How do kidney'a conserve water when the water content is low? Plzz explain experts!!!
Kidneys perform the function of osmoregulation by maintaining the amount of water and salts in the body. The glomerular filtrate in the Bowman's capsule is isotonic to blood plasma. In the proximal convoluted tubule, filtrate is isotonic to blood plasma. Maximum reabsorption of the glomerular filtrate occurs in the proximal convoluted tubule , therefore, filtrate becomes hypertonic to blood plasma in the descending limb of loop of Henle. In the ascending limb of loop of Henle, filtrate becomes hypotonic to blood plasma. In distal convoluted tubule the filtrate becomes isotonic to blood plasma because aldosterone and ADH increase sodium ions and water from the filtrate respectively. In collecting duct further reabsorption occurs which makes the filtrate hypertonic. Thus human urine is hypertonic.