Question

The pacemaker of the heart is

• A. Bundle of His
• B. AV node
• C. Purkinje fibers
• D. SA Node

Hint:

SA Node = Starts Action. It’s the origin of the heartbeat.

Answer 1

The Correct Option is D

Step 1: Concept
The heart has a specialized conduction system that generates electrical impulses to coordinate heartbeats.

Step 2: Meaning
The "natural pacemaker" is the structure that initiates the electrical signal and sets the rhythm for the entire heart.

Step 3: Analysis
While the AV node, Bundle of His, and Purkinje fibers are parts of the conduction path, the Sinoatrial (SA) Node is where the impulse normally originates.

Step 4: Conclusion
Because it initiates the rhythmic contraction, the SA Node is recognized as the heart's pacemaker.

Final Answer: (D)