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.

Surface anatomy

  • 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.