Physical Therapy Assistant Practice Exam

A female patient's difficulty in shrugging shoulders and turning her head suggests which cranial nerve may be affected?

1. Cranial Nerve III

2. Cranial Nerve VII

3. Cranial Nerve XI

4. Cranial Nerve X

The correct answer is: Cranial Nerve XI

The indication that a female patient is having difficulty with shoulder shrugging and head turning points toward a specific cranial nerve involved in motor function for specific muscles in the neck and shoulders. Cranial Nerve XI, also known as the accessory nerve, is primarily responsible for innervating the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle allows for head rotation and flexion, while the trapezius muscle is essential for shrugging the shoulders and moving them. Therefore, impairment in these actions suggests that there might be an injury or dysfunction affecting the accessory nerve. The other cranial nerves listed do have specific functions, but they do not correlate with shoulder and head movement the way that the accessory nerve does. For example, Cranial Nerve III is involved in eye movement and pupil constriction, Cranial Nerve VII is responsible for facial expressions and taste sensations, and Cranial Nerve X primarily influences the autonomic control of the heart and digestive tract. Thus, the clinical signs presented by the patient are specifically aligned with the function of Cranial Nerve XI.