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Flashcards in Endogenous Control of Pain Deck (28):
1

adequate stimulus for pain

anything causing tissue damage

2

peripheral receptors for pain

on free nerve endings
-branch out and disperse

3

types of free nerve endings for pain

nociceptors
A-delta and C fibers
silent
thermoreceptors
mechanoreceptors

4

A delta

small - light myelination

5

C fibers

small - no myelination

6

silent receptors

only with repeated pain stimuli
-or inflammation

7

pain stimulates

attention
emotion
ANS
memory

8

pain

perception of noxious stimulus

9

nociceptive information

has multiple destinations
(divergence)

10

spinothalamic tract

only conscious tract for pain

11

brainstem

spinoreticular and spinomesencephalic tract

12

hypothalamus

spinohypothalamic tract

13

limbic system

indirectly via RF and hypothalamus

14

spinothalamic tract

good localization
-because its contralateral and has somatotopy

easier to test as clinician
-because you are consciously aware

15

spinoreticular and spinomesencephalic tracts

bad localization
-because bilateral pathways

good for attention, emotion, ANS, and memory

16

noxious stimuli

not emotionally neutral events

17

perception of pain

not an unchangeable property
-can modulate

18

modulation of nociception

changes in nociceptors
-change in dorsal horn
-alter descending pathways

19

hyperalgesia

increased pain response to noxious stimulus
-pain much more intense after secondary injury

20

allodynia

pain perception to normally not painful stimulus
-ex/ sunburn

21

tissue injury

release of inflammatory mediators
-decrease threshold of regular nociceptors
-recruit silent nociceptors

22

axon reflex

pain stimuli come in
-free nerve endings have trigger zone
-great enough intensity, APs back out to free nerve endings
-for further vasodilation and inflammation

23

modulation by descending pathways

input from hypothalamus, amygdala, cortex
-to periaqueductal gray (midbrain)
-synapse at nucleus raphe-magnus (caudal pons)
-to dorsal horn

24

C fibers

absence of input from C fibers - tonic inhibition
-from interneurons
with strong pain - C fibers stop inhibition pathway
-allow stronger signal to go to brain

25

reticular formation

level of alertness to pain

26

hypothalamus

autonomic response to pain

27

limbic system

emotional response to pain

28

cognitive evaluation aspect

provides context, culture and experience
-mediated by association areas