Which of the following is NOT performed by CN VII (facial nerve)?

• A. Facial Expression Muscle Movement
• B. Muscles of Mastication Movement
• C. Lacrimation
• D. Dampening of Sound

Answer: (B)

The key idea is that the facial nerve (CN VII) is the motor and parasympathetic nerve for many facial and glandular functions, but not for chewing. It innervates the muscles of facial expression, and it carries parasympathetic fibers that drive lacrimation and salivation, plus it helps dampen sound by innervating the stapedius muscle in the middle ear. It also carries taste information from the anterior two-thirds of the tongue via the chorda tympani.

Movement of the muscles used for chewing is not part of CN VII’s responsibilities; those muscles—masseter, temporalis, and the medial and lateral pterygoids—are supplied by the mandibular division of the trigeminal nerve (CN V3). That’s why the statement about chewing muscle movement is the one CN VII does not perform.