STOMACH 



255 



Gland lumen 



FIG. 246. TRANSVERSE SECTION OF A 

 HUMAN GASTRIC GLAND. X 240. 



Axial lumen. 



Parietal cells with 

 intracellular se- \ 

 cretory capillar- \ 



wedge-shaped cells, having a narrow contact with the lumen. In general 



they have the aspect of serous cells, containing round nuclei and granular 



protoplasm. The granules, which are coarser toward the lumen, do not 



respond to mucin stains. They accumulate, and the chief cells enlarge, in 



the absence of food from the stomach; but 



during gastric digestion, the cells become .JftsSk Chief ceil. 



small and the granules disappear. They Parietal ceii. 



apparently give rise to the pepsin of the 



gastric juice, and are called zymogen 



granules. After death the chief cells 



rapidly disintegrate, and the granules are seldom well preserved except in 



special preparations. 



The parietal cells, even in fresh tissue, may be readily distinguished 

 from the chief cells; the latter are dark and contain refractive granules, 



whereas the parietal cells are clear. 

 They are large cells, containing one or 

 occasionally two round nuclei, and are 

 crowded away from the lumen like the 

 cells in the serous crescents (Figs. 245 

 and 246). They discharge their secre- 

 tion through secretory capillaries which 

 produce basket-like networks within 

 the protoplasm; thus they differ from 

 the chief cells which have only inter- 

 cellular secretory capillaries. The 

 secretory capillaries of the parietal cells 

 may be demonstrated by the Golgi 

 method, which produces a precipitate 

 wherever secretion is encountered (Fig. 

 247). After fasting, the parietal cells 

 are small and their intracellular capil- 

 laries have disappeared. Following 

 abundant meals, these cells enlarge and 

 may contain vacuoles due to the rapid 

 formation of secretion. They produce 

 the hydrochloric acid which is found in 

 the gastric juice. 



In ordinary preparations they are 

 better preserved than the chief cells, and exhibit a finely granular structure, 

 being deeply stained with the anilin protoplasmic dyes. They differ so 

 markedly from the chief cells that they have been erroneously believed to 

 develop from the surrounding tunica propria. As seen in Fig. 245 they 

 occur chiefly along the body of the tubule, being infrequent at its fundus. 



Intercellular secre- 

 tory capillaries. 



Chief cells./ 



FIG. 247. GOLGI PREPARATION, SHOWING THE 

 SECRETORY CAPILLARIES IN GASTRIC 

 GLANDS. X 230. 



