Where does filtration and selective reabsorption take place?
Kidneytubules
Kidneys can let more or less water move out of the tubules to change the water content of the blood- the more water that leaves the tubules and is reabsorbed into the blood , the more concentrated the urine will be
This process is controlled by a hormone called antidiuretichormone (ADH)
It does this by acting on the cells in the kidneytubules, causing them to be more or less permeable to water and so changing the volume of water that can be reabsorbed
ADH is released into the bloodstream by the pituitarygland
The brain monitors the watercontent of the blood and instructs the pituitary gland to release ADH into the blood according to how much is needed
