Role Of Brain In Thermoregulation: In brain Hypothalamus is homesostasis thermostate. The hypothalamus receive never message. from skin, body tissus abd themorecoptos. In hot season the hypothalamus closes all system of heat conservative. It makes heat release from body, the main source are vasodilation of blood vesseles, sweating by sweet glands in clod weather hypothalamus closes all the system of heat loss.

Excretion In Hydra: Ammonia is excreting product in Hydra. It is excreted out through skin as well as it comes into the gastrovascular cavity and then removed the body from the body along with water by simple diffusion.