Spinal cord Flashcards
(35 cards)
what is white and gray matter
white- tracts communicate from CNS to PNS
gray- neuron cell bodies
3 layers of spinal column
1- dura mater (outer)- thick collagenous tissue, single layered
2- Arachnoid- thin layer, runs to s2
3- Pia mater (inner)- thicker each side has ligament, acts as anchor
Where does cauda equina terminate
SC terminates at level of L1-L2
Cervical- how many vertebrae/ characteristics
- 7 vertebrae
- small vertebral bodies, Greater ROM, facets orientated along transverse plain
Thoracic- how many vertebrae/ characteristics
- 12 vertebrae
- facets oriented vertically
- Less ROM in extension/flextion
Lumbar- how many vertebrae/ characteristics
- 5 vertebrae
- larger vertebral bodies
- facets orientated in sagittal plane (increase extention)
Where is lumbosacral plexus
-l4-s4
sacral plexus- L4-s1 (superior gluteal N)
L5- S2- Inferior gluteal N
Sciatic N- L4 to S3 `
what does the dorsal root contain and where does it synpase
contains interneurons that are part of spinal circuits
-may synpase directly in spinal cord with neurons of the ipsilateral gray mater or ascends via white matter tracts to ipsilateral medula or thalmic relay center
what does ventral root do
volunatary + involuntary movement
final common pathway (lower motor unit)
Myotomes- c1-c8
1/2-head flex 3- side flex 4- shoulder elev 5- shoulder abduction 6- elbow flex/ wrist ex 7- elbow ex/ wrist flex 8- thumb ex
Myotomes- L2-s1
2- hip flex 3- knee ex 4- ankle dorsiflex 5- great toe ex 1- ankle plantar flex
What are deep tendon reflexes for
signs of lower motor lesion
- absent or decreased response
- flaccid paralysis
What is a negative babinski reflex indicitive of
signs of upper motor neuron lesion
- excessive or increased response
- spastic paralysis
Ascending tracts- where are cell bodies located
ipsilateral dorsal root
what is difference bw medial and lateral portion of ascending tracts
medial- increased mylination, larger diameter (for touch/proprioception)
T/F posterior column is organized somatotropically
T
Posterior column medial lemniscus- what does it get imput from/ where does i
input from mechanoreceptors
- enter medial division and ascend via posterior column
Where do axons in posterior column synapse
Caudal medulla
route of axons in posterior columm
dorsal root ganglia-> fasciculus cuneatus (lowr body)/ gracilis (upper body)-> nucleus cuteatus/gracilis
where do posterior column axons cross over
at medulla to form medial lemniscus
where do 2nd order and 3rd order neurons ascend
2nd- ascend through medial leminscus to synapse on VPL
3rd- project from VPL to SM1
what does damage to PCML result in
proprioceptive + tactile impairments (incordination)
Route of Anterior spinothalmatic tract
synapse w interneuron and cross midline
- ascends ipsilateral SC via anterolateral path
- enters the caudal medulla to midbrain to thalmus
Damage to anterior spinothalmatic tract results in
- absence of pain
