The human body is designed to function most efficiently at 37ºC. If you become too hot or too cold, there are ways in which your body temperature can be controlled.
When we get too hot:
When we get too cold:
The hairs on the skin also help to control body temperature. They lie flat when we are warm, and rise when we are cold. The hairs trap a layer of air above the skin, which helps to insulate the skin against heat loss.
The hypothalamus is the part of the brain which monitors the body's temperature. It receives information from temperature-sensitive receptors in the skin and circulatory system.
The hypothalamus responds to this information by sending nerve impulses to effectors to maintain body temperature. For example, if we become too cold, the hair erector muscles contract. This raises the skin hairs and traps a layer of air next to the skin.
Negative feedback mechanisms control body temperature. They include the amount of:
|Too cold||Too hot|
|Arterioles||Get narrower||Get wider|
|Blood flow in skin capillaries||Decreases||Increases|
|Heat loss from skin||Decreases||Increases|
These diagrams show the processes that take place when vasoconstriction and vasodilation occur.