pain 4d Flashcards
1
Q
pain
A
an unpleasant sensory and emotional experience associated with actual or potential tissue, damage or described in terms of such damage
2
Q
pain is __
A
protective and adaptive
alert for actual or potential threat to physical self
3
Q
pain is number one reason people___
A
seek medical treatment
4
Q
Noxious stimulus
A
activates nociceptive stimulus, painful, bothersome
5
Q
innocuous stimulus
A
non-nociceptive , does not elicit pain, example: gentle touch
6
Q
algesia
A
sensitivty to pain
7
Q
analgesia
A
reduced sensitivty to pain
8
Q
hyperalgesia
A
increased sensitivty to pain
9
Q
allodynia
A
sensation of pain in the absence of stimulus or pain resulting from normally painless stimuli
10
Q
Gate control theory
A
pain transmission modulated by impulses synapsing on spinal cord
-cells in substantial gelatinosa fxn as a “gate” that controls transmission of signal to higher centers in the brain
11
Q
___and___ sense painful stimuli and open gate
A
A delta, C fibers
12
Q
____FIBERS SENSE INOCUOUS STIMULI CLOSE the GATE
A
A beta
13
Q
hitting your elbow _____, ______ that same area makes pain subside faster
A
pain: noxious stimuli, rubbing : innocuous stimulus
14
Q
CNS signals can modify gate
A
ex: depression increases sensitivity to physical pain bc it allows gate to be opened more easily
15
Q
Neuromatrix theory
A
idea that brain produces patterns of nerve impulses perceived as pain from a variety of inputs: genetics, psychology, cognitive experiences
16
Q
patterns typically _____in periphery , BUT may also originate independently ______
A
activated by sensory inputs, in the brain without external sensations
17
Q
neuromatrix takes into account ___ aspect of pain
A
cognitive/emotional
18
Q
phantom limb pain, chronic pain
A
physical stimulus may be missing but pain is still perceived (neuromatrix theory)
19
Q
neuromatrix theory is ____to gate theory
A
supplemental
20
Q
nociceptors
A
free nerve endings throughout the body
-sense chemical, thermal, mechanical stimuli
21
Q
_____of nociceptors leads to differnces in pain sensitivity
A
uneven distribuation
-why fingertips are more sensitive than back, skin more sensnitve than internal organs
22
Q
A-delta fibers
A
-lightly mylinated
-transmit sharp , well localized pain
-respond to exteme mechanical and thermal stimulation
23
Q
C fibers
A
-unmyelinated
-transmit dull, aching, throbbing, burning pain
-respond to mechanical, thermal and chemical stimulation
24
Q
A-beta fibers
A
mylinated
-transmit touch and vibration
-do not perceive pain BUT play a role in pain modulation
25
nociceptor activation can be ___ or ___
direct, indirect
26
Direct excitation
threshold depolarization
-initiated by heat, radiation, toxins, tissue trauma
27
indirect excitation
tissue injury causes inflammation
-release of inflammatory mediators that cause pain
-prostaglandins, bradykinis, hisamine, leukotrenes
28
from nociception to pain
once nociceptors activated, signal undergoes many steps
-transmission (from periphery to brain)
-perception (awareness of pain)
-modulation (CNS to periphery)
29
Transmission occurs along a sequence of neurons
primary-> secondary-> third
30
primary- order neurons (periphery)
-pain-transmitting sensory neurons, A delta and C
-cell bodies located in gray matter of spinal cord : dorsal root ganglion (DRG)
-synapse on second-order neurons
31
second-order neurons (think spinal cord)
-gray matter of the spinal cord
-second-order neurons are interneurons
32
excitatory interneurons
relay transmission to projection neurons -> thalamus
33
inhibitory neurons
modulate pain transmission
34
synapse between primary and second-order neurons is _____
pain gate
35
third order neurons (think thalamus)
thalamus is major relay center for sensory info
-third-order neurons begin in thalamus
-project to portions of cortex involved in processing and interpreting pain signal
36
extensive corticol network that handles pain signals is called the
