Well, because it moves into an area where we have a high concentration of solute. And that concentration solute was basically built due to the movement of these ions into our cell. So we see that potassium, sodium, water, glucose and amino acids are all reabsorbed by our cell. Now, once they are reabsorbed by the cell, they move across the cell and they basically move across the bacillateral membrane this side of our cell, they move into our instertuum, and then they move into the peritubular capillaries, where they basically move into our bloodstream system. At the same time, the h and the bicarbonate ions move into our filtrate, and they are carried all the way across this region, into the proximal stray tubule, along the loop of Henley, then along our distal convoluted tubule, eventually along our collecting duct, which empties it out into our ureter, that travels into the urinary bladder, where it is stored. Eventually, it is secreted by our body.