Which of the following nerves is purely a motor nerve ?

Options

A. Vagus
B. Facial
C. Abducens
D. Trigeminal

Explanation

To determine which of the following nerves is purely a motor nerve, we need to analyze the cranial nerves and identify their functions. Here’s a step-by-step solution:

### Step 1: Understand the Types of Cranial Nerves
Cranial nerves can be classified into three categories:
- **Sensory nerves**: Carry sensory information to the brain.
- **Motor nerves**: Carry motor commands from the brain to muscles.
- **Mixed nerves**: Contain both sensory and motor fibers.

### Step 2: List the Cranial Nerves
There are 12 pairs of cranial nerves. The relevant ones for this question are:
1. Olfactory (I) - Sensory
2. Optic (II) - Sensory
3. Oculomotor (III) - Motor
4. Trochlear (IV) - Motor
5. Trigeminal (V) - Mixed
6. Abducens (VI) - Motor
7. Facial (VII) - Mixed
8. Vestibulocochlear (VIII) - Sensory
9. Glossopharyngeal (IX) - Mixed
10. Vagus (X) - Mixed
11. Accessory (XI) - Motor
12. Hypoglossal (XII) - Motor

### Step 3: Identify Purely Motor Nerves
From the list, the purely motor cranial nerves are:
- Oculomotor (III)
- Trochlear (IV)
- Abducens (VI)
- Accessory (XI)
- Hypoglossal (XII)

### Step 4: Analyze the Options
If the options provided include the Abducens nerve (VI), which is known to be purely motor, then that is the correct answer. Other nerves like the Vagus (X) and Facial (VII) are mixed nerves, meaning they have both motor and sensory functions.

### Conclusion
The correct answer to the question "Which of the following nerves is purely a motor nerve?" is the **Abducens nerve (VI)**.

---