The pericardial fluid is present in the

Options

A. Double walled membranous bag
B. Double walled cartilaginous cavity
C. Double walled coelomic cavity
D. Single walled membranous bag

Answer

To solve the question regarding the presence of pericardial fluid, we will analyze the options step by step.

### Step-by-Step Solution:

1. **Understanding Pericardial Fluid**:
- Pericardial fluid is a clear, pale yellow fluid found in the pericardial cavity, which surrounds the heart. Its primary functions are to reduce friction between the heart and the pericardium during heartbeats and to provide cushioning.

2. **Analyzing the Options**:
- **Option 1: Double-walled membranous sac**:
- This is the correct answer. The pericardium consists of two layers: the outer fibrous pericardium and the inner serous pericardium, which has two layers (parietal and visceral). The pericardial fluid is located in the space between these two layers.

- **Option 2: Double wall cartilaginous cavity**:
- This option is incorrect. The pericardial cavity is not cartilaginous; it is a membranous sac.

- **Option 3: Double wall coelomic cavity**:
- This option is also incorrect. While the pericardial cavity is a coelomic cavity, it is specifically a membranous sac, not just a double wall coelomic cavity.

- **Option 4: Single wall membranous sac**:
- This option is incorrect. The pericardium has two layers, making it a double-walled structure.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option 1: Double-walled membranous sac**.

### Final Answer:
The pericardial fluid is present in the **double-walled membranous sac**.

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