Trans - Spinal Cord Flashcards
SC reaches to what level in 3rd fetal moth
coccyx
SC reaches to what level at birth
L3
SC reaches to what level in adult
L2
dura mater merging with filum terminale
thecal sac
arachnoid mater ends at what level
S2
denticulate ligament - from what layer? function?
from pia mater, anchors SC to outer layers
regions of SC
cervical thoracic lumbar sacral coccygeal
what spinal nerves emerge above corresponding vertebral segments?
C1-C7
what spinal nerves emerge below what corresponding vertebral segments?
C8-most caudal spinal nerve
cervical enlargement supplies what region
upper limbs
lumbosacral enlargement supplies what region
lower limbs
tapered end of spinal cord
conus medullaris
conus medullaris ends at what level
L1
cauda equina is composed of:
lumbosacral nerve roots
which nerve roots are involved in the cauda equina
L2 to S5
pia mater that connects the conus medullaris with the thecal sac
filum terminale
filum terminale ends at what level
S1
thecal sac ends at what level
S1
location of gray matter in SC central canal
medial
location of white matter in SC central canal
lateral
sensory nerve root - dorsal or ventral
dorsal
motor nerve root - dorsal or ventral
ventral
sulcus involved with dorsal nerve root
posterolateral sulcus
sulvus involved with ventral nerve root
anterolateral sulcus
sulcus between posteromedian and posterolateral sulci
posterointermediate sulcus
at what level is the posterointermediate sulcus located?
cervical and thoracic
subdivisions of the gray matter in the SC
- anterior gray horn
- posterior gray horn
- lateral gray horn
- gray commissures
what neurons are in the posterior gray horn
somatic and visceral sensory neurons
what neurons are in the anterior gray horn
somatic motor neurons
what neurons are in the lateral gray horn
visceral motor neurons
the visceral motor neurons in the lateral gray horn are found in what region
cervical and upper lumbar
size of anterior gray horn by regions - arrange from largest to smallest. why this arrangement
lumbosacral > cervical > thoracic
anterior gray horn –> motor. regions with the most muscles have the thicker anterior gray horns
gray commissures - function
conduct decussating axons for cross reflexes
rexed lamina 1 - function
sensory - pain to thalamus
rexed lamina 2,3 - function
afferent input to spinal cord (e.g. pain gating)
substantia gelatinosa
rexed lamina 2, 3
rexed lamina 4,5,6
proprioceptive input and sensory information
most important sensory rexed lamina
lamina 6
rexed lamina 9 - function
involved in motor control of limbs
rexed lamina 10 - function
surrounds central canal, contains neurons that decussate to the contralateral side
funiculus - define
column of white matter
how many funiculi are in the SC
6
funiculi in the SC
2 anterior funiculi
2 lateral funiculi
2 posterior funiculi
function of ascending tract
conduct afferent signals to brain
function of descending tract
conduct efferent signals to effectors
3 nerve coverings
- endoneurium
- perineurium
- epineurium
endoneurium covers what
individual nerve fiber
perineurium covers what
nerve fasciculus
epineurium covers what
nerve
1st order neuron - function
deliver peripheral sensation to SC
1st order neuron - where is the soma located
root ganglion
2nd order neuron - function
interneuron, conduct impulse to thalamus or cerebellum
2nd order neuron - where is the soma located
SC or brain
3rd order neuron - function
conduct impulse from thalamus to cortex
anterior spinothalamic tract - what type of stimuli
fine touch
lateral spinothalamic tract - what type of stimuli
pain, temperature
dorsal column tracts - what type of stimuli
proprioception and vibration
somatotrophic arrangement - define
arrangement of sensory tracts according to site of origin
medial-lateral rule
neurons from lower levels are more medial in the SC
neurons from higher levels are more lateral in the SC
2 components of dorsal column tract
- fasciculus gracilis
2. fasciculus cuneatus
fasciculus gracilis - function
conduct somatic sense from lower limb
fasciculus cuneatus - function
conduct somatic sense from upper limb
spinothalamic tracts - what type of stimuli
pain, temperature, fine touch
spinocerebellar tract - what type of stimuli
proprioception
differentiate somatic and autonomic nervous systems
somatic is voluntary, contracts only skeletal muscles
autonomic is involuntary, directs glands, smooth muscles, cardiac muscle
2 major descending tracts
- corticospinal tract
2. subconscious tract
corticospinal tract - type of signal
somatic motor
corticobulbar tract - type of signal, where transmitted
somatic motor signals to face
lateral corticospinal tract - type of signal, where transmitted
somatic motor signals to limbs
anterior corticospinal tract - type of signal, where transmitted
somatic motor signals to axial muscles
subconscious tract - type of signal
visceral motor
subconscious tract - function
balance, muscle tone, eye, hand and limb position
vestibulospinal tract - function
response to input from inner ear (balance)
tectospinal tract - function
response to sudden stimuli
tectospinal tract - originates in
corpora quadrigemina
reticulospinal tract - function
eye movement and tone of respiratory muscles
rubrospinal tract - function
involved in flexor and extensor muscles
significance of dermatomal regions
each dermatomal region is innervated by a single pair of spinal nerves
anterior spinal artery supplies:
anterior 2/3 of spinal cord
each posterior spinal artery supplies:
half of posterior 1/3 of spinal cord
arteries that pass through intervertebral foramina to supply nerve roots
radicular arteries
arteries that supply roots and spinal cord
radiculomedullary arteries
the internal venous plexus and radicular veins drain into:
intervertebral veins
Artery of Adamkiewicz - at what level is it found
commonly on the left side between T8 and L1
Artery of Adamkiewicz supplies:
lumbar and sacral SC