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rate of its discharge into the intestine, as well as the total quantity secreted 

 daily, have been approximately determined by fistulous openings either 

 in the hepatic ducts or in the gall-bladder. Although the liver presents 

 some physiologic peculiarities, there is no reason to believe that the condi- 

 tions of secretion therein are different from those in any other secretor 

 organ, or that any other structure than the cell is engaged in this process. 

 As shown by chemic analysis, the bile consists of compounds, some of which, 

 like the bile salts, are formed in the liver cells, out of material furnished by 

 the blood by a true act of secretion, while others, such as cholesterin and 

 lecithin, principles of waste, are merely excreted from the blood to be finally 

 eliminated from the body. The bile is thus a compound of both secretory 

 and excretory principles. 



The flow of bile from the liver is continuous but subject to considerable 

 variation during the twenty-four hours. The introduction of food into the 

 stomach at once causes a slight increase in the flow, but it is not until 

 about two hours later that the amount discharged reaches its maximum; 

 after this period it gradually decreases up to the eighth hour, but never 

 entirely ceases. During the intervals of digestion though a small quantity 

 passes into the intestine, the main portion is diverted into the gall-bladder, 

 because of the closure of the common bile-duct by the sphincter muscle near 

 its termination, where it is retained until required for digestive purposes. 

 When acidulated food passes over the surface of the duodenum, there is an 

 increase in the secretion or at least the discharge of bile, and as this takes 

 place after the nerves distributed to the liver are divided, the assumption is 

 that an agent, possibly secretin, is developed in the duodenal mucous mem- 

 brane, which, absorbed into the blood, is ultimately distributed to the liver 

 cells and by which they are excited to activity. At the same time there is 

 excited, through reflex action, a contraction of the muscle walls of the gall- 

 bladder and ducts, a relaxation of the sphincter, and a gush of bile into the 

 intestine, the discharge continuing intermittently until digestion ceases and 

 the intestine is emptied of its contents. 



The storage and the discharge of bile, brought about by the alternate 

 contraction and relaxation of the muscle walls of the gall-bladder and of 

 the sphincter are regulated by the nerve system. As the result of his experi- 

 ments Doyon concludes, that during the intervals of intestinal digestion the 

 vagus nerve is carrying nerve impulses which on the one hand augment the 

 contraction of the sphincter and inhibit the contraction of the walls of the 

 gall-bladder, thus establishing the conditions for the storage of bile; but 

 when intestinal digestion is inaugurated the splanchnic nerve carries nerve 

 impulses which inhibit the sphincter and augment the contraction of the 

 walls of the gall-bladder, thus establishing the condition for the discharge of 

 the bile. 



The total quantity of bile secreted daily has been estimated to be from 

 500 to 800 grams. 



Physiologic Action of Bile. Notwithstanding our knowledge of the 

 complex composition of bile, the quantity discharged daily, and the time 

 and place of its discharge, its exact relation to the digestive process has not 

 been fully determined. No specific action can be attributed to it. It has 

 but a slight, if any, diastatic action on starch. It is without influence on 



