Which of the following openings is unpaired ?

Options

A. Foramen of Monro
B. Foramen of Magendie
C. Foramen of Luschka
D. None of these

Answer

To determine which of the following openings is unpaired, we need to analyze the options provided and their anatomical features. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Options**:
- Foramen of Monroe
- Foramen of Magendie
- Foramen of Lusca

2. **Analyze Foramen of Monroe**:
- The Foramen of Monroe is located between the lateral ventricles and the third ventricle of the brain.
- It is involved in the circulation of cerebrospinal fluid (CSF).
- **Pairing**: This foramen is present in two structures (lateral ventricle and third ventricle), hence it is paired.

3. **Analyze Foramen of Magendie**:
- The Foramen of Magendie connects the fourth ventricle to the cisterna magna.
- It is responsible for the drainage of cerebrospinal fluid from the fourth ventricle.
- **Pairing**: This foramen is found as a single structure, making it unpaired.

4. **Analyze Foramen of Lusca**:
- The Foramen of Lusca is located in the lateral recess of the fourth ventricle.
- It is involved in the drainage of cerebrospinal fluid and is also paired.
- **Pairing**: Since it exists in pairs, it is not unpaired.

5. **Conclusion**:
- After analyzing all the options, the Foramen of Magendie is the only opening that is unpaired.

### Final Answer:
The unpaired opening is the **Foramen of Magendie**.

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