Heart of Heart is
Pace maker of the heart is

Options

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

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the "Heart of Heart" or the "Pacemaker of the Heart". This refers to the part of the heart that initiates the heartbeat and regulates the rhythm.

2. **Identifying the Options**: The options provided are:
- A) SA Node
- B) AV Node
- C) Bundle of His
- D) Purkinje Fibers

3. **Analyzing Each Option**:
- **A) SA Node**: The SA (Sinoatrial) Node is known as the pacemaker of the heart. It generates electrical impulses that initiate the heartbeat and cause the atria to contract.
- **B) AV Node**: The AV (Atrioventricular) Node receives impulses from the SA Node and transmits them to the ventricles. It does not initiate the heartbeat but plays a crucial role in the conduction pathway.
- **C) Bundle of His**: This structure transmits impulses from the AV Node to the Purkinje Fibers. It is part of the conduction system but does not generate impulses.
- **D) Purkinje Fibers**: These fibers distribute the electrical impulse throughout the ventricles, causing them to contract. They receive signals from the Bundle of His.

4. **Conclusion**: The SA Node is the correct answer as it is the primary pacemaker of the heart, responsible for initiating the heartbeat.

5. **Final Answer**: The pacemaker of the heart is the **SA Node**.