Question

The net filtration pressure in Bob’s kidneys was 11 mm Hg, but it changed because hydrostatic pressure in the glomerulus increased by 3 mm Hg, while the colloid osmotic pressure in the glomerulus decreased by 1 mm Hg. As a result of these alterations, Bob’s net filtration pressure ________ by _________. Choose the best answer:

(a) increased; 3 mm Hg

(b) increased; 4 mm Hg

(c) decreased; 4 mm Hg

(d) increased; 2 mm Hg

(e) decreased; 2 mm Hg

Answer 1

Net filtration pressure = Outward pressure -inward pressure

Outward pressure = Hydrostatic pressure

Inward pressure = Colloidal osmotic pressure

Initially NFR= Hydrostatic pressure -Colloidal osmotic pressure

Finally Hydrostatic pressure increase by 3mmHg and Colloidal osmotic pressure decrease by 1mmHg

Finally NFR = Hydrostatic pressure +3 - Colloidal Osmotic pressure -1

= 2+ Hydrostatic pressure -Colloidal osmotic pressure

= 2+ Initial NFR

Thus Final NFR is increased by 2mmHg.