Facial motor nucleus corresponds to which cranial nerve?

Facial motor nucleus corresponds to which cranial nerve?

• A. V
• B. VII
• C. IX
• D. X

Answer: (B)

Think of brainstem motor nuclei as the origin points for each cranial nerve’s voluntary innervation. The facial motor nucleus is the dedicated source of motor fibers for the facial nerve, which controls the muscles of facial expression (and a few other small facial muscles). That means the nerve linked to this nucleus is the facial nerve, the seventh cranial nerve. This fits with how different motor nuclei map to different nerves: the trigeminal motor nucleus serves the muscles of mastication, the nucleus ambiguus provides motor fibers to the pharynx and larynx via IX and X, and the hypoglossal nucleus drives tongue muscles via XII. So the facial motor nucleus corresponds to the facial nerve.

Think of brainstem motor nuclei as the origin points for each cranial nerve’s voluntary innervation. The facial motor nucleus is the dedicated source of motor fibers for the facial nerve, which controls the muscles of facial expression (and a few other small facial muscles). That means the nerve linked to this nucleus is the facial nerve, the seventh cranial nerve. This fits with how different motor nuclei map to different nerves: the trigeminal motor nucleus serves the muscles of mastication, the nucleus ambiguus provides motor fibers to the pharynx and larynx via IX and X, and the hypoglossal nucleus drives tongue muscles via XII. So the facial motor nucleus corresponds to the facial nerve.