That means within the interstituum surrounding our descending loop of Henley, we have a high concentration of solute as compared to the inside. And because water always travels from a low solute concentration to a high solute concentration, water will passively move from the lumen from the inside of the descending loop of Penalty and to the outside. So at the top, our filtrate is isotonic with respect to our surrounding tissue. 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.