Which of the following is not a component of pulmonary circulation?

Options

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

Answer

To determine which of the following is not a component of pulmonary circulation, we need to understand the components and functions of pulmonary circulation.

### Step 1: Understand Pulmonary Circulation
Pulmonary circulation refers to the pathway of blood flow between the heart and the lungs. Its primary function is to carry deoxygenated blood from the heart to the lungs for oxygenation and then return oxygenated blood back to the heart.

### Step 2: Identify Components of Pulmonary Circulation
The key components of pulmonary circulation include:
- **Pulmonary Artery**: Carries deoxygenated blood from the right ventricle of the heart to the lungs.
- **Pulmonary Vein**: Carries oxygenated blood from the lungs back to the left atrium of the heart.
- **Heart**: Specifically, the right side of the heart (right atrium and right ventricle) is involved in pumping deoxygenated blood to the lungs.

### Step 3: Analyze the Options
Now, let's analyze the options:
1. **Pulmonary Artery** - Part of pulmonary circulation.
2. **Pulmonary Vein** - Part of pulmonary circulation.
3. **Heart** - Essential for pulmonary circulation.
4. **Aorta** - This artery carries oxygenated blood from the left ventricle to the rest of the body, not to the lungs.

### Step 4: Conclusion
The component that is not part of pulmonary circulation is the **Aorta**.

### Final Answer
The correct answer is the **Aorta**.

---