Which of the following option represents the correct blood flow pathway in pulmonary circulation?

Options

A.
B.
C.
D.

Answer

To determine the correct blood flow pathway in pulmonary circulation, we can break down the process into several steps:

### Step-by-Step Solution:

1. **Understanding Pulmonary Circulation**:
- Pulmonary circulation is the pathway through which deoxygenated blood is transported from the heart to the lungs and back to the heart as oxygenated blood.

2. **Starting Point - Deoxygenated Blood**:
- Deoxygenated blood returns to the heart from the body tissues via the **superior and inferior vena cava**. This blood enters the **right atrium** of the heart.

3. **Right Atrium to Right Ventricle**:
- From the right atrium, blood flows through the **tricuspid valve** into the **right ventricle**.

4. **Right Ventricle to Lungs**:
- The right ventricle then contracts and pumps the deoxygenated blood through the **pulmonary valve** into the **pulmonary artery**.

5. **Gas Exchange in the Lungs**:
- The pulmonary artery carries the blood to the lungs, where it undergoes gas exchange. In the lungs, carbon dioxide is released and oxygen is absorbed, converting the blood into oxygenated blood.

6. **Oxygenated Blood Returns to the Heart**:
- The oxygenated blood returns to the heart through the **pulmonary veins**, entering the **left atrium**.

7. **Left Atrium to Left Ventricle**:
- From the left atrium, the blood flows through the **mitral valve** into the **left ventricle**.

8. **Final Pathway**:
- The left ventricle then pumps the oxygenated blood out to the body through the aorta.

### Conclusion:
The correct pathway for blood flow in pulmonary circulation is:
- **Right Atrium → Right Ventricle → Pulmonary Artery → Lungs → Pulmonary Vein → Left Atrium → Left Ventricle**.

Thus, the correct answer is **Option B**.