Pain and Neural Transmission

Question 1

where in the skin layer are light touch receptors found?

Answer 1

near the top.

Question 2

where in the skin layer are harder touch receptors found?

Answer 2

further down than light touch.

Question 3

what in the skin layer are pain receptors?

Answer 3

free nerve endings.

Question 4

what are free nerve endings?

Answer 4

pain receptors/ nociceptors.

Question 5

In dermis are peripheral nerve firbe branches and terminals myelinated or unmyelinated?

Answer 5

unmyelinated.

Question 6

due to tissue damage and inflammation blood rushes to the area, what can it do in this area?

Answer 6

• bring substances
• sensitise peripheral nociceptors.
• induce hyperalgesia (heightened pain response)

Question 7

what are the 2 type of nociceptors that transduce painful stimuli?

Answer 7

• unmyelinated ‘C’ fibres.

- thinly myelinated ‘A delta’ fibres.

Question 8

what can nociceptors respond to?

Answer 8

• Mechanical stimuli
• thermal stimuli
• chemical stimuli.

Question 9

where is a thermoreception for heat found? where is it found? what fibre type is it? and what is its role?

Answer 9

• found in deep epidermis
• fibre type = C
  = role is warmth.

Question 10

where is a thermoreception for cold found? where is it found? what fibre type is it? and what is its role?

Answer 10

• found in deep epidermis
• fibre type - ‘A delta’
• role is cold.

Question 11

for short pain what is the type of receptor? what is its submodality, where is it found? and what are its fibre type?

Answer 11

• Nociception
• submodality = small and myeliated.
• found in epidermis
• fibre type - ‘A delta’

Question 12

for burning pain what is the type of receptor? what is its submodality, where is it found? and what are its fibre type?

Answer 12

• Nociception
• submodalitly = unmyelinated
• found in epidermis
• fibre type = C

Question 13

if a nerve fibre is myelinated what does this mean for the speed and duration of the pain?

Answer 13

fast shorter pain

Question 14

How do all sensory receptors work?

Answer 14

• stimulus deform/ changes the nerve ending.
• alters the membrane permeability of the receptor membrane
• produces a receptor potential
• triggers an action potential which travels along the axon to the CNS.

Question 15

For thermoreceptors or nociceptors: which one will give out a nerve signal to a max point and then not climb many more?

Answer 15

thermoreceptors.

Question 16

what fibres are involved in 1st pain?

Answer 16

fast A-delta fibres.

Question 17

what are the indications of 1st pain?

Answer 17

• sharp or prickling
• easily localised
• occurs rapidly
• short duration

Question 18

what type of receptors cause 1st pain?

Answer 18

• mechanical or thermal nociceptors.

Question 19

what fibres are involved in 2nd pain?

Answer 19

• slow C fibres.

Question 20

what are the indications of 2nd pain?

Answer 20

• dull ache,
• burning
• poorly localised
• slow onset
• persistent.

Question 21

what type of receptors cause 2nd pain?

Answer 21

polymodal nocaceptors.

Question 22

what are primary afferents?

Answer 22

axons bringing info from the somatic receptors (free nerve endings)

Question 23

what are motor efferents?

Answer 23

axons taking info from the CNS to peripheral structures.

Question 24

what is the afferents pathway?

Answer 24

feed into the spinal cord via the spinal nerve and the dorsal root.

Question 25

what is the efferents pathway?

Answer 25

leave the spinal cord via a ventral root and the spinal nerve.

Question 26

where is the nocicepive fibres cell bodies found?

Answer 26

within the dorsal root ganglion.

Question 27

What are the steps of the afferent pathway inside of the spinal cord?

Answer 27

- enter the dorsal horn - travel up/down a short distance within the zone of lissauer - synapse onto neurones within the superficial laminae of hte dorsal horn.

Question 28

what are the principle areas in the spinal cord that are innervated by nociceptor afferents?

