Question

In order to increase osmolarity and make a solution more concentrated, will the GFR increase or decrease.

Answer 1

GFR increases.

The rate of blood flow through the kidneys is the glomerular filtrate rate. This is one way of measuring kidney function.

As GFR increases there is less time for reabsorption of solutes like sodium in the PCT (proximal convoluted tubule ) resulting in higher osmolarity in the fluid.

When there is decrease in GFR , increased reabsorption of sodium occurs .

So if GFR increases urine will show increased osmolarity and if GFR decreases blood will show increased osmolarity.