Which hormone does the thyroid gland secrete?
In mammals,the thyroid gland consists of two lobes and lies below the larynx, secreting the following hormones:
i) Thyroxine or Tetra-iodothyronine, T4
ii) Tri-iodothyronine or T3
T3 and T4, the two hormones act in essentially the same way, acting the basal metabolic rate by stimulating the breakdown of glucose and the release of heat along with the generation of ATP.
These two hormones only differ in the sense that, T4 has 4 iodine atoms while T3 has 3.
Moreover, they also act in conjugation with Somatotrophin , bringing about growth and also affect brain development, causing the brain cells to differentiate. Furthermore, they also bring about Metamorphosis in amphibians.