196 



DIGESTION 



such it warms food too cold and cools food, usually liquids, taken too 

 hot for the duodenum to bear well. 



8. Another function similar to the last in its usefulness is the lique- 

 faction of the food before its entrance to the gut proper, thus avoiding 

 irritation and more or less injury. This process is a combination of 

 chemical, mechanical, thermal, and secretory agencies. 



FIG. 93 



LD. 



MU. 



Subm 



Section through the antrum-wall of the dog: Z, villi; LD., Lieberkiihn's glands (Brunner's glands 

 are in the submucosa, Subm.); MM, muscularis mucosae; Muse. R., transverse, and Muse. L., 

 longitudinal section of the muscularis. The veins are shown black, the arteries cross-striated* 

 44 /i- (Mall.) 



9. Another function is to invert sugars by means of its acid, whether 

 the former are introduced into the stomach as such or are produced 

 there by the hydrolysis of starch. 



10. A tenth usefulness of the stomach is a slight degree of absorption. 

 The materials absorbed are chiefly alcoholic solutions, alkaloids, salines, 

 and possibly a very small amount of water and of hydrolyzed or soluble 

 proteids. 



