Spinal Cord and Meninges Flashcards
1
Q
the central nervous system is comprised of the
A
brain and spinal cord
2
Q
the brain stem (medulla oblongata and pons) connects the
A
spinal cord to the brain
3
Q
the brain, brain stem, and spinal cord are covered by layers of
A
meninges
4
Q
meninges contain
A
csf
5
Q
sensory/afferent structures (4)
A
dorsal horn (gray matter) dorsal root ganglion ascending corticospinal pathways (white matter) axons from body traveling to dorsal root and dorsal horn
6
Q
gray matter
A
where you find cell bodies
7
Q
white matter
A
myelinated portions of axons
8
Q
motor/efferent structures (4)
A
ventral horn (gray matter)
lateral horn (autonomics)
descending corticospinal pathways (white matter)
axons from ventral and lateral horn traveling out to body
9
Q
the spinal nerve is a mix of
A
sensory and motor
10
Q
anatomical flow of spinal nerve information
A
information flows in through the dorsal ramus, to the spinal nerve, to the dorsal root ganglion, to the dorsal root, dorsal horn, lateral horn, ventral horn, ventral root, and out the ventral ramus
11
Q
of spinal nerves
A
31 pairs
12
Q
number of cervical nerves thoracic lumbar sacral coccygeal
A
8 (C1-C8) 12 (T1-T12) 5 (L1-L5) 5 (S1-S5) 1 (Co1)
13
Q
nerve C8 passes through
A
the IV foramen between vertebra C7-T1
14
Q
spinal cord stops at about
A
L2 in adults
15
Q
meningeal (dural) layers
outermost
middle
innermost
A
dura mater (closest to the bone) arachnoid mater (spider web like) pia mater (on the surface of the spinal cord)
16
Q
arachnoid mater adheres to
A
the dura mater
17
Q
pia mater is integral to the
A
spinal cord
if you peel this, you will begin peeling away the spinal cord
18
Q
denticulate ligament keeps the
A
spinal cord in place so it doesnt move
19
Q
where is CSF found?
A
in the subarachnoid space
20
Q
subdural space
A
a potential space between the arachnoid and dura mater
21
Q
epidural space
A
above the first layer of dura
where epidural is given
fat filled
22
Q
of posterior and anterior spinal arteries
A
2, 1
23
Q
denticulate ligaments are paired extensions of
A
pia mater that attach to the arachnoid and dura mater
24
Q
denticulate ligaments anchor the spinal cord
A
laterally in the dural sac
25
denticulate ligaments run in between the
ventral and dorsal rootlets of the spinal cord as they leave the dural sac
26
contents of the epidural space (2)
extradural adipose tissue (fat)
| internal vertebral venous plexus (Batson's Plexus)
27
contents of the subdural space (2)
a potential space between the dura and arachnoid mater
| may be opened as a result of trauma or disease (subdural hematoma)
28
contents of the subarachnoid space (3)
spinal veins and arteries
cerebrospinal fluid
arachnoid trabeculae
29
cervical enlargement vertebrae
C5-T1
30
cervical enlargement gives rise to the
cervical plexus and the brachial plexus (groupings of cervical and thoracic spinal nerves)
31
lumbar enlargement vertebrae
L1-S2
32
lumbar enlargement gives rise to the
lumbar plexus and the sacral plexus (groupings of lumbar and sacral spinal nerves)
33
conus medullaris
terminal end of spinal cord; usually at level L1-L2
34
filum terminale internum
pia mater extending from tip of conus medullaris to end of dural sac
35
filum terminale externum
all dural layers fused together; anchors dural sac in sacrum; extradural
36
lunbar cistern
enlargement of subarachnoid space from L2-S2
37
cauda equina
L2-S5 and Co spinal nerve roots that form a structure that looks like a horse tail in the lumbar cistern
38
cauda equina is encompassed by the
dural sac
39
why do we have the cauda equina?
for growth of the spinal cord
40
spinal cord stops growing in length while the
vertebral column is still developing
41
where is the conus medullaris located?
