NEET Zoology Heart & Circulation Assertion Reason Question
Assertion (A): The sino-atrial node (SAN) is responsible for initiating the contraction of the atria.
Reason (R): The SAN generates an action potential that causes the atrial systole, increasing blood flow into the ventricles.
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is not the correct explanation of (A).
(A) is true but (R) is false.
(A) is false but (R) is true.
Correct Answer
Detailed Explanation
The sino-atrial node (SAN) initiates the rhythmic contractile activity of the heart, causing the atrial systole and enabling increased blood flow into the ventricles.
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