1 7 8 



TEXT-BOOK OF PHYSIOLOGY. 



Mucosa. 



to the mucous coat. Its inner surface bears a thin layer of muscular 

 tissue, the muscularis mucosa, which supports the mucous membrane. 

 The internal or mucous coat is loosely attached to the muscular 

 coat. In the empty and contracted state of the stomach it is thrown 

 into longitudinal folds or rugae, which are, however, obliterated when 

 the organ is distended with" food. The mucous membrane in adult 

 life is smooth and velvety in appearance, grayjp. color, and covered 

 with a layer of mucus. Its average thickness is about one millimeter. 



The surface of the mem- 

 brane~ls coverecl with a 

 layer of columnar epi- 

 thelial cells, each of 

 wnldi possesses a nu- 

 cleus and nucleolus. At 

 the pylorus there is a 

 circular involution of 

 the mucous membrane 

 which is known as the 

 pyloric valve. This is 

 strengthened by fibrous 

 tissue and embraced by 

 the sphincter muscle pre- 

 viously described. 



Gastric Glands. 

 The surface of the mu- 

 cous membrane when 

 examined with a low 

 magnifying power pre- 

 'sents throughout in- 

 numerable depressions 

 polygonal in shape and 

 separated by slightly 

 elevated ridges. At the 

 bottom of these spaces 

 are to be seen small 

 orifices, which are the 

 mucous membrane. A 

 72) shows not only the 

 but the relation of the 



Serosa. 



FIG. 72-TKANSVERSE SECTION OF THE WALL OF A 



HUMAN STOMACH. X 15- The tunica propria 

 contains glands standing so close together that 

 its tissue is visible only at the base of the elands 

 toward the muscularis mucosffi. 



f i 

 mouths 



DOS 



r 

 of 



,, 



the glands 



6 



embedded in the 



the glands, 



mucosa 



the entire thickness 



