Spinal Cord Anatomy and Pia Mater Modifications

Vocabulary flashcards reviewing the extent, enlargements, terminations, meninges, and modifications of pia mater of the spinal cord.

Extent of spinal cord (Adult)

Extends from $C_1$ to the lower border of $L_1$.

Extent of spinal cord (Infant)

Extends from $C_1$ to the upper border of $L_3$.

Cervical enlargement

Spinal cord enlargement corresponding to spinal segments $C_4\text{ to }T_2$ .

Lumbar enlargement

L2 to S3

Conus medullaris

The cone-shaped terminal lower end of the spinal cord ending at $L_1$.

Filum terminale

A fine thread-like modification of pia mater extending from the tip of the conus medullaris down to the coccyx.

Filum terminale internum

The upper portion of the filum terminale composed solely of pia mater.

Filum terminale externum

The lower portion of the filum terminale formed by the merging of all $3$ meninges.

Subarachnoid space

The space between arachnoid and pia mater containing CSF, which ends at the lower border of $S_2$ and serves as the ideal site for lumbar puncture.

Lumbar puncture site

Procedure typically performed in the subarachnoid space between $L_3 - L_4$ or $L_4 - L_5$.

Linea splendens

A modification of pia mater that extends into the anterior median fissure.

Ligamentum denticulatum

Pia mater extension appearing as tooth-like structures on either side of the spinal cord, with $21$ projections on each side.