Biology / Unit 13 Bio 3239 short lesson, about 20 seconds
The Loop of Henle and the Countercurrent Multiplier
Captions available
The idea
The loop of Henle's descending and ascending limbs run fluid in opposite directions through a salt gradient, a countercurrent multiplier letting the kidney concentrate urine beyond blood's own concentration.
In practice
A longer loop, found in desert-adapted mammals, produces a steeper gradient and more concentrated urine.
Where people slip
The multiplier concentrates the surrounding salt gradient first — filtrate concentration changes as a result, not the reverse.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for Biology