Sensory systems II Flashcards Preview

Year 1 Neuroanatomy > Sensory systems II > Flashcards

Flashcards in Sensory systems II Deck (13)
Loading flashcards...
1
Q

what modalities are conveyed in the anterolateral system?

A

nociception and thermal sensation

2
Q

what percentage of nociceptive fibers transmit directly to the thalamus?

A

15%

3
Q

what percentage of nociceptive fibers transmit indirectly to the thalamus?

A

85%

4
Q

what type of pain sensation is transmitted by the neospinothalamic tract? does it reach consciousness?

A

fast, sharp, well-localized pain - yes

5
Q

which pathway is necessary for spatial and temporal discrimination of pain?

A

neospinothalamic

6
Q

what are the receptors for the neospinothalamic tract?

A

free nerve endings of Ad fibers

7
Q

where is the first order neuron cell body in the neospinothalamic tract?

A

DRG

8
Q

where is the second order neuron cell body in the neospinothalamic tract?

A

dorsal horn

9
Q

where do the axons from second order neospinothalamic tract cell bodies go?

A

cross in spinal cord and form spinothalamic tract

10
Q

where is the third order neuron cell body in the neospinothalamic tract?

A

VPL nucleus of thalamus

11
Q

where do the axons from first order neospinothalamic tract cell bodies go?

A

enter zone of Lissauer and then bifurcate to ascend or descend 1-3 levels to enter gray matter of dorsal horn (substantia gelatinosa)

12
Q

how is the lateral spinothalamic tract organized?

A

somatotopically - sacral most lateral, cervical most medial

13
Q

where do the axons from third order neospinothalamic tract cell bodies go?

A

axon traverses posterior limb of internal capsule and corona radiata to ascend to primary somatosensory cortex (Brodman’s area 3, 1, 2)