Physiology of Pain

Question 1

from what part of the brain does the descending pathway of pain inhibitory interneurons comes from

Answer 1

PAG (peri-aqueductal grey matter) in the midbrain

Question 2

what are the primary afferent fibres of pain (nociceptors)

Answer 2

A-delta and C

Question 3

how do A-delta and C fibres end

Answer 3

with free nerve endings

Question 4

true/false initial pain is mediated by A-delta fibres

Answer 4

true

Question 5

give an example of an opioid peptide produced by the body

Answer 5

endorphins

Question 6

which fibres give a sense of sharp pain

Answer 6

a-delta

Question 7

which fibres give a sense of dull diffuse pain

Answer 7

c fibres

Question 8

which fibres mediate initial pain

Answer 8

a-delta - myelinated so conduct APs faster

Question 9

which tract mediates heat

Answer 9

C fibres

Question 10

where in the thalamus does the lateral spinothalamic tract go to

Answer 10

the ventral posterior nucleus

Question 11

where does the perception of pain occur

Answer 11

in the somatosensory cortex

Question 12

the descending pathway of inhibiting pain is ____ergic

Answer 12

noradrenergic

Question 13

what is allodynia

Answer 13

experience of pain from a non-noxious stimulus

Question 14

what is hyperalgesia

Answer 14

increased sensitivity to pain

Question 15

3 components of gate control

Answer 15

wind-up, classical and long-term potentiation

Question 16

which type of pain, acute or chronic, resolves on healing

Answer 16

acute

Question 17

which type of pain, acute or chronic, is pathological

Answer 17

chronic pain

Question 18

difference between nociceptive and neuropathic pain

Answer 18

nociceptive pain comes from nociceptors being stimuated; neuropathic pain comes from lesion or dysfunction in somatosensory nervous system

Question 19

true/false neuropathic pain responds well to conventional analgesics

Answer 19

false - the pain signal does not come from the usual nociceptive origin and so cannot be dampened there with NSAIDs and opioids

Question 20

where is the problem in neuropathic pain

Answer 20

somewhere along the pain pathway (nerve, root, cord, brain)

Question 21

analgesia that targets the transfuction stage of pain (peripheral nerves)

Answer 21

NSAIDs, local anaesthetics, rest and ice

Question 22

analgesia that targets the transmission stage of pain (spinal cord)

Answer 22

nerve blocks
opioids
anticonvulsants

Question 23

analgesia that targets the perception stage of pain (cortical)

Answer 23

CBT
distraction
relaxation
mirror box therapy

Question 24

analgesia that targets the descending modulation stage of pain

Answer 24

placebos
opioids
antidepressants
surgical spinal cord stimulation

Question 25

true/false chronic pain does not serve any protective function

Answer 25

true