W9 Physiology and Pathophysiology of Pain Flashcards
-rapidly conducting, low stimulus threshold
-light touch, vibration, or movement of hairs
A(beta)
-intermediate velocity - sharp, intense pain
-cold, heat, and high-intensity mechanical stimuli
A(delta)
-slow conducting - dull, burning pain
-polymodal nociceptors: heat, warmth, intense mechanical stimuli, or chemical irritants
-some are silent (sleeping fibers) but become responsive during inflammation
C
dorsal horn of the spinal cord uses what neurotransmitters
glutamate
Co-transmitters include substance P and cGRP
visceral pain is mediated by both what type of nerve fibers
both sympathetic and parasympathetic afferent nerve fibers
visceral pain is typically linked to what
ischemia, inflammation, smooth muscle spasms and distention
what amplifies signals by increasing sensitivity of nerve endings to stimuli through direct stimulation, altering neural membrane thresholds to stimuli and by modifying the environment of the neural receptive fibers
inflammatory cytokines
what includes Beta-endorphins, enkephalins, and dynorphins
-alters mood and reduce emotional response to pain
-enhance descending inhibitory actions, inhibit release of pain neurotransmitters from pre-synaptic neurons, and hyperpolarize post synaptic neurons
opioids
what results in increased K+ conductance and decrease ca2+ conductance and acts via what
norepinephrine acts via alpha 2 recptors
what are 5 opioid receptors in the body
-brain
-brainstem
-spinal cord
-peripheral neurons
-intestine
what do endocannabinoids do
lipid metabolites that play a supportive role in homeostatis in general
what are central inhibitors of pain
NRM and NRPG
what is hyperalgesia
increased sensitivity to pain
what is central sensitization
enhanced response to same stimuli w repetitive, high intensity simulation (can be short or long term)
what receptor blockade prevents induction and maintenance of central sensitization
NMDA
activation fo what brain parts (3) produce autonomic responses
superior colliculus, hypothalamic, medial thalamic nuclei produce autonomic responses
how does NSAIDS work
anti-inflammatory action by inhibiting production of prostaglandins
how does corticosteroids work
decrease release of inflammatory mediators and inhibition of pro inflammatory gene expression
acetaminophen
little anti-inflammatory action but analgesic (relieve pain) and antipyretic (reduce pain) like aspirin
what is COX1, COX2
targets for anti-inflammatory drugs
what are pain receptors
nociceptors
modulation of pain is attributed in part to the release of what
endogenous opioids
what are descending pathways that are part of the intrinsic modulation of pain
NRM and NRPG neural pathways
altered gene expression in neural pathways results in increased sensitivity to pain can characterize what kind of pain
chronic pain
