Question

If the diameter of the afferent renal arteriole is decreased and that of efferent renal arteriole is increased , the ultrafiltration will

• A. Be faster
• B. Be slower
• C. Not take place
• D. Take play with the same speed

Answer 1

Answer: (B)

Be slower

The diameter of the afferent (incoming) arteriole is greater than the diameter of the efferent arteriole (by which blood leaves the glomerulus). The pressure of the blood inside the glomerulus is increased due to the difference in diameter of the incoming and outgoing arterioles. This increased blood pressure helps to force the components of the blood out of the glomerular capillaries. If the diameter of efferent arteriole becomes greater than the afferent arteriole, the process of glomerular filtration is hampered and it becomes very slow. The filtration of all the components is also not possible without the actual pressure gradient.