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Neuroscience Y3S1 > Pain - The Basics > Flashcards

Pain - The Basics Flashcards

1
Q

Name four general peripheral structures which are innervated by nociceptive free nerve endings. (4)

A
  • Skin
  • Joints
  • Muscles
  • Viscera
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2
Q

Describe the difference between the action potential profile produced in nociceptive neurones and non-nociceptive neurones. (1)

A

No difference

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3
Q

Describe what is meant by ‘transduction of a stimulus’. (1)

A

Conversion of a peripheral stimulus (eg pressure) into electrical activity in a neurone.

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4
Q

True or false? Explain your answer if appropriate. (1)

Action potentials produced in nociceptive neurones all have their peaks at the same membrane potential.

A

True - this is because action potentials are all or none

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5
Q

Describe what is meant if a receptor potential is described as ‘subthreshold’. (1)

A

The depolarisation does not meet the membrane potential required to produce an action potential.

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6
Q

What is meant by a ‘receptor potential’? (3)

A

A depolarising electrical signal

that occurs in a sensory receptor cell

when it is activated by an external stimulus.

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7
Q

Explain why we can refer to a receptor potential as a ‘sustained depolarisation’. (2)

A

The membrane potential does not repolarise to resting between action potentials - it repolarises to the receptor potential.

The depolarisation does not tend to adapt as long as the stimulus is present so the cell will stay depolarised.

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8
Q

Describe the relationship between the stimulus strength and the receptor potential. (2)

A

Rapid increase in receptor potential with increasing stimulus strength

when then reaches a plateau (no further RP increase with increased stimulus strength).

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9
Q

Describe the relationship between the receptor potential and the frequency of action potentials produced. (1)

A

Directly proportional (higher RP = more APs)

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10
Q

Very briefly describe how stimulus intensity (ie increased pain or touch) is conveyed in the nervous system. (1)

A

Increased frequency of action potentials = increased stimulus intensity

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11
Q

Briefly suggest four ways that C and A fibre nociceptors can be distinguished. (4)

A
  • Cell body size
  • Fibre conduction velocity
  • Molecular markers
  • Electrophysiological and response properties
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12
Q

Fill the gap relating to nociceptors and sensory neurones. (1)

Slowly conducting afferents tend to have …………………. cell bodies.

A

smaller

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13
Q

Describe the issue with identifying nociceptors by their small cell bodies. (3)

A

Small cell body means that the fibre is a slowly conducting afferent fibre

however not all slowly conducting afferents are nociceptive

so small cell does not always equal nociceptive.

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14
Q

True or false? Explain your answer if necessary. (1)

All C fibre sensory neurones are nociceptive, so all small cell bodies in the DRG will belong to nociceptive neurones.

A

False - a high proportion of C fibre neurones are nociceptive, so a high proportion of small DRG neurones will be nociceptive, but not all

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15
Q

Describe how a compound action potential is obtained/measured. (3)

A

A whole nerve (not individual fibres)

is stimulated in one place

and CAP is recorded at a different place.

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16
Q

Describe the number and ‘distribution’ of the peaks you would expect to see in a compound action potential of a sensory nerve. (2)

A

4 peaks

3 quick peaks quite close together, 1 peak a little while after

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17
Q

Describe the reasoning behind the number and distribution of peaks seen in the compound action potential of a sensory nerve. (2)

A

3 quick peaks from Aa, Ab, and Ad fibres respectively

followed by a delayed peak from C fibres.

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18
Q

Describe the diameter, myelination, and conduction velocity of Aa sensory fibres. (3)

A

Large diameter

Thickly myelinated

Fast conduction velocity

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19
Q

Describe the diameter, myelination, and conduction velocity of Ab sensory fibres. (3)

A

Second largest diameter

Thickly myelinated

Second fastest conduction velocity

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20
Q

Describe the diameter, myelination, and conduction velocity of Ad sensory fibres. (3)

A

Third largest diameter

Myelinated

Third fastest conduction velocity

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21
Q

Describe the diameter, myelination, and conduction velocity of C sensory fibres. (3)

A

Thin diameter

Unmyelinated

Slow conduction velocity

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22
Q

Name two structures innervated by Aa sensory fibres and describe their role. (3)

A

Muscle spindle

Golgi tendon organs

Muscle and joint proprioception

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23
Q

Are Aa fibres nociceptive or non-nociceptive? (1)

A

Non-nociceptive

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24
Q

Give an alternative name for Aa fibres, sometimes used when referring to fibres innervating muscle and joints. (1)

