The liver is an important organ for metabolism. It acts like a refinery of the body. The main functions of the liver are:

1. Secretory function
   Bile is secreted by the liver. It is composed of cholesterol, lecithin, bile salt and bilirubin. Bile salt facilitates the absorption of fat and fat soluble vitamins (vitamins A, D, E and K).
   
   Bilirubin is a breakdown product of hemoglobin. If the secretion of the bile becomes abnormal, bilirubin may accumulate inside the body. The skin will become yellowish. This condition is known as jaundice.
   
   
2. Detoxification
   A variety of exogenous toxins, like alcohol, drugs and endogenous toxic metabolites are modified by liver into less toxic or soluble forms.
   
   
3. Metabolic function
   Dietary sugar is stored in the liver in the form of glycogen. When blood sugar level is low, liver glycogen will be converted into glucose and then released into the blood stream, maintaining the glucose level.
   
   Protein is synthesized in the liver from amino acids that is absorbed from the intestines. Excessive amino acids will be converted into urea and excreted from the body.
   
   The liver is also important in the metabolism of fat, vitamins and hormones.