Answer 28

- Lamina l and Lamina ll

Question 29

what causes refereed pain?

Answer 29

- 'cross talk' - this is cause due to afferents from the internal organs/skin enter the spinal cord through common routes and so target overlapping populations of spinal neurones.

Question 30

is the ascending pain pathway a contralateral pathway? why?

Answer 30

It is because sensory inputs cross at the level of the spinal cord and ascend on the opposite side.

Question 31

what is phantom pain?

Answer 31

pain/touch sensations with no sensory inputs.

Question 32

what is endogenous analgesia and pain modulation?

Answer 32

sensory inputs without pain sensations

Question 33

what is alledynia?

Answer 33

damage to nerve fibres, meaning touching gently will cause chronic pain.

Question 34

where are opiates found? and what are they?

Answer 34

in the brain - they are reseptors.

Question 35

what do opiates control?

Answer 35

- pain - immune responses - other body functions.

Question 36

what does endocannabinoid do?

Answer 36

inhibits behavioural responses to acute noxious stimuli | - limits hyperalgesia and neuropathic pain.

Question 37

what is acute pain?

Answer 37

fast, not long lasting pain.

Question 38

what causes acute pain?

Answer 38

- skin abrasions, - deep tissue injury - postoperative - dental - superficial burns.

Question 39

what receptors are stimulated and what fibres are involved in acute pain?

Answer 39

- nociceptive stimulation | - C afferent fibres.

Question 40

what receptors are stimulated and what fibres are involved in non-painful sensation?

Answer 40

- innocuous stimulation | - A delta afferent fibres.

Question 41

what is chronic pain?

Answer 41

pain that lasts over 3 months.

Question 42

what causes chronic pain?

Answer 42

- inflammatory pain - neuropathic pain - neuralgias - musculo-skeletal pain - visceral- cancers.

Question 43

what fibres are involved in chronic pain?

Answer 43

C afferent fibres,

Question 44

what is hyperalgesia?

Answer 44

issue that has already been damaged or inflamed resulting in a reduced pain threshold in that area.

Question 45

what else can cause pain rather than just physical damage?

Answer 45

- prior experiance - attention/ expectation - mood (anxiety/depression) - neurochemistry/ structural changes. - genetics.

Question 46

why do we experience pain?

Answer 46

- provides constant feedback abut the body. - warning sign - triggers help - has psychological consequences.

Question 47

what is the Gate Control Theory?

Answer 47

- that there is a neural 'gate' in the spinal cord that regulates the experience of pain. - there are physiological and psychological causes to pain. - pain is a perception on experience rather than a sensation. - individuals actively interprets and appraises the stimuli. - pain is the result of the relative activity in large and small diameter nerve fibres.

Question 48

what information in the Gate Control Theory is believe be be sent to the gate?

Answer 48

- behavioural state - emotional state - previous experience or self-efficacy in dealing with the pain.

Question 49

According the the Gate Control Theory, Large fibres carrying sensory inform would do what to the gate?

Answer 49

close the gate - inhibiting information flow

Question 50

According the the Gate Control Theory, Small fibres carrying noxious inform would do what to the gate?

Answer 50

open the gate - facilitating info flow.

Question 51

How can you help with pain control? (without the need for drugs)

Answer 51

- avoid negatives - 'reframing' sensation - NEVEr say you wont feel anything - relaxation and lowered pain threshold - distraction - massage area - apple pressure or strech mucosa prior to injection.

Question 52

what are examples of chronic oro-facial pain?

Answer 52

- TMJ pain (facial arthromyalgra) - Atypical facial pain (PIFP) - Burning mouth syndrome - Atypical odontalgia (PDAP)

Question 53

How do you make a pain diagnosis?

Answer 53

S.O.C.R.A.T.E.S - Site - Onset - Character - Radiation - Association - Time course - Exacerbating/ Relieving factors - Severity.