pain

Question 1

What three things can activate the TRPV1 channel

Answer 1

acid
capsaicin
temperature

Question 2

what substances do nocioceptors release when activated

Answer 2

substance P

CGRP

Question 3

which mediators activate nocioceptors

Answer 3

bradykinin
serotonin
histamine
Prostaglandins
cytokines

Question 4

how does pain hypersensitivity or allodynia occur

Answer 4

transcription mediated cytokine and GFs increase the production of receptors, ion channels and NTs –> exaggerated responses

Question 5

difference between A delta and C fibres

Answer 5

A delta - sharp, acute, localised pain, thermal pain

C fibres - slow pain aching, throbbing, chemical pain

Question 6

what is the main NT involved in nocioception

Answer 6

glutamate

Question 7

what NT is inhibitory for nocioception

Answer 7

GABA

Question 8

what are the 2 main NTs activated by glutamate in nocioception

Answer 8

AMPA

NMDA

Question 9

what is the difference in activation of AMPA and NMDA in nocioception

Answer 9

NMDA only activated in situations where there is prolonged pain/stimulus

Question 10

explain the activation of the NMDA receptor

Answer 10

Mg plug is displaced causing cell remodelling and c-fos gene expssion –> causing spinal cord sensitisation

Question 11

what drug class are endorphins

Answer 11

opoid

Question 12

what endogenous molecule is produced to try and inhibit pain feeling

Answer 12

endorphins

Question 13

where is the primary site of action of opiods and how do they work

Answer 13

spinal cord - act pre-synaptically to decrease NT release and post-synaptically to hyperpolarise the dorsal root neurons

Question 14

what kind of fibres are descending pain fibres that interact with nocioception

Answer 14

noradrenergic and 5-HT3

Question 15

which receptor is targetted in neuropathic pain

Answer 15

N type Voltage gated Ca channel receptor

Question 16

which parts of the brain are involved in nocioception

Answer 16

superior colliculus

periaqueductal grey matter (PAG)

Question 17

how does the HR and BP increase with pain

Answer 17

through complex interaction between the cardiovascular centre and the PAG

Question 18

how can someone experience no pain

Answer 18

absence of sodium channel

Question 19

if you have the stargazer gene = what are you susceptible to

Answer 19

chronic pain

Question 20

side effects of opoids

Answer 20

ventilatory depression
drowsiness/sedation
postop nausea and vomiting
pruitis
urinary retention
constipation

Question 21

what is the theory behind multimodal analgesia

Answer 21

target pain transmission at multiple sites and reduce opoid requirement

Question 22

what is the theory behind pre-emptive analgesia

Answer 22

attenuate injury and the neuroplastic response