What is the synovial membrane which protects lungs from friction against abdominal wall?

Options

A. Pleura
B. Mesentery
C. Alveolar septum
D. Tracheal bifurcation

Explanation

**Step-by-Step Solution:**

1. **Understanding the Structure of the Lungs**: The lungs are vital organs in the respiratory system, located in the thoracic cavity. They are responsible for gas exchange, where oxygen is absorbed and carbon dioxide is expelled.

2. **Identifying the Protective Membrane**: The lungs are surrounded by a protective double membrane known as the pleura. This membrane consists of two layers: the visceral pleura and the parietal pleura.

3. **Describing the Layers of the Pleura**:
- **Visceral Pleura**: This is the inner layer that directly covers the lungs.
- **Parietal Pleura**: This is the outer layer that lines the thoracic cavity.

4. **Function of the Pleura**: The primary function of the pleura is to protect the lungs from friction. The space between the two layers of the pleura contains pleural fluid.

5. **Role of Pleural Fluid**: The pleural fluid acts as a lubricant, reducing friction between the lungs and the thoracic cavity during the breathing process. This cushioning effect is crucial during the expansion and contraction of the lungs during inhalation and exhalation.

6. **Conclusion**: Therefore, the synovial membrane that protects the lungs from friction against the abdominal wall and other structures is referred to as the pleura. It serves as a double membrane that ensures the lungs can function smoothly without mechanical stress or friction.

**Final Answer**: The synovial membrane that protects the lungs from friction is called the pleura.

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