The spinal accessory nerve is primarily involved in which type of movement?

The spinal accessory nerve is primarily involved in which type of movement?

• A. Tongue movement
• B. Shoulder and head movement
• C. Eye movement
• D. Swallowing

Answer: (B)

The spinal accessory nerve, also known as cranial nerve XI, plays a crucial role in the control of certain voluntary muscle movements, particularly those of the shoulder and neck. This nerve innervates the sternocleidomastoid and trapezius muscles, which are essential for movement of the head and shoulders. The sternocleidomastoid allows for the rotation and flexion of the head, while the trapezius facilitates shoulder elevation and movement, such as shrugging the shoulders. The other options provided do not correspond to the primary function of the spinal accessory nerve. Tongue movement is primarily controlled by the hypoglossal nerve; eye movement is managed by several cranial nerves including the oculomotor, trochlear, and abducens nerves; and swallowing involves components of the vagus and glossopharyngeal nerves. Thus, the role of the spinal accessory nerve is specifically aligned with shoulder and head movement.

The spinal accessory nerve, also known as cranial nerve XI, plays a crucial role in the control of certain voluntary muscle movements, particularly those of the shoulder and neck. This nerve innervates the sternocleidomastoid and trapezius muscles, which are essential for movement of the head and shoulders. The sternocleidomastoid allows for the rotation and flexion of the head, while the trapezius facilitates shoulder elevation and movement, such as shrugging the shoulders.

The other options provided do not correspond to the primary function of the spinal accessory nerve. Tongue movement is primarily controlled by the hypoglossal nerve; eye movement is managed by several cranial nerves including the oculomotor, trochlear, and abducens nerves; and swallowing involves components of the vagus and glossopharyngeal nerves. Thus, the role of the spinal accessory nerve is specifically aligned with shoulder and head movement.