Role of Liver in Metabolism

Liver is the largest gland associated with the alimentary canal. It is reddish brown in colour and is located on the upper side of the abdomen just below the diaphragm.

Its numerous functions can be grouped under major categories:

Blood Related Functions

(i) Produces red blood cells in the embryo. (In adults, RBCs are produced in bone marrow).

(ii) Produces prothrombin and fibrinogen required for blood clotting.

(iii) Produces heparin which prevents unnecessary coagulation of blood.

(iv) Destroys dead and worn out red blood cells.

(v) Removes toxic and metallic poisons from the blood (protective function).

Storage Functions

(i) Storage of iron and some other metallic ions.

(ii) Storage of vitamins A, D and B₁₂.

(iii) Converts extra blood glucose into glycogen and stores it.

Metabolic Functions

(i) Regulation of blood sugar level by retaining excess glucose received as product of carbohydrate digestion from the intestines, and storing it as insoluble glycogen to release it again as soluble glucose when the blood sugar level falls.

(ii) Breaking down of excess amino acids. Amino acids are the end products of protein digestion. Liver breaks down excess amino acids into urea and sugar. Urea is excreted out in urine and sugar is stored for use.

(iii) Synthesizes fatty acids from carbohydrates, which can be used or stored as fat.