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Flashcards in PAIN Deck (37)
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1

what is acute pain?

short term pain
less than 12 weeks

2

what is chronic pain?

continuous long term pain
more than 12 weeks

3

what is nociceptive pain?

pain that arises from actual or threatened damage to non-neuronal tissue

4

what is neuropathic pain?

pain initiated or caused by a primary lesion/dysfunction of the nervous system

5

what are first order neurons?

- enters the spinal cord through a spinal nerve, or the brainstem through the trigeminal nerve
- enters ipsilateral to peripheral receptor
- remains ipsilateral and synapses with second order neuron

6

what are second order neurons?

- cell body is located in the spinal cord/brainstem
- it decussates and ascends to the thalamus

7

what are third order neurons?

- cell body located within the thalamus
- axons project to the somatosensory cortex

8

what are nociceptors?

they are sensory neurons that can sense pain

9

what do nociceptors detect externally?

skin
cornea
mucosa

10

what do nociceptors detect internally?

viscera
joints
muscles
connective tissue

11

where are the cell bodies of nociceptors found?

dorsal root ganglion (body)
trigeminal ganglion (face/neck/head)

12

what is hyperalgesia?

it is the effect of bradykinin and prostaglandin E2
they reduce the nociceptive action potential threshold

13

what are alpha delta afferent fibres?

- thinly myelinated
- carries touch, pressure and temperature info
- fast fibres
- 1.5 micrometers
- conduction speed = 5-40m/s
- terminals release glutamate

14

what type of information do alpha delta afferent fibres carry?

touch
pressure
temperature

15

what do the terminals of alpha delta afferent fibres release?

glutamate

16

are alpha delta afferent fibres myelinated or unmyelinated?

thinly myelinated

17

are c fibres myelinated or unmyelinated?

unmyelinated

18

are alpha delta fibres fast or slow fibres?

fast

19

are c fibres fast or slow fibres?

slow

20

what type of information do c fibres carry?

pain
temperature
touch
pressure
itch

21

what are c fibres?

unmyelinated
carries pain, temperature, touch, pressure, itch
slow fibres
0.2-1.5 micrometres
conduction speed 0.5-2m/s
terminals release glutamate and substance P

22

what do the terminals of c fibres release?

glutamate
substance P

23

what is substance P?

it is a peptide neurotransmitter and vasodilator
it remains bound to receptors for a longer time
it therefore causes long-lasting pain

24

what is the effect of substance P?

it remains bound to receptors for a longer time
it therefore causes long-lasting pain

25

what type of fibres are alpha delta fibres and c fibres?

they are both first order neurons
they synapse with second order neurons in grey matter

26

what type of stimuli do A-beta fibres respond to?

non-noxious
mechanical stimulus

27

what type of stimuli do A-delta fibres respond to?

noxious
mechanical stimulus

28

what type of stimuli do C fibres respond to?

noxious heat
chemical stimuli

29

what are the different types of upper motor neurons?

thermal
mechanical
chemical
sleeping
polymodal

30

what are thermal UMNs activated by?

activated by noxious heat or cold
TRP channels respond to hot stimuli
TRPM8 channels respond to cold stimuli