unit 2 review - somatosensory

Question 1

what are the 3 divisions of the somatosensory syatem?

Answer 1

exteroreception
enteroreception
proprioception

Question 2

what does extero reception include?

Answer 2

nociception
thermoreception
mechanoreception

Question 3

what are the 4 types of mechanorecpetors on the skin?

Answer 3

meisseners
merkels
pacinian
ruffini

Question 4

name to receptive field size and adaptation kind?
of the 4 mechanoreceptors

Answer 4

meisseners
- small, rapid
merkels
- small, slow
pacinian
- large, rapid
ruffini
- large, slow

Question 5

what does rapid adaptation mean?

Answer 5

fires AP when stimulus is first placed and when stimulus is first removed

Question 6

what frequency is each corpsucle best for ?

Answer 6

pacinian=high
merissners=low

Question 7

describe mechanoreceptive channels?

Answer 7

all have unmyleinated axon terminals
- membranes of the axons convert mechanical force into a change of ionic current

Question 8

what do primary afferent axons do?
where are the cell bodies of these axons located?

Answer 8

bring information from sensory receptors into the CNS (spinal cord)
- cell bodies are located in the dorsal root ganglia

Question 9

what are the 4 types of axons?

Answer 9

Aalpha, Abeta, Adelta, C

Question 10

what do the 4 types of axons correlate with? mylein wise

Answer 10

Aalpha, Abeta, Adelta, C
most myleinated to least mylenated

Question 11

Aalpha info?

Answer 11

proprioceptors of the skeletal muscle

Question 12

Abeta info?

Answer 12

mechanoreceptors of the skin

Question 13

Adelta info?

Answer 13

pain and temperature

Question 14

C info?

Answer 14

temperature, pain anf itch

Question 15

what axon types go through the DCML?

Answer 15

Aalpha, Abeta

Question 16

what type of information does the DCML carry?

Answer 16

epicritic
- touch and vibration (no pain or temperature)

Question 17

describe the pathway of the DCML?

Answer 17

1) first order sensory afferents enter spinal cord through dorsal horn (grey matter)
3) travel up spinal cord through (white matter)
4) projects to S1

Question 18

where is the DCML first synapse?

Answer 18

dorsal column nuclei

Question 19

where does the DCML decussate?

Answer 19

medial lemniscus in medulla
- high

Question 20

where is the DCML second synapse?

Answer 20

ventral posterior lateral nucleus

Question 21

what is not part of the DCML?

Answer 21

face

Question 22

what happens when you lesion above the medulla?
below?

Answer 22

above=loss of contralateral touch
below=loss of ipsilateral touch

Question 23

where is S1 located?
where do those inputs usually go?

Answer 23

parietal lobe
- layer IV/4

Question 24

layer IV of S1 has two components?
name and describe them

Answer 24

area 1 = texture
area 2 = size and shape

Question 25

what are areas 5 and 7 concerned with?

Answer 25

intergration of the senses - movement planning, attentiveness

Question 26

damage to 5 and 7 what is agnosia?

Answer 26

inability to recognize objects

Question 27

neglect syndrome?

Answer 27

happens contralaterally, - will neglect everything on a side of body

Question 28

describe the meilenation of noiceceptors?

Answer 28

unmylenated

Question 29

what are the axons associated with slow vs. past pain?

Answer 29

slow = C axons fast = Adelta axons

Question 30

what information does the spinothalmatic pathway carry?

Answer 30

protopathic component - pain, temp, itch

Question 31

what fibers go through the spinothalamatic pathway?

Answer 31

Adelta and Ac

Question 32

describe the spinothalamatic pathway?

Answer 32

1) axons from dorsal root ganglia enter dorsal horn 2) ascends up the spinal cord to the S1

Question 33

where does the spinothalamatic pathway first synapse?

Answer 33

in the substantia gelatinosa

Question 34

where does spinothalamatic pathway dessucate?

Answer 34

immediatley in the spinal cord - very low

Question 35

where does spinothalamatic pathway synapse for the second time?

Answer 35

contralateral thalamus - intralaminar VP nuclei

Question 36

what are the 4 sections of the spinal cord?

Answer 36

cervical: neck and arms thoracic: torso lumbar: legs sacral

Question 37

describe is primary vs. secondary hyperglesia

Answer 37

primary=at site of damage secondary=around site of damage

Question 38

what does substance P do?

Answer 38

increases inflammation - relates to secondary anaglesia

Question 39

what is the descending pain control pathway?

Answer 39

1) periaquaductal grey signals raphe nuclei 2) affects noiceceptive inputs in the dorsal horn of the spinal cord *pathway can be activated by emotional factors or opioids*