Advanced Health Assessment Practice Exam

What is the primary function of cranial nerve XI (spinal accessory)?

1. Facial sensation

2. Muscles that turn the head and elevate shoulders

3. Control of the heart rate

4. Regulation of taste

The correct answer is: Muscles that turn the head and elevate shoulders

Cranial nerve XI, also known as the spinal accessory nerve, primarily functions in the innervation of certain muscles in the neck and shoulders. Specifically, it controls the sternocleidomastoid muscle and the trapezius muscle. The sternocleidomastoid is involved in rotating the head, while the trapezius helps in elevating the shoulders and allows for movements such as shrugging. The focus of cranial nerve XI on motor control for these specific muscle groups explains why its primary function centers on the muscles that turn the head and elevate the shoulders. Understanding this nerve's role is crucial in assessing neck movement and shoulder function during a health assessment.