126 ELEMENTS OF MAMMALIAN ANATOMY. 



ESOPHAGUS. 



The esophagus or gullet is that portion of the ali- 

 mentary canal leading from the pharynx to the stomach. 

 In the thoracic cavity it lies dorsal to the heart (Fig. 54) 

 by the side of the aorta. Immediately caudad of the 

 diaphragm it opens into the cardiac end of the stomach 

 (Fig. 58). 



STOMACH. 



The stomach is that dilated portion of the canal 

 lying immediately caudad of the diaphragm on the left 

 side. The esophageal end of the stomach is known as 

 the cardiac portion, and the intestinal end is the pyloric 

 portion (Fig. 58). Here a circular fold of mucous mem- 

 brane embraced by a sphincter muscle serves as a valve 

 to open and close the pylorus or gateway to the intes- 

 tine. The dorsal surface of the stomach is its lesser 

 curvature and the ventral convex surface is its greater 

 curvature. The structure of the walls of the stomach 

 is described below. 



INTESTINE. 



The intestine is that much contorted portion of the 

 canal leading from the stomach to the external aperture 

 or anus. The first portion, the small intestine (Fig. 58), 

 is about three feet long in a large cat, and is less in 

 diameter and much more convoluted than the second 

 portion, or large intestine. 



The small intestine consists of three parts: the duo- 

 denum, the jejunum, and the ileum. The duodenum is 

 the first twelve or fifteen centimeters. A duct from the 

 liver and the gall-bladder and two ducts from the pan- 

 creas, empty into it. The former is the ductus com- 



