Pain Mechanisms

Question 1

What two types of fibres make up nocioceptors?

Answer 1

A-delta fibres

C-fibres

Question 2

Describe A-delta fibres and what do they respond to?

Answer 2

Myelinated, fast fibres which respond to sharp objects and painful extremities to temperature

Question 3

Describe C-fibres and what do they respond to?

Answer 3

NON-myelinated, slow fibres which present with dull pain and aches, they respond to sharp objects and extremities to temperature and chemicals released from damaged tissue substances

Question 4

Name Rexed’s laminae layer 1?

Answer 4

Marginal zone

Question 5

Name Rexed’s laminae layers 2/3?

Answer 5

Substantia gelitanosia

Question 6

Name Rexed’s laminae layers 4/5?

Answer 6

Nucleus propius

Question 7

A-delta fibres from the periphery synapse with which dorsal horn laminae?

Answer 7

Laminae 1 and 5

Question 8

C-fibres from the periphery synapse with which dorsal horn laminae?

Answer 8

Laminae 1 and 2 - have inter-neurones

Question 9

In peripheral sensitisation what is Allodynia?

Answer 9

Nocioreceptors that have been sensitised to non-noxious stimuli via a decrease in threshold activation

Question 10

In peripheral sensitisation what is Hyperalgesia?

Answer 10

Nnocioreceptors that have been sensitised to noxious stimuli via an increase in responsiveness

Question 11

Name the post-synaptic receptors found in central components?

Answer 11

NMDA

AMPA

Question 12

Which intracellular pathways are activated by the NMDA and AMPA receptors?

Answer 12

PKC

CamKII

Question 13

Which intracellular pathways are activated by PKC and CamKII?

Answer 13

ERK

MAPK

Question 14

Which two fibres co-ordinate the gated theory of pain?

Answer 14

A-alpha (type 1a and 1b)

A-beta (type 2)

Question 15

Which dorsal horn laminae do the A-alpha and A-beta inhibitory neurones synapse onto?

Answer 15

Laminae 3