138 THE ABDOMEN. 



The Esophagus. From the pharynx the food passes to 

 the cardiac orifice of the stomach, opposite the tenth 

 dorsal vertebra, through the esophagus, a muscular tube 

 about nine inches long, which collapses when empty, its 

 lumen then appearing as a transverse slit. It, too, has 

 three coats: 1. an inner mucous coat; 2. an areolar coat, 

 and 3. a muscular coat, the muscles being arranged in two 

 sets, an outer longitudinal layer and an inner circular 

 layer. By a series of ryhthmic contractions, especially 

 of the circular fibers, the food is pushed along, though 

 sometimes with liquid food there is no peristaltic action 

 of the esophagus, the pharyngeal muscles alone sending 

 it to the stomach. At the lower end of the esophagus an 

 especially strong band of circular muscle fibers form a 

 sort of sphincter, which prevents the regurgitation of 

 food. The whole act of swallowing is a reflex, not a 

 voluntary, act and is due to irritation set up by the 

 stimulus of the foreign body, the food. Stricture of the 

 esophagus is common and may be of three kinds: 1. spas- 

 modic, occurring in nervous women; 2. fibrous, due to 

 scar tissue, or 3. malignant, due to cancer. 



The Stomach. The stomach is a pear-shaped dilata- 

 tion of the alimentary canal, lying under the liver and 

 diaphragm in the epigastrium and left hypochondrium 

 and connecting the esophagus with the small intestine. 

 It lies largely behind the ribs, but the greater curvature 

 is only two fingers' breadth above the umbilicus and can 

 be manipulated through the skin. The cardiac end, into 

 which the esophagus enters, is the larger and points 

 upward to the left. The lesser and lower end, known as 

 the pylorus, is at the right and its opening into the small 

 intestine is guarded by the pyloric sphincter. The lesser 

 curvature is concave and on the upper surface; the greater, 

 convex and on the under surface. The great omentum 

 is attached to the latter. 



In size the stomach varies more or less, that of a man 

 generally being larger than that of a woman, but it is 

 usually about ten inches long and four or five inches 



