I.K.I si K.\ 



stomach, consists not of many layers but of a single layer of 

 cylindrical cells. Opening on the surface of the epithelium 

 are a number of simple tubular glands lying side by side ; 

 in fact, the mucous membrane is almost entirely made up 

 <if these glands packed close together. Each gland is a simple 

 blind tube, the walls of which consist of somewhat cubical cells, 

 to which in the cardiac region a few scattered round or ovoid 

 cells arc added, opening at 

 the surface into the cavity of 

 the stomach. Beneath and 

 running up between the tubular 

 glands is connective tissue 

 containing blood-vessels which 

 supply the glands with blood. 

 Tin; connective tissue also 

 connects the mucous layer 

 with the muscular layer on the 

 outer side of it. When diges- 

 tion is not going on the mucous 

 membrane is pale, its blood- ov. 

 vessels being constricted, but 

 when food reaches the stom- 

 ach the blood-vessels dilate 

 and the mucous membrane is 

 (lushed with blood. The cells) 

 of the glands then secrete a 

 juice, the gastric juice, which 



trickles from the Open ends of IMG. 63. Three cbnds of the stomach - 



the tubes into the cavity of the cardiac part. 



Stomach *"' ''P' l ' lc '' um at i nncr surface of stomach ; 



... , A , . m, mouth of >;land ; /, princiiial cells 



Composition and Action of Rlaiii! . ^ ovoid c j s ^ Col 1 ineclivt . 



Of Gastric Juice. Gastric tissue below and between the glands. 



juice is a colourless fluid, con- 

 sisting of water containing in solution a very small amount of 

 salts, a little free hydrochloric acid, and two ferments. The 

 IK r hydrochloric acid, of which there is about .2 per cent, 

 renders its reaction always acid. The ferments are unorganised 

 ferments and are called pepsin and rennin. The ferments 

 are formed by the cells of the glands. 



trie juice has the power of (hanging proteids into a 



