Anatomy of the liver

Overview

• The liver is the largest solid organ in the body.
• It lies mainly in the right upper quadrant of the abdomen where it is protected by the thoracic cage and diaphragm.
• It is related by its domed upper surface to the diaphragm, which separates it from pleura, lungs, pericardium and the heart.
• Anatomically the liver is divided into four lobes:
  • Right lobe (largest);
  • Left lobe;
  • Quadrate lobe (lies between the gall bladder and the ligamentum teres);
  • Caudate lobe (lies between the IVC, ligamentum venosum, and porta hepatis).
• Functionally, the liver is divided into right and left lobes based upon its vasculature.
  • Each lobe receives a major branch of the hepatic artery, portal vein, hepatic vein, and biliary drainage.
  • Via the portal vein, the liver receives drainage from the GI tract, its accessory organs, and the spleen.

• The liver lies predominantly in the right hypochondrium and epigastric regions, and extends into the left hypochondrium.
• The outline of the normal liver can be traced as follows:
  • Lower border of the costal margin (10th rib) - Right side;
  • 5th ICS, mid axillary line - Right side;
  • 5th ICS, mid clavicular line (left nipple) - Left side.
• The liver moves with the diaphragm and is located more inferiorly when one is erect due to gravity.