Which of the following blood vessels carries oxygen-poor blood from the heart to lungs?

Options

A. Pulmonary vein
B. Pulmonary artery
C. Carotid artery
D. Aorta

Explanation

To answer the question "Which of the following blood vessels carries oxygen-poor blood from the heart to the lungs?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Circulatory System**: The circulatory system is responsible for transporting blood throughout the body. It works closely with the respiratory system to facilitate gas exchange.

2. **Identify Types of Blood**: Blood can be classified as oxygen-rich (oxygenated) and oxygen-poor (deoxygenated). Oxygen-poor blood is the blood that has delivered its oxygen to the body tissues and is now carrying carbon dioxide back to the lungs.

3. **Locate the Heart Chambers**: The heart has four chambers: two atria (upper chambers) and two ventricles (lower chambers). The right side of the heart receives oxygen-poor blood, while the left side handles oxygen-rich blood.

4. **Identify the Blood Vessels**:
- The **vena cava** brings oxygen-poor blood from the body to the right atrium.
- The **pulmonary vein** carries oxygen-rich blood from the lungs to the left atrium.
- The **pulmonary artery** carries oxygen-poor blood from the right ventricle to the lungs for oxygenation.

5. **Determine the Correct Vessel**: Since the question asks for the vessel that carries oxygen-poor blood from the heart to the lungs, we focus on the right ventricle, which pumps deoxygenated blood into the pulmonary artery.

6. **Conclusion**: The blood vessel that carries oxygen-poor blood from the heart to the lungs is the **pulmonary artery**.

### Final Answer:
The correct answer is **pulmonary artery**.

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