2O2 



HISTOLOGY. 



capillaries form a basket-like network within the protoplasm of the parietal 

 cells, as may be demonstrated by the Golgi method. This produces a 

 black precipitate wherever secretion is encountered (Fig. 225). Short 

 intercellular secretory capillaries are found between but not inside the chief 

 cells. In fresh preparations parietal cells are clearer than chief cells. They 

 do not disintegrate so readily. In preserved specimens they appear as 

 large cells with granular protoplasm which stains deeply with aniline 

 dyes, each cell containing one or two rather large, round nuclei. After 

 fasting, the parietal cells are smaller and their intracellular capillaries 



disappear. Following 



. 



Mucosa. 



Epithelium. 



Tunica propria. 



abundant meals they 

 enlarge and may con- 

 tain vacuoles due to 

 the rapid formation 

 of secretion. They are 

 thought to produce 

 hydrochloric acid, but 

 this is not beyond 

 question. 



The cardiac 

 glands (Fig. 221) are 

 much branched tubu- 

 lo-alveolar mucous 

 glands, often cystic, 

 containing a few chief 

 and parietal cells in 

 tubules. Those fur- 

 thest from the oesoph- 

 agus are the least 

 branched and resem- 

 ble gastric glands. 



The secreting cells of the cardiac glands suggest those in the necks of the 

 gastric glands; their mucous nature is not apparent and has been but re- 

 cently determined. Although cardiac glands are developed in many animals 

 much more extensively than in man, nothing is known of their special 

 function. 



The pyloric glands (Fig. 226) consist of very deep pits and of short 

 winding branched tubules. Gastric glands may be mingled with them. 

 The pyloric gland cells are chiefly mucous, but occasional parietal cells 

 are found among them, and in animals there are dark thin cells apparently 

 produced by compression. The usual type is columnar with a rounded 



Inner circular layer 

 of muscle. 



Connective tissue. 

 Muscularis. 



Outer longitudina 

 layer of muscle. 



Serosa. 



FIG. 227. TRANSVERSE SECTION OF THE WALL OF A 



HUMAN STOMACH. 



The tunica propria contains glands standing so close together that 

 its tissue is visible only at the base of the glands toward the mus- 

 cularis mucosae. 



