Which task should a nurse ask a client to perform to assess the function of cranial nerve XI (accessory nerve)?

• A. Follow a moving object with the eyes
• B. Shrug the shoulders against resistance
• C. Stick out the tongue and move it side to side
• D. Smile and frown

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the function of cranial nerve XI (accessory nerve). This nerve is primarily responsible for motor functions, specifically controlling the sternocleidomastoid and trapezius muscles, which are involved in movements like shoulder shrugging and head rotation.
2. Step 2: Eliminate options that do not align with the motor function of cranial nerve XI. For example, following a moving object with the eyes involves cranial nerves III, IV, and VI, which control eye movements. Similarly, sticking out the tongue and moving it side to side involves cranial nerve XII (hypoglossal nerve), and smiling and frowning involve cranial nerve VII (facial nerve).
3. Step 3: Focus on the task that directly tests the muscles controlled by cranial nerve XI. Shrugging the shoulders against resistance is a direct assessment of the trapezius muscle, which is innervated by this nerve.
4. Step 4: Explain the procedure for testing cranial nerve XI. The nurse should ask the client to shrug their shoulders while applying resistance with their hands. This tests the strength and function of the trapezius muscle.
5. Step 5: Conclude that the correct task to assess cranial nerve XI is to ask the client to shrug their shoulders against resistance, as this directly evaluates the nerve's motor function.