2.68b Osmoregulation

Key Points:
1. Osmoregulation: Osmo = Osmosis and Regulation = To control
2. Ideally, the tissue fluid surrounding cells in the body should be isotonic with the cytoplasm of the cells. This means the amount of water going in and out is equal and they will maintain their size.
3. The danger is that the blood going into the tissue may be concentrated causing a hypertonic tissue fluid. Or it could be dilute causing a hypotonic tissue fluid. The aim would be to maintain a isotonic tissue fluid.
4. This is done by controlling the composition of blood.
5. The kidney controls the composition of the blood. Blood flows into the kidney and excess water or salts will be excreted. The tissue fluid will maintain an isotonic behaviour.