pain Flashcards
1
Q
pain
A
- final line of defense for protection
- results in reflexes or changes in behavior
- response: physiological, cultural, emotional
2
Q
pain reactions
A
- emotional response expressed in a variety of ways
- cultural influence of response - linked to ethnicity, socioeconomic status
3
Q
pain=special perceptual quality
A
-has complex phenomenological facets(behavioral, sensory, emotional)
4
Q
assessing pain: subjective
A
-what the athlete tells you
5
Q
assessing pain: objective
A
- visual analog scale (VAS)
- numeric rating scale (NRS)
- McGill pain questionnaire (MPQ)
- submaximal effort tourniquet test (SETT)
6
Q
internal anatomy
A
- gray matter
- white matter
- gray commissure
- central canal
- dorsal & ventral nerve roots
7
Q
white matter-pathway generalizations
A
- ascending & descending fibers
- long tracts: peripheral in white matter
- short tracks: near gray matter
8
Q
nociceptors
A
- respond only to noxious stimuli
- generate impulses brain interprets as pain
- free nerve endings
9
Q
afferent nerves
A
- sensory fibers
- carry info to brain/SC
- enter SC through dorsal root
10
Q
efferent nerves
A
- motor fibers
- carry info from brain/SC
- exit SC through ventral root
11
Q
nerve conduction velocity
A
-affected by myelination, diameter
12
Q
ADelta fibers
A
- fast
- large diameter
- thinly myelinated
- high velocity
- responsible for: immediate, sharp, well-localized pain
13
Q
c fibers
A
-slow
-small diameter
-unmyelinated
-low velocity
responsible for: continue, dull, diffuse pain
14
Q
pain initiators
A
- glutamate (central)
- substance P (central)
- bradykinin (peripheral)
- prostaglandins (peripheral)
15
Q
pain inhibitors
A
- serotonin
- endorphins
- enkephalins
- dynorphin
16
Q
environment to action potentials
A
- to detect a stimuli form the environments - energy must be converted into action potential
- sensory neurons - first order neurons
17
Q
first order neurons
A
- in ganglia of peripheral nerves
- peripheral process - transduction
- central process - travel to CNS
- peripheral & central process= primary afferent fiber
18
Q
peripheral process (first order neurons)
A
-sensory receptor organs at end peripheral process respond to - mechanical, thermal, noxious
19
Q
ABeta nerve fibers
A
- very little myelination
- medium diameter
- medium velocity
20
Q
mechanoreceptors
A
- superficial located in/on skin
- merkels disks, hair follicle receptors, meissner corpuscles, pacinian corpuscles
- deep in muscles, tendons
21
Q
merkels disks
A
- low threshold to mechanical pressure
- slow adapting
22
Q
hair follicle receptors
A
- very low threshold to bending hair
- sense very light touch on skin
- linked with merkels disks
23
Q
meissners corpuscles
A
- low threshold to pressure, movement, vibration on skin
- rapidly adapting to constant pressure
- slow adapting to movement, vibration
24
Q
pacinian corpuscles
A
- low threshold to movement, deep pressure
- rapidly adapting to constant pressure
25
central process
-synapses w/2nd order neurons
26
sending signals along nerves
- info from primary afferents travel to SC
- ABeta & c fibers syapse on intreneuron (dorsal horn)
- c inhibit interneuron - activate T cell
- ABeta excite interneuron - inhibit T cell
27
dorsal column/medial lemniscus system (DC/ML) tract
- sensation - touch, proprioception
| - ABeta fibers
28
anterior lateral system (ALS) tract
- sensation - pain, temp
| - ADelta, ABeta, c fibers
29
DC/ML system
- posterior spinal cord
| - fibers ascend directly to medulla, synapse w/2nd order neuron
30
anterolateral system
- dorsal horn of SC
| - fibers 2nd order neurons
31
pain
- results from stimulation nociceptors
| - chemical, mechanical
32
chemical pain
- prostaglandins & potassium lower threshold of nociceptors
- bradykinins stimulate nociceptors
- action potential generated
- info from noxious afferents to SC to cortex
- pain perception in cortex
33
withdrawal reflex
