Explain in an easy way and function

The "countercurrent multiplier" in the Loop of Henle -Start w/ Ascending limb of Lol: -pumps Na+ from filtrate into surrounding interstitial space, **water can't follow** thus filtrate entering DCT becomes relatively dilute (mostly water, ~100 mOsm) -Result: Interstitial space at base of loop gets saltier... - adjacent Vasa recta: water in blood plasma chases salt into interstitial space, vasa recta plasma becomes saltier... and it is headed back towards the descending limb. Establishing the concentration gradient Descending Ascending limb limb Glomerulus=> PCT -> 300 mOsm -100 mosm -> DCT -> collecting duct Interstitial Cortex fluid Tubular fluid Blood Medulla Descending limb Ascending limb loses water and the loses salts and the tubular fluid becomes interstitial fluid becomes more concentrated. more concentrated. Salts Salts Loop of Salts Salts Henle Water Vasa recta lose Vasa recta gain salts, gain water. Water salts, lose water. 1200 mOsm