Number of lobes in liver as per Couinaud's classification: March 2005

Ans. D: 8 The Couinaud classification of liver anatomy divides the liver into eight functionally independent segments. Each segment has its own vascular inflow, outflow and biliary drainage. In the centre of each segment there is a branch of the poal vein, hepatic aery and bile duct. In the periphery of each segment there is vascular outflow through the hepatic veins. Right hepatic vein divides the right lobe into anterior and posterior segments. Middle hepatic vein divides the liver into right and left lobes (or right and left hemiliver). This plane runs from the inferior vena cava to the gallbladder fossa. Left hepatic vein divides the left lobe into a medial and lateral pa. Poal vein divides the liver into upper and lower segments. The left and right poal veins branch superiorly and inferiorly to project into the center of each segment. Because of this division into self-contained units, each segment can be resected without damaging those remaining. For the liver to remain ble, resections must proceed along the vessels that define the peripheries of these segments. This means, that resection-lines parallel the hepatic veins. The centrally located poal veins, bile ducts, and hepatic aeries are preserved