BODY TISSUES AND FLUIDS 



465 



to roughly 500 to 1000 c.c. in 24 hrs. It is usually alkaline in reaction to 

 litmus, and ordinarily possesses a decidedly bitter taste. The specific 

 gravity varies between 1.010 and 1.040. As secreted by the liver bile is a 

 rather limpid fluid, but the addition of mucus and the abstraction of 

 water in the gall bladder raise both the specific gravity and the viscosity. 

 The table below, compiled from analyses given by Hainmarsten, gives* a 

 good idea of bladder and liver bile. 



The most important constituents of bile are the bile acids and bile 

 pigments. The bile acids may be divided into two groups, the glycocholic 

 and taurocholic acid groups, the former being considerably in excess in 

 human bile as indicated in the table above. The bile acids are conjugate 

 amino-acids, in which glycocoll or taurin are joined to cholic acid. This 

 latter acid exists in several forms. There is- some reason for believing 

 that cholic acid is derived from cholesterol. The bile acids generally exist 

 in the bile in the form of sodium salts. The bile salts have the power of 

 holding the cholesterol and lecithin of the bile in solution. They also act 

 as a coferment to the pancreatic lipase, thus facilitating fat digestion. 

 The bile salts have a strong hemolytic action on the red blood cells. 



The bile pigments are derived from the decomposition of the hematin 

 portion of hemoglobin, after the removal of the iron. (Whipple and 

 Hooper (6) have recently suggested the possibility of another origin.) 

 Although the liver is apparently chiefly concerned in this transformation, 

 the formation of the bile pigments may take place elsewhere in the body. 

 Bilirubin and biliverdin, an oxidation product of bilirubin, are the two 

 chief bile pigments, the one possessing a golden yellow and the other an 

 emerald green color. Bilirubin is identical with the hematoidin of old 

 blood clots, and isomeric with the hematoporphyrin of pathological urines. 

 Under the action of intestinal bacteria bilirubin is reduced. It would 

 appear that hydrobilirubin prepared by the chemical reduction of 

 bilirubin, the stercobilin of the feces and the urobilin of the urine were 



