The hypoglossal nerve is the twelfth cranial nerve XII, and innervates muscles of the tongue. The name hypoglossus springs from the fact that its passage is below the tongue, hypo meaning “under”, and glossus meaning “tongue”, both of which are from Ancient Greek. The nerve is involved in controlling tongue movements required for speech, food manipulation (i.e. formation of bolus), and swallowing.
The hypoglossal (with or without grafts) and masseter nerves are frequently used as axon donors for facial reinnervation when no proximal stump of the facial nerve is available.