nerv terms

Dermatome

A specific area of skin supplied by sensory nerve fibers from a single spinal nerve root.

Conus medullaris

The tapered, cone-shaped lower terminus of the spinal cord.

Filum terminale

A delicate fibrous strand and extension of the meninges that anchors the spinal cord to the coccyx.

Gray horns

Regions of the internal H-shaped spinal core that contain neuron cell bodies and unmyelinated fibers.

White columns

Myelinated nerve tract pathways that carry ascending and descending signals up and down the spinal cord.

Anterior median fissure

A deep, wide groove running along the front midline of the spinal cord.

Posterior median sulcus

A narrow, shallow groove located along the back midline of the spinal cord.

Gray commissure

A horizontal bridge of tissue connecting the right and left sides of the central gray matter.

Central canal

A narrow internal lumen running longitudinally through the spinal cord containing cerebrospinal fluid (CSF).

Ventral root

An efferent nerve root emerging from the spinal cord that carries motor signals out toward target organs.

Dorsal root

An afferent nerve root entering the spinal cord that carries incoming sensory signals from peripheral receptors.

Dorsal root ganglion

A distinct nodular swelling on the dorsal root containing the cell bodies of unipolar sensory neurons.

Mixed spinal nerve

A peripheral nerve formed by the merging of dorsal and ventral roots that conveys both sensory and motor impulses.