CHAP, XXXIII.] NERVES AND LYMPHATICS. 



473 



ings of the small branches of 

 the hepatic vein (intralobular 

 vein) are seen in the centre of 

 each lobule, while in Fig. 220, 

 which represents a portal vein 

 laid open, the orifices of the 

 smallest branches are seen in 

 the spaces between two lobules 

 (interlobular veins) . 



The capillaries in the cen- 

 tral part of the lobule open 

 into the small twig of the 

 hepatic vein upon all sides. 

 These points are well seen in 

 the pig's liver, where the lo- 

 bules are distinct, but in the 

 human and other livers, the 

 arrangement varies slightly in 

 consequence of the lobules 

 communicating with each other of the canal from which the vein has been ren - oved - 



Longitudinal section of an hepatic vein. a. Portion 



n 



b. Orifices of ultimate twigs of the vein (intralobular) 

 situated in the centre of the lobules, after Kiernan. 

 Compare the arrangement of the small veins in this 



the intervals between the 

 iuterlobular fissures ( Fig. 217). figur " e with the braifches of the P rtal vein in Fi &- 22 - 



Nerves and Lymphatics. The nerves of the liver are derived 

 chiefly from the sympathetic, but a few branches of the vagus are 

 also distributed to the organ. They consist of tubular and gelati- 

 nous nerve fibres, and are distributed principally upon the walls of 

 the artery over which they form a network. 



Branches may be traced into Glisson's capsule, and to the coats 

 of the gall bladder and larger ducts, as well as to the coats of the 

 larger branches of the hepatic vein. 



The lymphatics are found in considerable abundance in the 

 liver ; they are distributed to the gall bladder, and form a network 

 upon the surface of the organ underneath the peritoneum. An 

 abundant network of lymphatics exists in the largest portal canals, 

 and when the ducts are injected, it not unfrequently happens that 

 a small branch bursts, and the injection escapes into the lymphatics. 

 In this way, some lymphatic glands near the liver are often in- 

 jected, and the injection sometimes even reaches the thoracic duct, 

 as occurred to Mr. Kiernan, and also to Dr. Beale. 



Of the Liver Cells. From what has been already stated, with 

 regard to the arrangement of the solid capillary venous plexus of the 

 lobules, it will be inferred that the cells occupy the meshes of this 



VOL. II. I I 



