68 



APPLIED PHYSIOLOGY 



87. Glands of the stomach. The mucous membrane of 

 the stomach contains numerous glands which secrete a 

 special digestive fluid called the gastric juice. The glands 

 are short tubes each about ^J^ of an inch in diameter, 

 and -fa of an inch in length. The tubes are set closely 

 together and resemble pinpricks in the mucous mem- 

 brane. Each tube is lined with 

 a single layer of epithelial cells 

 which produce the gastric juice 

 from material supplied by the 

 blood. Besides these glands 

 there are many others which 

 secrete only mucus. 



88. Gastric juice. The gas- 

 tric juice is a yellowish fluid, 

 and consists of water holding 

 in solution hydrochloric acid 

 and two ferments. These are 

 the essential agents in stomach 

 digestion. Hydrochloric acid is 

 produced by the epithelium of 

 the gastric tubes from the salt 

 contained in the blood, and 



forms from -^Vir to mhr of the 

 gastric juice. The ferments 

 are white, albuminous substances produced from the blood 

 by the epithelium of the glands, and form about -^-$ of 

 the gastric juice. The flow of gastric juice is promoted 

 by a slow, steady in-taking of food at about the tempera- 

 ture of the body. The saliva, which is slightly alkaline, 

 an agreeable taste of the food, and a pleasant frame of 

 mind also aid its flow. About three quarts enter the 

 stomach each day. 



Gastric glands in the stomach 



(X200). 



a epithelium of the surface of the 



stomach. 

 b epithelium lining the tubes of the 



glands. 

 c connective tissue between the 



tubes. 





