which cranial nerves are purely sensory ?

Options

A. I, II and VIII
B. I, II and IV
C. I, V and VII
D. None of these

Answer

To determine which cranial nerves are purely sensory, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Cranial Nerves**:
- Cranial nerves are a set of twelve nerves that emerge directly from the brain, primarily responsible for relaying information between the brain and various parts of the body.

2. **Classify Cranial Nerves**:
- Cranial nerves can be categorized into three types:
- **Sensory Nerves**: Relay information from sensory organs to the brain.
- **Motor Nerves**: Control muscle movements.
- **Mixed Nerves**: Have both sensory and motor functions.

3. **Identify the Total Number of Cranial Nerves**:
- There are a total of 12 cranial nerves.

4. **Count the Types of Cranial Nerves**:
- Out of these 12 cranial nerves:
- 3 are purely sensory.
- 5 are purely motor.
- 4 are mixed.

5. **List the Purely Sensory Cranial Nerves**:
- The purely sensory cranial nerves are:
- **1st Cranial Nerve**: Olfactory (smell)
- **2nd Cranial Nerve**: Optic (vision)
- **8th Cranial Nerve**: Vestibulocochlear (hearing and balance)

6. **Evaluate the Options**:
- The question provides options to choose from. We need to identify which option correctly lists the purely sensory cranial nerves.
- The correct option is **1, 2 & 8**.

7. **Conclusion**:
- The answer to the question "Which cranial nerves are purely sensory?" is **the 1st (Olfactory), 2nd (Optic), and 8th (Vestibulocochlear) cranial nerves**.

### Final Answer:
The cranial nerves that are purely sensory are the **1st, 2nd, and 8th cranial nerves**.

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