THE LIVER

THE LIVER
Anatomy of the liver its parenchyma is entirely covered by a thin capsule and by visceral peritoneum on all but the posterior surface of the liver, termed the ‘bare area’
The blood supply to the liver is unique, 80 per cent being derived from the portal vein and 20 per cent from the hepatic artery. The arterial blood supply in most individuals is derived from the coeliac trunk of the aorta, where the hepatic artery arises along with the splenic artery. Structures in the hilum of the liver;
The porta hepatis, a transverse fissure on the visceral surface of the liver, is the hilum of the liver .The usual anatomical relationship of the structures is for the bile duct to be within the free edge of the lesser omentum or the ‘hepatoduodenal ligament’, the hepatic artery to be above and medial, and the portal vein to lie posteriorly; and together with nerves and lymphatics enter the liver at the porta hepatis .
SEGMENTAL ANATOMY OF THE LIVER
Couinaud, a French anatomist, described the liver as being divided into eight segments . Each of these segments can be considered as a functional unit, with a branch of the hepatic artery, portal vein and bile duct, and drained by a branch of the hepatic vein. The overall anatomy of the liver is divided into a functional right and left ‘unit’ along the line between the gall bladder fossa and the middle hepatic vein (Cantlie’s line). Liver segments (V–VIII), to the right of this line, To the left of this line (segments I–IV), functionally is the left liver.