the terminal end of the spinal cord (L1-L2) however can be located anywhere in the T12-L3 range
42
cauda equina forms as a result of
differential growth of spinal cord and vertebral column
43
cauda equina syndrome
a relatively rare but serious disorder in which the spinal nerve roots that comprise the cauda equina become compressed and cause a characteristic pattern of neuromuscular and urogenital symptoms. onset tends to be gradual
44
causes of cauda equina syndrome (6)
* *anything that compresses the cauda equina
- herniated intervertebral disk
- stenosis (narrowing) of vertebral canal
- fracture or other trauma
- lesion
- infection or hemorrhage in the lumbar cistern
- developmental abnormality
45
symptoms of cauda equina syndrome (6)
- bowel and/or bladder dysfunction
- sexual dysfunction
- "saddle anesthesia" (involves sacral dermatomes)
- pain or weakness in both lower limbs
- loss of knee and ankle reflexes
- lower back pain
46
the spinal cord receives blood regionally from corresponding arteries in the
cervical, thoracic, lumbar, and sacral regions of the vertebral canal
47
subclavian aa gives rise to (3)
vertebral aa
ascending cervical aa
deep cervical aa
48
descending aorta gives rise to (2)
posterior intercostal aa
| lumbar aa
49
internal iliac aa gives rise to (1)
lateral sacral aa
50
these arteries contribute to arteries that run longitudinally from the brainstem to the conus medullaris (2)
anterior spinal artery
| paired posterior spinal artery
51
anterior spinal artery arises from
vertebral aa
52
paired posterior spinal arteries arise from
vertebral artery or cerebellar artery
53
anastomosis
arteries that come together to supply blood to something
54
anastomosis is important for (2)
blood supply to asymmetrical arteries
| if blood gets cut off on one side
55
the segmental spinal arteries enter the intervertebral foramina and split into (2)
anterior and posterior radicular arteries
| these follow and supply the dorsal and ventral roots of the spinal cord
56
the segmental spinal arteries also give off
segmental medullary arteries that anastomose directly with the anterior spinal artery
57
the largest of the segmental medullary arteries is the
radicularis magna, or artery of ademkiewicz, which arises in the lower thoracic or upper lumbar region and supplies the lower spinal cord, including the lumbar enlargement
58
the veins that drain the spinal cord form several longitudinal channels that drain into the
internal vertebral venous plexus that lies in the epidural (extradural) space of the vertebral canal
59
posterior and anterior spinal veins flow to the
anterior and posterior medullary veins
60
the anterior and posterior medullary veins flow to the
radicular veins
61
from the radicular veins, the internal vertebral venous plexus then drains into
segmental veins that connect to other major systemic routes of venous drainage
62
the internal vertebral venous plexus mainly drains the
vertebral bodies
63
the internal vertebral venous plexus provides a
protective cushion for contents of the vertebral canal
64
these veins do not have
valves
65
the venous plexus is an alternative route of venous return in the following cases (4)
- the jugular veins of the neck are compressed or occluded
- blood flow through vena caval system is obstructed
- intrathoracic pressure is increased
- intraabdominal pressure is increased
66
the internal vertebral venous plexus also communicated with (5)
-dural venous channels in cranium
-veins scalp and face
-veins of thoracoabdominal wall
pulmonary and caval system veins
-pelvic and sacral veins
67
within the CNS, there are ascending and descending pathways in the brain and spinal cord that
bring information back to the CNS and control the activities of skeletal muscle
68
ascending tracts are
sensory pathways that originate in the peripheral body and travel to the primary sensory cortex
69
descending tracts are
motor pathways that originate in the cerebral cortex and brainstem and travel to muscle
70
dorsal column pathway functions in
fine touch and proprioception
71
proprioception
sensory innervation from muscle and joints which tell you where you are in space, balance, how to move
ex. putting your hand down on the table
72
2 sensory neurons in the dorsal column pathway
first order neurons
second order neurons
third order neurons
73
first order neurons
signals from upper and lower limn to medulla oblongata
74
second order neurons
pick up signal from first order neuron and carry it from the fasciculus gracilus (or f. cuneatus) to the thalamus
75
third order neurons
from the thalamus carry the signal from the second order neuron to the ipsilateral primary sensory cortex of the brain
76
2 tracts of the spinothalamic pathway
anterior (touch and pressure)
| lateral (pain and temperature)
77
3 sensory neurons of the spinothalamic pathway
first order neurons
second order neurons
third order neurons
78
first order neurons
arise from peripheral sensory receptors in the body, enter spinal cord and synapse at the substantia gelatinosa
79
second order neurons
carry sensory info to the thalamus
touch and pressure uses the anterior spinothalamic tract
pain and temperature uses lateral spinothalamic tract
80
third order neurons
from the thalamus carry signal from second order neurons to the ipsilateral primary sensory cortex of the brain
81
in the CNS, there are at least 2 motor neurons in a
somatic motor pathway that involves voluntary movement
82
upper motor neuron nucleus is in the
cerebral cortex/brainstem
83
lateral corticospinal tract
85-90% to limbs
84
anterior corticospinal tract
10-15% to trunk
85
lower motor neuron nucleus is in the
anterior horn of the spinal cord or cranial nerve brainstem center
86
axons from the lower motor neuron are what will project out to innervate
skeletal muscle
