Deep cervical artery
The deep cervical artery (latin: arteria cervicalis profunda) is a branch of the costocervical trunk that supplies the deep muscles and spinal cord in the neck region.
The deep cervical artery passes posteriorly above the eight cervical spinal nerve between the transverse process of the seventh cervical vertebra and then ascends to the deep muscles of the neck and back.
In the neck the deep cervical artery gives off several spinal branches that supply the spinal cord, and muscular branches to supply the deep muscles in the neck and upper back.
To sum up, the deep cervical artery supplies the deep muscles of the neck and back, as well as the cervical spinal cord.