AN57.1-5 | Spinal Cord — Glossary

Widened segment of the spinal cord (C4-T1) containing motor neurons for the upper limb via the brachial plexus.

Widened segment of the spinal cord (L1-S3) containing motor neurons for the lower limb via lumbar and sacral plexuses.

The cone-shaped terminal end of the spinal cord, located at the L1-L2 vertebral level in adults.

Bundle of lumbar and sacral nerve roots descending below the conus medullaris, resembling a horse's tail.

Ventral portion of spinal grey matter containing lower motor neurons (alpha motor neurons) that innervate skeletal muscle.

Lateral projection of grey matter present only at T1-L2 (sympathetic) and S2-S4 (parasympathetic), containing preganglionic autonomic neurons.

Ten layers (I-X) of spinal cord grey matter classified by cell type and function, from posterior horn sensory regions to anterior horn motor regions.

Medial tract in the posterior column carrying fine touch, vibration, and proprioception from the lower body (T7 and below).

Lateral tract in the posterior column carrying fine touch, vibration, and proprioception from the upper body (above T7).

Major descending motor tract carrying crossed fibres from the motor cortex to lower motor neurons, controlling voluntary movement.

Ascending tract carrying pain and temperature (lateral) and crude touch (anterior) from the body to the thalamus.

Clinical syndrome from spinal cord hemisection causing ipsilateral motor and proprioception loss with contralateral pain and temperature loss.

Condition caused by a fluid-filled cavity (syrinx) in the central spinal cord, characteristically producing cape-like loss of pain and temperature sensation.

Nucleus dorsalis located at T1-L2/L3 in lamina VII, the origin of the posterior spinocerebellar tract carrying proprioceptive input to the cerebellum.

Slender thread of pia mater extending from the conus medullaris to the coccyx, anchoring the spinal cord inferiorly.

Neuron with cell body in the motor cortex whose axon descends through the corticospinal tract to synapse on lower motor neurons.

Neuron with cell body in the anterior horn whose axon exits via ventral roots to directly innervate skeletal muscle.

Deep longitudinal groove on the anterior surface of the spinal cord separating the two halves.