THE STOMACH. 



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consisting of small polygonal areas pitted by the crypts which receive the orifices of 

 the glands. 



The gastric glands constitute two principal groups, the fundus and ihe pyloric 

 glands ; the former occupy the major part of the stomach, including the fundus, the 

 anterior and posterior walls, and the curvatures ; the latter occur in the pyloric fifth 

 of the organ. An additional fundus variety — the cardiac glands — is represented by 

 a narrow zonular group in the immediate vicinity of the oesophageal opening. 



The fundus or peptic glands — the gastric glands proper — consist of numerous 

 closely set tubules, usually somewhat wavy and from. 4-2 mm. long, which extend 

 the entire thickness of the mucosa and abut against the muscularis mucosae. Each 

 gastric crypt, corresponding to the excretory duct, usually receives a group of sev- 

 eral of the smaller tubules, which include the body and fundus of the gland, the 

 constricted commencement of the tubule constituting the 7ieck. At the latter position 



astric glands 



Muscularis 

 mucosae 



Blood-vessel 



Submucosa 



Musculari 



Obliquely cut 

 bundles of 

 circular 

 muscle 



Transverse section of stomach (left end), showing general arrangement of coats. X 20. 



the columnar epithelium prolonged into the crypts from the free surface becomes 

 lower and modified into the secreting elements. 



The cells lining the gastric tubules are of two kinds, the chief and the parietal. 



The chief, central or adelomorphous cells correspond to ordinary glandular epi- 

 thelium, being low columnar or pyramidal, and surrounding a circular lumen from 

 .002 to .007 mm. in diameter. During certain stages of digestion they contain 

 numerous granules, which are probably concerned in producing pepsin. 



The parietal cells, known also as acid, oxyntic, or delomorphous, although rela- 

 tively few, are conspicuous elements which occupy the periphery of the gland-tubes. 

 Their position is indicated by protrusions of the profile of the gastric tubules caused 

 by the cells lying immediately beneath the basement membrane. The parietal cells, 

 although arranged with little regularity, are most numerous in the vicinity of the 

 neck, where they may equal or even outnumber the central cells ; in the body of the 



