THE DIGESTIVE ORGANS. 



143 



Fig. 122. 



Fig. 121. 



/,— -f ■ 



d--^L 



Fig. 121.— Vertical section through mucous 

 membrane of pyloric end of stomach ; 

 human. (BOhm and PavidofF.) a, co- 

 lumnar epithelium covering surface of 

 mucous membrane; b, crypt lined with 

 somewhat lower columnar epithelium ; 

 c, gastric tubules; d, tunica propria, 

 somewhat lymphoid in character; e, mus- 

 cularis mucosae, of smooth muscular 

 tissue. 



Fig. 122.— Nearly vertical section of the mucous membrane near the cardiac end of the stom- 

 ach ; rabbit: a, columnar epithelium covering the surface of the mucous membrane ; 

 h, that lining a crypt ; c, duct ; d, parietal cell extending to the lumen of the gland: 

 c, lumen, readily traced for only a short distance;/, central or chief cells; g, small 

 artery, to the left and above it, a small vein ; /(, muscularis mucosa-, consisting of three 

 thin layers of smooth muscular tissue, the middle layer in transverse, the others in 

 longitudinal section ; i, portion of submucosa. The specimen was taken from an animal 

 some time after the ingestion of food, and the chief cells are, in consequence, relatively 

 small in comparison with the size of the parietal cells. 



