CHAPTER XI. 



THE CONSTITUENTS OF BILE. 



Bile is secreted continuously into the hepatic ducts 

 by the liver. During the intervals of digestion it is stored 

 in the gall bladder, being poured into the duodenum when 

 the acid chyme passes through the pylorus. 



During its stay in the gall bladder there is an absorp- 

 tion of water and an increase in the protein content, 

 resulting in an increase in the specific gravity from about 

 1010 to 1040. 



The percentage composition of human bile varies 

 considerably. The following are average figures : 



Water 

 Solids 



Bile salts 



Protein 



Bile pigments 



Cholesterol 



Lecithin and fat 



Inorganic salts 



The bile salts are the sodium salts of glycocholic 

 and taurocholic acids. They are formed by the condensa- 

 tion of cholalic acid (C24H 4 O 5 ) with glycine (amino-acetic 

 acid, CH 2 .NH 2 .COOH) and taurine respectively. Glycine 

 is one of the products obtained by the hydrolysis of 

 proteins. 



