Pain Worksheet

Question 1

Explain the finding of the study investigating the sex differences in pain

Answer 1

• No significant sex differences at low temp
• Females reported higher pain at same high heat as males

Question 2

A-beta fibers
- Information carried
- myelinated?
- Diameter (Smallest to largest)
- Conduction (Slowest to fastest)

Answer 2

• Touch
• yes
• largest
• fastest

Question 3

A-delta fibers
- Information carried
- myelinated?
- Diameter (Smallest to largest)
- Conduction (Slowest to fastest)

Answer 3

• Pain
• yes
• moderate
• moderate

Question 4

C fibers
- Information carried
- myelinated?
- Diameter (Smallest to largest)
- Conduction (Slowest to fastest)

Answer 4

• Pain
• no
• smallest
• slowest

Question 5

Meissner Corpuscle
- Stimulus response
- Fiber type
- Adaptation Rate
- Activation Threshold

Answer 5

• Touch (dynamic deformation)
• A-beta
• Rapid
• Lower

Question 6

Pacinian Corpuscle
- Stimulus response
- Fiber type
- Adaptation Rate
- Activation Threshold

Answer 6

• Touch (Vibration)
• A-beta
• Rapid
• Lower

Question 7

Merkle’s disk
- Stimulus response
- Fiber type
- Adaptation Rate
- Activation Threshold

Answer 7

• Touch (indentation depth)
• A-beta
• moderate
• Lower

Question 8

Ruffini Corpuscle
- Stimulus response
- Fiber type
- Adaptation Rate
- Activation Threshold

Answer 8

• touch (stretch)
• A-beta
• moderate
• lower

Question 9

Free Nerve Ending
- Stimulus response
- Fiber type
- Adaptation Rate
- Activation Threshold

Answer 9

• Pain
• A-Delta and C
• Slow
• Higher

Question 10

What receptors are activated when you burn your hand in boiling water

Answer 10

• Free nerve endings

Question 11

What receptors are activated when you get kicked in the shin

Answer 11

• Free Nerve endings
• merkle’s Disk

Question 12

What receptors are activated when giving a vigorous handshake

Answer 12

• Free Nerve Endings
• Meissner Corpuscle

Question 13

Spinothalamic Tract

Answer 13

• Originates in the nociceptor
• Cells extend from A-delta and C-fibers and synapse in the dorsal horn with the second order neurons
• Second-order neurons ascend to the thalamus on the contralateral side
• Second-order neurons synapse with third-order neurons in the thalamus
• third-order neurons terminate in the somatosensory cortex

Question 14

Lemniscal Tract

Answer 14

• Originates with mechanoreceptors
• Cells extend to form a-beta fibers that synapse in the medulla oblongata with second order neurons
• Second-order neurons ascend to thalamus on the contralateral side
• Second-order neurons synapse in the thalamus with third-order neurons that terminate in the somatosensory cortex

Question 15

Gait Control Theory

Answer 15

• Applying though to the sight of injury activates the A-beta neuron
• Which activates the interneuron
• The interneuron inhibits the second-order neuron of the spinothalamic tract closing the gait to pain

Question 16

What aspect of pain perception does acetaminophen impact?

Answer 16

Emotional

Question 17

What brain regions are involved in emotional pain

Answer 17

Insula and ACC

Question 18

What impact did acetaminophen have on the participant’s pain perception in De Wall et al (2010) study

Answer 18

Reduces activation in the insula and ACC, which reduces feelings of hurt caused by social rejection

Question 19

How can chronic back pain impact the brain?

Answer 19

• Increased activity of insula
• decrease in grey matter density in the prefrontal cortex

Question 20

What is the impact of increased activity of the insula caused by chronic back pain?

Answer 20

Increased hyperalgesia/ sensitivity to pain
- can relate to increased rates of anxiety and depression in individuals with chronic back pain

Question 21

What is the impact of decreased grey matter density in the prefrontal cortex?

Answer 21

reduction in cognitive function, specifically executive function related to decision making

Question 22

What are the similarities between phantom limb pain and allodynia

Answer 22

Both result from maladaptive neuroplasticity

Question 23

What are the differences between phantom limb pain and allodynia

Answer 23

1. One is due to maladaptive neuroplasticity in the spine and the other is in the somatosensory cortex
2. Damage to nerve vs loss of limb
3. Does not respond to mirror therapy vs does

Question 24

How does intention affect pain when someone hurts you?

Answer 24

Malicious intent causes an increase in pain

Question 25

How does attention affect pain perception

Answer 25

- Not attending to pain decreases how much it hurts -Periaqueductal Grey (PAG) becomes more activated -Prefrontal cortex inhibition of the PAG when attending to pain

Question 26

How does more intense pain affect perception of moderate level pain?

Answer 26

- More intense pain inhibits moderate pain - Periaqueductal gray (PAG) released endogenous opioids which bind to opioid receptors to inhibit pain and raises threshold for pain (analgesic effect)

Question 27

Pain in neonates

Answer 27

- Neonates feel pain - historically, insufficient scientific understanding of the brain meant that neonates were not offered pain relief, even for major surgeries

Question 28

Characteristics of Pain

Answer 28

- unpleasant at both sensory and emotional levels - potentially but not necessarily associated with tissue damage - Subjective

Question 29

Non-verbal response to pain

Answer 29

- Facial expressions - Crying characteristics - Cortisol levels - Neural Activity

Question 30

How do expectations influence pain?

Answer 30

- Positive and negative expectations elicit powerful placebo or nocebo effects - Anxiety about pain increases the pain

Question 31

Def: Empathy

Answer 31

Feeling another's pain

Question 32

Compared to pain administered to self, what does empathy cause

Answer 32

- No activity of the somatosensory cortex - Similar activation of the insula and ACC - Activation of the insula depends on the extent to which one feels empathetic

Question 33

Distinctions between social and physical pain

Answer 33

- Social pain appears to hurt more than physical pain when relived - Context matters

Question 34

How long must pain persist to be considered chronic pain?

Answer 34

longer than 3 months

Question 35

What are the three types of chronic pain

Answer 35

1. Nociceptive - Tissue damage 2. Neuropathic - Nerve damage 3. Nociplastic - Sensitized nervous system

Question 36

What causes chronic pain?

Answer 36

- Dysfunctional neuronal signaling in the periphery, dorsal horn and cortex - Resulting in neural degeneration that impairs pain perception, mood and decision making

Question 37

How can chronic pain be treated

Answer 37

-Hyperalgesia may benefit from opioids but there are risks of addiction - Allodynia is resistant to opioids -talk therapy and physiotherapy may be the best approaches to rewire the nervous system for nociplastic pain

Question 38

Explain the Rubber Hand Illusion

Answer 38

- Visual input tricks the brain into believing the rubber hand is your real hand -Causes temporary representation of the rubber hand in somatosensory cortex

Question 39

Virtual reality effect on neck pain

Answer 39

- Visual information tricks the brain into thinking the head has rotated more or less than it has

Question 40

What causes phantom limb pain?

Answer 40

-Neighboring body parts takeover the S1 area that used to represent the amputated limb - When that region is activated, it can cause pain in the former location of the amputated limb

Question 41

Function of mirror therapy

Answer 41

Helps to suppress S1 activity and phantom pain