GASTRIC GLANDS 85 



testinal muscular tissue from the lower end of the esophagus 

 to the external sphincter. 



3. The submucous coat consists of loose fibro-elastic con- 

 nective tissue which allows free movement between the mus- 

 cular and mucous coats. It contains rather large blood-ves- 

 sels and a nerve-plexus, the plexus of Meissner. 



4. The mucous coat has an average thickness of about ^5 

 in., is loosely attached to the submucous coat, and, except 

 during gastric digestion, is thrown into longitudinal rugae. 

 It consists of columnar epithelium resting upon a basement 

 membrane, beyond (underneath) which is the capillary blood 

 supply. Throughout the greater part of the stomach the 

 mucous membrane can be shown to be divided by delicate 

 connective tissue into numerous polygonal depressions, from 

 the bottom of which extend the gastric glands. 



The Gastric Glands. 



In the mucous membrane of the stomach are found two 

 kinds of glands. According to their relative position with 

 reference to the two ends of the stomach they are called 

 fundic and pyloric. It is to be noted, however, that neither 

 of these divisions is confined strictly to that portion of the 

 stomach which its name would seem to indicate. Accord- 

 ing to their secretion the glands are called acid and peptic. 

 The fundic and acid, and the pyloric and peptic are consid- 

 ered to be identical. But attention is called to the fact that 

 while peptic (pyloric) glands secrete pepsin only, the acid 

 (fundic) secrete both acid and pepsin. 



Structure. Some of the gastric glands are simple tubules, 

 while others may be bifurcated, so that two (or more) tu- 

 bules communicate with the surface by a single canal. They 

 may all, however, be classified as belonging to the simple 

 tubular variety. They have a deep secreting portion and a 

 superficial non-secreting portion. The latter is lined by 

 columnar epithelium, and is the duct proper. The former is 



