Critical Care Registered Nurse (CCRN) Practice Exam

How can CN IX be assessed during a physical examination?

1. By checking the gag reflex

2. By observing the patient's ability to puff out their cheeks

3. By testing symmetry in shoulder shrugging

4. By assessing the patient's speech clarity

The correct answer is: By checking the gag reflex

The assessment of cranial nerve IX, also known as the glossopharyngeal nerve, is primarily conducted by checking the gag reflex. This nerve is responsible for various functions, including the sensory component of the gag reflex, which involves the oropharynx. When the back of the throat is stimulated, the glossopharyngeal nerve relays signals that trigger a gag response, indicating its proper function. In contrast, observing a patient's ability to puff out their cheeks assesses cranial nerve VII (the facial nerve), which controls the muscles of facial expression. Testing symmetry in shoulder shrugging is related to cranial nerve XI (the accessory nerve), while assessing speech clarity can involve multiple cranial nerves, including cranial nerves V (trigeminal), VII (facial), IX (glossopharyngeal), and X (vagus). Therefore, checking the gag reflex is the most direct and relevant method to specifically assess cranial nerve IX during a physical examination.