Spinal Cord Anatomy Flashcards

Flashcards on Spinal Cord Anatomy

Spinal cord

The part of the central nervous system that lies in the vertebral canal.

Spinal cord morphology

Cylindrical structure flattened in the front and back, located in the upper two-thirds of the vertebral column.

Vertebral column

7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused to form the sacrum), 4 coccygeal (the lower 3 are commonly fused).

Vertebra

Formed of a body and a vertebral arch which includes two pedicles and two laminae (thin plates).

Intervertebral foramen

Formed by the superior notch of one vertebra and the inferior notch of an adjacent vertebra; transmits spinal nerves and blood vessels.

Anterior median fissure

Midline groove on the ventral side of the spinal cord.

Dorsally: posterior median sulcus.

Posterior median sulcus

Spinal cord length

Ranges from 42-45 cm in length and 2 cm in diameter.

Termination of spinal cord

In adults, it usually ends at the intervertebral disc between L1-L2.

Spinal meninges

Outer dura, inner pia, and in-between arachnoid layers.

Spinal dura (theca)

A tubular sheath extending downward through foramen magnum to the level of S2.

Spinal pia matter

Vascular layer that invests the surface of CNS.

Denticulate ligament

Fibrous structures that help to anchor the spinal cord in place.

Subarachnoid space

Between the pia and dura layers; accommodates about ½ of the CSF amount (75 ml).

H-shaped grey matter

Contains the nerve cells enclosed in the outer cylindrical mass of white matter.

Grey commissure

Contains the central spinal canal, which begins as a continuation of the 4th ventricle.

Horns and columns

Anterior, lateral, and posterior parts of grey and white matter.

Spinal nerve root

Anterior and posterior roots.

Dorsal root ganglion (DRG)

Collection of neurons on the posterior root.

Medial group of anterior gray matter

Innervates the skeletal muscles in the neck and trunk.

Central group of anterior gray matter

Situated in the cervical region of the spinal cord and innervates the diaphragm.

Lateral group of anterior gray matter

Situated in the cervical and lumbosacral region and innervates the skeletal muscles of the limbs.

Substantia gelatinosa

Receives sensory input for pain, touch, and temperature.

Nucleus proprius

Receives sensory stimuli from proprioception, 2-points discrimination and vibration.

Dorsal nucleus of Clark's

Concerned with proprioceptive endings in neuromuscular tendon spindles.

visceral afferent nucleus

receives visceral sensory information.

Morphology of spinal cord

The cells in the grey mater of the spinal cord are in specific functional areas or laminae, designated from I to X, the cells of II lamina which constitutes the gelatinous substance.

Lamina II

Involved in sensation of noxious and non-noxious stimuli, Sends information to Lamina III and IV

Lamina III

Involved in proprioception and sensation of light touch.

Lamina IV

Involved in non-noxious sensory information relay and processing. Cells connect with those in lamina II

posterior white column

This posterior column is occupied by the ascending fibers of gracile and cuneate, these are concerned with somatic sensation.

White mater

White color is due to the high proportion of myelinated nerve fibers