Chapter 6: Pain Flashcards
nociceptors
afferent pain nerve fibers that respond to noxious stimuli
substantia gelatinosa (sg)
center of spinal cord, H shaped region
Where do spinal nerve enter?
posterior region of sg called, dorsal horn
Afferent neurons
sensory nerves that carry pain, temp, touch, proprioception, vibration and pressure sensations to spinal cord
Efferent neurons
motor neurons that exit the spinal cord through the ventral horn and extend to muscles of the body
a delta fibers
large in diameter, and myelinated; conduct impulses rapidly and cause first, short-lived acute
c-delta fibers
smaller in diameter and unmyelinated; conduct impulses slowly and cause longer persistent dull pain
Simple reflex arc
afferent neurons carry sensory impulses into the dorsal horn; protective: immediate action without time or interpretation from brain
nociception
response of nervous system to painful stimuli
neurotransmitters
excitator or inhibitory chemical mediators that are released from 1 neuron to stim another
Acetylcholine and norepinehrine are what type of neurotransmitters?
excitatory neurotransmitters
Dopamine, serotonin and GABA are what type of neurotransmitters?
Inhibitory
Endogenous Opioids
natural analgesic neurochemicals that inhibit pain sensation
examples of endogenous opioids
endorphins, enkephalins, and dynorphins
Prostaglandins
enhances inflammation, pain and edema
interleukin
enhances inflammation, pain, edema
tumor necrosis factor
enhances inflammation, edema, and bronchospasm
Bradykinins
enhances inflammation
Glutamate
Amplifies pain signal
Substance P
Amplifies pain signal
Enkephalins, endorphins
natural opioid
Acetylcholine
inhibitory action on pain in spinal cord
Gamma-aminobutryic acid
inhibitory action on pain in spinal cord and brain
Norepinephrine
inhibitory action on pain in spinal cord
Dopamine
inhibitory action on pain in spinal cord and brain
Serotonin
convey anagelsic signals from PAG area to NRM of the brain
dermatome
skin area innervated by sensory fibers of a single nerve root
myotome
group of muscles primarily innervated by the motor fibers of a single nerve root
Gate control theory 2 major points
1:Pain is not necessarily proportional to amount of tissue injury; 2: Sensation travels both to and from the brain
Gate control theory 4 processes
transduction, transmission, modulation, and perception
transduction
initial converting painful stimuli into neuronal impulses
transmission
travel of impulse along axon
modulation
influence on afferent neuron by other neurons in the spinal cords
Perception
conscious awareness of the experience of pain
Neuromatrix Theory
Pain is multidimensional experience; explains phantom limb pain
Acute pain
new onest of tissue injury or inflammation; sudden, lasts hours to days and resovles with healing of the disorder
chronic
persists beyond expected time; greater than 3 months
neuropathic pain
caused by injury or malfunction of the spinal cord and/or peripheral nerves; burning, tingling, shooting, stinging, or pins and needles
paresthesia
pins and needles sensation
cutaneous pain
injury to skin or superficial tissue; well defined, localized pain of short duration
deep somatic pain
originated from ligaments, tendons, bones, blood vessels and nerves; poorly localized pain of longer duration
myofascial pain
tender points in muscles, tendons and fascia
Visceral pain
pain from deep organs, vague, pressure-like squeezing
referred pain
pain response occurs at a distance from the actual spot
phantom limb pain
sensation of pain originating in amputated part
OLDCART
onset, location, duration, characteristics, aggravating factors, relieving factors, treatment
Ladder of pain treatment
1: non opioids 2: weak opioids 3: strong opioids, 4: physiotherapy, OT
Schedule of opioids
I; greatest risk for abuse; as you increase number, decreases potential for abuse
Cancer pain
can be dull, aching or sharp; tumors apply pressure; cancer cells secret enzymes and inflammatory to irritate tissues; tumors secret a vasodilator= decreases circulation
spinal nerve radiculopathy
aka radiculitis, spinal nerve impingement
diabetic peripheral neuropathy
affects sensory and motor nerves in extremities
post-herpetic neuralgia
pruitic, vesicular rash that often starts on trunk and spreads out to the extremities
trigeminal neuralgia
nerve disorder that causes a stabbing or electric shock
fibromyalgia
long-term, body wide pain, linked to fatigue; pain in tender points; Diagnosis: at least 3 months of pain, 11 of 18 tender points
Spinothalmic tract
primary ascending tract for pain signals from spinal cord to the brain
corticospinal tract
outgoing signals from the brain travel on descending tract
sensitization
decrease pain inhibitory signals, exaggerates excitment of pain nerve fibers
open gate
interneuron allows transmission of pain to ascend spinal cord-brain
closed gate
interneuorn does NOT allow transmission of neural stimulus from pain fibers in periphery
TENS unit, hot and cold packs and rubbing cause what?
help blocks pain
The somatosensory system consists of 3 types of sensory neurons. The special somatic type of afferent sensory neurons has receptors that sense?
Muscle position
A women has cut her finger while dicing onions in the kitchen, drops knife in pain. Which components of this pain signal was transmitted by 3rd order neuron?
Between thalamus and cortex
1st order neuron
info to periphery to CNS(sensory info)
2nd order neuron
various reflex, spinal cord pathways to thalamus
3rd order neuron
relay info from thalamus to cerebral cortex
Nociceptors are sensory receptors that are activated by?
noxious stimuli
When a person is stung on index finger, the thalamus interprets the pain as?
somewhere on the hand
