neuroanatomy Flashcards
where do we inject an epidural and where do we lumbar puncture for CSF - what is the difference?
Epidural - epidural space (between dura and vetebral periosteum) contains fat and venous plexus
CSF - subaarachnoid space (between arachnoid and pia matter - posteriorly)
where do sensory nerves have their cell bodies?
dorsal root ganglion
where do motor nerves have their cell bodies?
in grey matter of spine
where is a spinal anaesthetic injected?
subarachnoid space
what are the grey and white matter of spine?
grey matter - cell bodies
white - tracts
anterior root is
posterior root is
anterior root is sensory
posterior root is motor
which tract carries pain and temperature (sensory)?
spinothalamic tract
takes it to contralateral side of the body
which tract carries motor signals?
corticospinal tracts:
ipsilaterally - lateral (voluntary mvment) + anterior csp tract
contralaterally - anterior csp
where do spinothalamic tracts cross?
at the level of the spinal cord at the anterior white commissure
anterior corticospinal (motor) tracts cross here too
which tracts carry proprioception?
All ipsilateral
Spinocerebellar
Fasciculus gracilis - proprioception form lower limb
Fasciculus cuneatus - proprioception form upper limb
which tracts carry fine touch, vibration, propioception all in one?
Fasciculus gracilis - from lower limb
Fasciculus cuneatus - from upper limb
which are the only tracts which really cross over?
Spinothalamic - pain and temperature (travel up 1-2 segments before crossing)
anterior corticospinal - motor
links
https://imperial.cloud.panopto.eu/Panopto/Pages/Embed.aspx?id=a1ebefe6-e007-4207-8002-32c3d690e328&query=neuro
what are the order of neurons in sensory pathway
1st order:
- skin to spinal cord (pain temp)
- skin to medulla (touch proprioception)
2nd order:
above to thalamus
3rd order:
thalamus to cortex
pain and temp tract crosses?
deep touch, vibration and prioception tract crosses?
motor tracts?
spinothalamic tract:
pain and temp, light touch tract crosses - spine
dorsal columns:
deep touch, vibration and prioception tract crosses - medial leminiscus in medulla
motor tract; medulla
lesion of spinothalamic tract will cause?
flaccid paralysis
if regained, will end up as hyperreflexia or spasticity
How does Brown sequard present?
Saying lesion is on the left
It is a hemisection of the spine
hIP VIP:
Ipsilateral loss of vibration, temperature, motor - paralysis (so left)
conTEMPlate:
Contralateral loss of pain and temperature
where is the motor cortex found?
frontal lobe
define paresis
graded weakness of movements - NOT paralysis
define plegia
paralysis
UMN lesions present how?
Loss of function: Paresis or Plegia
Increased tone: Spasticity
Hyperreflexia
Clonus
Babinsky sign
LMN lesions present how?
weakness
hypotonia
fasciculations
hyporeflexia or mute
what would cause a monoocular vision loss?
optic nerve lesion - before optic chiasm
IPSILATERAL
no vision in 1 eye
causes of a homonymous hemianopia?
how do we differentiate cause?
Optic tract lesion - vascular or neoplastic
Stroke - Occipital lobe (usually macular sparing - as dual blood supply - MCA + PCA)
Stroke - Parietal lobe (usually have hemispatial neglect too)
patient presents with left sided arm and leg weakness and right sided facial weakness. likely level of the lesion?
Brainstem lesion - clearly not high enoughh that its all on one side
tracts have not yet decussated.