"pain matrix"
37
perception
conscious awarness of pain
38
awarness occurs in the ______before it reaches the brain it is considers _______
brain, nociception
39
perception is highly subjective: depends on
mood, culture, percived gender role, life experinces, past experiences of pain
40
Perception is mediated by
somatosensory cortex, prefrontal cortex, limbic system , cerebral cortex
41
Modulation
supresses or facilitaes pain
-occurs in spinal cord or brain
most involved interneurons
42
mechanisms of modulation
segmental
desceding, diffuse noxious inhibition
expectancy-related corticol activation
43
Segmental inhibition
A-beta fibers close the pain gate in SC vis inhibitory interneuron
ex: rubbing an injured area to make it hurt less- decreasing pain sensation
44
Descending modulation
signals from cortex/amygdala-> periaqueductal gray (PAG) of midbrains -> spinal cord
-activate inhib. excit. interneurons, depending on NT
(DECR OR INCr pain sensation)
45
Diffuse noxious inhibition
pain stimulation in another area counteracts pain of injury (distracts from origin of pain)
-mediated by interneurons in spinal cord
theory behind sucuess of massage/ acupuncture)
46
expectancy related cortical activation
cognitive expectations can sig attenuate of intensify pain (thinking abt situation)
ex: expecting something to hurt will increase perception of pain
47
Excitatory NTs involved in pain
-glutamate
-AMPA, NMDA receptors
-serotonin
48
Inhibitory NTs involved in pain
-GABA (y-aminobutyric acid)
-norepi, serotonin
-endogenous opioids: morphone-like substances that inhibit pain transmission: Endorphins, enkephalins
49
Endogenous opioids
3 types of opoid receptors in body:
mu, kappa, delta
50
ligand binding to opioid receptors inhibits release of_____
excitatory nts
51
Endorphins (endogenous opioid)
-concentrated in hypothalamus and pituitary gland
-strong agonist of u (mu) receptors
-inhibit sensation of pain, relieve stress, produce exhilaration or "high"
-releases during exercise, orgasm, tissue injury
52
Enkephalins
-found in brain and adrenal medulla
-agonist at mu and delta receptors
-released in response to stress, pain
53
Neurophysiogically pain type
due to tissue damage or NS damage
54
Temporally pain type
acute or chronic
55
etiologically pain type
cancer pain, postoperative pain
56
regionally pain type
abdominal pain, pelvic pain, chest pain
57
Nocicpetive activation of nociceptors
somatic, visceral, referred
58
Neuropathic due to injury/lesion of NS
central, peripheral
59
Acute pain
resolves on its own as injury heals
-self-limiting
60
Chronic pain
persistent pain even after tissue damage has healed
-changes in CNS implicated
61
Somatic pain
nociceotive pain, due to activation of perpheral nociceptors
-superficial, arises from collective tissue, muscle, bone and skin
-A-delta (sharp), C-fibers (dull)
62
Visceral pain
nociceotive pain, due to activation of perpheral nociceptors
-pain in organs and lining of body cavities
aching, gnawing, throbbing, crmaping quality
-poorly localized bc fewer nociceptors in veiscera
-associated w/ nasuea, vomitting, hypotension, restlessness, shock
-can radiate or be referred
63
Referred pain
pain felt in an area differnt from its point of origin
-site of referred pain supplied by same spinal nerves as actual site of pain
-skin has more nerve endings, so pain is experienced there instead of at origin
64
Neuropathis pain
NOT the result of tissue damage
causes by lesion or injury of the NS
65
sensitization
creates pain signals despite lack of stimulus
66
Central neuropathis pain
(brain or SC)
Physical trauma to CNS
tumors
MS
Parkinsons
67
Peripheral neuropathis pain
(everywhere else)
physical trauma to peripheral nerves
diabetes
alcholism
HIV infection
68
Central and peripheral sensitization trauma to nerves causes:
spontaneous activity
abnormal excitability
heightened sensitivity
69
There may be other changes as well
decreased pain inhibition pathway (descending modulation)
