ANATOMY OF DIGESTIVE TRACT 115 



sketching the larynx, trachea, lungs and heart, remove them by 

 freeing blood-vessels and other attachments: 



a) Trace and sketch the esophagus, stomach, liver and 

 intestines, disturbing their natural positions as little as possible. 



b) Turn liver out of the way and follow esophagus to 

 stomach : 



Note form of stomach; its projection (fundus} to the left 

 of esophagus; its great and small curvatures; its narrower 

 pyloric portion on the right, from which the small intestine 

 proceeds. 



Notice a thin membrane (the omentum) attached to stomach 

 and hanging down over the abdominal contents, ordinarily 

 loaded with fat. 



c) Follow and unravel the coils of small intestine, spreading" 

 out as far as possible the delicate membrane (mesentery) which 

 suspends it from the upper dorsal part of the abdominal cavity. 



Note the blood-vessels and lacteals running in the numerous 

 bands of fat in the mesentery. 



d) Cut open the side of large intestine opposite entrance of 

 small intestine : 



Note the termination of small intestine in the ileocecal valve ; 

 the cecum or blind end of large intestine, projecting beyond the 

 ileocecal valve. 



Compare the position of vermiform appendix and cecum with 

 that in the human body. See pp. 97, 105. 



Follow large intestine through ascending, transverse, and 

 descending colon, sigmoid flexure, and rectum, to its end at anal 

 aperture, cutting away front of pelvis to follow terminal 

 portion. 



e) Spread out the portion of mesentery lying in the con- 

 cavity of the first coil (duodenum) of small intestine: 



Note the pancreas, a thin, branched, glandula'r mass; the 

 portal vein entering the under side of liver by several branches 

 which drain the intestinal tract ; near it the gall duct, formed by 

 the union of two branches and proceeding as a slender tube to 

 open into duodenum about l 1 /^ in. from pyloric orifice of 

 stomach. 



f ) Cut off esophagus and rectum, remove the whole alimen- 

 tary canal, cut away mesentery, and spread the canal out at 

 full length : 



