The spinal n. C3 is formed by the dorsal and ventral roots of C3. Although branches from the ventral primary rami of both C3 and C4 combine with the accessory n. to form the subtrapezial plexus, C3 and C4 provide only proprioception to the trapezius m. Damage to either spinal n. C3 or C4 would have no effect on raising the shoulder.

Try again.