298 ANATOMY FOR NURSES [Chap. XV 



by a delicate envelope supplied from the albumin in the pancreatic 

 juice, so that they cannot fuse together to form the large drops, 

 which would soon float to the top.^ 



(b) The fats that are not emulsified are broken up into glycerine 

 and fatty acids. The glycerine is absorbed, and the fatty acids 

 in the presence of an alkali form soaps which are soluble in water 

 and capable of absorption. It is probable that the greater part 

 of the fat is absorbed by the latter method. 



Succus entericus, or intestinal juice. — Succus entericus is 

 the secretion of the intestinal glands. It is a clear, yellowish 

 fluid, having a marked alkaline reaction and containing a certain 

 quantity of mucus. 



The number of enzymes ^ described as present in succus enteri- 

 cus differs with different authorities audit is probable that the entire 

 physiology is not known. Its chief function seems to be a continu- 

 ation of the work of pepsin and trypsin and the inversion of com- 

 plex sugars to simple ones. It also acts as a diluent and supplies a 

 loss of fluid. 



Bile. — Bile, secreted in the lobules of the liver and stored in 

 the gall-bladder until needed, is a fluid of a golden brown or 

 greenish color ^ with an alkaline reaction. The quantity secreted 

 in twenty-four hours varies with the amount of food taken, but 

 is estimated at about one quart. 



Bile contains no enzyme, but the fact that it is poured into the 

 intestine through an orifice common to it and the pancreatic 

 juice suggests that these two fluids cooperate in their action on 

 food. 



Action of bile. — Its most important function as a digestive is 

 noted in its action on fats. 



(1) It splits up neutral fats and, assisted by the pancreatic 

 juice, emulsifies and saponifies them. 



(2) It aids in the absorption of fats. The passage of digested 

 food through membranes is assisted by wetting the membranes 

 with bile or with a solution of bile salts. It is known that oil 



1 This fine subdivision of fats gives the white color to the chyle, which is' its 

 most striking external characteristic, the innumerable tiny oil drops reflecting all 

 the light that falls on its surface. 



2 See Summary at end of this chapter. 



^ The color of bile is determined by the respective amounts of the bile pigments : 

 (1) biliverdin, and (2) bilirubin, that are present. 



