The cardiac impulse is initiated and conducted further upto ventricle. The correct sequence of conduction of impulse is

Options

A. `"SA Node AV Node Purkinje fibre AV Bundle"`
B. `"SA Node Purkinje fibre AV Node AV Bundle"`
C. `"SA Node AV Node AV Bundle Purkinje fibre "`
D. `"SA Node Purkinje fibre AV Bundle AV Node"`

Answer

To determine the correct sequence of conduction of the cardiac impulse from initiation to the ventricles, we can break down the process into clear steps:

### Step-by-Step Solution:

1. **Initiation of Cardiac Impulse**:
- The cardiac impulse begins at the **Sinoatrial (SA) Node**. This node is often referred to as the natural pacemaker of the heart because it generates electrical impulses that initiate the heartbeat.

2. **Conduction to the Atria**:
- After the SA node generates an impulse, it spreads through the **atria** (the upper chambers of the heart), causing them to contract and push blood into the ventricles.

3. **Reaching the Atrioventricular (AV) Node**:
- The impulse then travels to the **Atrioventricular (AV) Node**. The AV node acts as a gatekeeper that slows down the impulse before it moves to the ventricles, allowing the atria to finish contracting.

4. **Conduction through the AV Bundle**:
- From the AV node, the impulse travels down the **AV Bundle** (also known as the Bundle of His). This bundle conducts the impulse from the atria to the ventricles.

5. **Distribution via Purkinje Fibers**:
- Finally, the impulse spreads through the **Purkinje Fibers**, which are specialized fibers that distribute the electrical signal throughout the ventricles, causing them to contract and pump blood out of the heart.

### Correct Sequence:
- The correct sequence of conduction of the cardiac impulse is:
1. **SA Node**
2. **AV Node**
3. **AV Bundle**
4. **Purkinje Fibers**