The functions of the normal liver

The liver is the largest internal organ in the body. It is located mainly in the upper right side of the abdomen, situated mostly under the lower ribs. It weighs about three pounds and is roughly the size of a football.

The normal liver is soft and smooth and is connected to the small intestine by the bile duct which carries the bile formed in the liver to the intestines. Nearly all of the blood that leaves the stomach and intestines must pass through the liver. Acting as the body's largest chemical factory, it has thousands of functions including:

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  The production of clotting factors, blood proteins, bile, and more than a thousand different enzymes


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  The breakdown of old red blood cells


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  The metabolism of cholestrol

• The storage of energy (glycogen) to fuel muscles
  
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  Maintenance of normal blood sugar concentration


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  The regulation of several hormones


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  Detoxification of drugs and poisons, including alcohol

The relationship of the liver to the blood is unique. Unlike most organs in the body, only a small amount of blood is supplied to the liver by arteries. Most of the liver's supply of blood comes from the intestinal veins as the blood returns to the heart. The main vein that returns blood from the intestines is called the
portal vein. As the portal vein passes through the liver, it breaks up into increasingly smaller and smaller veins. The tiniest veins (called sinusoids because of their unique structure) are in close contact with the liver cells. In fact, the liver cells line up along the length of the sinusoids.

This close relationship between the liver cells and blood from the portal vein allows the liver cells to remove and add substances to the blood. Once the blood has passed through the sinusoids, it is collected in increasingly larger and larger veins that ultimately form a single vein, the hepatic vein that returns the blood to the heart.

Under normal circumstances, the liver has the ability to heal itself by repairing or replacing damaged cells. With cirrhosis, the healing process is altered.