Family Nurse Practitioner Exam

Which cranial nerve is assessed when asking a patient to shrug their shoulders?

1. CN IX

2. CN X

3. CN XI

4. CN XII

The correct answer is: CN XI

The cranial nerve assessed when asking a patient to shrug their shoulders is cranial nerve XI, also known as the accessory nerve. This nerve is primarily responsible for innervating the sternocleidomastoid and trapezius muscles, both of which play crucial roles in head movement and shoulder elevation. When a patient shrugs their shoulders, they are engaging the trapezius muscles, which pull the shoulders upwards. A deficit in cranial nerve XI may result in weakness or inability to perform this action effectively, making this assessment important in clinical evaluations. The other cranial nerves listed have different functions; for instance, cranial nerve IX (glossopharyngeal) is involved in taste and swallowing, cranial nerve X (vagus) is associated with autonomic functions and heart rate regulation, and cranial nerve XII (hypoglossal) controls tongue movements. Therefore, while they may be vital for other assessments, they do not relate to the action of shrugging the shoulders.