Functions of the Liver

The Liver

Diagram of the liver

Internal liver structure

External liver structure

Functions of the liver

Homeostatic functions of the liver

The Liver in Detoxification and Metabolism of Drugs

Drug Administration

Liver Disease

Causes of Liver Disease


The Liver

The liver is the largest gland, and the largest solid organ in the body.   It weighs approximately 1.8kg in men and 1.3kg in women.   It holds approximately 13% (0.57 litres) of the body's total blood supply at any one time and is estimated to have over 500 functions.
It is divided into two main lobes, the right being much larger than the left, which are divided by the falciform ligament, and subdivided further into 100,000 lobules.   About 80% of the liver consists of hepatocyte liver cells.   These are the major functional cells of the liver and perform a wide range of metabolic, secretary, and endocrine functions.   They are specialised epithelial cells which form complex three dimensional arrangements called hepatic laminae.

The laminae are one cell thick plates; these are bordered by endothelial lined vascular spaces called hepatic sinusoids.  
Hepatic sinusoids are highly permeable blood capillaries between the rows of hepatocytes that receive oxygenated blood from the hepatic artery and nutrient rich deoxygenated blood via the hepatic portal vein.   Also residing in the hepatic sinusoids are fixed phagocytes called stellate reticuloendothelial (Kupffer) cells.   These destroy worn out white and red blood cells, bacteria and other foreign matter.

Grooves in the cell membranes between hepatocytes provide spaces for canaliculi.   Bile canaliculi are small canals into which bile flows when it is excreted by the hepatocytes.
Bile is a green/yellow fluid that acts as an excretory product and as a digestive secretion.
From the canaliculi the bile passes into bile ductules and on to the bile ducts.   These all lead to the right and left hepatic ducts that exit...