Which nerve controls tongue movement?

Which nerve controls tongue movement?

• A. Glossopharyngeal (CN IX)
• B. Vagus (CN X)
• C. Hypoglossal (CN XII)
• D. Facial (CN VII)

Answer: (C)

Movement of the tongue is driven by the hypoglossal nerve. It supplies motor innervation to all intrinsic tongue muscles and most of the extrinsic tongue muscles (genioglossus, hyoglossus, styloglossus), enabling actions like protrusion, retraction, and shaping the tongue for speech and swallowing. The nerve fibers originate in the hypoglossal nucleus in the medulla, exit the skull through the hypoglossal canal, and extend to the tongue. An important exception is the palatoglossus, which helps elevate the posterior tongue and is innervated by the vagus nerve. If the hypoglossal nerve is impaired on one side, the tongue weakens on that same side, causing it to deviate toward the side of the lesion when asked to protrude. The other nerves—glossopharyngeal, vagus, and facial—have roles in sensation, taste, or other muscles in the head and neck, but they do not primarily control tongue movement.

Movement of the tongue is driven by the hypoglossal nerve. It supplies motor innervation to all intrinsic tongue muscles and most of the extrinsic tongue muscles (genioglossus, hyoglossus, styloglossus), enabling actions like protrusion, retraction, and shaping the tongue for speech and swallowing. The nerve fibers originate in the hypoglossal nucleus in the medulla, exit the skull through the hypoglossal canal, and extend to the tongue. An important exception is the palatoglossus, which helps elevate the posterior tongue and is innervated by the vagus nerve.

If the hypoglossal nerve is impaired on one side, the tongue weakens on that same side, causing it to deviate toward the side of the lesion when asked to protrude. The other nerves—glossopharyngeal, vagus, and facial—have roles in sensation, taste, or other muscles in the head and neck, but they do not primarily control tongue movement.