A

Type 1a and type 1b fibres

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25
Q

Are Ab fibres nociceptive or non-nociceptive? (1)

A

Tend to be non-nociceptive

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26
Q

Give an alternative name for Ab fibres, sometimes used when referring to fibres innervating muscle and joints. (1)

A

Type II fibres

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27
Q

Are Ad fibres nociceptive or non-nociceptive? (1)

A

Can be either

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28
Q

Give an alternative name for Ad fibres, sometimes used when referring to fibres innervating muscle and joints. (1)

A

Type III fibres

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29
Q

Are C fibres nociceptive or non-nociceptive? (1)

A

Tend to be nociceptive

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30
Q

Give an alternative name for C fibres, sometimes used when referring to fibres innervating muscle and joints. (1)

A

Type IV

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31
Q

Name a molecular marker that could be used to identify myelinated nociceptors. (1)

A

NF200 (neurofilament)

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32
Q

Give two general categories of unmyelinated nociceptors that can be distinguished with molecular markers. (2)

Name two molecular markers for each group that can distinguish them. (4)

A

Peptidergic (CGRP, substance P marker)

Non-peptidergic (IB4, P2X receptor marker)

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33
Q

Apart from using the molecular markers CGRP and IB4, describe two other ways that peptidergic and non-peptidergic nociceptors can be distinguished. (2)

A

They respond to different growth/neurotrophic factors

They express different receptors

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34
Q

Which of the following categories of nociceptor is the most common? (3)

a) myelinated

b) peptidergic

c) non-peptidergic

A

b) peptidergic

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35
Q

Which nociceptor fibres (Ab, Ad, C) express substance P? (2)

A
  • About 50% C nociceptors
  • A few Ab/d nociceptors
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36
Q

In which sensory nerve fibres (Aa, Ab, Ad, C) is CGRP expressed? (2)

A

Mostly A/C nociceptors

Some A-LTM non-nociceptive fibres

*LTM = low threshold mechanoreceptors

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37
Q

In which sensory nerve fibres (Aa, Ab, Ad, C) is Nav1.9 expressed? (1)

A

Only nociceptors (Ab/d and C)

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38
Q

In which sensory nerve fibres (nociceptors/low-threshold) is Nav1.8 expressed? (2)

A

Strong expression in nociceptors

Weak expression in a few LTM

*LTM = low threshold mechanoreceptors

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39
Q

In which sensory nerve fibres (Aa, Ab, Ad, C, nociceptors, low-threshold) is Nav1.7 expressed? (1)

A

Both nociceptors and non-nociceptors

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40
Q

In which sensory nerve fibres (Aa, Ab, Ad, C) is TrkA expressed? (1)

What is TrkA? (1)

A

Only nociceptors (Ab/d and C)

TrkA is a receptor for NGF

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41
Q

In which sensory nerve fibres (Aa, Ab, Ad, C) is IB4 expressed? (3)

A

Only C fibres

which are nociceptive

and non-peptidergic

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42
Q

In which sensory nerve fibres (Aa, Ab, Ad, C) is P2X3 expressed? (2)

What is P2X3? (1)

A

On nociceptive C fibres

which are IB4-positive.

It is an ATP receptor.

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43
Q

In which sensory nerve fibres (Aa, Ab, Ad, C) are TRPV1/TRPA1 expressed? (2)

A

Nociceptive C fibres

Both peptidergic and non-peptidergic populations

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44
Q

Describe both the thermal and mechanical thresholds for non-nociceptive Aa and Ab fibres. (2)

A

Thermal - none (unresponsive)

Mechanical - Low

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45
Q

Give two sensory modalities that are conveyed by non-nociceptive Aa and Ab fibres. (2)

A
  • Proprioception
  • Light touch
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46
Q

Describe Type I AMH fibres, in terms of Aa, Ab, or Ad fibres. (1)

A

Account for about a third of Ab fibres

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47
Q

Describe AMH nociceptors in terms of modalities and fibre type. (2)

A

Ab/d fibres

which respond to mechanical and heat stimuli (polymodal)

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48
Q

Describe both the thermal and mechanical thresholds for nociceptive Type I AMH fibres. (2)

A

Thermal - High >53C

Mechanical - Low

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49
Q

Describe the proposed role for nociceptive type I AMH fibres in both thermal and mechanical pain. (2)

A

Thermal - sensitisation

Mechanical - first pain

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50
Q

Describe Type II AMH fibres, in terms of Aa, Ab, or Ad fibres. (1)

A

Account for all nociceptive Ad fibres

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51
Q

Describe both the thermal and mechanical thresholds for nociceptive Type II AMH fibres. (2)

A

Thermal - ~46C

Mechanical - High

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52
Q

Describe the proposed role for nociceptive type II AMH fibres in both thermal and mechanical pain. (2)

A

Thermal - first pain

Mechanical - may be silent or unresponsive

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53
Q

In general which nerve fibres (Aa, Ab, Ad, C) are responsible for ‘first pain’? (1)

A

Ab/Ad

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54
Q

Give four sensory modalities that are transmitted by C fibres. (4)

A
  • Nociception
  • Innocuous temperature
  • Itch
  • Pleasant touch (stroking)
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55
Q

Give eight separate types of C fibres (relating to modalities and thresholds). (8)

A

C-HTM
C-heat
C-cold
C-polymodal
C-unresponsive
C-cool/warm
C-pruriceptive
C-LTM

*HTM = high threshold mechanoreceptor
*LTM = low threshold mechanoreceptor

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56
Q

Describe the threshold for both thermal and mechanical stimuli seen in C-HTM fibres. (2)

A

Thermal - High (~43C)

Mechanical - High

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57
Q

Describe the threshold for thermal stimuli seen in C-heat fibres. (1)

A

High

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58
Q

Describe the threshold for thermal stimuli seen in C-cold fibres. (1)

A

Low (~6C)

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59
Q

Describe the threshold for both thermal and mechanical stimuli seen in C-polymodal fibres. (2)

A

Thermal - High

Mechanical - High

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60
Q

Describe the threshold for both thermal and mechanical stimuli seen in C-unresponsive fibres. (2)

A

Thermal - no response

Mechanical - no response

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61
Q

Describe the threshold for both thermal and mechanical stimuli seen in C-cool/warm fibres. (2)

A

Thermal - low

Mechanical - no response

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62
Q

Describe the threshold for both thermal and mechanical stimuli seen in C-pruriceptive fibres. (2)

A

Thermal - no response

Mechanical - no response

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63
Q

Describe the threshold for both thermal and mechanical stimuli seen in C-LTM fibres. (2)

A

Thermal - no response

Mechanical - Low

64
Q

In general which nerve fibres (Aa, Ab, Ad, C) are responsible for ‘second pain’? (1)

A

C fibres

65
Q

Name the general group of ion channels that act as thermoreceptors. (1)

A

TRP (transient receptor potential) channels

66
Q

Name the subtypes of TRP channels, in a general order from detecting the hottest stimuli to the coldest stimuli. (9)

A
  • TRPV2
  • TRPV1
  • TRPV4
  • TRPM2
  • TRPV3
  • TRPM4
  • TRPM5
  • TRPM8
  • TRPA1
67
Q

Which TRP channel detects taste? (1)

Give two particular tastes it can detect. (2)

A

TRPM5

  • Soy sauce
  • Sugar
68
Q

Which TRP channel acts as a mechanoreceptor in C nociceptors? (1)

A

TRPV4

69
Q

Which TRP channel is located in keratinocytes and detects warm stimuli? (1)

A

TRPV3

70
Q

Which TRP channel is known to detect noxious thermal stimuli in C fibres? (1)

A

TRPV1

71
Q

Which TRP channel is suspected to be located in Type I AMH fibres? (1)

A

TRPV2

72
Q

Which TRP channels are able to respond to cooling stimuli? (2)

A

TRPM8
TRPA1

73
Q

Which TRP channel may be involved in nervous system sensitisation? (1)

Suggest why this might be? (1)

A

TRPA1

It responds to a variety of natural chemical activators

74
Q

Give three specific stimuli that TRPV1 may respond to. (3)

A

Chilli peppers

Garlic

Camphor

75
Q

Give two specific stimuli that TRPM8 may respond to. (2)

A

Mint

Eucaliptol

76
Q

Give four ‘food’ stimuli that may activate TRPA1 channels. (4)

A
  • Garlic
  • Mustard oil
  • Wasabi
  • Cannabinoids
77
Q

Name two TRP channels that are activated endogenously by changes in pH and acidity. (2)

A

TRPV1

TRPA1

78
Q

Describe the specific sensory modality carried by C-fibre low threshold mechanoreceptors. (1)

A

Gentle and pleasant touch

79
Q

Describe the general threshold and adaptation properties of mechano-nociceptors and polymodal nociceptors. (2)

A

Threshold - tends to be high

Adaptation - slowly adapting (response is maintained)

80
Q

What is piezo? (1)

How are they related to pain? (1)

A

Mechanotransducers/receptors

They detect painful mechanical stimuli

81
Q

Describe the adaptation properties of piezo1. (1)

A

Appears to be slowly adapting

82
Q

Describe the adaptation properties of piezo2. (1)

A

Rapidly adapting

83
Q

Name a location where piezo2 is abundant. (1)

A

Small and large DRG neurones

84
Q

Describe the threshold properties of the piezo mechanotransducers. (1)

A

It is unknown whether they have high or low thresholds.

