Distal Tubule and Collecting Duct

by Jason Amores Sumpter
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the distal convoluted tubules connects the loop of Henley to the collecting duct, and it's going toe actively re absorb salutes and can also re absorb water. The collecting duct is the final tube UAL element, and it can re absorb water and Yuria. In fact, the region in the inner medulla of the collecting duct is permissible to Yuria, which helps to create that strong, osmotic Grady int inside the medulla. So just another way that, uh, the nef Ron uses, you know, simple concentration. Grady INTs in order. Thio, you know, maintain those osmotic and osmotic balances to help drive this whole process. Here you can see another legend of how the nef Ron is structured and what gets reabsorbed. Where, um, you know, I've basically tried to provide many different images that all kind of showed the same thing more or less so that, you know, hopefully one of them is one that you really like and is gonna be one that you want to refer back to you. It's the reason I'm providing all these different images, even though a lot of the information is redundant just to give you a Knop shin of a diagram Thio refer Thio. Now the fill trait that makes it through the collecting duct is ultimately going thio be excreted as urine. But before that happens, there's going to be some hormonal regulation. Uh, that's going to affect the distal, convoluted tube you'll and the collecting duct, and we're actually gonna talk about two hormonal systems here. The first is anti diuretic hormone, which sometimes called a th or vasopressin. Now I'm just gonna call it a T H. A. T H is a hormone secreted by the pituitary gland in response to high blood Osma clarity, meaning like high solute concentration in the blood. What it's going to do is cause the walls of the distal tube you'll and the collecting duct to become more permeable toe water. And it does this by adding aqua poor ins to the A pickle membrane. So here you can see a small model of that happening. I don't want you to worry about the details here. All I want you to notice is that we have a TH which is a hormone that's gonna move through the bloodstream, bind to receptor on a collecting ducts cell, and that's going to cause mawr aqua porn's, uh, to be integrated into the membrane to allow for mawr transport of water. And this is ultimately going to lead to a large increase in water re absorption right before it's lost his year. And right, this is sort of like the last place that we can really do. You re absorption and that water re absorption is going to lead to an increase in blood volume. But because we're on Lee re absorbing water, we're only increasing the re absorption of water and not increasing the re absorption of salutes. We're actually going to decrease our blood. Ah, similarities. That's why this is secreted in response to high blood, a similarity to lower the blood off similarity. And it also will help increase the blood volume. So this will also be mechanism involved in maintaining blood pressure, and you can see that it actually could get quite complicated. I don't want you to try to memorize this chart. Uh, really. I'm just putting here to illustrate how complex and interconnected the maintenance of the system the system is. So with that, let's flip the page and talk about our last hormonal system involved with kidneys