spinal cord Flashcards
(16 cards)
what are the spinal nerves ?
8 cervical
12 thoracic
5 lumbar
5 sacral
after it is conus medullaris L1 and L2
after it is cauda equina
what is the difference between white and grey matter ?
white matter - fibres
gray matter - cells
where is a lumbar puncture usually performed ?
between l4 and l5 or between l3 and l4
must stay between L3 and L5
what are the specific contents of the white matter vs the gray matter ?
white matter - has dorsal horn (sensory) , anterior horn(motor neurons) and lateral horn (sympathetic)
grey matter , has the posterior column , lateral corticospinal and the spinothalamic
what do each of the fibres of the white matter correspond to ?
posterior column - vibration and proprioception
lateral corticospinal - motor tract
spinothalamic - pain and temperature
all sensory information in the body eventually goes where ?
to the thalamus , except smell
what is the 3 neuron system associated with the spinothalamic tract
1st order neuron - dorsal root ganglia
2nd order - spinothalamic tract , decussates as soon as it enters the spine
3rd order - VPL nucleus of the thalamus
what is the stimulus carried by each of the pathways ?
spinothalamic pathway - pain, temp and crude touch
DCML pathway - fine touch, vibration and proprioception
what is the 1st, 2nd and 3rd order neuron associated with the dorsal column ?
1st order neuron - dorsal root ganglia abd ascends ipsilaterally
2nd order neuron - nucleus gracilie , cuneate , gracille for below T6 and cuneate for above T6 , they decussate at the medulla , then ascends contralaterally
2nd synapse is at the VPL of the thalamus
3rd order neuron - projects to the somatosensory
what are the receptors associated with the dorsal column ?
meisseners corpuscle and pacinian corpuscle
what are the tracts associated with sensory information ?
spinothalamic
posterior column howa howa el dorsal column
what is the motor tract called ?
the corticospinal tract
what is the median leminiscus ?
the part of the dorsal/posterior tract after it decussates at the medulla
what is the 1sr, 2nd and 3rd order nucleus associated with the corticospinal tract ?
1st order neuron - primary motor cortex descebds ipsilateraly , decussates at the lower medulla then descends contralaterally
1st synapse is the anterior horn
2nd order neuron - LMN leaves the spinal cord
then synapses at the NMJ
which level of the spinal cord is the lateral column found ?
only in the thoracic part of the spine
what are the different tests associated with sensation ?
romberg - reveals poor proprioception and tests the posterior column
vibration is tested with a tunning fork