85
Q

Give three general stimuli that are detected by the TRPA1 channel. (3)

A
  • Cold
  • Pathological mechanical forces (injuries)
  • Natural chemical activators
86
Q

Give 9 examples of natural chemical activators that can activate the TRPA1 channel. (9)

A
  • pH
  • O2
  • ROS (inflammation)
  • UVA light
  • NO
  • H2S
  • CO2
  • Local and general anaesthetics
  • THC (cannabinoid)
87
Q

Give two examples of mechanotransducers. (2)

A
  • PIEZO2
  • TRPA1
88
Q

True or false? Explain your answer if necessary. (1)

ASICs are mechanotransducers, and are important modulators in pathology.

A

False - ASICs are NOT mechanotransducers, however they ARE important modulators in pathology

89
Q

Give the proper name for the ion channel group called ASICs. (1)

A

Acid-sensing ion channels

90
Q

Name a stimulus that can activate ASICs. (1)

A

Low pH

91
Q

Where do nociceptive neurones have their efferent functions? (1)

A

On small blood vessels

92
Q

Give another name for the efferent effects of nociceptive neurones. (1)

Explain this name. (1)

A

Axon reflex

The effects can occur without contribution from the CNS

93
Q

Give the general name for the efferent effect that nociceptive neurones have on blood vessels. (1)

Name the general mechanism by which this effect occurs. (1)

A

Neurogenic inflammatory response

Vasodilation

94
Q

Name two molecules that are released by nociceptive neurones which mediate their efferent effects. (2)

A

Substance P

CGRP

95
Q

Name a cell type (apart from neurones) which are involved in the neurogenic inflammatory response. (1)

Name two molecules released by this cell type. (2)

A

Mast cell

  • Histamine
  • Substance P
96
Q

Name the three elements of the neurogenic inflammatory response. (3)

A
  • Reddening
  • Flare
  • Wheal (oedema)
97
Q

Give four normal physiological functions of the dorsal root ganglion (cell body) of the sensory neurone. (4)

A
  • Control of neurotrophin expression
  • Calcium binding and store handling
  • Synthesis of transducers and neuropeptides, etc
  • Transport towards axon terminals
98
Q

Give two normal physiological functions of the fibres (axons) of the sensory neurone. (2)

A

Insert ion channels and space them appropriately along the length of the fibre for action potential generation/conduction

Ortho and anterograde transport

99
Q

Give five normal physiological functions of the fibres (axons) terminals of the sensory neurone. (5)

A
  • Feature multiple sites of transduction
  • Proximity of transduction to spike initiators
  • Modality specificity (due to transducer molecules)
  • Some local protein synthesis
  • Efferent function (peripheral release of SP/CGRP; neurogenic inflammation)
100
Q

Describe the distribution of ion channels/transducers along the length of a sensory neurone. (1)

Give a potential consequence of this. (1)

A

Spaced out all along the length of the nerve fibre.

The neurone is vulnerable to activation all the way along the fibre (potential for neurogenic pain and sensitisation).

101
Q

True or false? Explain your answer if necessary. (1)

In sensory neurones, protein synthesis is only able to occur in the cell body, and proteins must then be transported along the axons.

A

False - there is also some local protein synthesis in peripheral terminals

102
Q

Describe a benefit of local protein synthesis occurring in peripheral terminals of sensory nerves. (1)

A

Transport from the cell body can be slow and sensory axons can be very long.

(So proteins can reach the terminal quicker).

103
Q

Suggest a group of structures that can be referred to as ‘spike initiators’ in sensory neurones. (1)

A

Voltage-gated sodium channels

104
Q

Fill the gaps relating to pain signalling in the nervous system. (8)

……………….-threshold nociceptors are activated by intense ……………………., ………………………., or …………………….. stimuli and feed this information to nociceptive neurones in the ……………………………….
Neurones then project via the ………………. to cortical areas generating the sensory and emotional qualities of pain.
These spinal cord pathways are subject to descending inhibitory and facilitatory influences from the …………………..
Normally, activity in low-threshold afferents is carried by independent peripheral and central pathways and only generates ……………………… sensations.

