Glossary

Nerve Root - The bony arch of the posterior aspect of a vertebra that surrounds the spinal cord, also referred to as the vertebral arch.

Neurosurgery - The surgical speciality involved in the treatment of disorders of the brain, spinal cord, and peripheral nerves.

Non-Union - Failure of the fragments of a fractured bone to heal or to obtain bony fusion following an arthrodesis.

Normal disc - A fully and normally developed disc with no changes attributable to trauma, disease, degeneration, or aging. The bilocular appearance of the adult nucleus is considered a sign of normal maturation.

Nucleus of origin - The central, nuclear portion of the disc of reference, usually used to reference the disc from which tissue has been displaced. Syn: parent nucleus, disc of origin.

Nucleus Pulposus - The semi-gelatinous tissue in the center of an intervertebral disc. It is surrounded and contained by the annulus fibrosus which prevents this material from protruding outside the disc space.