AQA GCSE Biology - Control in the Human Body

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.