THE LIVER. 



743 



Fissures (Fig. 408). Five Fissures are seen upon the under surface of the 

 liver, which serve to divide it into five lobes. They are the longitudinal fissure, 

 the fissure of the ductus venosus, the transverse fissure, the fissure for the gall- 

 bladder, and the fissure for the vena cava. 



The longitudinal fissure is a deep groove, which extends from the notch on 

 the anterior margin of the liver to the posterior border of the organ. It sepa- 

 rates the right and left lobes ; the transverse fissure joins it, at right angles, 

 about one-third from its posterior extremity, and divides it into two parts. The 

 anterior half is called the umbilical fissure it is deeper than the posterior part, 

 and lodges the umbilical vein in the foetus, or its remains (the round ligament) 

 in the adult. This fissure is often partially bridged over by a prolongation of 

 the hepatic substance, the pons hepatis. 



The fissure of the ductus venosus is the back part of the longitudinal fissure ; 

 it is shorter and shallower than the anterior portion. It lodges in the foetus the 

 ductus venosus, and in the adult a slender fibrous cord, the obliterated remains 

 of that vessel. 



Fig. 408. The Liver. Under Surface. 



The transverse or portal fissitre is a short but deep fissure, about two inches in 

 length, extending transversely across the under surface of the right lobe, nearer 

 to its posterior than its anterior border. It joins, nearly at right angles, with 

 the longitudinal fissure. By the older anatomists, this fissure was considered 

 the gateway (porta) of the liver; hence the large vein which enters at this 

 point was called the portal vein. Besides this vein, the fissure transmits the 

 hepatic artery and nerves, and the hepatic duct and lymphatics. At their 

 entrance into the fissure, the hepatic duct lies in front to the right, the hepatic 

 artery to the left, and the portal vein behind (Fig. 412). 



The fissure for the gall-bladder (fossa cystidis fellese) is a shallow, oblong fossa, 

 placed on the under surface of the right lobe, parallel with the longitudinal 

 fissure. It extends from the anterior free margin of the liver, which is occa- 

 sionally notched for its reception, to near the right extremity of the transverse 

 fissure. 



The fissure for the vena cava is a short deep fissure, occasionally a complete 

 canal which extends obliquely upwards from a little behind the right extremity 

 of the transverse fissure, to the posterior border of the organ, where it joins 

 the fissure for the ductus venosus. On slitting open the inferior vena cava 

 which is contained in it, a deep fossa is seen, at the bottom of which the hepatic 



