Homeostasis: all the functions in your body that try to maintain a ‘constant internal environment’.
Your body needs some things to be kept constant:
All body cells are bathed in tissue fluid, which is just blood plasma which has leaked out of the capillaries (on purpose). This fluid must be just right to keep cells working properly – in other words, certain things must be kept at the right level, not too high, not too low.
Bodily levels that need to be controlled include:
1. Ion content
2. Water content
3. Sugar content
Ion content is regulated by the kidneys:
1. Ions are taken into the body by food and then absorbed into the blood.
2. If the food contains too much of any kind of ion then the excess ions need to be removed.
3. Some ions are lost in sweat.
4. The kidneys will remove any of the excess from the blood – this is disposed of in urine.
Water is lost from the body in various ways: