Which cranial nerve is primarily responsible for elevating the soft palate and mediating the motor aspect of swallowing?

• A. Glossopharyngeal
• B. Vagus
• C. Hypoglossal
• D. Accessory

Answer: (B)

Elevating the soft palate and driving the motor aspect of swallowing are actions mainly carried out by the vagus nerve. The levator veli palatini, which raises the soft palate during swallowing and speech, is innervated by the pharyngeal branch of the vagus via the pharyngeal plexus. This same nerve also provides much of the motor control of the pharynx and larynx involved in swallowing. In contrast, the glossopharyngeal nerve mainly supplies the stylopharyngeus muscle and sensory innervation to the oropharynx; the hypoglossal nerve controls tongue muscles; and the accessory nerve controls neck muscles. Tensor veli palatini, which tenses the palate, is innervated by the mandibular division of the trigeminal nerve, not the vagus. So the nerve most responsible for elevating the soft palate and the motor aspect of swallowing is the vagus.