Ipsilateral deviation of tongue in 12th nerve palsy is due to -: (A) Unaltered action of ipsilateral genioglossus, (B) Unaltered action of contralateral genioglossus, (C) Action of hyoglossus, (D) Action of lateral pterygoid
Answer is B. Injury to hypoglossal (12th) nerve paralyzes ipsilateral half of the tongue. When the tongue is protruded, its tip deviates towards the paralyzed side because of unopposed action of genioglossus muscle on the normal side of the tongue.