86 



HUMAN PHYSIOLOGY 



CHAP. 



771 



well. But if the pieces are too large or the amount too 

 great the juice cannot get at the foods as it should, and 

 the muscles get tired out before all the 

 foods are dissolved. The stomach is 

 a hard-working organ, but it should 

 not be abused. After it has worked 

 hard for three or four hours it should 

 get some rest before the next meal, 

 so that it will be ready to do its work 

 as it should. If the stomach is not 

 abused, a person will always be hun- 

 gry at meal times. 



The stomach is a very important 

 organ of digestion, for it serves as a 

 storehouse for foods, dissolves pro- 

 teids, and destroys many kinds of 

 disease germs by means of its acid ; 

 and yet a person can live without a 

 stomach. In a few cases of serious 

 diseases the stomach has been entirely 

 removed. The oesophagus was sewed 

 directly to the intestines, and the 

 person recovered and lived for years 

 afterwards. We see that it is possi- 

 ble for a person to live without a stomach. That is 

 because the digestive fluids of the small intestine can 

 do all that the gastric juice does. But a person who 

 has had his stomach removed cannot eat as much at 

 one time as he could before, and hence he is obliged to 

 take food at shorter intervals. 



-P 



FIG. 48. One of the 

 glands which manu- 

 factures gastr i c j uice. 

 ( From Huxley. ) 

 D, mouth of the 

 gland; m, epithelial 

 cells; c, central cells 

 which make pepsin ; 

 p, parietal cells 

 which make acid. 



