Assertion: The kidneys have built in mechanisms for the regulation of lomerular filtration rate (GFR).
Reason: ANF mechanism is one such efficient mechanism.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. if both assertion and reason are true but reason is not the correct explanation of assertion.
C. if assertion is true but reason is false
D. if both assertion and reason are false.

Answer

C

Explanation

The kidneys have built-in mechanisms for the regulation of glomerular filtration rate. One such efficient mechanism, known as renin-angiotensis mechanism, is carried out by juxtaglomerular apparatus (JGA). A fall in GFR can activate the JB cells to release renin which can stimulate the glomerular blood flow the thereby the GFR back to normal. An increase in blood flow to the atria of the heart can cause the release of Atrial natriuretic factor (ANF). ANF can cause vasodilation (dilation of blood vessels) and thereby decrease the blood pressure ANF mechanism, therefore,acts as a check on the renin-angiotensin mechanism.