NORMAL ANATOMY OF THE LIVER. 



173 



from the preceding in being lodged in canals 

 formed by the capsular surface of the lobules, 

 the hepatic venous canals, which are analogous 

 to the portal canals excepting in the absence 

 of a proper investment of Glisson's capsule. 

 It follows from this circumstance, that there 

 are no vessels in connection with the hepatic 

 veins at all resembling the vaginal branches 

 and plexuses of the portal vein. The general 

 course of the hepatic veins is from the two 

 surfaces and free margin of the liver towards 

 the vena cava in the posterior border ; that of 

 the portal vein radiates from the transverse fis- 

 sure in the centre of the under surface to all 

 parts of the circumference; hence the two 

 veins cross each other in their course, the 

 former proceeding from before backwards, and 

 the latter from the centre towards the circum- 

 ference. In examining either of these sets of 

 vessels, we should, therefore, be guided in the 

 direction of our section by this peculiar ar- 

 rangement. There is another mode by which 

 we arrive at a knowledge of the means of dis- 

 criminating between the two veins in a section. 

 The hepatic vein being closely adherent to the 

 lobules forming the canal in which it is lodged, 

 remains open, and retains the form of its cy- 

 linder upon the face of a section ; it may also 

 be recognised by being solitary. The portal 

 vein, on the contrary, being surrounded by the 

 loose, vasculo-cellular web of Glisson's cap- 

 sule, is permitted to collapse; it is also charac- 

 terised by being associated with a branch of the 

 hepatic artery and duct. In the consideration 

 of the hepatic veins 1 shall describe, first, the 

 intralobular, next the sublobular, and then the 

 hepatic trunks. 



In the centre of each lobule is situated an 

 intralobular vein (Jig. 34, 5,) which is 

 formed by the convergence of from " four to 

 six or eight" minute venules, from the processes 

 upon the surface of the lobule. In the super- 

 ficial lobules, the intralobular vein commences 

 directly from the surface, and the minute ve- 

 nules by which it is formed may be seen in an 

 ordinary injection converging from the circum- 

 ference towards the centre. The vein then 

 takes its course through the centre of the longi- 

 tudinal axis of the lobule, and piercing the 

 middle of its base opens into the sublobular 

 vein. The intralobular veins have no direct 

 communication with the portal vein or with 

 the hepatic artery, and they simply serve to 

 collect the blood which has circulated through 

 the lobular venous plexus, and convey it into 

 the general current of the hepatic veins. 



The sublobular veins {fig. 34) are named from 

 their position at the base of the lobules. They 

 are lodged in canals which are formed by the 

 bases of all the lobules of the liver. They are 

 extremely thin and " delicate in texture," and 

 lie in close contact with the substance of the 

 lobules, so that upon laying open one of these 

 veins, the bases of the lobules may be seen 

 distinctly through its coats. In the centre of 

 the base of each of the lobules will be ob- 

 served the opening of the intralobular vein, so 

 that the whole internal surface of the vein is 

 pierced by these minute openings. In the 



smaller portal veins, on the other hand, where a 

 number of small foramina were seen upon the 

 internal surface of that side of the vessel 

 which lay in contact with the canal, and where 

 the outline of the lobules was also perceptible, 

 it was observed that the small openings cor- 

 responded with the interlobular spaces, and were 

 the entrances of the interlobular veins. 



The hepatic trunks receiving the blood from 

 the sublobular veins take their course along the 

 " hepatic venous canals," and terminate by 

 two large openings corresponding with the 

 rie,ht and left lobes in the inferior cava, at the 

 point where that vessel is lying deeply im- 

 bedded in the posterior border of the liver. A 

 number of minor hepatic veins also terminate 

 in the cava at this part of its course. The he- 

 patic venous canals resemble the portal canals 

 in being formed by the capsular surfaces of the 

 lobules, lined by a prolongation of the proper 

 capsule. The hepatic trunks are thick and 

 dense in their structure, and their external coat 

 is composed of " longitudinal bands," From 

 the thickness of their texture the outline of the 

 lobules is not apparent through their coats, nor 

 have they any intralobular veins opening into 

 them. 



The coats of the hepatic veins are supplied 

 with blood by the hepatic artery, and the venous 

 blood is returned to the ramifications of the 

 portal vein. 



The lymphatic vessels of the liver are divi- 

 sible into the deep and superficial. The former 

 take their course through the portal canals, and 

 through the right border of the lesser omentum, 

 to the lymphatic glands situate in the course 

 of the hepatic artery, and along the lesser curve 

 of the stomach. They are easily injected (by 

 rupture of course) from the hepatic ducts, and 

 Kiernan remarks, that " injection sometimes 

 passes from the arteries and portal veins into 

 the lymphatics. I have frequently seen them 

 in the right border of the lesser omentum, 

 when distended with injection, as large as small 

 veins. The superficial lymphatics, (Jigs. 32 and 

 33,) are situated in the cellular structure of the 

 proper capsule, over the whole surface of the 

 liver. Those of the convex surface are divided 

 into two sets; 1st, those which pass from be- 

 fore backwards ; and 2d, those which advance 

 from behind forwards. The former unite to 

 form trunks, which enter between the folds of 

 the lateral ligaments at the right and left extre- 

 mities of the organ, and of the coronary liga- 

 ment in the middle. Some of them pierce the 

 diaphragm, and join the posterior mediastinal 

 glands ; others converge to the lymphatic 

 glands situated around the inferior cava. Those 

 which pass from behind forwards consist of two 

 groups ; one ascends between the folds of the 

 broad ligament, and perforates the diaphragm 

 to terminate in the anterior mediastinal glands ; 

 the other curves around the anterior margin of 

 the liver to its concave surface, and from thence 

 to the glands in the right border of the lesser 

 omentum. The lymphatic vessels of the con- 

 cave surface are variously distributed according 

 to their position ; those from the right lobe 

 terminate in the lumbar glands ; those from 



