Psychiatric-Mental Health Nurse Practitioner Exam

Which cranial nerve is assessed with a gag reflex test?

1. Accessory

2. Hypoglossal

3. Glossopharyngeal

4. Oculomotor

The correct answer is: Glossopharyngeal

The glossopharyngeal nerve is primarily responsible for several functions including the sensation of the oropharynx and the gag reflex. When assessing the gag reflex, sensory input from the glossopharyngeal nerve (cranial nerve IX) is engaged. This nerve provides sensory innervation to the posterior one-third of the tongue and the oropharynx, both of which are critical in the gag reflex response. When a practitioner stimulates the back of the throat, the activation of the glossopharyngeal nerve creates a reflex that signals the need to manage potential threats to the airway. Therefore, the action and assessment of the gag reflex effectively demonstrate the integrity of the glossopharyngeal nerve. The accessory nerve, while important for neck and shoulder movement, does not have a role in the gag reflex. Similarly, the hypoglossal nerve primarily controls tongue movements and is not involved in the gag reflex. The oculomotor nerve is responsible for eye movement and does not relate to the function of the gag reflex. Thus, the glossopharyngeal nerve is the correct choice for assessing this reflex.