Cranial Nerve XII functions include which of the following?

Cranial Nerve XII functions include which of the following?

• A. Tongue movement
• B. Neck movement
• C. Swallowing and parasympathetic supply
• D. Hearing and balance

Answer: (A)

Cranial nerve XII, the hypoglossal nerve, is a pure motor nerve that innervates both the intrinsic and extrinsic muscles of the tongue, enabling voluntary tongue movements essential for speech and manipulating food. It does not control neck muscles (that role belongs to cranial nerve XI), nor does it govern swallowing with parasympathetic supply (parasympathetic functions to glands come from other nerves such as VII, IX, and X, and swallowing involves more than just this nerve). It also isn’t involved in hearing or balance (which are handled by cranial nerve VIII). Therefore, the best description is tongue movement. If a lesion occurs, the tongue will tend to deviate toward the weakened side when protruded.

Cranial nerve XII, the hypoglossal nerve, is a pure motor nerve that innervates both the intrinsic and extrinsic muscles of the tongue, enabling voluntary tongue movements essential for speech and manipulating food. It does not control neck muscles (that role belongs to cranial nerve XI), nor does it govern swallowing with parasympathetic supply (parasympathetic functions to glands come from other nerves such as VII, IX, and X, and swallowing involves more than just this nerve). It also isn’t involved in hearing or balance (which are handled by cranial nerve VIII). Therefore, the best description is tongue movement. If a lesion occurs, the tongue will tend to deviate toward the weakened side when protruded.