60 ORGANS OF DIGESTION. 



The Hepatic Artery is a branch of the cceliac, and in ap- 

 proaching the transverse fissure divides into three or more 

 branches, that penetrate the substance of the liver, between the 

 sinus vena3 portarum and the ducts as they come out; one branch 

 goes to the right lobe, another to the left, and a third to the 

 lobulus spigelii. There is some variety in regard to the pre- 

 cise mode of distribution, and their division into subordinate 

 ramifications frequently occurs before they get fairly into the 

 substance of the liver. When there, they seem to be intended 

 for the nourishment of this organ, according to the observations 

 of several able anatomists; and follow the ramifications of the 

 vena portarum and of the biliary ducts, forming upon them a 

 very delicate and complicated tissue of anastomosing vessels; 

 some of which, probably the vasa vasorum, communicate with 

 the vena portarum. 



The Hepatic Veins arise in the acini from the capillary ter- 

 minations of the vena portarum and the hepatic artery. Their 

 branches are successively accumulated into three large trunks, 

 the collective area of which vastly exceeds that of the vessels 

 bringing the blood to the liver. Two of these trunks come 

 from the right lobe and one from the left, to empty into the 

 ascending cava, while it is still in contact with the liver, im- 

 mediately below the diaphragm; just below the preceding 

 trunks there are five or six, sometimes more, small hepatic 

 veins, coming from the posterior margin of the liver, and from 

 the lobulus spigelii. The hepatic veins are destitute of valves, 

 and remarkable for the thinness of their parietes. An injec- 

 tion passes readily from them into the other systems of vessels. 

 They may be recognised by their insulated course, by their 

 consisting in trunks which converge from the periphery of the 

 liver to the vena cava, while all the other vessels diverge from 

 the transverse fissure to the periphery, and consequently cross 

 the course of the hepatic veins. 



The commencing radicles or ramifications of the hepatic 

 duct, take their origin in the acini; and, as is said, upon the 

 boundary between the two kinds of matter, avoiding the brown 

 and passing through the cortical.* The larger branches con- 

 verge into their respective trunks successively or in pairs; 



* J. F. Meckel, loc. cit. 



