Spinal Meninges and Spinal Cord

Question 1

three spinal meninges?

Answer 1

dura, arachnoid, and pia mater

Question 2

function of the spinal meninges

Answer 2

surround, support, and protect spinal cord

also, contain the CSF

Question 3

dura mater

Answer 3

outermost and strongest layer

Question 4

location of dura mater?

Answer 4

continuous with dura of cranium

fused with occipital periosteum

Question 5

how far does dura extend inferiorly?

Answer 5

SV2

Question 6

how far does dura extend laterally?

Answer 6

along spinal nerves to fuse with neural sheath distal to dorsal root ganglia and with margins of intervertebral foramina

Question 7

attachment of dura mater?

Answer 7

posterior spinal ligament
-upper cervical and lower lumbar

**provides support

Question 8

what is dura below SV2?

Answer 8

surrounds filum terminale to form the coccygeal ligament

Question 9

coccygeal ligament

Answer 9

dura below SV2
-surrounds filum terminale

-attaches inferiorly to periosteum of coccyx

Question 10

epidural space

Answer 10

area outside dura
-contains fat and blood vessels

**location of internal vertebral venous plexuses

Question 11

internal vertebral venous plexus?

Answer 11

located in epidural space (outside dura)

Question 12

subdural space?

Answer 12

area between dura and arachnoid

possible location for subdural hematoma**

Question 13

arachnoid mater

Answer 13

“spidery mother”

delicate trabeculated layer continuous with cranial arachnoid

Question 14

extent of arachnoid inferior?

Answer 14

follows limits of dura to SV2

Question 15

extent of arachnoid laterally?

Answer 15

adheres DIRECTLY to ventral and dorsal roots

becomes continuous with neural sheath at spinal nerve

Question 16

subarachnoid space

Answer 16

below the arachnoid

**contains CSF

continuous with cranial subarachnoid

Question 17

pia mater

Answer 17

connective tissue covering spinal cord

*invests blood vessels of the cord and continuous along dorsal and ventral roots to spinal nerve

Question 18

filum terminale?

Answer 18

formed by the pia mater at the conus medullaris

becomes ensheathed by dura at SV2

Question 19

denticulate ligaments

Answer 19

lateral pia that forms fibrous bands piercing arachnoid to attach to dura between nerve roots

Question 20

what anchors the spinal cord?

Answer 20

denticulate ligaments and filum terminale

Question 21

what is shock absorber for spinal cord?

Answer 21

CSF

Question 22

length of spinal cord?

Answer 22

45cm

tapers inferiourly to form the conus medullaris
-ends opposite the LV1-LV2 interspace (adults)

pia-glial extensions continue inferiorly to SV2 as filum terminale

Question 23

spinal cord length through development?

Answer 23

fetus - entire length of spinal column
infant - ends opposite LV3
adult - ends opposite LV1-LV2 interspace

Question 24

do spinal cord segments coincide with vertebral segments?

Answer 24

no

because of development of the spinal cord

Question 25

what forms dorsal and ventral roots?

Answer 25

rootlets of a single spinal cord segment

Question 26

what do dorsal root ganglion contain?

Answer 26

cell bodies of origins (CBO's) of most of the sensory neurons which einnervate the body below the level of the head

Question 27

how many pairs of spinal nerves?

Answer 27

31

Question 28

how many of each type of spinal nerve?

Answer 28

``` 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal ```

Question 29

what happens as you move laterally along rootlets?

Answer 29

when fuse and form spinal nerves | -become invested with all three layers of meninges and fuse with the neural sheath

Question 30

where do lower lumbar and sacral rootlets leave spinal cord?

Answer 30

conus medullaris forming the cauda equina

Question 31

cauda equina

Answer 31

from the rootlets past the conus medullaris

Question 32

conus medularis

Answer 32

tapering end of the spinal cord

Question 33

what vertebral level is the spinal cord level of lumbar?

Answer 33

T11-12

Question 34

what vertebral level is spinal cord level of sacral nerves?

Answer 34

LV1

Question 35

anterior spinal artery?

Answer 35

arises from both vertebral arteries which fuse to form single artery - courses in the ventral median fissure - supplies anterior gray and white matter

Question 36

segmental medullary arteries?

Answer 36

important for the continuity of the anterior spiral artery

Question 37

posterior spinal artery?

Answer 37

arise as branches of the posterior inferior cerebellar artery (PICA) along the dorsal root joining with opposite counterpart

Question 38

radicular arteries?

Answer 38

to the dorsal and ventral roots -receive a segmental blood supply * radicular arteries that reach the spinal cord are segmental medullary arteries - not all do - leaves certain areas of the spinal cord subject to ischemia

Question 39

segments of spinal cord most vulnerable to ischemia?

Answer 39

T1-4 and L1

Question 40

possible cause of ischemia to spinal cord?

Answer 40

thoracic or abdominal surgery can lead to ligation of intercostal arteries