3 - Tracts of Spinal Cord (13) Flashcards
the spinal cord extends from _ to _
foramen magnum to L1
What is the major descending pathway called?
corticospinal (aka pyramidal tract)
lesions prior to decussation ascending tracts produce _ sensory defects
ipsilateral
lesions after decussation of ascending tracts produce _ sensory defects
contralateral
lesions prior to decussation of descending tracts produce _ motor defects
contralateral
lesions after decussation of descending tracts produce _ motor defects
ipsilateral
1st order neuron of ascending pathway is in _
cell body of posterior root ganglion of spinal cord
cell body of 2nd order neuron of ascending pathway is in _
gray matter of spinal cord (decussates here)
cell body of 3rd order neuron in ascending pathway is in_
thalamus
in posterior column:
fasciculus gracilis: _
fasciculus cuneatus: _
up to and including T6
above T6
posterior column neurons decussate at _
caudal medulla
posterior column is for what sensations?
fine touch, pressure, vibration
anterolateral system carries what sensations?
anterior - crude touch and pressure
lateral - pain and temp
anterolateral system uses which tract? and decussate where?
spinothalamic; immediately
spinotectal tract carries which sensory information?
reflexive and head movements towards tactile stimuli
spinotectal tract synapses in _ of midbrain
superior colliculus
spinotectal tract decussates where?
immediately
posterior spinocerebellar tract relays info about _
proprioceptive information from lower limbs
cuneocerebellar tract relays info about _
proprioceptive information from upper limbs
anterior spinal cerebellar tract relays information about _
integrates proprioceptive and descending motor with lower limbs
rostral spinocerebellar tract relays information about _
integrates proprioceptive and descending motor info with upper limbs
most descending (including corticospinal) pathways decussate and _
medulla (85% at pyramids)
main descending pathway:
corticospinal tract (pyramidal tract)
2/3 fibers originate in _, 1/3 originate in _
precentral, postcentral
2/3 fibers originate in _, 1/3 originate in _
precentral, postcentral
vestibulospinal tract does:
stablization of head during body movements
reticulospinal tract does:
coordination of primitive motor movements (breathing)
rubrospinal tract does:
motor control of upper limbs (comatose posturing)
tectospinal tract does:
orientaton of head and neck during eye movements
lateral corticospinal tract does:
movement of limbs
anterior corticospinal tract does:
postural stabilization of trunk and core
lesion of midbrain-red nucleus, _ posture
decerebrate
decerebrate posture: _
extension of all limbs
lesion rostral to red nucleus, _ posture
decorticate
decorticate posture: _
flexion of upper limbs
