeno-jejunal flexure, being the point at 

 which the jejunum, or second part of the small intestine,, 

 begins. 



In the curve of the duodenum lies the head of the pancreas, 

 the body passing to the left between the two ends. The 

 duodenum lies on the vena cava and aorta and the two psoas 

 muscles. It touches the right kidney, and is covered by coils of 

 small intestine. 



