Which two cranial nerves are responsible for the gag reflex?

Which two cranial nerves are responsible for the gag reflex?

• A. Glossopharyngeal (CN-IX) and vagus (CN-X)
• B. Vagus (CN-X) and Accessory (CN-XI)
• C. Accessory (CN-XI) and Hypoglossal (CN-XII)
• D. Facial (CN-VII) and Glossopharyngeal (CN-IX)

Answer: (A)

The gag reflex relies on an afferent limb from the oropharynx via the glossopharyngeal nerve and an efferent limb via the vagus nerve. Sensory input from the posterior tongue and the oropharynx travels through the glossopharyngeal nerve to the brainstem, and the brainstem sends motor commands through the vagus nerve to the pharyngeal muscles to produce the gag response. Other nerves listed don’t participate in this reflex: their roles are in other regions or actions (for example, accessory moves neck muscles, hypoglossal controls the tongue, and facial handles facial muscles and other functions).

The gag reflex relies on an afferent limb from the oropharynx via the glossopharyngeal nerve and an efferent limb via the vagus nerve. Sensory input from the posterior tongue and the oropharynx travels through the glossopharyngeal nerve to the brainstem, and the brainstem sends motor commands through the vagus nerve to the pharyngeal muscles to produce the gag response. Other nerves listed don’t participate in this reflex: their roles are in other regions or actions (for example, accessory moves neck muscles, hypoglossal controls the tongue, and facial handles facial muscles and other functions).