Brainstem and cervical vertebrae. False-colour nuclear magnetic resonance (NMR) sagittal image of the neck showing the brainstem (top centre), the cerebellum (top right), the initial part of the spinal cord (centre) and the cervical vertebrae. The brainstem is a stalk of nerve tissue which forms the lowest part of the brain and links it with the spinal cord. The wider and initial part of the brainstem, the pons, contains thick bundles of nerve fibres that connect with the cerebellum. The cervical part of the spine is formed by seven vertebrae, the topmost of which supports the skull.