Which cranial nerve controls tongue movement?

• A. Vagus
• B. Glossopharyngeal
• C. Hypoglossal
• D. Accessory

Answer: (C)

Tongue movement is carried by a cranial nerve that provides motor input to all intrinsic tongue muscles and most extrinsic tongue muscles. That nerve is the hypoglossal nerve. It comes from the medulla and travels to the tongue to control actions like protrusion, retraction, and shaping the tongue for speech and swallowing. If this nerve is impaired, the tongue weakens on the affected side and will deviate toward that side when protruded.

The other nerves listed have different roles: the vagus influences muscles of the pharynx and larynx (swallowing and voice) and autonomic functions; the glossopharyngeal nerve contributes to sensation and taste in part of the tongue and to swallowing; the accessory nerve supplies neck muscles such as the sternocleidomastoid and trapezius. None of these primarily control tongue movement, so the hypoglossal nerve is the one that directly governs tongue motion.