What is the Liver?

The liver is the largest glandular organ of the body. It weighs about 3 lb (1.36 kg). It is reddish brown in color and is divided into four lobes of unequal size and shape. The liver lies on the right side of the abdominal cavity beneath the diaphragm. Blood is carried to the liver via two large vessels called the hepatic artery and the portal vein. The heptic artery carries oxygen-rich blood from the aorta (a major vessel in the heart). The portal vein carries blood containing digested food from the small intestine. These blood vessels subdivide in the liver repeatedly, terminating in very small capillaries. Each capillary leads to a lobule. Liver tissue is composed of thousands of lobules, and each lobule is made up of hepatic cells, the basic metabolic cells of the liver.

What is its major function?

The liver has many functions. Some of the functions are: to produce substances that break down fats, convert glucose to glycogen, produce urea (the main substance of urine), make certain amino acids (the building blocks of proteins), filter harmful substances from the blood (such as alcohol), storage of vitamins and minerals (vitamins A, D, K and B12) and maintain a proper level or glucose in the blood. The liver is also responsible for producing cholesterol. It produces about 80% of the cholesterol in your body.

Diseases of the Liver

Several diseases states can affect the liver. Some of the diseases are Wilson's Disease, hepatitis (an inflammation of the liver), liver cancer, and cirrhosis (a chronic inflammation that progresses ultimately to organ failure). Alcohol alters the metabolism of the liver, which can have overall detrimental effects if alcohol is taken over long periods of time.


http://en.wikipedia.org/wiki/Liver

Regeneration

The liver is the only internal human organ capable of natural regeneration of lost tissue; as little as 25% of a liver can regenerate into a whole liver. A human liver is known to grow back in no less than 8 years, due to hyptochronatin cells in the remaining liver. ^[8]

This is predominantly due to the hepatocytes re-entering the cell cycle. That is, the hepatocytes go from the quiescent G0 phase to the G1 phase and undergo mitosis. This process is activated by the p75 receptors.^[9] There is also some evidence of bipotential stem cells, called ovalocytes or hepatic oval cells, which are thought to reside in the canals of Hering. These cells can differentiate into either hepatocytes or cholangiocytes, the latter being the cells that line the bile ducts.

The liver is the only internal human organ capable of natural regeneration of lost tissue; as little as 25% of a liver can regenerate into a whole liver. A human liver is known to grow back in no less than 8 years, due to hyptochronatin cells in the remaining liver. ^[8]

This is predominantly due to the hepatocytes re-entering the cell cycle. That is, the hepatocytes go from the quiescent G0 phase to the G1 phase and undergo mitosis. This process is activated by the p75 receptors.^[9] There is also some evidence of bipotential stem cells, called ovalocytes or hepatic oval cells, which are thought to reside in the canals of Hering. These cells can differentiate into either hepatocytes or cholangiocytes, the latter being the cells that line the bile ducts.