Question

Of the 12 cranial nerves, which is a motor nerve to muscles in the shoulder and neck?

a) Trochlear
b) Vestibulocochlear
c) Accessory
d) Hypoglossal

Answer 1

The accessory nerve, also known as the spinal accessory nerve, is the motor nerve that controls muscles in the shoulder and neck.

Step-by-step explanation:

Of the 12 cranial nerves, the one that is a motor nerve to muscles in the shoulder and neck is the accessory nerve, also referred to as the spinal accessory nerve. This nerve innervates the sternocleidomastoid and trapezius muscles, enabling a range of movements of the head, neck, and shoulders. When both sternocleidomastoid muscles contract, they facilitate the forward flexion of the head, while individually, they allow for rotation to the opposite side. Alternatively, the trapezius muscle can extend and hyperextend the neck acting as an antagonist. Together, the muscles contribute to postural control and are necessary for movements such as shrugging the shoulders.