Urology/Kidney/Tubules/WaterReabsorption/ControlToWaterIntake/basic

POINT!

With water intake, the (red→blue) negative feedback decreases the water reabsorption.

① Water intake decreases plasma osmolarity, and the water reabsorption 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 water reabsorption. The plasma osmolarity-decreasing effect of the water reabsorption becomes weaker, and plasma osmolarity returns to normal.

Challenge Quiz

1.

Water intake increases decreases  正解! plasma osmolarity, and the water reabsorption increases decreases  正解! plasma osmolarity. Since these effects are in the same opposite  正解! direction, negative feedback increases decrease  正解! the water reabsorption.