The maintenance of a constant internal environment is called homeostasis.
Water in the body has to be controlled to protect cells from either too much water entering or too much water leaving them
- the lungs - when we exhale.
- the skin - through sweating.
- passing urine- produced by the kidneys.
Ions (salts) are controlled to protect cells from too much water entering or leaving them.
- the skin - through sweating
- passing urine - produced by the kidneys.
Temperature of the body
Has to be kept constant to maintain the temperature at which enzymes work. An enzyme is a protein which catalyse or speed up chemical reactions inside our bodies (37 degrees celsius).
Blood sugar levels
This is controlled to supply cells with a constant level of glucose. Glucose is controlled by insulin, which is produced in the pancreas.