LIVER. 317 



mately unite to form the hejDatic duct which leaves the liver at 

 the transverse fissure. 



It is believed by some of the best authorities that the so-called 

 intralobular bile tubes or capillaries are mostly mere spaces 

 between the cells, the tubes being formed only at the periphery 

 of the lobule. 



The hejDatic or bile duct {ductus choledochus) thus results 

 from the union of the branches of the hepatic tubes in the pos- 

 terior fissure of the liver. On leaving the liver, it passes between 

 the folds of the gastro-hepatic omentum, and reaches the walls of 

 the duodenum, where it meets with the principal duct from the 

 pancreas ; both these ducts, in the horse, enter the duodenum 

 together, some five inches 

 from the pylorus. In some 

 cases the two ducts have 

 been found to unite before 

 reaching the wall of the 

 duodenum, thus forming a 

 short, single canal, termed 

 the ductus communis. The „ ,. , • *u ' '• ,-, ., r.-, 



Section showing the manner in which the Bile and 



opening is guarded by a Pancreatic Ducts enter the Intestine, a, Duct of 



, • T r 1 1 c Wirsuuc; ; b, Bile duct ; c, rnion of the two ducts on 



prominent circular fold of the eminence of Vater ; rf, Vahe : e. Muscular coat of 



mucous membrane, the emi- duodenum ; /, mucous coat of ditto. 

 nence of Vater, which serves as a valve, preventing the entrance 

 of food from the duodenum. The ductus choledochus and larger 

 bile tubes consist of an external fibrous and slightly muscular 

 coat, and an internal mucous coat, lined with columnar epithelium, 

 and studded with numerous glands. 



The nerves come from the solar plexus, with branches from the 

 pneumogastric and diaphragmatic nerves. 



The blood of the portal vein, returned chiefly from the 

 abdominal alimentary canal, is charged with bile, which it is the 

 principal function of the liver to remove. This is achieved by 

 the vital power of the hepatic cells, while the blood is passing 

 through the intralobular capillaries. The blood thus deprived of 

 bile, passes into the intralobular veins, and so into the sublobular 

 and hepatic veins, while the bile gains the bile tubes, and ulti- 

 mately the hepatic duct, to be poured again into the intestine. 

 Bile is a greenish-yellow, viscid fluid, with an alkaline reaction ; 

 it is believed to stimulate peristaltic action, and the secretions 

 of the glands in the mucous membrane. 



