THE LIVER III 



cin and various inorganic salts, such as sulphates, carbonates, 

 phosphates, etc., and a quantity of carbon dioxide. The 

 quantity of bile secreted in twenty-four hours is about two 

 and a half pounds. 



In human bile sodium taurocholate largely predominates 

 over glycocholate. These are formed as acids by the liver 

 cells, are absorbed in their passage down the intestine, and 

 are presumably those parts of the bile which are concerned 

 in its digestive action, particularly in the absorption of fats. 

 So far as these constituents are concerned, the bile is a typi- 

 cal secretion. 



Cholesterin, on the other hand, seems to be simply re- 

 moved from the blood by the liver cells, and is discharged in 

 the feces, where, however, it exists in a slightly changed 

 form, stercorin. It is thought to be held in solution by the 

 bile acids, glycocholic and taurocholic. So far as this con- 

 stituent is concerned, therefore, the bile is a typical excretion. 

 It is produced in many of the body tissues, and no function 

 has been discovered for it. 



Bilirubin is the characteristic coloring matter of the hu- 

 man bile; that of herbivorous animals is biliverdin, and a 

 little of this latter is also present in human bile. These pig- 

 ments originate from hemoglobin. It is supposed that when 

 the red corpuscles break down, "the hemoglobin is brought 

 to the liver, and then under the influence of liver cells is con- 

 verted into an iron-free compound, bilirubin, or biliverdin." 

 (Howell.) 



The lecithin is probably an end product of physiological 

 activity in the tissues, and is apparently an excretion. 



The mucin gives the fluid its viscid character. 



The production of bile is continuous, but this does not 

 mean that its discharge into the duodenum is continuous, for 

 in the intervals of digestion it is not admitted (freely at 

 least) into the intestine, but regurgitates from the ductus 

 communis choledochus through the cystic duct into the gall 

 bladder, which acts as a reservoir until its contents are 



