Pain Modulation Flashcards
two types of nociceptive pain?
somatic and autonomic
two types of neuropathic pain?
peripheral and central
pain that originates from nonorganic sources. Associated with emotional, cognitive, and behavioral responses.
psychogenic pain
list the four categories of pain
nociceptive, neuropathic, psychogenic, carcinogenic
type of pain that is time limited
acute
type of pain that is associated with increased sympathetic activity
acute
type of pain associated with rapidly conducting pathways
acute
type of pain that is most likely localized
acute
type of pain that only exists as long as the noxious stimuli persists
acute
define chronic pain
long-term pain lasting more than 12 weeks or beyond the expected healing time for the particular pathology
type of pain that lasts several months to years
chronic
type of pain that has a history of many symptom treatment failures
chronic
type of pain that is unbearable and incapacitating with multiple attempts to find the right treatment
chronic
type of pain that elects increased sensitivity to both noxious and non noxious stimuli
chronic
define referred pain
pain felt at a location other than its source
why does referred pain occur
peripheral nerve pathways converge on the same area of the spinal cord due to embryonic development. brain learns that musculoskeletal pathologies are more common so it may refer pain. for example, during a heart attack the brain is not used to such strong signals from the heart so it interprets it at chest and left arm pain.
name the four types of mechano receptors
meissner’s corpuscles, pacinian corpuscles, merkle cells, and ruffini endings
name the 7 types of superficial peripheral sensory receptors
meissener’s corpuscles, pacinian corpuscles, merle cells, ruffini endings (MECHANO) cold and hot receptors (THERMO), and free nerve endings for nociception
name the four types of deep peripheral sensory receptors
golgi tendon organs, pacinian corpuscles, ruffini endings (proprio), free nerve endings (nociceptors)
nerve pathway in which the neuron has its cell body outside the spinal column in the dorsal root ganglion
afferent nerve pathway
afferent fiber, 6-12 micrometers in diameter, myelinated, transmits impulses at >30 /sec
A beta
afferent fiber, 1-6 micrometer in dimeter, myelinated and transmits impulses at up to 30 m/sec
A delta
type of afferent fiber, 1mm thick non-myelinated transmits impulses at 1-4 m/sec
C fibers
what information do alpha beta afferent fibers transmit
touch, vibration
what information do alpha delta afferent fibers transmit
touch, temp, pressure and pain
where are c fibers located and what information do they transmit
located in the muscles and skin and transmit pain, touch, pressure, and temperature
alpha beta fiber characteristics (4)
originate from mechanoceptors, sense touch and vibration, are late myelinated and fast conducting, have a low stimulation threshold
alpha delta fiber characteristics (5)
originate from warm/cold receptors, few hair follicles, and free nerve endings. sense noxious mechanical stimulus (pinching, pricking, crushing). may transmit non-noxious stimulus as well. large and myelinated but slower than A beta
characteristic of A-delta fibers (4)
quick onset short duration, well localized to area of injury, not involved with an emotional response, cannot be blocked by opiates
80% of afferent danger transmitting fibers
c-fibers
group 3 afferents
a-delta
group 4 afferents
c-fibers
result in sensation felt as dull, throbbing, burning, aching
c-fibers
type of fiber with slow onset after initial stimulus
c-fibers
fibers that transmit long lasting pain that is emotionally difficult to tolerate
c fibers
fibers that transmit diffusely localized pain
c-fibers
type of fibers that are reduced by opiates or blocked by opiate antagonist naloxone
c-fibers
type of fibers that ascend in lateral spinothalamic tract and synapse with 3rd order neurons in the thalamus. relay info to somatosensory cortex in post central gyrus
a-delta fibers
type of fibers that ascend in the anterior spinothalamic tract and synapse in reticular formation and intralaminar nuclei of the thalamus. relay info to the association cortex
c-fibers
central transmission tract that is the primary nociceptive pathway-transmits type/location of pain
spinothalamic tract
central transmission tract that transmits motivational, emotional, and unpleasant aspect of pain
spinoreticular tract
central transmission tract that sensorimotor integration of pain
spinomesencephalic tract
central transmission tract that is a limbic tract, autonomic responses associated with pain
spinohypothalamic tract
sub-cortical center that mediates motor autonomic, and sensory functions
reticular formation
sub-cortical center that directs descending inhibition
periaqueductal gray
type of sub-cortical center that controls endocrine functions and vegetative state
hypothalamus
master gland for the endocrine system that is part of the sub-cortical center
pituitary gland
association cortex
responsible for affect that is associated with danger signals. appraises the danger and results in pain tolerance
theory that states that the sensation of pain depends upon the stimulation of specific nerve endings that are specialized for that sensation
specificity theory (Von Frey)
theory that states that the sensation of pain results from appropriate intensity or frequency of stimulation of receptors that also respond to other stimuli like touch, pressure, and temperature
pattern theory
control pain by binding with specific opiate receptors in the nervous system
opiopeptins
theory that states: pain is multidimensional experience. produced by characteristic patterns of nerve impulses generated by widely distributed nerve networks in the brain
neuromatrix theory
define allodynia
that which did not hurt, now does
