Question

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The conduction in the Atrio-ventricular (AV) node is slow i.e. 0.05 m/sec, there is a delay of approx. 0.1 second before excitation spreads to the ventricles.
Reason (R) : AV node delay enables the atria to empty the blood present within them into the ventricles before these contract.
In the light of the above statements, choose the most appropriate answer from the options given below :

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• B. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• C. (A) is correct but (R) is not correct
• D. (A) is not correct but (R) is correct

Hint:

Think of the AV node as an electrical "speed bump" or "traffic light" in the heart. It deliberately pauses the electrical signal (delay) so the atria can finish their job of topping off the ventricles with blood before the main pumping action begins.

Answer 1

The Correct Option is A