pain science Flashcards
types of pain
acute, referred, and chronic
acute pain
- symptom resulting form an injury or disease
- less than 12 wks
- well localized/defeined
- example: c spine pain after mva
referred pain
- pain that occurs at a side different from the source of disease or injury
- convergence of cutaneous, visceral and skeletal muscle nociceptions at nerve root of the spinal cord
- example - left shoulder, UE, JW , chest pain with MI
chronic ic pain
- recurring pain existing for 3-6 months beyond normal time expected for healing
- can follow acute pain
- associated with structural and functional changes in CNS
- example: fibromyalgia
purpose of acute pain
to warn of danger and to provoke a withdrawal response
purpose of persistent pain
no longer severs as a protective mechanism
how is pain communicated to the brain
1- sensory receptor
2 - first order neuron
3- second order neuron
4- thalamus
5 - third order neuron
6 - sensory cortex
output
Aa fibers characteristics
- myelinated yes
- large diameter (fast)
- sensation - proprioception
- receptor type (GTO, muscle spindle)
AB fibers
- myelinated
large fast
proprioception, light touch, pressure, vibration, hair movement
A delta fibers
- myelinated
- small slow
- extrem temp/nocicpetion
- precise location , withdraw reflexes
- free nerve endings
C fibers
- no myelinated
- smallest slow
- extreme touch and temp/nociceptin
- slow, second sensation, prevents further tissue damage
- free nerve endings
facilitators
substance P, glutamate
inhibitory
enkephalins, GABA, B endorphin
three main pain control theories
- gate control theory
- descending pain control theory
- endogenous opioid theory
Gate control theory
stimulation of AB fibers transmit information fastest, and therefore first, up tot the SC, therefore closing the gate and preventing nociceptive transmission from delta and C fibers
descending pain control theory
ADelta and C fiber transmission to the thalamus, activated efferent nerves to activated enkephalin interneurons located at dorsal horn, releasing serotonin, which suppresses substance P, inhibits transmission
endogenous opioids theory
stimulation of Adelta and C fibers at hypothalamus causes release of endogenous opioids called endorphins
is there pain center in the brain
no
pain is an output of the brain 100% of the time (3)
- tissue input
- environment
- other beliefs
pain
is a multiple system output activated by an individuals specific pain neuromatrix
nociceptive pain
is the normal pain from tissue damage
neuropathic pain
is parian from nerve damage or dysfunction
nociplastic pain
is pain that doesn’t have a clear physical cause and may be influenced by various factors
periphery nerve level
ion channels creating more sensitive nerve fibers that fire more easily, so more frequent firing
SC level
less interneurons present to inhibit, substance P increases, which can amplify transmission
brain level
