Where does the Loop of Henle primarily function in the nephron?

The Loop of Henle primarily functions between the cortex and medulla of the nephron. This structure extends into the medulla and then returns back to the cortex. It plays a crucial role in concentrating urine and regulating water and electrolyte balance in the body.

In the descending limb of the Loop of Henle, water is reabsorbed into the surrounding medullary interstitial fluid, which becomes increasingly concentrated. Conversely, the ascending limb is impermeable to water but actively transports sodium and chloride ions out into the interstitium, contributing to the osmotic gradient necessary for water reabsorption. This counter-current multiplication is key to maintaining the body's overall fluid balance and is fundamentally tied to the anatomical location of the Loop of Henle in the nephron. It uniquely positions itself to effectively carry out these functions, leveraging the differences in osmolarity between the cortex and medulla.