Describe what happens to organisms who optimum temperature zone is between 21°C and 32°C when the temperature rises from 21°C to 50 degrees Celsius

Answer and Explanation:

The hypothalamus contains the central thermoreceptors which detect blood temperature as well as the thermoregulatory centre. The skin of organism contains peripheral thermoreceptors which detect the environmental temperature.

Increase in body temperature above the normal initiates the appropriate corrective mechanisms that include sweating, lowering of hair for mammals, vasodilation of superficial blood vessels and decrease in metabolic rates. This has an overall effect of causing the body temperature to fall and the normal body temperature is restored.

Sweat is secreted by sweat glands that evaporates from the surface of the body cooling the body as it absorbs latent heat of vaporization. Superficial blood vessels vasodilate so that more blood flows near the surface to encourage heat loss. Hair is lowered so that it lies against the body surface. This encourages heat loss from the body to the external environment.