Question

Determine whether the statements regarding countercurrent multiplication are true or false. 1. Approximately 20% of water is reabsorbed in the descending limb due to countercurrent multiplication. (Click to select) 2. The countercurrent multiplier system is an example of a negative feedback mechanism. (Click to select) 3. The reabsorption of water in the descending limb creates a lower NaCl concentration entering the ascending limb. (Click to select) 4. The more water that is drawn out in the descending limb, the more hypertonic the inner medulla will become. (Click to select)

Answer 1

1.True.

Descending limb of loop of Henle is permeable to water and impermeable to solutes. Because it contains aquaporin which allow only water reabsorption.

So that the statement is true.

2. False.

Countercurrent multiplier system is an example for positive feedback mechanism. Just it keeps the mechanism active until reaching the equilibrium

3.False

Water reabsorption in the descending limb makes the filtrate or urine more concentrated. Because descending limb is impermeable to solutes. So that fluid that enters ascending limb is with Nacl concentration

4. True.

More water is absorbed in descending limb makes urine concentrated which means hypertonic.