344 



FOOD AND DIGESTION 



The mucous membrane of the stomach, which rests upon a layer of loose 

 cellular membrane, or submucous tissue, is smooth, soft and velvety. It is 

 of a pale pink color during life, and in the contracted state is thrown into 

 numerous longitudinal folds or rugae, which disappear when the organ is 

 distended. It is composed of a mass of short tubular secreting glands. 



The Gastric Glands. The glands of the mucous membrane of the 

 stomach are of two varieties, Cardiac and Pyloric. 



FIG. 256. 



FIG. 257. 



FIG. 256. Longitudinal Section of Fundus of Gland from Dog's Stomach, a, 

 Lumen of gland; b, intracellular canals in parietal cells; c, cut-off portion of parietal cell; 

 d, chief cells; e, intercellular canals leading from lumen of gland to canals in parietal cells. 

 (Bailey.) 



FIG. 257. Tubule of Pyloric Gland of Man. (Highly magnified.) Note the thin 

 basal layer of cytoplasm; the reticular cell body containing secretion; the subdivision of the 

 latter in some cells into proximal and distal masses. (Bailey.) 



Cardiac glands are found throughout the whole of the cardiac end of the 

 stomach. They are arranged in groups of four or five, which are separated 

 by a fine connective tissue. Two or three tubes often open into one duct, 

 figure 254, which forms about a third of the whole length of the tube and 

 opens on the surface. The ducts and the free surface are lined with colum- 

 nar epithelium. The body of the gland is composed of granular secreting 

 cells, called chief cells or peptic cells. Between these cells and the membrana 

 propria of the tubes are large oval or spherical cells, granular in appearance 

 with clear oval nuclei; these cells are called oxyntic or parietal cells. They do 

 not form a continuous layer, figure 254. Intercellular tubules extending 



