Which cranial nerve provides sensation to the face and the anterior two-thirds of the tongue and also innervates the muscles of mastication?

• A. Trigeminal (CN V)
• B. Facial (CN VII)
• C. Glossopharyngeal (CN IX)
• D. Hypoglossal (CN XII)

Answer: (A)

The trigeminal nerve is responsible for the described mix of functions. It provides sensory input to the face and, through its mandibular division, carries sensation from the anterior two-thirds of the tongue via the lingual nerve. At the same time, this division also supplies motor innervation to the muscles of mastication (such as the masseter, temporalis, and pterygoids).

The other nerves don’t fit all parts: the facial nerve mainly handles facial expression and taste from the anterior tongue but not facial sensation or mastication; the glossopharyngeal nerve covers sensation and taste for the posterior tongue and some throat structures but not the face or muscles of mastication; the hypoglossal nerve controls tongue muscles only, with no facial sensation or chewing muscles involved.