 Welcome back to our MedSmarter question of the week where we're taking a smarter approach to preparing future physicians. Before we get started, if you'll take just a quick minute and click that like button and also subscribe and turn the bell on so that you'll be notified when we post new videos. Let's get right to that question. As always, we start with the last sentence of the vignette and then work our way back. Which of the following is the site of pathology in this patient? A 30 year old man develops polyurea. His nephrologist monitors him closely on a water deprivation test and he continues to have increased urine output. A diagnosis of diabetes and sypetis is made. The nephrologist orders an anti-diuretic hormone level and determines that it is inappropriately elevated, which of the following is the site of the pathology in this patient. So this is a pretty straightforward question. They give you all the information you need to know and they want to know what patient has diabetes and sypetis with an elevated ADH level. Where are they having a pathology occur? So take a second, look at these answer choices, come up with your answer and write it in the comment box below. So let's look at this real quick. Anti-diuretic hormone level is elevated. So a patient is peeing a lot of urine and we have anti-diuretic hormone in the body that's elevated but they continue to pee. What does that tell you? That tells me that the anti-diuretic hormone is not working on its target. The target of anti-diuretic hormone is the kidney. So we have a problem somewhere in the kidney. So that's going to be able to come in and mark out some of these answer choices. So obviously the pituitary function is up in the brain, that's not going to be anything here. Same with the adenohypothesis and then also D1 receptors, those are all in the central nervous system as well. So now we're down to the V1 and V2 receptors. V1, vasopressin 1 receptors are mostly going to be affecting the smooth muscle issues. So not so much in the ADH role alongside of diabetes and sypetus. So that's not going to be my choice. That leaves me with V2 is my only answer. So E, V2 is my final answer. And E is the correct answer. As we said, this is nephrogenic diabetes and sypetus. Because of this elevated anti-diuretic hormone level. If that was lower, then we'd be talking more central diabetes and sypetus and our answer choice would change. But because it's nephrogenic diabetes and sypetus, this is a problem with anti-diuretic hormone receptors in the actual kidneys themselves, not in the brain or in the central nervous system. So the only receptor in the kidney that has to do with diabetes and sypetus with an elevated anti-diuretic hormone level has to be E, the V2 receptors. If you found this material helpful for your studying, please like and consider subscribing to the channel. Also, share this video so that more people can benefit from it like you have.