This results in the production of very small quantities of very concentrated urine. The result of reabsorbing water is to reduce the concentration of the blood. Too little water in the blood, detected by the hypothalamus. More ADH produced by the pituitary gland. Blood becomes less concentrated.
Blood returns to correct osmotic concentration.
Waterlogging The hypothalamus detects that there is too much water in the blood. Animal cells are in danger of swelling and bursting if they are placed in a solution which is too dilute. It is very important that the blood does not become so dilute that our cells are stressed by waterlogging. The kidney stops reabsorbing water. Large volumes of very dilute urine are formed.