Dysphagia can result from damage to which cranial nerves?

• A. II and III
• B. IX and X
• C. V and VII
• D. XI and XII

Answer: (B)

Swallowing is controlled mainly by the glossopharyngeal and vagus nerves. The glossopharyngeal nerve provides sensory input from the oropharynx and the posterior third of the tongue, helping to trigger the swallow reflex. The vagus nerve supplies motor commands to the pharyngeal constrictors, soft palate, and laryngeal muscles, driving bolus propulsion and protecting the airway during swallowing. Damage to either disrupts the coordinated swallow, producing dysphagia. Other nerves listed aren’t the primary drivers of swallowing: the optic and oculomotor nerves govern vision and eye movements; the trigeminal and facial nerves mainly handle facial sensation, mastication, and facial expression; the spinal accessory nerve isn’t a key swallowing contributor; and while the hypoglossal nerve (tongue movement) can affect swallowing, the most characteristic impairment from cranial nerve damage is due to IX and X.