enlargement of sensory receptive field
70
Central and peripheral sensitization experienced as
-hyperalgesia
-allodynia
-incident pain: pain evoked by particular movement
-hyperesthesia: increased sensitivity to touch
-paresthesia: tingling sensation, pins and needles
71
Acute pain
protective
alerts individual to immediate threat; mobilizes individual to take action
typically short-lived; last a few seconds to a few days
72
Chronic pain
lasts at least 3 months
lasts well beyond expected healing time
seves no physiologic purpose
can be continous or intermittent
73
no one knows :
how acute pain develops in chronic
why some people get chronic pain and others dont
74
Neuroimagaing studies show that ____ pain changes that brain
chronic
75
possible mechanisms of chronic pain
changes in nerve sensitivity
-lower thershold for activaation
-central and peripheral sensitization
spontaneous impulses from regen peripheral nerves
-up-regulation of nociceptive chemokines and their receptors
-loss of pain inhibition in spinal cord
-structural and functional changes in brain processing centers
76
manifestation of chronic pain : central
increased excitabilty of neurons in CNS
77
manifestation of chronic pain : peripheral
increase excitabilty of neurons in PNS
78
Back pain
most common chronic pain condition worldwide
presents a sig personal and economic burdern
79
possible causes of back pain
-muscle strains (excertion, poor muscle tone)
-verterbal damage (spondylosis)
-pressure on spinal cord (spinal canal stenosis, herniated discs)
80
Myofascial pain
2nd most common chronic pain condition
-associated with injury to muscle or connective tissue (fascia, tendons)
ex: muscle strain, myostis, myalgia, fibromyalgia
-begins sharp, localized due to injury or strain
-over time-> more generalized, deeper aching
example of acute --> to chronic
81
Cancer pain
assciated with tumor growth and invasion:
increased pressure from tumor growth, destruction of healthy tissue
-distension (stretching) of organs or tissues
-difficult to treat effectivlty as cancer spreads and pain evolves
82
Cancer tx
chemo, radiation
-damge to nerves by anticancer tx leading to sensitization
83
phantom limb pain
pain experienced at site of amputation after stump has healed
-80-100% of amutees affected
-more likely pts who had pain before amputation
84
highlights the brains role in pain percepion:
phantom limb pain
85
possible causes of phantom lib pain
-regen of hyperactivity in injured or cut nerves
-scar tissue or neuroma forming on cut nerves
-alterations in thalamus or cortex
-CNS plasticity in somatosensory cortex
86
treating chronic pain
a huge challenge bc
-manifestations of pain can be so varied
-so parents' response to treatment
-being in constant pain makes ppl sad/hopeless, more sensitve to pain
87
Pain thershold
point at which stimulus is perceived as pain
determines by genetic, anatomy
88
pain tolerance
-duration of time OR intensity of pain that one can endure before acting on. aresponse (like withdrawal)
-influenced by individuals cultural perception, physical and mentla health, gender, fatigue, mood
-may be incr by warmth, hypnosis, alcohol, pain meds, strong beliefs or faith
89
Congenital insensitivity to pain
very rare genetic condition (autosomal recessive)
-mutatation in SCN9A gene
-encodes subunit of sodium channel (Nav1.7) present in sensory nerves
-mutation= absence of Nav1.7 channel, inabilty to transmit nociceptive info to brain
90
TYPES of insensitivty to pain
WT: wild type
PE: primary erythermalgia
PEPD: paroxysmal extreme pain disorder
CIP: songential insensitivty to pain
91
congenital insensitivty to pain affected individuals :
-can feel differnece btwn sharp and dull, hot and cold
-do not sens epainful stimuli
ex: can tell beverage is hot but not that it is burnign them
results in reduced life expectancy due to accumulation of wounds, burns, bruises, broken bones
-ppl with this used to work in circus shows
