How does the countercurrent multiplication work? - Answers

Countercurrent multiplication is a mechanism in the nephron of the kidney that enhances the concentration of urine. It involves the interaction between the descending and ascending limbs of the loop of Henle. As water is reabsorbed from the descending limb, the fluid becomes more concentrated, while the ascending limb actively transports sodium and chloride ions out, creating a gradient that allows for further water reabsorption in the collecting ducts, ultimately resulting in highly concentrated urine. This process is crucial for maintaining the body's water and salt balance.