- Liver performs a number of functions.
- Due to its function, it is also called master laboratory of the body.
- It is an important organ for metabolism in vertebrates.
- A summary of its important function is as follows:
1) Secretion of bile
- The liver cells synthesize the constituents of bile from the mixed arterial and venous blood in the sinusoids.
- Bile juice is a dark green coloured alkaline fluid.
- It consists of bile salts, bile pigments, cholesterol, lecithin, water, etc.
- Bile has various functions as follows:
i) Makes the chyme alkaline better suited for the action of pancreatic juice.
ii) Brings about emulsification of fats.
iii) Helps in removing the excretory product like bile pigments, inorganic salts, toxins, etc. from the body.
iv) Checks the bacterial growth and multiplication as it works as antiseptic.
v) Bile salts help in absorption of fat soluble vitamins like A, D. E, K.
vi) Stimulates peristalsis.
- Decomposes the excess proteins and amino-acids to ammonia
- From ammonia, urea is formed through a chain of reactions.
- Breaks down the nucleic protein of worn out cells of the body.
- Nucleic protein gets converted to uric acid which is then excreted in the urine.
- Converts excess glucose to glycogen in the presence of insulin.
- Converts glycogen to glucose in the presence of glucagon.
- Thus, helps to maintain glucose level in the blood.
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- Converts stored fat to a form in which it can be used by the tissues to provide energy.
- Serves as storage organs for various substances.
- The substances are:
a) Vitamin B12.
b) Fat soluble vitamins A, D, E, K.
c) Water soluble vitamins, e.g., riboflavin, niacin, folic acid, pyridoxine.
d) Iron, copper, etc.
- Synthesizes vitamin A from carotene, the pro-vitamin found in some plants, e.g., green leafy vegetables and carrots.
- Produces fibrinogen and pro-thrombin for clotting blood.
- Produces heparin to prevent coagulation of blood in blood vessels.
- Synthesizes non-essential amino acids, lymph and plasma proteins.
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- Detoxicates drugs and noxious substances such as toxins produced by microbes.
8) Production of heat
- Uses a considerable amount of energy and produces a great deal of heat.
- Main heat producing organ of the body.
- Helps in removing various unwanted substances.
- Substances like carbolic acid, cresol, etc. are removed from blood which comes from alimentary canal.
10) Production of RBC
- Produces red blood corpuscles in the foetus of mammals.
- Kupffer cells of liver kill harmful bacteria and worn out RBC by phagocytosis.
Various functions of liver