Thyroid axis is involved in calorigenesis.
Thyroid hormones increases body metabolic rate by stimulation of
cellular metabolism and resets the energystat.
This maintains the body temperature.
Mechanism- it may be due to uncoupling of oxidative
phosphorylation,excess energy is released in the form of heat.
Also,they heve have marked effect on lipid, carbohydrate and
protein metabolism.
They bring about- lipolysis,glycogenolysis, gluconeogenesis and
catabolic effect on protein metabolism.
All this processes are being utilized As Energy source.