The Liver. 121 



(a) The common bile duct (d. choledochus) is formed on the 

 posterior surface of the liver by the union of a left hepatic 

 duct (d. hepaticus) with a similar duct from the right anterior 

 lobule. The latter receives the cystic duct (d. cysticus) from 

 the gall bladder. Special ducts from the right posterior 

 lobule and from the caudate lobe enter the common bile 

 duct through a short common trunk. The common bile 

 duct passes backward on the right side of the portal vein, and 

 enters the digestive tube on the dorsal surface of the first 

 (superior) portion of the duodenum immediately beyond the 

 pylorus. 



(b) The hepatic artery (a. hepatica) approaches the liver by 

 passing forward on the right side of the portal vein ventral to 

 the bile duct. It distributes branches to the right posterior 

 lobule and the caudate lobe, and at the base of the liver 

 proper divides into right and left rami. The right ramus 

 sends a branch, the cystic artery (a. cystica), to the gall 

 bladder. 



(c) The portal vein (v. portae), a vessel of large calibre, but 

 usually found in a collapsed condition, enters the lesser 

 omentum from the dorsal surface of the pyloric antrum. It 

 distributes branches to the right posterior lobule and the 

 caudate lobe; then passing directly forward to the base of 

 the left lobe is distributed to the latter, a right branch being 

 given off to the right anterior lobule. 



4. Divide the lesser omentum with the structures described above. 

 Divide the coronary and triangular ligaments, being careful not to injure 

 the central tendon of the diaphragm, which resembles the coronary 

 ligament. Remove the liver and examine its dorsal surface for the 

 following : 



(a) The inferior vena cava ; it is accommodated in a depression 

 of the thickened dorsal portion of the organ. The vessel 

 should be opened lengthwise. 



(b) The hepatic veins (vv. hepaticae) open almost directly ffom 

 the substance of the liver into the inferior cava. They are 

 typically four in number, there being separate vessels for the 

 anterior and posterior parts of the right lobe and for the 

 caudate lobe, in addition to a large vessel for the left lobe. 



(c) The renal impression (impressio renalis), an extensive 

 excavation of the right posterior lobule for the accommoda- 

 tion of the right kidney. 



