LIVER. 3:57 



have distinct membranous walls, or whether they originate in the spaces 

 between the cells by open orifices, has not been satisfactorily determined. 



The bile-channels empty into the interlobular ducts, which measure about 

 2oW f an inch in diameter and are composed of a thin, homogeneous 

 membrane lined by flattened epithelial cells. 



As the interlobular bile-ducts unite to form large trunks, they receive an 

 external coat of fibrous tissue, which strengthens their walls; they finally 

 unite to form one large duct (the hepatic duct), which joins the cystic duct; 

 the union of the two forms the ductus communis choledochus, which is about 

 three inches in length, the size of a gooze-quill, and opens into the duodenum. 



The gall-bladder is a pear-shaped sac, about four inches in length, 

 situated in a fossa on the under surface of the liver. It is a reservoir for the 

 bile, and is capable of holding about one ounce and a half of fluid. It is 

 composed of three coats: 



1. Serous, a reflection of the peritoneum. 



2. Fibrous and muscular. 



3. Mucous. 



Functions of the Liver. The liver is a complex organ having a variety 

 of relations to the general processes of the body. While its physiologic 

 actions are not yet wholly understood, it may be said that it is engaged: 



1. In the secretion pf bile. 



2. In the production of starch (glycogen) and sugar (glucose). 



3. In the formation of urea. 



The Secretion of Bile. The characteristic constituents of the bile do not 

 preexist in the blood, but are formed in the interior of the liver cells of 

 materials derived from the venous and arterial blood. The hepatic cells, 

 absorbing these materials, elaborate them into bile-elements, and in so doing 

 undergo histologic changes similar to those exhibited by other secretory 

 glands. The bile once formed, it passes into the months of the bile capil- 

 laries, near the periphery of the lobules. Under the influence of the vis 

 a tergo of the new-formed bile it flows from the smaller into the large 

 bile-ducts, and finally empties into the intestine, or is regurgitated into the 

 gall-bladder, where it is stored up until it is required for the digestive process 

 in the small intestine. The study of the secretion of bile by means of biliary 

 fistulas reveals the fact that the secretion is continuous and not intermittent; 

 that the hepatic cells are constantly pouring bile into the ducts, which con- 

 vey it into the gall-bladder. As this fluid is required only during intestinal 

 digestion, it is only then that the walls of the gall-bladder contract and dis- 

 charge it into the intestine. 



The flow of bile from the liver cells into the gall-bladder is accomplished 



