Week 2: Pain Flashcards
What is pain
-unpleasant sensation
-discomfort caused by stim.of pain receptors
what causes pain
-Inflammation
- Infection
- Ischemia and tissue necrosis
- Stretching of tissue
- Stretching of tendons, ligaments, joint capsule
- Chemicals
- Burns
- Muscle spasm
what is somatic pain
from the skin (cutaneous)
bone muscle
conducted by sensory fibres
what is visceral pain
originates in organs
conducted by sympathetic fibres
may be acute or chronic
what are sensory dimensions
the perception of pain by the individ
what do sensory dimensions include
location
intensity
pattern
quality
pain threshold
point at which stimulus is perceived as pain
whats a pain tolerance
max intensity or duration of pain that a person can endure before acting
whats an autonomic pain response
protecting an individual
ex. moving hand from a hot stove
whats a behavioural pain resposne
learned behav as a method to coping with the pain
ex. rubbing a sore leg
what is hyperalgesia
-increased sensit to pain
-result of damage to nociceptors or peripheral nerves
ex. shingles
what are the 4 major processes of nociception
transduction
transmission
perception
modulation
what is transduction
conversion of a
- mechical
- thermal
- chemical stimulus
- neuronal ap
mechanical stimulus
trauma
surgery
muscle spasm
thermal stimulus
extreme heat or cold
chemical stimulus
lactic acid
bradykinins
enzymes
where does tranduction occur
free nerve endings of nociceptors
what occurs once free nerve endings are stimulated (transduction)
noxious stimuli results in release of chemicals around peripheral afferent nociceptor
what chemicals are released once free nerve endings are stimulated
bradykinin
serotonin
histamine
acetylcholine
substance p
what occurs when a stimulus causes released chemicals to excite the peripheral afferent nociceptor
ap fires
what is an ap necessary for
convert pain stimulus to an impulse and move it from the periphery to the spinal cord
what is transmission
movement of pain impulses from the site of the transduction to the brain
what are 2 main types of peripheral nerve fibres
a fibers (beta and delta)
c fibers
A fibers
small
myelinated
transmit signals fast
produce sharp localized pain
C fibers
large
unmyelinated
transmit signals slowly
produce dull achy pain in deeper structures
what does dorsal horn processing include
release of nt (substance p) which may either excite or inhibit the cell
what happens when the pain reaches the somatosensory area in the cerebral cortex
perception and localization of sensation
what happens when pain reaches the hypothalamus and limbic system
emotional factors
what occurs within the reticular activating system
reticular formation in the pons and medulla
awareness of incoming brain stimuli
what do cortical structures provide
meaning of pain
what is the perception of pain
occurs wehn pains recognized
concious awareness of pain
subjective interpretation
what are effective non medical pain reducing interventions
music
distraction
relaxation
imagery
what are pathways that integrate nervous system impulses
modulation
what does modulation involve
activation of descending pathways that exert inhibitory or excitatory effects on pain transmission that will suppress or facilitate pain
where does modulation occur
periphery
spinal cord
brain stem
cerebral cortex
what may be released that inhibits pain transmission
serotonin
NE
endogenous opiods
