Primary motor innervation to the larynx and velum is provided by which cranial nerve?

• A. X
• B. V
• C. VII
• D. IX

Answer: (A)

Motor control for both the larynx and the soft palate comes from the vagus nerve. In the larynx, the intrinsic muscles are mainly supplied by the recurrent laryngeal nerve, a branch of the vagus, with the cricothyroid muscle coming from the external branch of the superior laryngeal nerve (also a vagal branch). For the velum, most elevating and other soft-palate muscles receive innervation via the pharyngeal branch of the vagus (the pharyngeal plexus). The tensor veli palatini, which tenses the palate, is primarily innervated by the mandibular division of the trigeminal nerve, not the vagus, but the laryngeal and the majority of velum motor control still rely on the vagus. So the nerve providing the main motor innervation to both structures is the vagus nerve.