Describe and explain how the secretion of ADH affects urine production in the kidneys (4 marks)

ADH diffuses into the blood stream and binds to receptors present on the lining of the collecting duct/ DCT (1)This increases the permeability of the membrane of the collecting duct/ DCT (1)Therefore, more water leaves the collecting duct/ DCT via osmosis into the medulla so the volume of urine produced will decrease. (1)So, the concentration of urine will increase (1)