The heart beat of which one of the following animal is myogenic in nature

Options

A. Cockroach
B. Echinus
C. Elephant
D. All of these

Answer

To determine which animal has a myogenic heartbeat, we need to understand what myogenic means and how it differs from neurogenic heartbeats.

### Step-by-step Solution:

1. **Understanding Myogenic Heartbeat**:
- Myogenic heartbeat refers to a type of heartbeat that originates from the heart muscle itself, specifically from specialized cardiac muscle cells. This means that the heart can contract independently of nerve impulses.
- The sinoatrial (SA) node, often referred to as the natural pacemaker of the heart, is responsible for initiating the heartbeat in myogenic hearts.

2. **Identifying Neurogenic Heartbeat**:
- In contrast, a neurogenic heartbeat is one that requires nerve impulses to initiate contractions. This type of heartbeat is common in some invertebrates.

3. **Analyzing the Options**:
- **Option 1: Cockroach**: The heartbeat of a cockroach is neurogenic, as it relies on nerve impulses for contraction. Therefore, this option is incorrect.
- **Option 2: Echinus (Sea Urchin)**: Echinoderms like sea urchins do not have a myogenic heartbeat. They have a different mechanism for their circulatory system, so this option is also incorrect.
- **Option 3: Elephant**: Elephants, being mammals, have a myogenic heartbeat. Their heartbeats are initiated by the SA node, making this option correct.
- **Option 4: All of these**: This option cannot be correct since we have already established that only the elephant has a myogenic heartbeat.

4. **Conclusion**:
- The correct answer is **Option 3: Elephant**, as it is the only animal listed that has a myogenic heartbeat.