- nociceptive fibers synapse w/ interneuron (dorsal horn)
- interneuron synapse w/ efferent fibers (ventral horn)
- stimulate efferent fibers -> withdrawal from source pain
34
mechanical pain
- occur from edema
- info from noxious afferents transmitted to SC
- continued pain perception in cortex
35
ascending pain control
- AB & c fibers synapse w/ interneurons (dorsal horn)
- AB fibers stimulated - synapse & excite interneuron & inhibit T cell
- prevent c fiber stimulation transmission beyond SC
36
descending pain control
- periaqueductal gray matter (PAG)
- brain stem
- pituitary gland
- neurotransmitter release, T cell inhibition
37
treat pain
change/alter individuals perceptions of pain
38
pain control - analgesis mechanisms
- stimulation from ascending AB afferents - block impulses at SC
- stimulation of descending pathways by AD & c afferents - blocking impulses carried by AD & c
- stimulation AD & c afferents - release endogenous opiods - prolonged activation descending pathway
39
gate control theory of pain
-stimulus activates only non-nociceptive nerves - inhibit pain
-AD fibers - transmit noxious impulses associated w/ intense pain
c fibers - carry noxious impulses associated with long term/chronic pain
AB fibers - carry sensory info from cutaneous receptors but are non-nociceptive & and don't transmit pain
40
gate control theory of pain process
- pain impulses ascending fibers stimulate substantia gelatinosa as enter dorsal horn of SC
- AB fibers inhibit effects of AD&c fibers
- gatekeeper - closes gate to transmission stimuli to 2nd order neuron
- pain message never reaches sensory centers
- increase stimulation large diameter fibers (AB) cause analgesic response
- substantia gelatinosa - modulates afferent nerve impulses, permit only 1 type nerve impulse to pass ' switch operator'
41
gate control theory pain example
- sprain ankle - send message to SC via AD & c fibers - substantia gelatinosa decided to send to brain or not - transmission cell - thalamus - pain
- apply ice to ankle - AB fibers - substantia gleatinosa - pain inhibited
42
gate control theory of pain
- nonpainful stimulus can block transmission of noxious stimulus
- increased neural activity in AB afferent pathways - release enkaphalin - inhibits AD & c pathways
- substantia gelatinosa modulates afferent nerve impulses - permits only one type of nerve impulse to pass
- impulses traveling on fast, non pain fibers increase activity in substantia gelatinosa, causing gate to swing close - not allow painful stimulus to pass to T cells
43
central biasing theory of pain
- input from higher centers in brain through descending system
- stimulation of periaqueductal gray region of the midbrain & raphe nucleus activates descending mechanism
- serotonergic efferent pathway activated by enkephalin interneurons in substantia gelatinosa
- impulses from the thalamus & brain stem are carried to the dorsal horn on efferent fibers
- close gate, inhibit transmission of pain
- provides physiologic explanation for analgesic response to brief, intense stimulation
44
endogenous opiod theory of pain
- stimulation of small diameter afferents (AD & c fibers), endorphins
- betaendorphin & adrenocorticotropin releases into blood - travel to brain
- AB impulses trigger release enkephlin from interneurons in dorsal horn - pain message blocks (inhibits AD &c fibers)
45
approach pain
- identify source
- provide pain relief
- match therapeutic agent to individuals situation
46
physical agents
- stimulate larger diameter afferent fibers
- decrease pain fiber transmission velocity
- stimulate small diameter afferent fibers (AD & c fibers) & descending pain control mechanisms
- stimulate release of beta-endorphin through prolonged small diameter fiber stimulation
47
pain control strategies
- minimize tissue damage (#1 goal)
- maintain ine of communication
- encourage supervised exercise
- encourage cognitive processes that influence pain perception
