Lateral oesophageal hearts in earthworm connect

Options

A. Supra-oesophageal and dorsal vessel to ventral vessel
B. Dorsal vessel to sub-oesophageal vessel
C. Lateral oesophageal vessel to subneural vessel
D. Dorsal vessel to subneural vessel

Answer

**Step-by-Step Solution:**

1. **Understanding the Circulatory System of Earthworm**: The circulatory system of an earthworm is classified as a closed type, which means that the blood circulates within vessels and does not leave the system.

2. **Identifying the Hearts**: In earthworms, the hearts are located in the 12th and 13th segments of the body. These specific hearts are referred to as lateral esophageal hearts.

3. **Identifying the Major Vessels**: The lateral esophageal hearts connect three major blood vessels:
- **Dorsal Vessel**: This is the longest vessel that runs along the top of the earthworm's body, situated above the elementary canal.
- **Ventral Vessel**: This vessel is located below the elementary canal and runs in an antero-posterior direction.
- **Supraesophageal Vessel**: This vessel is positioned in the median area, lying between the dorsal and ventral vessels, and is associated with the esophagus.

4. **Connection of the Vessels**: The lateral esophageal hearts serve as a connection point between these three vessels:
- They connect the **dorsal vessel** to the **ventral vessel**.
- They also connect the **supraesophageal vessel** to the **ventral vessel**.

5. **Final Answer**: Therefore, the lateral esophageal hearts in earthworms connect the dorsal vessel and the supraesophageal vessel to the ventral vessel.

---