Anatomy of physiology of pain

Question 1

3 types of pain

Answer 1

Nociceptive
Prolonged/ inflammatory
Neuropathic

Question 2

Define nociceptive pain

Answer 2

Pain elicited by brief noxious stimulus

Question 3

What is function of noxious pain

Answer 3

Prevent further damage

Question 4

What is the result in a mutation of Nav1.7 channel

Answer 4

Presents with abnormal pain sensations

Question 5

What is CIPA

Answer 5

Congenital insensitivity to pain with anhydrosis

Question 6

What mutation causes CIPA

Answer 6

trkA

Receptor for nerve growth factor

Question 7

What does trkA mutation lead to

Answer 7

Decreased pain sensitivity

Anhydrosis (inability to sweat)

Question 8

Is prolonged/ inflammatory pain central or peripheral

Answer 8

Peripheral

Question 9

What is prolonged/ inflammatory pain

Answer 9

Hypersensitivity from inflammation around an area of the body that has been injured

Question 10

What is the biological function of inflammatory pain

Answer 10

Prevent further damage and assist tissue repair

Question 11

Is chronic pain central or peripheral sensitisation

Answer 11

Central

Question 12

Define chronic pain

Answer 12

Pain that has been present for 3 months that results from disease/ damage to PNS/CNS

Question 13

What is neuropathic pain

Answer 13

Pain persists in the absence of initial injury

Several PNS and CNS abnormalities

Question 14

What nerves sense pain from internal organs

Answer 14

General visceral afferents

Question 15

What does pain from general visceral affarents respond to

Answer 15

Distention

Not sensitive to cutting or burning

Question 16

Name the 4 stages of pain

Answer 16

Transduction
Transmission
Perception
Modulation

Question 17

Describe phase 1 of pain

Answer 17

Transduction–> at the receptor

Noxious stimuli translated into electrical activity at sensory nerve endings

Question 18

Describe phase 2 of pain

Answer 18

Transmission–> nerve fibres

Propagation of impulses along pain pathway

Question 19

Describe phase 3 of pain

Answer 19

Perception–> areas of brain

Descrimination/ affect/ motivation

Question 20

Describe phase 4 of pain

Answer 20

Modulation

Stages 1-3 are modified

Question 21

What are nociceptors

Answer 21

Non-specialised receptors that use free nerve endings

Often polymodal

Question 22

Define polymodal

Answer 22

Respond to more than one type of stimulus

Question 23

Name 3 types of nociceptors

Answer 23

Cutaneous
Muscular
Visceral

Question 24

Function of cutaneous nociceptors

Answer 24

Aid conversion of a noxious stimuli into an electrical impulse

Question 25

What pain does TRPV1 receptor detect

Answer 25

heat and acid

Question 26

What pain does ASIC receptor detect

Answer 26

Acid

Question 27

What pain does TRPM8 receptor detect

Answer 27

Cold/ menthol

Question 28

Define transmission

Answer 28

Travel of the receptor impulses along different pain pathways to different parts of the brain

Question 29

Function of first order neurones

Answer 29

Carry sensory impulse from sensory receptor to CNS

Question 30

What kind of pain is associated with a-delta fibres

Answer 30

Fast, prick pain

Question 31

Function of a-delta fibres

Answer 31

Localising source of stimulus

Question 32

What kind of pain is associated with c fibres

Answer 32

Slow burning pain

Question 33

Where do the impulses travelling via peptide poor C fibres travel to

Answer 33

Dorsal horn

Question 34

Where do impulses travelling via peptidergic C fibres tro travel

Answer 34

Dermis

Question 35

Once at the dermis what do peptidergic C fibres release?

