Outer pleural membrane is in close contant with

Options

A. Surface of lungs
B. Thoracic cavity
C. Both (1) and (2)
D. Alveoli

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the outer pleural membrane and what it is in close contact with. The options provided are the surface of the lungs, the thoracic cavity, the alveoli, or both 1 and 2.

2. **Identifying the Structure**: The pleural membrane is a double-layered membrane that surrounds the lungs. It consists of an outer pleura and an inner pleura.

3. **Outer Pleural Membrane**: The outer pleural membrane is the layer that is in contact with the thoracic cavity. It lines the chest wall and is attached to the structures of the thoracic cavity.

4. **Inner Pleural Membrane**: The inner pleural membrane is the layer that is in direct contact with the surface of the lungs. It adheres to the lung tissue itself.

5. **Pleural Fluid**: Between these two membranes (outer and inner pleura), there is pleural fluid which acts as a lubricant, reducing friction during breathing movements.

6. **Conclusion**: Since the outer pleural membrane is in close contact with the thoracic cavity, the correct answer to the question is option B: the thoracic cavity.

**Final Answer**: The outer pleural membrane is in close contact with the thoracic cavity (Option B).

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