What is the role of TSH in metabolism?
1. It controls the various aspects of the functioning of the thyroid gland.
2. Promotes accumulation of iodine and increases the quantity of intracellular colloids in the epithelial cells of the thyroid gland. This induces the liberation of the hormone thyroxin.
There is a negative feed back between the level of thyroxin and TSH. If the secretion is decreased the level of thyroxin is also decreased resulting in hypothyroidism. This results in reduced growth. On the other hand increased TSH secretion resulting in increased thyroxin production causes hyperthyroidism. This is characterised by irritability, increased rate of metabolism, bulging of the eye balls etc.
The production of TSH is controlled by thyrotrophin releasing hormone (TRH) produced from the hypothalamus.