Question

The pacemaker of heart is

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

Hint:

SA node is the natural pacemaker of the heart.

Answer 1

The Correct Option is B

Concept:
The heart has a conducting system that generates and spreads electrical impulses for rhythmic contraction.

Step 1: Meaning of pacemaker.
A pacemaker is a structure that initiates electrical impulses automatically.

Step 2: SA node.
The sinoatrial node, or SA node, is located in the right atrium. It generates impulses at the highest natural rate.

Step 3: Why SA node is pacemaker.
Since the SA node initiates the heartbeat and controls the rhythm, it is called the natural pacemaker of the heart.

Step 4: Checking other options.
AV node delays and passes impulses to ventricles.
Bundle of His and Purkinje fibres conduct impulses.
SA node initiates impulses. \[ \boxed{\text{SA node}} \]