But as the water continually flows out and out and out, eventually at the bottom of our descending loop of Henley, because so much water left our tubule, the inside of our tubule will become hypertonic with respect to the surrounding tissue. And this leads directly to the thin ascending loop of Henley. Now, before we go on to the thin ascending loop of Henley, let's mention the following things. So previously I said that the function of the loop of Henley is to ultimately allow the nephron to absorb more water. And it absorbs more water via passive diffusion without actually using any energy. So the thick ascending loop of Henley uses energy to establish an electrochemical gradient, so that the water inside the descending loop of penalty flows out of the tubule without actually using any ATP molecules.