And so what happens on the apical side of our cell? The apical side is the side that points towards the lumen of the thick loop of Henley. The inside of the tubule, we have these passive co transport proteins that allow the movement of the ions down their electrochemical gradient. So, because we established a sodium concentration gradient in which we have less sodium inside, the sodium will move down its electrochemical gradient from the outside to the inside of the cell. And at the same time, because this is a co transport protein membrane, it will allow the movement of other ions as well. So for every one sodium that is moved inside the cell down the electrochemical gradient, our single potassium will be moved and two chlorides will also be moved.