Urology/Kidney/Tubules/WaterChannels/ControlToWaterIntake/basic

POINT!

With water intake, the (red→blue) negative feedback decreases the number of water channels.

① Water intake decreases plasma osmolarity, and water reabsorption (through the water channels) decreases plasma osmolarity. These effects are in the same direction (red).

② Since these effects are in the same direction (red), negative feedback decreases (blue) the number of water channels and the water reabsorption. The plasma osmolarity-decreasing effect of the water reabsorption becomes weaker, and the plasma osmolarity returns to normal.

Challenge Quiz

1.

Water intake increases decreases  正解! plasma osmolarity, and water reabsorption (through the water channels) increases decreases  正解! plasma osmolarity. Since these effects are in the same opposite  正解! direction, negative feedback increases decreases  正解! the number of water channels.