142 



ANATOMY AND PHYSIOLOGY 



(Fig. 109). It begins at the pyloric end of the stomach and 

 is about ten inches long; curves upward, backward, to the right 

 and downward, and then continues across to the left side of the 



spinal column. 



About four inches from the 

 pylorus the mucosa presents an 

 elevation the bile papilla, 

 where the common bile and 

 pancreatic duct opens. 



The circular folds of the 

 mucous coat begin in the lower 

 portion and are unusually large. 



FIG. 107. SECTION OF INJECTED SMALL FIG. 108. CIRCULAR FOLD OR VAL- 



INTESTINE OF CAT. VUL.E CONNIVENTES. (Brinton.) 



a, b. Mucosa. g. Villi. i. Their absorbent 

 vessels, h. Simple follicles, c. Muscularis 

 mucpsae. j. Submucosa. g. Circular and 

 longitudinal layers of muscle. /. Fibrous 

 coat. All the dark lines represent blood- 

 vessels filled with the injection mass. 

 (Piersol) 



Note. The inferior part of the duodenum is behind the peritoneum, this 

 part has no serous coat. 



The jejunum is the second division of the small intestine 

 so named because it is found empty. It possesses all of the char- 

 acteristic structures: villi, circular folds, intestinal and solitary 

 glands. It lies in the umbilical and the two lumbar regions. 



The ileum is the third division of the small intestine so 

 named because of its frequent twisting. There is no definite 



