Which statement best describes normal function of the facial nerve (CN VII)?

Which statement best describes normal function of the facial nerve (CN VII)?

• A. Smiling, frowning, wrinkling the forehead, and raising the eyebrows
• B. Hearing
• C. Swallowing
• D. Gag reflex

Answer: (A)

The facial nerve mainly supplies the muscles of facial expression. The movements listed—smiling, frowning, wrinkling the forehead, and raising the eyebrows—are exactly the facial muscles this nerve activates. While CN VII also carries other functions (such as taste from the anterior two-thirds of the tongue and parasympathetic signals to some glands), the core exam-level description is its role in facial movement. The other functions come from different nerves: hearing is CN VIII, swallowing involves CN IX and CN X (and sometimes CN XII for tongue movements), and the gag reflex uses CN IX and CN X. Therefore, describing facial expression movements best reflects CN VII’s normal function.

The facial nerve mainly supplies the muscles of facial expression. The movements listed—smiling, frowning, wrinkling the forehead, and raising the eyebrows—are exactly the facial muscles this nerve activates. While CN VII also carries other functions (such as taste from the anterior two-thirds of the tongue and parasympathetic signals to some glands), the core exam-level description is its role in facial movement. The other functions come from different nerves: hearing is CN VIII, swallowing involves CN IX and CN X (and sometimes CN XII for tongue movements), and the gag reflex uses CN IX and CN X. Therefore, describing facial expression movements best reflects CN VII’s normal function.