ORGANS OF DIGESTION. 115 
thoracic cavity it lies dorsal to the heart (Fig. 55) by the 
side of the aorta. Immediately caudad of the diaphragm 
it opens into the cardiac end of the stomach (Fig. 60). 
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 por- 
tion, and the intestinal end is the pyloric portion (Fig. 60). 
Here a circular fold of mucous membrane embraced by a 
sphincter muscle serves as a valve to open and close the 
pylorus or gateway to the intestine. 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. 60), 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 duode- 
num, 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 pancreas, 
empty into it. The former is the common bile duct and 
the latter are the pancreatic ducts. The jejunum is the 
portion of the small intestine next to the duodenum. It 
is about twenty-five centimeters long. No special mark 
indicates its limits. It is so called because that portion 
of the canal in man is frequently empty after death. The 
