And at the bottom of our loop, we have a hypertonic environment. Hypertonic with respect to our interstitium, we have a high concentration of sodium and chloride. And because our cells within our thin ascending lupinly allow the movement of sodium and chloride passively, these sodium and chloride ions will move down their electrochemical gradient from a hypertonic environment, from where we have a high concentration of solute, to a low where we have a lower concentration. So within a thin ascending lupa fennelly, the chloride and sodium ions will once again move passively without using any energy to the interstituent. Now, as we'll see in the next lecture, when we discuss our collecting duct, what the loop of Henley does is it increases the concentration of solute inside the surrounding tissue. And that allows water to be reabsorbed not only in the descending loop of Henley, but also in the collecting duct, the final tubial portion of our nephron.