CNS blood flow CSF and spinal cord Flashcards
galea aponeurotica
protective layer: aponeurosis of the fascia of the occipitalis and frontalis muscles
subgaleal space
below SCALP: space has small connections to dural sinuses
what if the pressure in the dural sinuses increases?
blood can shift from the sinus out to the subgaleal space - decreasing the intracranial sinus pressure
connection between dural and subgaleal space via the __ veins
emissary
2 functions of emissary veins
- they can move blood that has cooled by the cranium into the dural sinus - helping to cool the brain
- if ICP is elevated - blood can be transferred the other way out to the scalp which can help decrease ICP
___ amount of CSF at one time in ventricles
__ produced in one day
125-500ml CSF
600mL in one day
arachnoid vill grow through ___
dura mater - forming tufts in the SSS
arachnoid villi have___
one way valve function: venous blood cannot go backwards back into the ventricular space
what should not be in CSF
red blood cells, bacteria, white cells ( or numbers should be pretty low)
elevated PRO in CSF think..
- Cells that shouldn’t be there (RBC, WBC, bacteria)
- presence of cell breakdown (myelin dz, cancer, brain dz)
Lots of disease that include inflammation
low CSF glucose?
bacteria, cancer cells or lots WBC
low ICP?
dehydration, shock, CSF leak (whole in meninges)
high ICP
blockage of CSF
things that take up space in CSF containing regions
other CSF liquid space
___ is primary regulator of CNS blood flow
CO2 carbon dioxide
circle of willis is the connection of …
carotid and vertebral
nucleus pulpous
gel inner middle of the disc
conus medullaris is the __ around __
end of spinal cord around L1/ L2
cauda equine is __
a nerve bundle at the end of the spinal cord that extends to S 5
location of cell bodies for upper and lower motor neurons
upper: in brain, axons travel down cord to appropriate level and synapse with lower motor neuron there in spinal cord
lower: in gray matter of spinal cord, axons extend into PNS
NT of lower motor neuron
acetylcholine
upper motor neuron
glutamate
posterior dorsal columns
afferent : basic perception of touch, priopioception, vibration
Fibers cross at medulla to contralateral side
spinothalamic tract
afferent
vague sense of touch
pain sensations (nociception)
temperature sense
these fibers cross at site of entry
*2 synapses: at level of entry and at other levels nearby
corticospinal tract
motor to areas below the hand
crosses at the medulla but 10% remain ipsilateral in anterior region
ipsilateral fibers innervate proximal muscles in extremities
most common cause of central cord syndrome
hyperextension of the spinal cord
arms are more effected with central cord syndrome
because sacral and lumbar fibers are more lateral in the corticospinal tract and rarely injuried
sacral sparing
someone with central cord syndrome will have better rectal tone than anterior leg function
anterior cord syndrome
usually from hyperflexion .. loss of motor function with preservation of position, vibration and touch sense
brown sequard syndrome
penetrated injury damages one side of cord
motor loss and dorsal column sensory loss on the same side and spinothalamic sensory loss on opposite side
cause of subacute degeneration
caused by B12 deficiency
leads to demyelinization of posterior and corticospinal tracts… can be perminant if not treated
tabes dorsalis
loss of myelin within the posterior columns of spinal cord
cause: untreated syphilis
sx: decreased ability to sense proprioception, light touch and vibration below site of lesion
KEY: advanced syphilis, abnormal sensory, dorsal columns
