71 - pain (Barker) Flashcards
classification of pain
acute
chronic - pain > __ months
- nociceptive (somatic) - inflammatory (arthritis, osteosarcoma)
- neuropathic - central and peripheral
- viceral - internal organ
- mixed - lower back, cancer, fibromyalgia
3
functions of pain
- warning system - avoid injury
- aid in repair ( ___ )
- can be ___ - (irreversivle neuropathy)
- hypersensitivity
- maladaptive
characterization of pain
temporal features
- onset, duration, course, pattern
intesity
- average, least, worst, current pain
location
- focal, generalized, referred, deep, superficial
- opioid induced ___ (generalized)
quality
- ___ - throbbing, pulsating
- ___ - stabbing, shooting, buring, tingling
- ___ - squeezing
referred - MI (lawn, arm, back, epigastrium)
- hyperalgesia
- inflammatory
- neuropathic
- viceral
pain scale
wong-baker ___ may be beneficial for children
subjective - can be abused
pain is an ___ and impacts moofd
- faces
- emotion
pain transmission
activation of periphery sysrem → transmission → activation of ___ at spinal cord → input → transmission of the pain signal to the brain →
back down to spinal cord for __
- CNS
- modulation
peripheral receptors
temperature sensitive
- TRP - transient receptor potential cation channel
- TRPV (Vannilod) - ___
- TRPM (Melastatin) - ___
acid sensitive
- ASIC - acid sensing ion channel
- activated by ___
- conduct ___
pressure receptos
- MDEG
- DRASIC
- TREK-1
chemical irritant
- ___ and ___
- heat/spice
- cold
- H
- Ca
- histamine, bradykinin
reflex upon painful stimuli
reflex can ___ brain
- hand on hot stove. signal will travel to brainstem via afferent. efferent will make muscles in hand move away from hot stove
bypass
nerve transmission from periphery to the spinal cord involves many different ion channels
- action potential: ___ 1.2, 1.6, 1.7, 1.8
- spinal cord: ___ (excitatory) binds to AMPA, mGluR, NMDAR to send signal to brain or peripherly
Na
glutamate
Three Different Pain Fibers
___ fibers
- non-noxious: touch and pressure
- super thick myelin
- innervate skin
- faster (35-75 m/s)
___ fibers
- pain, cold
- myelinated
- fast (2-35 m/s)
- firt pain reflex arc, sharp and prickly
___ fibers
- pain, temp, touch, pressure, itchy (polymodal)
- unmyelinated
- slow (0.5-2 m/s)
- “second pain” - dull and aching
- Aß
- A delta
- C
peripheral sensitization - substance P
plays an important role in heightening pain responding
- repeated stimuli ___ firing threshold
substance P
- vasodilation
- degranulation of ___ cells
- release of ___
- inflammation and ___ and ___ release
increase ___ of pain receptors
- sensitization
- = more signal sent to spinal cord
- reduces
- mast
- prostaglandins, bradykinin
- expression
pain circuitry spinal - neuropathic pain sensitization
nerve injury leads to peripheral nerve degeneration, ___
- can lead to ___ afferent activity or spinal ___
- causes spontaneous dysethesias (shooting, burning) or ___ (light touch hurts)
spontaneous afferent activity could be caused by enhanced expression of ___ channels
- enhanced excitability
- generation of ectopic action potentials
neuropetides such as ___ and ___ can increase ___ and ___ expression and sensitivity
- neuroma
- spontaneous, sensitization
- allodynia
- Na
- substance P, CGRP, AMPA, NMDA
pain cicuitry in the brain
high expression of ___ receptors in the brain stem along the descending pathway
opioid
activation of the Mu opioid receptor
brain
- alter mood
- produce sedation
- reduce ___ reaction
brainstem
- increase activity of ___ fibers
spinal cord
- inhibit ___ release
- ___ post-synaptic membrane
periphery
- reduce activation of primary ___
- modulate immune activity
- emotional
- descending
- vesicle
- hyperpolarize
- afferent
pain in the brain
cortex
- where is pain/preception
pre-frontal coretex
- decision making, fight/flight
amygdala
- feeling, emotion
nucleus accumbens
- pleasure of opioid use, ___ and ___ release during pleasure/pain
DA, 5HT
