Final answer:
The ascending limb of the nephron loop terminates at the distal convoluted tubule. It plays a key role in ion reabsorption and urine concentration. The ascending limb is water-impermeable but actively transports ions, affecting filtrate osmolarity.
Step-by-step explanation:
The ascending limb of the nephron loop returns to the renal cortex and terminates at the distal convoluted tubule (DCT). The DCT is the last part of the nephron and plays a crucial role in the regulation of ion and pH balance, as well as working with the collecting ducts to fine-tune water reabsorption. The ascending limb, specifically its thick portion, is impermeable to water due to the absence of aquaporin proteins but actively reabsorbs Na+ and Cl- ions, influencing the overall osmolarity of the filtrate that reaches the DCT.
The loop of Henle, composed of both descending and ascending limbs, functions to concentrate urine and reclaim water and ions from the filtrate. The actions of the ascending limb help to create a hypoosmotic filtrate and contribute to the hyperosmotic environment necessary for proper kidney function.