AND PHYSIOLOGY. 



175 



three minutes for each revolution. And in order that all of 

 it may be permeated by this fluid, contractions frequently 

 take place in the muscular coat of the stomach, resembling a 

 churning process. 



318. Intestinal Digestion, Chyme. — The process thu$ 

 far is Gastric Digestion, or that which takes place in th£ 

 stomach, and the object accomplished seems to be the con* 

 version of the nitrogenous constituents of the food into albu- 

 minose called histogenetic digestion, or the preparation of the 

 food to be made into the tissues of the body. But when all 

 the food is thoroughly dissolved, or made into a liquid condi- 

 tion called Chyme, the Pyloric orifice is opened, and the food 

 passes into the Duodenum. When it arrives here — and never 

 sooner, in a healthy state — the secretions of the Liver, Pan- 

 creas, and mucus of the Intestine mix with it, performing the 

 second or Intestinal digestion, which is called calorifacient or 

 heat making, since it prepares the food which supports the heat 

 of the body. The process, however, is somewhat obscure, al» 

 though it is certain that food is not perfectly fitted for absorp- 

 tion until it has well completed this process. 



319. Use of the Pancreatic Fluid. — The Pancreatic Fluid 

 secreted at the rate of from five to seven ounces per day, re- 

 sembles quite closely the Saliva, converting starch into sugar, 

 and aiding in the absorption cf fatty matters, by forming an 

 emulsion, which, however, is much more readily formed by 

 the presence of bile. 



320. Action of the Bile, an Antacid and Excre- 

 tory Agent. — The Bile, thrown out at the rate of fifty-four 

 ounces a day, seems from its large quantity to be of no 

 little importance. And since the juices of the stomach are 

 mostly acid in their character, it seems desirable that there 

 should be some counteracting ao;ent, which is furnished in the 



318. What is the principal thing accomplished by stomach digestion ? What is food 

 called after it has passed through this process? Describe Intestinal digestion and its 

 use. 319. What amount of Pancreatic fluid is secreted daily ? What is its principal use ? 

 320. How much Bile is secreted daily ? 



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