What Would Be True for the Accessory Nerve?

What functions does the accessory nerve carry out?

a. Autonomic

b. Sensory

c. Afferent

d. Somatic

Answer:

The correct answer is d. Somatic.

The accessory nerve is classified as a somatic motor nerve, being responsible for sending efferent (motor) impulses to muscles that control the head and neck movements such as in the sternocleidomastoid and trapezius muscles. It does not handle sensory or autonomic functions.

Explanation:

The accessory nerve is primarily a somatic motor nerve that is responsible for sending impulses leading to the movement of the sternocleidomastoid and trapezius muscles, which play a vital role in the movement of the head and neck. Being a motor nerve, it carries efferent signals from the central nervous system to muscles, therefore, the correct option for the accessory nerve is 'somatic'. The accessory nerve does not carry sensory impulses (which would be afferent signals) nor is it involved with the autonomic nervous system, which handles involuntary bodily functions. The accessory nerve facilitates important functions such as turning the head, flexion of the neck, and elevating the shoulders, which is apparent during actions such as shrugging.