ACTION OP INTESTINAL JUICE VI'l 



alkaline salt present, and form soaps which are, of course, 

 soluble. 



In emulsification the fat is separated into tiny droplets 

 and surrounded by the fatty acid or alkaline material in 

 such a way as to prevent these drops from uniting again. 

 In this form they may be absorbed directly without further 

 action. Whether emulsification precedes saponification or 

 vice versa is still a disputed point. 



In general, then, the pancreatic juice first transforms the 

 acid chyme of the stomach into an alkaline fluid through 

 the neutralizing action of the alkaline salts in the juice, 

 and then by the action of the three enzymes it converts 

 proteids, albuminoids, starches, and fats into substances fit 

 for absorption. Chyme is neutralized mainly by bile salts. 



Action of the bile. — (See Ex. XXXVIII., d.) It has 

 been found by experiment that when pancreatic juice 

 is mixed with bile the emulsifying power of the steapsin 

 is greatly increased thereby. The alkaline bile salts are 

 of aid in the splitting of fats and consequently in the 

 saponification. Its presence is also supposed to prevent, 

 to a certain degree, the putrefaction of foods, though this 

 antiseptic power is disputed by some authorities. Finally, 

 it takes a direct part in destroying the peptic digestive 

 action of the acid chyme. It not only neutralizes the acid 

 but also causes a precipitation or separation of the proteids 

 in such a form that they may be acted upon directly by 

 the trypsin. 



Action of intestinal juice (succus entericus). — This juice 

 is produced by the simple glands known as the crypts of 

 Lieberkiihn. It is a yellowish liquid with a strong alka- 

 line reaction. This alkaline character it derives from 

 the presence of sodium carbonate, and the presence of this 



