THE LIVER. 



381 



The hepatic veins empty into the vena cava. The lym- 

 phatics are numerous and are distributed through the 

 portal canals. The portal vein enters the liver at the 

 transverse fissure and divides into a right and left branch ; 

 these give off vaginal branches that run in the portal ca- 

 nals ; from these are given off the inteiiobular ; and these 

 send off numerous vessels into the lobule, called the 

 lobular. The lobular are the smallest radicles of the 

 portal system ; they all converge toward the centre of the 

 lobule and run into the middle lobular or intralobular 

 veins, which empty into 

 the sublobular, and these 

 form the hepatic, three or 

 five in -number, which 

 open into the ascending 

 vena cava as it lies in the 

 fissure in the posterior 

 border of the liver. The 

 nerves of the liver are the 

 pneumogastric and sympa- 

 thetic. 



In structure the liver 

 is composed of great num- 

 bers of lobules held together by delicate connective tissue, 

 arteries, ducts, veins, lymphatics, and nerves, the entire 

 mass being invested by a serous coat, the peritoneum, 

 and a fibrous coat, which is blended with the serous in- 

 vestment; it is reflected into the interior of the liver as 

 the capsule of Glisson. An examination of the lobules 

 shows them to be about one-twelfth of an inch in diam- 

 eter, and, viewed in the erect position, they may be said 

 to be conoidal in form with undulate sides; so that a 

 vertical section gives a foliated outline. The bases, by 

 mutual pressure, are polygonal in outline. 



FIG. 165. TRANSVERSE SECTION OF 

 LOBULES OF LIVER. 



a, interlobular vein ; b, intralobular or central vein. 



