The conditions inside our body must be very carefully controlled if the body is to function effectively. Homeostasis is the maintenance of a constant internal environment. The nervous system and hormones are responsible for this.
One example of homeostasis is the concentration of carbon dioxide in the blood being carefully controlled. Here are some of the other internal conditions that are regulated:
This is controlled to maintain the temperature at which the body’s enzymes work best, which is usually 37°C.
This is controlled to protect cells by stopping too much water from entering or leaving them. Water content is controlled by water loss from:
- the lungs - when we exhale
- the skin - by sweating
- the body - in urine produced by the kidneys
Homeostatic control is achieved using negative feedback mechanisms:
- if the level of something rises, control systems reduce it again
- if the level of something falls, control systems raise it again