Which cranial nerves are central to airway protection during the pharyngeal swallow and what are their roles?

• A. CN VII and XII
• B. CN IX and X
• C. CN VII and V
• D. CN VIII and XI

Answer: (B)

Airway protection during the pharyngeal swallow relies on a sensory trigger followed by rapid motor action to seal the airway. Sensation from the oropharynx and posterior tongue is carried by glossopharyngeal nerve fibers to the brainstem, helping initiate the swallow and its protective reflexes. The vagus nerve then provides the motor commands that close the airway: it innervates the intrinsic laryngeal muscles (via the recurrent laryngeal nerve) to adduct the vocal folds and tighten the laryngeal entrance, and it coordinates the pharyngeal constrictors to move the bolus safely away from the airway. In short, sensation through glossopharyngeal nerve triggers the protective swallow, while the vagus nerve executes the airway-closure actions that protect the airway during the swallow. Other nerves don’t play the central, direct role in this protective mechanism.