Which vertebrate organ receives only oxygenated blood

Options

A. Gill
B. Lung
C. Liver
D. Spleen

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks which vertebrate organ receives only oxygenated blood. This requires knowledge of the circulatory system in vertebrates and the specific functions of various organs.

2. **Identifying Organs and Their Blood Supply**:
- **Heart**: The heart pumps both oxygenated and deoxygenated blood, depending on which side is being referred to (right side for deoxygenated, left side for oxygenated).
- **Lungs**: The lungs receive deoxygenated blood from the right side of the heart through the pulmonary artery, where it gets oxygenated and then returns to the left side of the heart via pulmonary veins.
- **Gills**: In aquatic vertebrates like fish, gills receive deoxygenated blood for oxygenation.
- **Liver**: The liver receives deoxygenated blood from the digestive organs through the hepatic portal vein.

3. **Identifying the Correct Organ**:
- The spleen is the only organ that receives only oxygenated blood in vertebrates. It is supplied by the splenic artery, which branches from the celiac trunk, and it does not receive deoxygenated blood.

4. **Conclusion**: Based on the information gathered, the spleen is identified as the organ that exclusively receives oxygenated blood in vertebrates.

5. **Final Answer**: The vertebrate organ that receives only oxygenated blood is the **spleen**.

---