Question

What is meant by counter-current?

(a) When blood flows in the opposite direction in two limbs of the Henle’s loop

(b) When the blood flows in the same direction in two limbs of the Henle’s loop

(c) When the blood does not flow through any of the limbs of Henle’s loop

(d) When some blood flows in Henle’s loop and the other blood flows in the vasa recta

The question was asked during a job interview.

This question is from Mechanism of Concentration of the Filtrate in section Excretory Products and Elimination of Biology – Class 11

Answer 1

Correct choice is (a) When blood flows in the opposite direction in two limbs of the Henle’s loop

To explain I would say: As the flow of filtrate in the two limbs of Henle’s loop is in opposite directions, therefore it forms a counter current. The flow of blood through the two limbs of the vasa recta is also in a counter-current pattern.