A

High

mechanical

thermal

chemical

spinal cord

thalamus

brainstem

innocuous

105
Q

Which laminae of the spinal cord receive inputs from nociceptors? (3)

A

I, II, V

106
Q

Describe the type of input that is received by laminae I, II, and V of the spinal cord. (3)

A

I = pain only

II = pain only

V = integrates pain and innocuous input

107
Q

Prostatic acid phosphatase (PAP) can be used as a marker to identify some sensory neurones.

Describe the types of sensory neurones that can be identified using PAP staining. (1)

A

Nociceptive DRG neurones (peptidergic and non-peptidergic)

108
Q

Briefly describe a method using rodents than can allow activity in the spinal cord to be measured. (4)

A

Rodent anaesthetised

Electrode inserted into spinal cord

Nociceptive stimuli applied to foot

Spinal cord responses recorded

109
Q

Briefly describe and explain the response expected when recording activity in the spinal cord when a painful stimulus is applied. (4)

A

Early response

due to A fibres

and a later response

due to C fibres

110
Q

Name the two general types of post-synaptic spinal neurone which are activated by painful stimuli. (2)

Which is more common? (1)

A

Wide dynamic range (more common)

Nociceptor specific

111
Q

Give three alternative names for wide dynamic range neurones in the spinal cord. (3)

A

WDR

type 2

convergent

112
Q

In which lamina of the spinal cord are wide dynamic range neurones predominantly located? (1)

A

Lamina V

113
Q

Describe the general role of wide dynamic range neurones in the spinal cord. (1)

Describe how their firing relates to pain behaviour. (1)

A

They code stimulus intensity accurately from innocuous to painful range.

In behavioural studies their firing correlates well with pain behaviour.

114
Q

Give 2 alternative names for nociceptor specific neurones found in the spinal cord. (2)

A

NS

type 3

115
Q

What type/s of stimulus (noxious/innocuous) do nociceptor specific neurones in the spinal cord respond to? (1)

A

Noxious

116
Q

Describe the proposed role of nociceptor specific neurones in the spinal cord. (1)

Describe how their firing relates to pain behaviour. (1)

A

May be more important to transmit the general presence and localisation of pain rather than the intensity.

Firing does not correlate with pain.

117
Q

Name the major excitatory neurotransmitter used in the spinal cord (in the context of pain). (1)

A

Glutamate

118
Q

Name the two receptors which allow fast glutamatergic synaptic transmission. (2)

A

AMPA

Kainate

119
Q

Which ion/s are AMPA and kainate receptors permeable to? (2)

A

Na

Some subunits permeable to Ca

120
Q

Which receptor is activated by A fibre and C fibre inputs to the spinal cord? (1)

Describe how this receptor discriminates pain inputs from non-pain inputs. (1)

A

AMPA

It does not

121
Q

Describe how NMDA receptors are activated by pain. (1)

What role do these receptors play in pain? (1)

A

Activated by sustained noxious input (removal of Mg block)

Contribute to pain facilitation mechanisms

122
Q

Which NMDA receptor subunits are the most common in the spinal cord? (2)

A

NMDAR1

NMDAR2B

123
Q

Fill the gaps relating to NMDA receptors. (4)

NMDA receptors feature a ……………………… assembly of subunits.
The common subunits are called ……………. and ………………., and the subunits …………….. can also feature in these receptors.

A

hetero-oligomeric

GluN1

GluN2A-D

GluN3A-B

124
Q

As well as AMPA, NMDA, and kainate receptors, name another general type of receptor that can be activated by nociceptor inputs to the spinal cord. (1)

A

metabotropic glutamate receptors

125
Q

Name the three groups of mGluR and state which subtypes feature in each group. (3)

A

Group I (mGluRs 1 and 5)

Group II (mGluRs 2 and 3)

Group III (mGluRs 4, 6, 7, 8)

126
Q

Describe the G protein coupling and general downstream effects (including excitation/inhibition) of group I mGluRs. (3)

A

Coupled to Gq

Activation of PLC and increased calcium

Neuronal excitation

127
Q

Describe how activation of group I mGluRs can affect other glutamate receptors. (1)

Describe how they achieve this. (1)

A

Can enhance the effects of NMDA, AMPA, and kainate receptors

They do this via phosphorylation

128
Q

Describe the G protein coupling and general downstream effects (including excitation/inhibition) of group II mGluRs. (3)

A

Coupled to Gi

Inhibition of adenylyl cyclase and decreased cAMP

Inhibition

129
Q

Describe the G protein coupling and general downstream effects (including excitation/inhibition) of group III mGluRs. (3)

A

Coupled to Gi

Inhibition of adenylyl cyclase and decreased cAMP

Inhibition

130
Q

Which group/s of mGluRs can act as autoreceptors?

