Question

Effective filtration pressure in glomerulus is caused due to
A. Powerful pumping action of the heart
B. Secretion of adrenaline
C. Afferent arterioles is slightly larger than efferent arterioles
D. Vacuum develops in proximal convoluted tubules and sucks the blood

Answer 1

Hint:- Afferent arterioles are the set of blood vessels that carry blood to the kidneys. Different arterioles are the set of blood vessels that carry blood away from the kidneys. Effective filtration pressure is the net pressure that is responsible for the process of ultrafiltration. The powerful pumping action of the heart regulates the amount of blood reaching the kidneys.

Complete Answer:-
Ultrafiltration is the process by which blood is filtered into the glomerulus of the kidneys under high pressure. This high pressure is the hydrostatic pressure. The glomerulus is a network of capillaries. It is contained in the Bowman’s capsule. The pressure in the glomerulus is high enough to filter the blood into the bowman’s capsule.
This pressure difference is mainly created by the difference in diameter of the efferent and the afferent vessels. Different arterioles are larger than the efferent arterioles in diameter which allows lesser blood to pass through the afferents at a time than the afferent vessels.
Thus, the fluid part of the blood gets filtered into the bowman’s capsule leaving behind the cellular part along with the proteins in the vessel itself. This fluid passes into the PCT (proximal convoluted tubule). From the PCT, The fluid passes into the loop of Henle, then to the DCT and finally to the collecting ducts.
The pressure difference is also because proteins are not filtered, so the colloidal osmotic pressure in the bowman’s cavity increases.

Thus, the answer is (C).

Note:- Ultrafiltration is followed by selective absorption and tubular secretion. The glomerulus is present in the cortex of the kidneys. Glomerular filtration rate (GFR) depends on the effective filtration rate. If it increases, it increases the GFR.