1 1 8 Life and Health 



The pancreas lies behind the stomach, across the body, 

 from right to left, with its large head embraced in the 

 horseshoe bend of the duodenum. Its main duct enters 

 the duodenum in company with the common bile duct. 

 ^ 179. The Action of Pancreatic Juice. The pancreas 

 secretes an alkaline digestive fluid called the pancreatic 

 juice. Combined with bile, this fluid acts upon the large 

 drops of fat which pass from the stomach into the duode- 

 num, and either emulsifies or saponifies them. Emulsified 

 fats consist of particles sufficiently minute to permit of 

 their absorption into the blood. Sapomfication is a chemi- 

 cal change in which the fat is broken up into glycerine and 

 a fatty acid, the latter combining with an alkali to form 

 a soap. 



This most important digestive fluid also produces on 

 starch an action similar to that of saliva, but much more 

 powerful. During its short stay in the mouth, very little 

 starch is changed into sugar, and in the stomach the action 

 of the saliva is soon arrested. Now, the pancreatic juice 

 takes up the work in the small intestine and changes the 

 greater part of the starch into sugar. Nor is this all, for 

 it also acts powerfully upon the proteids not acted upon in 

 the stomach, and changes them into peptones that do not 

 differ materially from those resulting from gastric digestion. 



The pancreatic juice is able to assist in digesting all 

 three kinds of foodstuffs because it contains three fer- 

 ments : trypsin, acting on proteids ; amylopsin, acting on 

 starches ; and steapsin, acting on fats. 

 4 180. Digestion in the Small Intestines. After digestion 

 in the stomach has been going on for some time, successive 

 portions of the semidigested food begin to pass into the 

 duodenum. The pancreas now takes on new activity, and 

 a copious flow of pancreatic juice is poured along its duct 



