How does the loop of henle differ in animals living in dry conditions to animals in wet conditions?
The Loop of Henle is part of the nephron as you know. However, there are two types of nephrons, and all animals have a combination of both. One is the juxtamedullary nephron, where the glomerulus is around the corticomedullary junction and the loop of Henle descends deep into the medulla of the kidney. This allows more water to be reabsorbed from the urine, which is advantageous in dry conditions. One would expect a lot more of these types of nephrons in animals in dry conditions where water is scarce. The other type of nephron is the cortical nephrons. These sit high up in the cortical region, and the result is that the loop of Henle barely enters the medulla where water is reabsorbed. Hence, only a little of water is reabsorbed resulting in copious amounts of dilute urine. This would be more prominent in animals used to living in wet conditions where there is more water to be found. So basically the different types of nephrons affect how MUCH water is reabsorbed without affecting the
