Nerves of the Back and Spinal Region

Nerve: Accessory
Origin: Medulla and cervical spinal cord
Course: Spinal root ascends into cranial cavity via foramen magnum; exits via jugular foramen; traverses posterior triangle of neck
Innervation: Sternocleidomastoid and trapezius

Nerve: Dorsal scapular
Origin: Anterior ramus of C5 with contribution from C4
Course: Scalenus medius, descends deep to levator scapulae, enters deep surface of rhomboids
Innervation: Rhomboids and occasionally supplies levator scapulae

Nerve: Greater occipital
Origin: Medial branch of posterior ramus of spinal nerve C2
Course: Deep muscles of neck and trapezius to ascend posterior scalp to vertex
Innervation: Multifidus cervicis, semispinalis capitis; posterior scalp

Nerve: Suboccipital
Origin: Posterior ramus of C1 spinal nerve
Course: Between occipital bone and atlas, inferior to transverse part of vertebral artery, into suboccipital triangle; communicated with occipital nerve
Innervation: Suboccipital muscles