C3 Cervical Spinal Nerve: Function, Location & Muscle Control

Cervical spinal nerve 3 (C3) arises from the spinal cord at the level of the third cervical vertebra. It exists between the 3rd and 4th cervical vertebrae and continues to the deep muscles located in the side and back of the neck.

Functions of C3 spinal nerve:

Motor Functions:

1. Innervation of neck muscles: C3 primarily controls and provides nerve supply to the deep neck muscles, which are responsible for various neck movements.

2. Shoulder movement: C3 also contributes to the innervation of the trapezius muscle, a large muscle that extends from the base of the skull to the middle of the back. The trapezius assists in shoulder elevation and retraction (pulling the shoulder blades closer together).

Sensory Functions:

Cutaneous innervation: C3 provides sensory innervation to a small area of the skin over the upper back of the neck. This area includes the lower part of the hairline and the surrounding region.

The C3 spinal nerve, along with other cervical nerves, plays a crucial role in enabling neck movements, shoulder function, and sensation in a small portion of the upper neck region.