A

Group II and III

131
Q

Given that group II and group III mGluRs are all inhibitory and decrease cAMP, explain why they are classed as separate groups. (1)

A

They have different pharmacological responses

132
Q

Which mGluRs are present in the periphery on primary afferent fibres?

A

mGluR1 and 5

(Group I receptors)

133
Q

Describe the phenomenon which would occur due to exogenous activation of group I mGluRs on primary afferent fibres. (1)

A

Hyperalgesia

134
Q

Describe what the effect would be of applying mGluR1 and mGluR5 antagonists to peripheral primary afferent fibres. (1)

A

Inhibition of inflammatory pain responses

135
Q

Which group of mGluRs are involved in central sensitisation in the spinal cord? (1)

A

Group I

136
Q

Describe whether mGluR1 and mGluR5 are located pre- or postsynaptically in the spinal cord. (2)

A

mGluR1 = postsynaptic

mGluR5 = pre and post synaptic

137
Q

Which mGluRs have a role in normal nociceptive processing in the thalamus?

A

mGluR1

mGluR5

138
Q

Describe the role that NMDA receptor blockade has in altering pain responses. (2)

A

Spinal NMDA antagonists attenuate facilitated pain responses (post-synaptic)

No change in A or non-facilitated C fibre responses in spinal neurones (presynaptic)

139
Q

Describe the concept of ‘wind-up’. (2)

A

Spinal neurones show an increasing, exaggerated response

to continued peripheral stimulus of the same intensity.

140
Q

Describe how NMDA receptor blockade affects ‘wind-up’ in the spinal cord. (1)

A

Prevents wind-up

141
Q

Name a pain process which can be contributed to by the process of ‘wind-up’. (1)

A

Sensitisation

142
Q

Which receptor does substance P bind to in the spinal cord? (1)

A

NK1

143
Q

Define ‘facilitation’. (1)

Briefly explain the molecular process behind this phenomenon. (1)

A

Amplification of pain signals

Neurotransmitters released from sensory neurones (eg. glutamate, SP) are able to increase the perception of pain

144
Q

Define ‘sensitisation’. (1)

Briefly explain the molecular process behind this phenomenon. (1)

A

The CNS becomes more responsive to pain.

The nervous system undergoes structural, functional, and chemical changes to make neurones more sensitive to noxious or innocuous stimuli.

145
Q

True or false? Explain your answer if necessary. (1)

Facilitation and sensitisation tend to influence each other, and the relationship can work in both directions.

A

True

146
Q

Define ‘pain’. (4)

A

An unpleasant

sensory and emotional experience

associated with, or resembling that associated with

actual or potential tissue damage.

147
Q

Very briefly describe the molecular mechanism behind acute pain. (1)

A

Activity in nociceptors

148
Q

Describe the time scale of acute pain. (1)

A

Less than 3 months

149
Q

Give two specific causes of chronic (ongoing acute) pain. (2)

A

Inflammation (eg. arthritis)

Space occupying lesion (eg. tumour)

150
Q

Very briefly describe the molecular mechanism behind chronic (ongoing acute) pain. (1)

A

Ongoing activity in nociceptors due to ongoing active pathology

151
Q

Describe the time scale for chronic pain. (1)

A

Longer than 3-6 months

152
Q

Chronic (ongoing acute) pain is often treatable with standard analgesics.

Explain why it is still such a huge problem. (2)

A

Have to be careful with long-term treatment.

Can produce behavioural changes (depression) and postural changes to guard the site of pain.

153
Q

Briefly describe the pathology behind neurogenic/neuropathic pain. Give examples. (3)

A

Result of nerve damage

eg. direct trauma such as wear and tear

or illnesses such as diabetes or herpes (shingles)

154
Q

True or false? Explain your answer if necessary. (1)

Neurogenic/neuropathic pain is not necessarily the result of activity in nociceptors.

A

True

155
Q

Neurogenic/neuropathic pain can sometimes resolve with appropriate treatment.

Describe an issue with this treatment. (1)

A

We don’t always understand why treatments work

Neuroscience Y3S1 (7 decks)

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