The correct pathway of initiation and passing route 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 solve the question regarding the correct pathway of initiation and conduction of impulses in the heart, we can break it down step by step.

### Step-by-Step Solution:

1. **Identify the Starting Point**: The conduction of electrical impulses in the heart begins at the **Sino-Atrial (S-A) node**. This node is often referred to as the natural pacemaker of the heart.

2. **Conduction to the Atrioventricular Node**: After the S-A node generates an impulse, it spreads through the atria, causing them to contract. The impulse then travels to the **Atrioventricular (A-V) node**. This node acts as a gatekeeper, slowing down the impulse before it moves to the ventricles.

3. **From A-V Node to A-V Bundle**: The impulse then moves from the A-V node to the **A-V bundle**, also known as the Bundle of His. This bundle is located at the junction of the atria and ventricles.

4. **Conduction through the Bundle Branches**: The A-V bundle splits into right and left bundle branches, which extend into the ventricles.

5. **Final Pathway to Purkinje Fibers**: The impulse travels through the bundle branches and reaches the **Purkinje fibers**. These fibers spread throughout the ventricular walls, causing the ventricles to contract and pump blood out of the heart.

6. **Summary of the Pathway**: Therefore, the correct pathway of initiation and conduction of impulses is:
- **S-A node → A-V node → A-V bundle → Purkinje fibers**.

### Final Answer:
The correct pathway of initiation and passing route of conduction of impulse is: **S-A node → A-V node → A-V bundle → Purkinje fibers**.

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