Pain and analgesia

Question 1

Pain?

Answer 1

“An unpleasant sensory and emotional experience, associated with actual tissue damage or described in terms of such damage”

Question 2

What are the 3 classified pain? with example of fire alarm

Answer 2

(i) Nociceptive (acute/sharp) pain (e.g. pin prick, visceral distension)
(ii) Inflammatory (prolonged) pain (e.g. sunburn, inflamed wound)
(iii) Pathological pain

Question 3

Nociceptive pain begins with the activation of —–

Answer 3

nociceptors

Question 4

about nociceptors?

Answer 4

Question 5

Nociceptive pain is —- ; serves as an early warning system to detect and minimise contact with damaging stimuli (noxious events)

Nociceptive pain is —- threshold – provoked only by intense stimuli that activate nociceptors

Answer 5

adaptive
high

Question 6

Nociceptors are —– order neurons that relay information to second order neurons in the CNS by chemical synaptic transmission.

Answer 6

first

Question 7

what is the benefit of nociceptive pain?

Answer 7

• initiates a withdrawal reflex
• is extremely unpleasant
• engages adverse emotional components
• serves to inscribe memories that allow avoidance of harm in the future

Question 8

Inflammatory pain?

Answer 8

Question 9

Pathological pain?

Answer 9

Question 10

what mutation causes the absence of pain?

Answer 10

in the gene SCN9A that encodes a particular voltage-activated Na+ channel (Nav1.7) that is highly expressed in nociceptive neurons

Question 11

Nociceptors are —– —– neurons innervating peripheral tissues—activated only by mechanical, thermal, or chemical stimuli that are noxious. Comprise —– and —–fibres.

Answer 11

primary afferent
mechanical
thermal
chemical
noxious
Aδ
C

Question 12

Aδ?

Answer 12

fibres are mechanical/thermal nociceptors that are thinly myelinated (conduction velocity of 6-30 ms-1 ) & respond to noxious mechanical and thermal stimuli. Mediate ‘first’, or fast, pain.

Question 13

C-fibres?

Answer 13

C-fibres are nociceptors that are unmyelinated (conduction velocity of 0.5 – 2.0 ms-1) – collectively they respond to all noxious stimuli (i.e. they are polymodal). Mediate ‘second’, or slow, pain

Question 14

Aδ vs C fibre?

Answer 14

Question 15

examples of stimuli that activate the peripheral terminals of polymodal nociceptors

Answer 15

Question 16

Primary afferent axons terminate centrally in the —- horn of the spinal cord in —- to —- laminae of Rexed

Answer 16

dorsal
I to V

Question 17

Nociceptive C- and Aδ-fibres mostly terminate superficially in laminae—– and —– (and also V for — -fibres)

Answer 17

I and II
Aδ

Question 18

Strategies in the pharmacological management of pain?

Answer 18

Question 19

—— – substances extracted from opium, or of similar structure to those in opium
—— – any agent (including endogenous peptides, known collectively as endorphins/enkephalins) that act upon opioid receptors

Answer 19

Opiates
Opioids

Question 20

Non-steroidal anti-inflammatory drugs (NSAIDs) reduce ——
Non-selective NSAIDs have analgesic, antipyretic and anti-inflammatory actions, largely by inhibiting the synthesis and accumulation of prostaglandins by enzymes; —— and ——-
Examples of NSAIDs?

Answer 20

nociceptor sensitization
COX 1 and COX 2
Non-selective NSAIDs

aspirin
ibuprofen
naproxen
diclofenac
indometacin

Question 21

Cellular action of opioids and analgesia

Answer 21