Pain

Question 1

what is pain

Answer 1

unpleasent sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage

Question 2

pain is multi-dimensional

Answer 2

sensory-location, radiation, intensity
negative emotions-anxiety, depression
social-affects social structure, conspecifics in pain
environmental- being unable to hide, disturbed by environ can affect pain

Question 3

pain perception and use

Answer 3

ability to detect noxious stimuli is essential to survival and well being

• pain is active process
• involves peripheral and central mechs
• multiple plastic changes determine pain experience

Question 4

pain experience

Answer 4

1. transmission of signal: noxious stim>brain (nociception)
2. perception of unpleasant experience
3. behavioural or cognitive response to pain

Question 5

nociception

Answer 5

negative stimulus transfer and response in brain

-nociceptors are terminal endings of primary afferent nerve fibers

Question 6

nociceptor types

Answer 6

• myelinated A-delta fibers
• non-myelinated C-fibers
• both synapse at DORSAL horn of spinal cord

Question 7

Pain pathway, 4 processes

Answer 7

1. transduction
2. transmission
3. modulation
4. perception

Question 8

transduction

Answer 8

-noxious stimuli translated to electrical activity at sensory nerve endings and nociceptors

Question 9

transmission

Answer 9

propagation of impulses in nervous system, moves through sensory nerves nerves

Question 10

modulation

Answer 10

amplification or suppression or nerve signals at spinal cord

Question 11

perception

Answer 11

integration, processing, and recognition of nerve signals at brain

Question 12

how do we know animals feel pain?

Answer 12

• similar nervous system with brain, spinal cord, and pain receptors
• show behaviour indicating pain, ie. vocal and flinching
• do signs go away when given drugs to remove pain?

Question 13

types of pain

Answer 13

acute: immediate, severe pain, ie. colic
chronic: duller, over time pain, ie. arthritis

Question 14

importance of pain assessment

Answer 14

underestimation of pain and ineffective analgesia can results in ethical obligations not being met
-limiting effect of pain in research is ethically vital

Question 15

traditional assessments

Answer 15

subjective: appearance, posture, gait, demeanour
objective: activity, food/water intake, respiratory/heart rate, blood pressure

Question 16

equine signs of pain

Answer 16

head down, on three legs, rolling, tucked abdomen, ached back, dropped ears, aggressive, kicking, striking, biting, fighting, defeated, docile, escaping, quiet, grunting moaning, lameness, slow, odd gait, non-weight bearing, reluctant to move, self-trauma, dull eyes

Question 17

limitations of traditional assessments

Answer 17

• little evidence of how is it related to pain intensity
• requires detailed species knowledge
• requires a baseline of species/individual
• observers may vary interpretation

Question 18

behavioural assessment

Answer 18

• improve effectiveness of pain assessment

- behaviour gives immediate cage assessment, and relationship between pain and behaviour

Question 19

principles of behavioural assessments

Answer 19

• pain causes certain behaviours to be more or less frequent
• analgesics should therefore reduce the increase or decrease
• appropriate controls are necessary to ensure relationships and changes are in response to pain

Question 20

problems with behavioural indicators

Answer 20

-few procedures assessed in small number of species
-time consuming process:
must establish which behaviours indicate pain, applying scoring system
-still only 80% accurate

Question 21

facial expressions of pain

Answer 21

-established in humans, and validated tool for rats and mice as well

Question 22

horse grimace scale

Answer 22

• back/sideways ears
• tension above eyes
• orbital tightening
• prominenet strained chewing muscles
• strained nostrils and mouth