GASTRIC GLANDS 85 



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 mem- 

 brane, beyond (underneath) which is the capillary blood supply. 

 Throughout the greater part of the stomach the mucous mem- 

 brane 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. According to their secretion the glands 

 are called acid and peptic. The fundic and acid, and the 

 pyloric and peptic are considered 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) tubules 

 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-secret- 

 ing portion. The latter is lined by columnar epithelium, and is 

 the duct proper. The former is lined by cuboidal epithelium 

 which discharges its secretion into the lumen, this lumen being 

 only a continuation of the duct. These cuboidal cells are called 

 peptic cells because they produce pepsin, or its forerunner, 

 pepsinogen. The fundic (acid) glands are found to have lying 

 close to the basement membrane a number of large cells at inter- 

 vals between the cuboidal cells and not extending outward to the 



