What occurs if the hypoglossal nerve is injured?

Injuring the hypoglossal nerve primarily affects the muscles responsible for tongue movement. The hypoglossal nerve innervates most of the intrinsic and extrinsic muscles of the tongue, which are crucial for speech and swallowing.

When the hypoglossal nerve is damaged, the tongue can deviate towards the side of the injury when the individual sticks out their tongue. This occurs because the muscles on the affected side are weak or paralyzed, causing the stronger muscles on the opposite side to pull the tongue towards the injured side. Therefore, a deviation to the ipsilateral side—meaning towards the same side as the injury—correctly characterizes this condition.

Other choices relate to different functions and nerves. Loss of taste sensation in the anterior two-thirds of the tongue is primarily associated with the facial nerve, not the hypoglossal nerve. Difficulty chewing food would more likely involve branches of the trigeminal nerve, which control mastication. Deviation of the tongue to the contralateral side would suggest normal function on the injured side, which does not occur in hypoglossal nerve injury. Thus, the manifestation of the tongue deviating to the ipsilateral side accurately describes the result of hypoglossal nerve injury.