Flashcards in Lecture 2-spinal cord Deck (63)
what are the boundaries of the spinal cord?
-1mm caudal to the pyramidal decussation
-btwn L1 and L2 vertebrae
site of conus medullaris
what do the cervical enlargements innervate?
what about the lumbar enlargement?
which space is CSF in
what are the differences btwn cranial and spinal meninges?
1. dura in the cord has only 1 layer. in the brain there are 2
-outer dural layer that is present i nthe brain end at the foramen magnum, so the cord only covered by an inner investing dural layer
2. epidural space is not a potential space in cord but an actual space filled w/ fat and veins
what do the meninges of the brain and cord have in common
shared subarachnoid space bc CSF is able to bathe the cord and spinal nerve roots
CSF heads caudally to the
how is the spinal cord pairs divided up
what does each spinal nerve innervate?
what does each spinal cord segment innervate?
a single dermatome and myotome
a dermatome and a myotome
what does the cervical enlargemnt innervate
upper extremities from C5 to T1
what does the lumbosacral enlargement innervate
lower extremities from L2 to S3
where does the spinal cord end
btwn L1 and L2 vertebrae
what is a papilledema
the bilateral sweling of both optic discs due to increased intracranial pressure
-if the pt develops a space occupying lesion (tumor or bleeding) there's not enough room in skull so the ICP increases and can be transmistted along both optic nerves due to the SHARED SUBARACHNOID SPACE.
-same CSF that circulates around the brain and cord so its also around the optic nerces
what are the two investigations needed for possible causes of elevated ICP
1. neuroimaging (MRI/MRV) to look for structural lesions
2. if imaging is normal, next is CSF analysis by lumbar puncture
if LP proves that the ICP is high, then the bilarteral disc edema can be specifically called a papilledema
where is CSF sampled from in a LP
what does a LP allow documentation of?
the CSF sample is sent to a lab to analyze its...?
1. opening pressure
where is the lumbar cistern located
just below the spinal cord itself but still within the dural sac (from L1-L2 vert to S2 vert)
where is the needed in an LP for adults placed?
L3-L4 or L4-L5
what is the preferred pt position when doing an LP?
-lying on side
-in fetal position
what is the cut-off of the normal range of the opening pressure?
> 250 mmH2O
where does the dural sac end
S2 (therefore thats where the lumbar cistern ends also)
where is the conus medullaris
what is it
just below L1
caudal termination of the cord
where is the cauda eqina
spinal nerve roots from the lumbosacral region extending beyond the conus medullaris
what is the filum terminale
a thickening of the meninges which anchors the spinal cord around the coccyx
are spinal nerves CNS?
no, they are PNS
what are spinal nerves covered by
what are dorsal roots
afferent sensory fibers entering the cord.
what type of neurons are dorsal root ganglion
pseudo-unipolar neurons w/ both central and peripheral processes
what are ventral roots
where are their cell bodies or origin
-efferent motor fibers going out to the periphery. probaby to innervate somatic or autonomic muscles
-inside the spinal cord's gray matter
each spinal nerve if formed by the union of what?
what kind of fibers do they contain?
dorsal and ventral root
sensory and motor fibers (mixed nerve(