Answer 35

Substance P for vasodilation and mast cell histamine release

Question 36

Cardinal signs of inflammation

Answer 36

Heat Red Pain Swelling

Question 37

What do first order neurones synapse with

Answer 37

Second order neurones

Question 38

What do c fibres innervate

Answer 38

Lamina 1

Question 39

What do a delta fibres inneravte

Answer 39

Project neurones at laminae 1 and 5

Question 40

As well as a-delta fibres, what else does lamina 5 receive input from

Answer 40

A-beta | C fibres

Question 41

Where does the anterior/ neo spinothalamic tract go to

Answer 41

Primary and secondary somatosensory cortex

Question 42

Where does lateral/ paleo spinothalamic tract go

Answer 42

Anterior cingulate anad rostral insular cortex

Question 43

Which aspects of pain does the anterior spinothalamic tract detect

Answer 43

Where/ how

Question 44

What fibres does neo spinothalamic tract use

Answer 44

Fast a-delta fibres

Question 45

Where does the spinothalamic tract project to

Answer 45

VPL and VPM of thalamus | Projects to primary and secondary cortex

Question 46

What does the lateral spinothalamic tract detect

Answer 46

Affective- motivation | Quality of pain

Question 47

What fibres does lateral spinothalamic tract use

Answer 47

C fibres | A-delta fibres

Question 48

What does the lateral spinothalamic tract project to

Answer 48

Mediodorsal nucleus | Posterior thalamus- posterior nucleus and ventral mediate nucleu

Question 49

Where does the MDvc project to

Answer 49

Anterior cingulate cortex

Question 50

Where do Pom and Vmpo project to, and what information does this give

Answer 50

Insula | Quality of pain

Question 51

What does the primary somatosensory cortex perceive about pain

Answer 51

Pain localisation

Question 52

What does secondary somatosensory cortex perceive about pain

Answer 52

Pain intensity

Question 53

What does insula perceive

Answer 53

Pain intensity

Question 54

What does anterior cingulate cortex perceive

Answer 54

Emotion and attention

Question 55

What does prefrontal cortex perceive

Answer 55

Emotion and memory

Question 56

What is the gate control theory of modulation

Answer 56

Projection neurone of lamina 1

Question 57

What is counter stimulation analgesia

Answer 57

Convergence | 2 difference sensory inputs fuse into 1 when trave

Question 58

Stimulation of which fibres are involved in counter stimulation analgesia

Answer 58

A-beta fibres that stimulaate lamina 2

Question 59

What does TENS stand

Answer 59

Transcutaneous electrical nerve stimulators

Question 60

How do TENS machine work

Answer 60

Stimulate a-beta fibres Stimulate area around painful region through low intensity and high frequency stimuli Aim to stimulate inhibitory lamina 2 interneurones

Question 61

What is meant by supraspinal (descending) analgesia

Answer 61

Type of modulation whereby descending systems modulate the transmission of ascending pain signals

Question 62

Which is the main region of the brain involved in supraspinal descending analgesia

Answer 62

Periaqueductal grey in main region

Question 63

Deep brain stimulation of which area is used to decrease pain

Answer 63

Periaqueductal grey

Question 64

Name 3 areas of the brain that the periaqueductal grey stimulates

Answer 64

Locus coeruleus Nucleus raphe magnus Reticular formation

Question 65

What does nucleus raphe magnus transmit

Answer 65

Serotonin and encephalin

Question 66

What is meant by arousal analgesia

Answer 66

Sympathetic system stimulation via reticular formation

Question 67

What does arousal analgesia cause

Answer 67

Noradrenaline release | Activation of inhibitory lamina 2

Question 68

What does phospholipase A2 releases from cell membranes

Answer 68

Arachidonic acid

Question 69

What drugs can target arachidonic acid

Answer 69

Steroids

Question 70

What molecules use arachidonic acid as substrate for prostaglandin synthesis

Answer 70

COX-1 and COX-2

Question 71

Is COX-2 always present or just in inflammation

Answer 71

Inflammation

Question 72

What is peripheral sensitisation

Answer 72

Increased sensivity to pain (heat induced pain means primary thermal hyperalgesia, pressure pain- primary mechanical hyperalgesia)

Question 73

What is central sensitisation

Answer 73

Increased mechanical sensitisation extending outside the region of flare Thermal responses normal

Question 74

Why does flare occur

Answer 74

Release of peptides by C fibres and other local inflammatory mediators

Question 75

What is dysfunctional pain

Answer 75

No known lesion or inflammation

Question 76

How do COX-1 and COX-2 enzymes used arachnoid acid?

Answer 76

For prostagalndin synthesis

Question 77

How do prostaglandins sensitise C fibres

Answer 77

Increasing number of other receptors and by increasing number of open sodium channels

Question 78

What do nociceptor affarents release during central sensitisation, and what is the result of this

Answer 78

Glutamate and peptides | Results in increased sensitivity of dorsal horn nociceptive second order neurones to inputs

Question 79

How is acupuncture thought to work?

Answer 79

- Activates A delta fibres - Thus stimulating diffuse noxious inhibitory control (DNIC) of pain - Pain can inhibit pain