As a result of long-term starvation the glomerular filtration of a man was accelerated by 20%. The most probable cause of filtration changes under such conditions is:

Answer options

1. Rise of systemic arterial pressure
2. Fall of oncotic pressure of blood plasma
3. Increase of renal plasma flow
4. Growth of filtration coefficient
5. Increased permeability of renal filter

Explanation

Glomerular filtration is the renal process whereby fluid in the blood is filtered across the capillaries of the glomerulus. Glomerular filtration occurs due to the pressure gradient in the glomerulus. Increased blood volume and increased blood pressure (increased hydrostatic pressure) will increase GFR. A decrease in oncotic pressure increases the filtration rate. The oncotic pressure is normally determined by protein synthesis and since there is starvation, protein synthesis (Albumin) is reduced.