Analgesia and Pain Flashcards
what two drugs completely block both A-delta and C fibers
local blocks and ketamine
what is pain
an unpleasant sensory and emotional experience associated with actual or potential tissue damage
T/F the pain pathway involves decussation at the grey matter of the spinal cord
T
what starts the signal transduction pathway
thermal, mechanical and chemical signals (ex. inflammatory molecules)
what are the 4 overarching body responses to pain and why do we need to know about them from a pharmacology/anesthesiology pov
- increase in hr/bp
- increase in metabolism
- increase in coagulability
- decrease in immune function
We need to be aware that some of our drugs will modify the responses to pain
T/F the more chronic the stimulus, the more the effects of pain
T
what is nociception
the event of sensing mechanical, chemical and thermal stimuli by nociceptors (neuronal structures)
what is the difference between pain and nociception
pain includes nociception as well as the emotional and psychological consequences
describe the relationship of pain, perception and nociception
pain includes nociception and perception
nociception does not include perception
what are the types of pain
pain can be physiologic or pathologic. physiologic pain is called nociceptive/inflammatory. pathologic pain can be neuropathic or nociplastic
acute pain:
- type of fibers
chronic pain:
- type of fibers
acute: large diameter, myelinated, Aδ fibers
chronic: small diameter, unmyelinated, C fibers
somatic pain involves what systems and what fibers?
visceral pain involves what systems and what fibers?
somatic: skin and musculoskeletal; Aδ fibers
visceral: organs; C fibers
somatic pain is ______ pain and visceral pain is ____ pain
fast; slow
transmission of pain goes from _________ to the ______
nociceptors; brain
where are first order neurons
from nociceptors to the spinal cord
fast pain is activated by __________ stimuli whereas slow pain is activated by ___________
thermal and mechanical; thermal, mechanical and chemical
does Aδ or C fibers transmit signals with a faster velocity
Aδ (because they are large and myelinated)
what are the nociceptive fibers
Aδ and C fibers
what is the neurotransmitter for A-delta fibers
glutamate
what is the neurotransmitter for C fibers
substance P and glutamate
where do Aδ and C fibers go in the spinal cord
dorsal horn
what laminae in the spinal cord to the following go to:
Aβ (touch):
Aδ (fast pain):
C (slow pain):
Aβ: laminae II and IV
Aδ: laminae I (II also mentioned)
C: laminae I and II
what is important about wide dynamic range neurons and what is this pain called
can convert touch sensation to pain; nociplastic pain
what is alodynia
pain due to a stimulus which does not normally result in pain
what is hyperalgesia
increased response to a stimulus that usually results in pain
glutamate and substance P are both excitatory or inhibitory
excitatory
what are the characteristics of glutamate
- excitatory
- lasts for a few milliseconds
- acts rapidly
what are the characteristics of substance P
- excitatory
- released over a period of seconds or minutes
how does the DOUBLE PAIN sensation work
glutamate gives the faster pain sensation, followed by the lagging pain sensation of substance P
what fibers are involved in the following tracts:
- neospinal thalmic
- paleospinal thalmic
- archispinal thamlic
- neospinal thalmic: Aδ (fast pain)
- paleospinal thalmic: C (slow pain)
- archispinal thalmic: C (slow pain)
what type of tract is visceral pain
involves C fibers: paleospinothalmic and archispinothalmic
what type of tract is somatic pain
can be sharp (Aδ, neospinothalmic) or dull/aching (C fibers, paleospinothalmic and archispinothalmic)
what type of tract is the trigeminal system
neospinothalmic tract
what ganglion does the trigeminal system synapse in
the trigeminal ganglion
what responses to pain are mediated by the paleospinalthamic tract? what about the archispinalthamic tract?
paleo: emotional and visceral response to pain
archi: emotional, visceral and autonomic response to pain
what is the pathway from nociceptors to the somatosensory cortex (5 main words)
transduction -> transmission -> modulation -> projection -> perception
T/F transduction involves a signal threshold, and the strength and duration of the stimulus will affect the action potential that is ultimately created
T
T/F nociceptors express a good ability to adapt
F; adapt very little or not at all
what is the important implication of the non-adapting nature of nociceptors
the excitation of pain fibers becomes progressively greater as the pain stimulus continues (it wont calm itself down), leading to hyperalgesia or allodynia
T/F Aδ and C fibers are carried by both sympathetic and parasympathetic nerves
T
what is a key location of the brain involved in:
- perception
- integration
- modulation
perception: cortex
integration: thalamus
modulation: periaqueductal gray (PAG)
T/F the thalamus is physically located close to systems involved in fear, anxiety and memory
T
what causes peripheral sensitization
tissue damage and inflammation
what causes central sensitization
frequent or severe peripheral nociceptor input
wind-up involves what receptors and build-up of what
AMPA -> NMDA; build up of Ca2+ in pre-synaptic terminal
T/F neuropathic pain involves stimulating the nociceptive system without specifically stimulating the receptors
T
