6. Somatosensory system II

Question 1

which is more lateral:

gracile or cuneate tract?

Answer 1

cuneate

Question 2

where is the primary somatosensory cortex located? (numbers)

Answer 2

1,2,3

Question 3

where is the primary motor cortex located? (numbers)

Answer 3

4

Question 4

what is the name of the structure where the somatosensory cortex is located?

Answer 4

post central gyrus

Question 5

what info is carried in the cuneate tract?

Answer 5

info from upper body

Question 6

what order are the neurones which project from the VP complex of thalamus to the S1 region ?

Answer 6

third order

Question 7

4 types of afferent nerve fibres - thinnest to thickest

Answer 7

1. C
2. Adelta
3. A beta
4. A alpha

Question 8

what does DCML stand for

Answer 8

Dorsal column medial lemniscus

Question 9

what does the DCML process?

Answer 9

innocuous touch from skin and joint receptors

Question 10

2 tracts of DCML - describe what they are

Answer 10

Cuneate tract - upper body + limbs - rostral to T6

Gracile tract - lower body + limbs - caudal to T6

Question 11

which 2 places do the axons in the DCML synapse?

Answer 11

1. caudal medulla

2. Ventral posterior lateral nuclei of thalamus

Question 12

where do they tracts decussate in the DCML?

Answer 12

caudal medulla

Question 13

when do the tracts in the DCML become the medial lemniscus ?

Answer 13

after decussating

Question 14

which lobe is the primary somatosensory cortex 1,2,3, lcated?

Answer 14

parietal

Question 15

tract which carries innocious info from the face?

Answer 15

trigeminothalamic

Question 16

3 divisions of the trigeminal nerve

Answer 16

1. opthalmic
2. mandibular
3. maxillary

Question 17

2 places where axons in trigeminothalamic synapse?

Answer 17

1. trigeminal complex nucleus

2. Ventral Posterior medial nucleus of thalamus

Question 18

where do axons in the trigeminothalamic tract decussate?

Answer 18

trigeminal complex nucleus

Question 19

difference between innocous and nociceptive pathways?

Answer 19

nociceptive axons decussate in the spinal cord rather than caudal medulla

Question 20

where do 1st neurones synapse first in the proprioceptive pathways of both the upper and lower body?

Answer 20

dorsal and ventral horns at the spinal cord

Question 21

difference between proprioceptive pathways of the upper and lower body?

Answer 21

lower body has extra synpase at Clarke’s nucleus in the thoracic spinal cord - this axon ascends as the spinocerebellar tract which is more lateral than the upper body

Question 22

where does decussation occur in the proprioceptive pathways ?

Answer 22

VPL nucleus of the thalamus

Question 23

what is the primary sensory processing area?

Answer 23

postcentral gyrus

Question 24

what is the secondary sensory processing area?

Answer 24

posterior parietal

Question 25

what is the limbic system?

Answer 25

learning and memory

Question 26

which area of the brain recieves sensations of touch?

Answer 26

somatosensory cortex

Question 27

which area of the brain controls movement?

Answer 27

motor cortex

Question 28

the size of the central cortical areas in the brain correlate with what?

Answer 28

areas which have high peripheral sensory innervation

Question 29

which area of the primary somatosensory cortex recieves the majority of input from the VPL nucleus?

Answer 29

3b

Question 30

how does plasciticity occur?

Answer 30

creating new dendrites, proteins and changes in synpases