520 STRUCTURAL ANATOMY OP THE LIVER. 



The Sullobular veins are contained in canals formed solely by the 

 bases of the lobules, with which, from the absence of Glisson's cap- 

 sule, they are in immediate contact. Their coats are thin and trans- 

 parent ; and, if they be laid open by a longitudinal incision, the 

 bases of the lobules will be distinctly seen, separated by interlobular 

 fissures, and perforated through the centre by the opening of the 

 intralobular vein. 



The Hepatic trunks are formed by the union of the sublobular 

 veins; they are contained in canals (hepatic venous) similar in 

 structure to the portal canals, and lined by a prolongation of the 

 proper capsule. They proceed from before backwards, and termi- 

 nate by two large openings, corresponding to the right and left lobe 

 of the liver in the inferior vena cava. 



It is to Kiernan that anatomical science is indebted for the clear, 

 distinct, and intelligible idea of the structure of this most compli- 

 cated organ, which has been furnished by the researches of that 

 anatomist. To value this knowledge as it deserves, we have but to 

 reflect upon the unsuccessful, though not fruitless, labours of those 

 great discoverers in structural anatomy, Malpighi and Ruysch, upon 

 the same subject, and the strange misconceptions of modern authors, 

 among whom Miiller and Cruveilhier occupy so conspicuous a place. 

 It is not, however, in an anatomical, or even a physiological point 

 of view merely, that we have to admire these discoveries ; for in 

 their practical application to the elucidation of pathological appear- 

 ances, and the explanation of the phenomena of disease, they are 

 still more interesting. 



Summary. The liver has been shown to be composed of lobules ; 

 the lobules (excepting at their bases) are invested and connected 

 together, the vessels supported, and the whole organ enclosed by 

 Glisson's capsule ; and they are so arranged, that the base of every 

 lobule in the liver is in contact with an hepatic vein (sublobular). 



The Portal vein distributes its numberless branches through portal 

 canals, which are channeled through every part of the organ ; it 

 brings the returning blood from the chylopoietic viscera ; it collects 

 also the venous blood from the ultimate ramifications of the hepatic 

 artery in the liver itself. It gives off branches in the canals, which 

 are called vaginal, and form a venous vaginal plexus ; these give 

 off interlobular branches, and the latter enter the lobules and form 

 lobular venous plexuses, from the blood circulating in which the bile 

 is secreted. 



The Bile in the lobule is received by a network of minute ducts, 

 the lobular biliary plexus ; it is conveyed from the lobule into the 

 interlobular ducts ; it is thence poured into the biliary vaginal plexus 

 of the portal canals, and thence into the excreting ducts, by which 

 it is carried to the duodenum and gall-bladder, after being mingled 

 in its course with the mucous secretion from the numberless muci- 

 parous follicles in the walls of the ducts. 



The Hepatic artery distributes branches through every portal 

 canal ; gives off vaginal branches which form a vaginal hepatic 



