Card Set Information
Identify on gross spinal cord specimen
spinal nerves with ant/post roots
What is the epidural space (level of sc)?
- TRUE epidural space - between dura and bones - there is lots of fat here
Spinal cord anatomy (single level)
Identify the spinal tracts (on sc cross-section)
The spinothalamic tract (where is it, what does it do)?
- in the 'anterolateral system'
- does pain and temperature (ascending)
PCML (where is it, what does it do)?
in the 'dorsal columns'
: discriminative touch, pressure, vibration, proprioception
fasciculs cuneatus is more medial carries info from above T6
fasciculus gracilus is more lateral, carries info from T6 and below
Spinothalamic tract (where do fibers enter, cross, end)?
Fibers enter at spinal levels, can ascend or descend a couple of levels in Lissaeur's tract
synapse in posterior horn
post-synaptic neurons cross the midline (anterior white commisure) & ascend in the spinothalamic tract
synapse in VPL of thalamus
Fibers project to primary somatosensory cortex
PCML (where do fibers enter, cross, end)?
fibers enter in posterior horn of sc and synapse in posterior horn
axons travel in cuneatus or gracilis
synapse with 2nd order neuron in the nucleus cuneatus or nucleus gracilis
fibers cross the midline as internal arcuate fibers (caudal medulla)
synapse with VPL of thalamus
fibers project to primary somatosensory cortex
What is conscious vs unconscious proprioception and where does this information travel?
conscious = PCML (to cerebrum)
unconscious = spinocerebellar tract (to cerebellum)
Corticospinal tract (where do fibers enter, cross, end)?
From the motor cortex, fibers travel in the internal capsule
In the rostral medulla, fibers come together as the pyramids
In the caudal medulla, 85% of fibers cross to become the lateral CST (at the pyramidal decussation)
The other 15% of fibers become the anterior CST
Lateral fibers exit contralateral at SC
anterior fibers exit bilaterally at SC
Corticospinal tract function (A and L)?
anterior = postural muscles
lateral = voluntary limb movement
Where are the SNS and PSNS in the sc?
SNS = T1 - L2
PSNS = S2 - 4
cell bodies for both in the lateral horn
Micturition neuronal control