Flashcards in Sensory systems II Deck (13):
1
what modalities are conveyed in the anterolateral system?
nociception and thermal sensation
2
what percentage of nociceptive fibers transmit directly to the thalamus?
15%
3
what percentage of nociceptive fibers transmit indirectly to the thalamus?
85%
4
what type of pain sensation is transmitted by the neospinothalamic tract? does it reach consciousness?
fast, sharp, well-localized pain - yes
5
which pathway is necessary for spatial and temporal discrimination of pain?
neospinothalamic
6
what are the receptors for the neospinothalamic tract?
free nerve endings of Ad fibers
7
where is the first order neuron cell body in the neospinothalamic tract?
DRG
8
where is the second order neuron cell body in the neospinothalamic tract?
dorsal horn
9
where do the axons from second order neospinothalamic tract cell bodies go?
cross in spinal cord and form spinothalamic tract
10
where is the third order neuron cell body in the neospinothalamic tract?
VPL nucleus of thalamus
11
where do the axons from first order neospinothalamic tract cell bodies go?
enter zone of Lissauer and then bifurcate to ascend or descend 1-3 levels to enter gray matter of dorsal horn (substantia gelatinosa)
12
how is the lateral spinothalamic tract organized?
somatotopically - sacral most lateral, cervical most medial
13