Spinal cord sheaths

The spinal cord is - like the brain - covered by the following coverings

Dura mater spinalis

Made up of dense collagenous connective tissue and shaped into a sac – sacus durae matris spinalis .
The sac begins around the foramen magnum and continues to the body of S2, where it converges into a conical end. From the end of the sac, the fibrous filum terminale externum continues to the coccyx .
The epidural space is the space between the dura mater and the endorheic sac (periosteum of the spinal canal). This space is filled with loose connective tissue and fat, and contains the internal vertebral plexus .
Only the protrusions of the dura mater accompanying the roots of the spinal nerves to the intervertebral foramina reach the endorhachis (Periostium of the spinal canal).
Spatium subdurale – physiologically just a gap, significant only in case of injury and subsequent bleeding (blood from the superficial veins of the brain or from the venous sinuses creates a hematoma between the dura mater and the arachnoid, this hematoma enlarges and "creates" the subdural space)

Made up of connective tissue made of collagen and reticular fibers.
Inside the dura mater, attached to its inner wall.
Subarachnoid space – between the arachnoid and pia mater, contains small fibrous trabeculae that connect the arachnoid and pia mater. There are fewer trabeculae here than in the cranial cavity. The subarachnoid space is filled with cerebrospinal fluid .
As a layer of flat cells, it envelops the spinal nerves and accompanies them all the way to the receptor bodies, where it passes into their sheaths.

Made of fine connective tissue.
Closely attached to the surface of the spinal cord. It also envelops the blood vessels that penetrate it and accompanies them into the CNS .
Thicker than the pia mater cranialis, it accompanies the roots of the spinal nerves into the intervertebral foramina (see dura mater).
Ligamenta denticulata – the suspension apparatus of the spinal cord, 20–23 fibrous processes connecting the spinal cord to the arachnoid and subsequently to the dura mater spinalis. They maintain the correct position of the spinal cord within the saccus durae matris during various movements of the spine.
Subarachnoid septum – a fibrous sagittal partition in the midline (incomplete in places), directed dorsally.

PETROVICKÝ, Pavel, et al. Anatomie s topografií a klinickými aplikacemi. 1. edition. Martin : Osveta, 2002. 542 pp. vol. 3. ISBN 80-8063-048-8.