Osmoregulation in the kidneys determines how much water is lost from the body through waste, in urine. Its ultimately controlled by a section of the brain called the hypothalamus, but the processes are done in the kidneys. I haven't done this particular subject in a while, but after the kidneys have performed ultrafiltration, the job of osmoregulation comes in.
As far as I can remember, its primarily done in two places in the kidney nephron - the loop of henle and the collecting duct (although it may be done by the distal convuluted tubule too). I'm sorry if this is a bit vague, but its all I can remember. The kidney performs osmoregulation by changing the concentration of ions in the medulla of the kidneys (outside the tubes in which the filtrate is passing through). When the body wants to preserve water, the kidney will concentrate ions in the medulla, so as to draw water from the filtrate, out of the tubes and into the medulla where its reabsorbed by the blood, via osmosis.
As far as I can remember, its primarily done in two places in the kidney nephron - the loop of henle and the collecting duct (although it may be done by the distal convuluted tubule too). I'm sorry if this is a bit vague, but its all I can remember. The kidney performs osmoregulation by changing the concentration of ions in the medulla of the kidneys (outside the tubes in which the filtrate is passing through). When the body wants to preserve water, the kidney will concentrate ions in the medulla, so as to draw water from the filtrate, out of the tubes and into the medulla where its reabsorbed by the blood, via osmosis.
