cervical spinal nerve 5 cervical spinal nerve 5 the cervical spinal nerve 5 (c5) is a spinal nerve of the cervical segment. cervical spinal nervethe plan of the cervical and brachial plexuses.the spinal cord with spinal nerves.detailsidentifierslatinnervi spinalisfma6446anatomical terminology it originates from the spinal column from above the cervical vertebra 5 (c5). it contributes to the phrenic nerve, long thoracic nerve, and dorsal scapular nerve before joining cervical spinal nerve 6 to form the upper trunk, a trunk of the brachial plexus, which then forms the lateral cord, and finally the musculocutaneous nerve. additional images cervical spinal nerve 5