Glossary of medical terminology

annulus fibrosis: tough, fibrous rings surrounding nucleus pulposus of discs

anteroposterior: from front to back

arachnoid: middle layer of the membranes which cover the brain and spinal cord

arachnoiditis: pain disorder caused by the inflammation of the arachnoid

atlas: first cervical vertebra unique for having no body, allows head to move forward and backward

axis: second cervical vertebra forming a pivotal joint with the atlas, allows side to side movements of head

cauda equina: collection of nerves which branch from the lumbar and sacral levels of the spinal cord and must run a distance in the vertebral column before they can exit

caudal: towards the tail; when referring to the spine, down

central canal: very center of the spinal cord, so named because it starts as a hollow tube which closes in most people as they age

cerebellar tonsils: portion of the cerebellum located at the bottom, so named because of their shape

cerebellum: part of the brain located at the bottom of the skull, near the opening to the spinal area; important for muscle control, movement, and balance

cerebral spinal fluid (CSF): clear liquid in the brain and spinal cord, acts as a shock absorber

cervical: relating to the upper part of the spine, neck area

Chiari malformation (CM): condition where the cerebellar tonsils are displaced out of the skull area into the spinal area, causing compression of brain tissue and disruption of CSF flow

choroid plexus: lines the walls of the lateral ventricles of the brain and roof of the third and fourth ventricles, produces CSF

cine MRI: a type of MRI which can measure the flow of moving fluid in the body.

coccygeal: lowest region of spine containing 4 fused vertebrae to form the coccyx or tailbone

decompression surgery: common term for any of several variations of a surgical procedure to alleviate a Chiari malformation

discs: parts of the spine which separate and cushion vertebral bodies

dorsal nerve root: one of two nerve fiber bundles of a spinal nerve that carries sensory information to the central nervous system

dorsiflex: to bend a body part backward.

dura: thick, outer covering of the brain and spinal cord

duraplasty: surgical procedure where a patch - or graft - is sewn into the dura

ectopia: abnormal position; refers to the cerebellar tonsils being displaced

epidural cavity: the space between the walls of the vertebral canal and the dura

fasciculi (or tracts): related bundles of nerve fibers in the spinal cord which transmit motor and sensory signals to and from the brain

foramen magnum: large opening at the base of the skull, through which the spinal cord passes and joins with the brain

glia: connective tissue of the brain and spine; cells which provide structure and serve other functions

gliosis: abnormal thickening and hardening of the glia

intracranial hypertension: condition where a person's intracranial pressure is chronically, abnormally high

intracranial pressure: the pressure of the CSF inside the skull

laminae: two broad plates which form the back part of the vertebral arch

laminectomy: surgical removal of part (the bony arch) of one or more vertebrae

lumbar: lower part of the spine

meninges: the three membranes that cover the brain and spinal cord

meningitis: inflammation of the lining around the brain and spinal cord.

myelopathy: spinal cord injury.

MRI: Magnetic Resonance Imaging; diagnostic device which uses a strong magnetic field to create images of the body's internal parts nucleus pulposus: gel-like substance found in the central core of each disc of a healthy spine

parenchyma: Animal tissue that constitutes the essential part of an organ, as contrasted with, for example, connective tissue and blood vessels..

pedicles: two short, thick parts of vertebral arch which joins with the vertebral body

phase contrast MR: a type of MR that is capable of obtaining fluid velocity

pia mater: membrane which adheres to the surface of the spinal cord

plasma: the liquid part of blood in which blood cells float

pronate: to turn or rotate (the hand or forearm) so that the palm faces down or back.

pseudotumor cerebri (PTC): another name for intracranial hypertension

rostral: towards the mouth; when referring to the spine, up

sacral: region of spine containing five vertebrae united to form the sacrum

scoliosis: abnormal curvature of the spine.

spinal nerves: 31 pairs of nerves which branch off from the spinal cord and exit through openings between vertebrae

spinous process: part of the vertebral arch which juts out and serves for the attachment of ligaments and muscles

subarachnoid space (SAS): the space between the arachnoid and the pia mater containing cerebrospinal fluid

suboccipital craniectomy: surgical removal of part of the skull, or cranium, in the back of the head, near the base

superior facets: two large oval, cup-like areas of the atlas which articulate with the occipital bone of the skull

supinate: to turn or rotate (the hand or forearm) so that the palm faces up or forward.

syringomyelia (SM): neurological condition where a fluid filled cyst forms in the spinal cord

syrinx: fluid filled cyst in the spinal cord

thoracic: middle part of the spine, the chest area

transverse processes: two projections one at either side of the vertebral arch which serve for attachment of ligaments and muscles

valsalva maneuver: straining

ventral nerve root: the other nerve fiber bundle of a spinal nerve, consisting of motor fibers, that branches off from the spinal cord

vertebrae: 33 bones which form the flexible spinal column

vertebral arch: part of vertebra which joins with body of a vertebra to enclose spinal cord

vertebral body: largest part of a vertebra, when joined in a column the bodies form strong support

vertebral foramen: opening in spinal column through which spinal cord passes

• a number of glossary terms are courtesy of Rick Labuda and the Chiari-syrigo-news web site,

www.chiari-syringo-news.org/.