And these tight junctions prevent the leaking or the movement of water from the lumen and into our interstituum. So no water is actually absorbed and no water actually flows into our thick ascending loop of Henley. The thick loop of Henley is impermeable to water. Now, by the way, because we essentially increase the concentration of our interstituum found in the mid dull of the kidney. What that means is we increase the hemotic pressure in the interstituum, and we'll see why that's important in just a moment. So let's move on to our descending loop of Henley, which is this section here.