Spinal Meninges

Front 1

Describe the Spinal Dura Mater

Back 1

composed mainly of tough fibrous with some elastic tissue
the outermost covering membrane of the spinal cord

Front 2

Spinal Dura Mater Innervation

Back 2

Nerve fibers are distributed to the spinal dura by the (recurrent) meningeal nerves

The function of these afferent and sympathetic fibers is unclear, although it is known that the afferent fibers supply pain receptors that are involved in the referred pain characteristic of spinal disorders and become irritated when there is inflammation of the meninges (meningitis).

Front 3

Describe the Spinal Dural Sac

Back 3

a long tubular sheath within the vertebral canal formed by the dura mater

adheres to the margin of the foramen magnum of the cranium, where it is continuous with the cranial dura mater

anchored inferiorly to the coccyx by the filum terminale.

evaginated by each pair of posterior and anterior roots as they extend laterally toward their exit from the vertebral canal

Front 4

Describe Dural Root Sheaths

Back 4

tapering lateral extensions of the spinal dura that surround each pair of posterior and anterior nerve roots

Distal to the spinal ganglia they blend with the epineurium that adheres to the periosteum lining the IV foramina.

Front 5

Describe the Arachnoid Mater

Back 5

a delicate, avascular membrane composed of fibrous and elastic tissue that lines the spinal dural sac and its dural root sheaths.

encloses the CSF-filled subarachnoid space

not attached to the spinal dura but is held against its inner surface by the pressure of the CSF

Front 6

Describe the Pia Mater

Back 6

the innermost covering membrane of the spinal cord

thin and transparent, closely follows all the surface features of the spinal cord

directly covers the roots of the spinal nerves and the spinal blood vessels.

continues as the filum terminale inferior to the conus medullaris

Front 7

Describe Denticulate Ligaments

Back 7

left and right, run longitudinally along each side of the spinal cord

consist of a fibrous sheet of pia extending midway between the posterior and the anterior nerve roots from the lateral surfaces of the spinal cord

suspend the spinal cord in the dural sac

Front 8

Denticulate Ligament Attachments

Back 8

The 20–22 sawtooth-like processes attach to the inner surface of the arachnoid-lined dural sac.

The most superior process of the right and left denticulate ligaments attaches to the cranial dura immediately superior to the foramen magnum

the inferior process extends from the conus medullaris, passing between the T12 and the L1 nerve roots.

Front 9

Describe the Filium Terminale

Back 9

Arises from the tip of the conus medullaris, descends among the spinal nerve roots in the cauda equina

the vestigial remnant of the caudal part of the spinal cord that was in the tail-like caudal eminence of the embryo

an anchor for the inferior end of the spinal cord and spinal meninges

Front 10

Describe the Filium Terminale Internum

Back 10

proximal end (the pial part of the filum terminale)
consists of vestiges of neural tissue, connective tissue, and neuroglial tissue covered by pia mater

Front 11

Describe the Filium Terminale Externum

Back 11

perforates the inferior end of the dural sac, gaining a layer of dura and continuing through the sacral hiatus

dural part of the filum terminale, also known as the coccygeal ligament

attaches to the dorsum of the coccyx.

Front 12

Epidural Space Location

Back 12

Space between periosteum lining bony wall of vertebral canal and dura mater,

runs the length of the vertebral canal, terminating superiorly at the foramen magnum and laterally at the IV foramina, as the spinal dura adheres to the periosteum surrounding each opening, and inferiorly, as the sacral hiatus is sealed by the sacrococcygeal ligament

Front 13

Describe the Contents of the Epidural Space

Back 13

Fat (loose connective tissue); internal vertebral venous plexuses; inferior to L2 vertebra, ensheathed roots of spinal nerves

Front 14

Describe the Subdural Space

Back 14

No actual space occurs naturally at this site

a weak cell layer at the dura–arachnoid interface, the apposition of the dura mater and arachnoid mater

Front 15

Describe the Subarachnoid Space

Back 15

"leptomeingeal space"

located between the arachnoid and pia mater

Front 16

Subarachnoid Space Contents

Back 16

CSF; radicular, segmental, medullary, and spinal arteries; veins; arachnoid trabeculae

Front 17

Describe the Lumbar Cistern

Back 17

The enlargement of the subarachnoid space in the dural sac, caudal to the conus medullaris and containing CSF and the cauda equina

extends from the L2 vertebra to the second segment of the sacrum.

Dural root sheaths, enclosing spinal nerve roots in extensions of the subarachnoid space, protrude from its sides

Front 18

Describe the Longitudinal Arteries that Supply the Spinal Cord

Back 18

3 arteries; an anterior spinal artery and paired posterior spinal arteries.

run longitudinally from the medulla of the brainstem to the conus medullaris of the spinal cord

Front 19

Describe the Anterior Spinal Artery

Back 19

formed by the union of branches of the vertebral arteries, runs inferiorly in the anterior median fissure

Sulcal arteries arise from the anterior spinal artery and enter the spinal cord through this fissure

The sulcal arteries supply approximately two thirds of the cross-sectional area of the spinal cord

Front 20

Describe the Posterior Spinal Artery

Back 20

Each is a branch of either the vertebral artery or the posteroinferior cerebellar artery

The posterior spinal arteries commonly form anastomosing channels in the pia mater.

Front 21

Describe the Anterior and Posterior Segmental Medullary Arteries

Back 21

derived from spinal branches of the ascending cervical, deep cervical, vertebral, posterior intercostal, and lumbar arteries.

occur mainly in association with the cervical and lumbosacral enlargements, regions where the need for a good blood supply is greatest.

enter the vertebral canal through the IV foramina.

Front 22

Describe the Great Anterior Segmental Medullary Artery

Back 22

Artery of Adamkiewicz

on the left side in about 65% of people, reinforces the circulation to two thirds of the spinal cord, including the lumbosacral enlargement

much larger than the other segmental medullary arteries, usually arises via a spinal branch from an inferior intercostal or upper lumbar artery and enters the vertebral canal through the IV foramen at the lower thoracic or upper lumbar level.