Function of Liver
Being the largest chemical factory of the body, the liver performs innumerable functions. Some of these functions are known to us, about some others we have ideas, but possibly
we are not aware of many of the functions of liver. Similarly, how the liver works is far from clear to us.
Some of the functions of liver are as follows:
1.Synthetic functions: The following substances are synthesised by the liver.
(a) Bile salts.
(b) Proteins : (i) Albumin, (ii) Blood coagulation factors
I, I, V, VII, IX and X and also fibrinolytic agents, (Gii) Transport
proteins like ceruloplasmin, transferrin, (iv) Angiotensinogen, (V) IGF-1.
(c) Lipids: VLDL, LDL, etc.
(d) Carbohydrates: Glycogen and also glucose (neoglucogenesis).
(e) Vitamins: 25 hydroxylation of vitamin D,.
( f) Conversion of T, to T,.
(g) Formation of urea.
(h) Together with these the liver forms metabolites of many substances and synthesises many enzymes. It is the place of metabolism of protein, fat and carbohydrate.
2. Liver is responsible for inactivation of many drugs used in treatment of diseases. The drugs are usually hydroxylated, Oxidised or reduced and then are conjugated with glucuronic acid or sulphated and then excreted through bile.
3. Glucostatic function: Liver takes up excess glucose from blood after a meal and then releases glucose during fasting.
4. Metabolism of ethanol.
5. De-activation of various hormones.
6. Excretion of bile pigments, cholesterol and some metals.
7. Storage function: Liver stores vitamin B,, (sufficient for 4 years), vitamin A (sufficient for 2 years) and also vitamin D, K, riboflavin, nicotinamide, pyridoxine and folic acid. It acts as a store for body iron as ferritin and also of copper. It provides the energy store by its glycogen content.
8. Detoxification function: Liver can destroy many toxic substances.