Osmoregulation

A homeostatic process that controls the amount of water in body fluids (e.g. blood). Poor control can lead to the osmotic damage of body cells.

Gain waterLose water
DrinkingEvaporation in lungs
EatingEvaporation of sweat
RespirationProduction of urine/faeces

In normal conditions, the amount of water gained balances with the amount lost.

If conditions change, osmoregulation brings the volumes back into balance.

Hot weather/exerciseDrink more than normal
Body water levelsLose more water as sweatMore water in body
OsmoregulationKidney produces small volume of concentrated urine. Makes us thirsty so we increase water brought into body Kidney produces large volume of dilute urine
EffectMore water is retained = water levels increase More water is lost = water levels decrease