What are the three divisions of the trigeminal nerve?

What are the three divisions of the trigeminal nerve?

• A. Opthalmic (V1), Maxillary (V2) and Mandibular (V3)
• B. Facial (VII) and Vestibulocochlear (VIII)
• C. Glossopharyngeal (IX) and Vagus (X)
• D. Accessory (XI) and Hypoglossal (XII)

Answer: (A)

The key idea is that the trigeminal nerve splits into three distinct divisions that carry facial sensation (and, for one division, motor function). These divisions are the ophthalmic division, the maxillary division, and the mandibular division. The ophthalmic and maxillary divisions are purely sensory, supplying the forehead and scalp (and around the eye) and the midface (cheek, upper lip, upper teeth, palate), respectively. The mandibular division is mixed, providing sensory input to the lower face and jaw while also carrying motor fibers that control the muscles used for chewing. This is why the named trio—ophthalmic, maxillary, and mandibular—best fits the question. The other options mention different cranial nerves (facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal) that are not divisions of the trigeminal nerve.

The key idea is that the trigeminal nerve splits into three distinct divisions that carry facial sensation (and, for one division, motor function). These divisions are the ophthalmic division, the maxillary division, and the mandibular division. The ophthalmic and maxillary divisions are purely sensory, supplying the forehead and scalp (and around the eye) and the midface (cheek, upper lip, upper teeth, palate), respectively. The mandibular division is mixed, providing sensory input to the lower face and jaw while also carrying motor fibers that control the muscles used for chewing. This is why the named trio—ophthalmic, maxillary, and mandibular—best fits the question. The other options mention different cranial nerves (facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal) that are not divisions of the trigeminal nerve.