The PNS interfaces the CNS to the Body. Seven cervical vertebrae are joined to 12 thoracic, 5 lumbar and 5 fused sacral vertebrae. Flexible joints between the vertebrae are filled by ligament attachments. Dura lines the spinal canal and adheres to the bone of vertebrae.

The PNS interfaces the CNS to the Body. Seven cervical vertebrae are joined to 12 thoracic, 5 lumbar and 5 fused sacral vertebrae. Flexible joints between the vertebrae are filled by ligament attachments. Dura lines the spinal canal and adheres to the bone of vertebrae.
The spinal cord extends through the vertebral canal from the cranium to the second lumbar vertebra. Openings for the spinal nerves are lateral within inter-vertebral foramen at each segment. Dorsal and ventral roots are found along the entire vertebral canal.
The cauda equina extends below the termination of the spinal cord that ends at L1 - L2.

The spinal cord extends through the vertebral canal from the cranium to the second lumbar vertebra. Openings for the spinal nerves are lateral within inter-vertebral foramen at each segment. Dorsal and ventral roots are found along the entire vertebral canal.