936 THE ORGANS OF DIGESTION. 



the foetus, and its remains (the round ligament) in the adult ; the posterior part 

 contains the ductus venosus, and is known as the fissure of the ductus venosus. 

 This fissure lies between the quadrate lobe and the left lobe of the liver, and 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, 

 and is situated mainly on the posterior surface of the liver. It lies between the 

 left lobe and the lobe of Spigelius. It lodges in the foetus the ductus venosus, and 

 in the adult a slender fibrous cord, the obliterated remains of that vessel. 



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

 length, extending transversely across the under surface of the left portion of the 

 right lobe, nearer to its posterior surface than its anterior border. It joins, nearly 

 at right angles, with the longitudinal fissure, and separates the quadrate lobe in 

 front from the caudate and Spigelian lobes behind. By the older anatomists this 

 fissure was considered the gateway (porta) of the liver ; hence the large vein which 

 enters at this fissure 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 and to the right, 

 the hepatic artery to the left, and the portal vein behind and between the duct 

 and artery. 



CEsophageal groove. Portal win. Suprarenal impression. 



FIG. 513. Posterior and under surfaces of the liver. (From Ellis.) 



The fissure for the gall-bladder (fossa vesicaUs) 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 notched for its 

 reception, to the right extremity of the transverse fissure. 



The fissure for the inferior vena cava is a short, deep fissure, occasionally a com- 

 plete canal, in consequence of the substance of the liver surrounding the vena cava. 

 It extends obliquely upward from the lobus caudatus, which separates it from the 

 transverse fissure, on the posterior surface of the liver, and separates the Spigelian 

 from the right lobe. On slitting open the inferior vena cava the orifices of the 

 hepatic veins will be seen opening into this vessel at its upper part, after perforat- 

 ing the floor of this fissure. 



Lobes. The lobes of the liver, like the ligaments and fissures, are five in 

 number the right lobe, the left lobe, the lobus quadratus, the lobus Spigelii, and 

 the lobus caudatus, the last three being merely parts of the right lobe. 



