Question

Given below are assertion and reason. Point out if both are true with reason being correct explanation (A), both are true but reason is not correct explanation (B), assertion is true but reason is wrong (C), and both are wrong (D).
Assertion. SA node produces excitatory impulses in heart
Reason. SA node is self excitatory.

• A. A
• B. B
• C. C
• D. D.

Answer 1

The correct option is A A

A. A

EXPLANATION: SA node has unique property of self excitation. Self excitation enables SA node to act like the pacemaker of heart. It continuously initiates waves of contraction, which spreads over both the auricles. When excitation signals reach the atrioventricular node, the signal is delayed and then it is conducted into the bundle of His.