And each one of these sections serves its own purpose, as we'll see in the next several lectures. We have the descending loop of Henley that is basically permeable to water. So water exits the descending loop of Henley. And we have the thin ascending loop of Henley and the thick ascending loop of Henley that becomes impermeable to water. And the entire function of the loop of Henley is to basically increase the concentration of solution in our renal medulla. And that basically Increases the Osmotic pressure inside our medulla.