The dissector's manual of practical and surgical anatomy / By Erasmus Wilson.

  • Wilson, Erasmus, Sir, 1809-1884.
Date:
1856
Catalogue details

Licence: Public Domain Mark

Credit: The dissector's manual of practical and surgical anatomy / By Erasmus Wilson. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    portion orrupics tlu* intorlobiilar fissures and spaces, and the lo>)ular l)orti()n forms tlie .suj)porting tissue of tlie substanee of tlie lobules. The portdl rclfi, ent(Ming the liv«*r at the transverse fissure, ramifies through its structure in canals, wliich resemble, by their surfaces, the external superficies of tlxe liver, and are formed by the capsular surfaces of the lobules. These are the portal canals, and contain, besides tlic portal vein, with its ramifications, the artery and duct with their branches. In the larger canals, the vessels are separate<l from the parietes by a web of Glisson's capsule ; but, in the smaller, the jwrtal vein is in con- tact with the surface of the canal for about two-thirds of its cylinder, the opposite third l)eing in relation with the artery and duct and their invest- ing capsule. If, th(;refore, the portal vein were laid open V)v a longitudinal incision in one of these smaller canals, the coats being transparent, the outline of the lobules, bounded by their interlobular fissures, would be as distinctly seen as upon the external surface of the liver, and the smaller venous branches would be observed entering the interlobular spaces. The branches of the portal vein are, the vaginal, interlobular, and lobular. The vagiiial hranrhes are those which, being given off in the l)ortal canals, have to pass through the sheath (vagina) of Glisson's cap- sule, previously to entering the interlobular spaces. In this course they form an intricate plexus, tlie vaginal plexus, which, depending for its existence on the capsule of Glisson, necessarily surrounds the vessels, as does that capsule in the larger canals, and occupies the capsular side only in the smaller canals. The interlobular branches are given off from the vaginal portal plexus where it exists, and directly from the portal veins, in that part of the smaller canals where the coats of the vein are in con- tact with the walls of the canal. They then enter the interlobular spaces and divide into branches, which cover with their ramifications every part of the surface of the lobules, with the exception of their bases and those extremities of the superficial lobules which appear upon the surfaces of the liver. The interlobular veins communicate freely with each other, and with the corresponding veins of adjoining fissures, and establish a general portal anastomosis throughout the entire liver. The lobular branches are derived from the interlobular veins ; they fonn a j^lexus within each lobule, and converge from the circumference towards the centre, whore they terminate in the minute radieles of the intralobular vein. This plexus, interposed between the interlobular portal veins and the intralobular hepatic vein, constitutes the venous part of the lobule, and maybe called the lobular venous plexus.''^ The irregular islets of tho substance of the lobules, seen between the raeslies of this plexus l)y moans of the microscope, are the acini of Malpighi, and are portious of the lobular biliary plexus. The i)ortal vein n^turns the venous blood from the chylopoietic vis- cera, to b(» eirculatod through the lobules ; it also receives the venous blood, which rosults from the distribution of tho hopatic artery. The hej>atic duct, ontoring tho liver at the transverse fissure, divides into branches, which ramify through the ]H>rtal canals, with the jv^rtal vein and hopatic artery, to terminate in the substance of tho lobules. Its branches, like those of the jxirtal vein, are vaginal, interlobular, and lobular. The raqlnnl branches ramify through the capsule of Glisson. and fonn a vaginal 6///ffr///»/«'.r»/.s-, which, like the vaginal juMtal j)loxus, surrounds the vessels in the large canals, but is deficient on that side of the smaller canals near which the duct is placed. The branches given otT by the vaginal biliary plexus are interlobular aud lobular. The interlobular