1.1.1 Flashcards by Yanique Dobson

refers to reception of signals in the CNS evoked by the activation of specialized sensory receptors that provide information about tissue damage

nociception

How well did you know this?

Not at all

Perfectly

receptors in this system are called _____ sensory neurons carrying then ____

nociceptors and nociceptive neurons

How well did you know this?

Not at all

Perfectly

preventing the action of nociceptors or nociceptive neurons is called

antinociception

How well did you know this?

Not at all

Perfectly

refers to the perception of an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in these terms

pain

How well did you know this?

Not at all

Perfectly

preventing pain is called

analgesia

How well did you know this?

Not at all

Perfectly

pain resulting from normally innocuous stimuli, even without sensory input

allodynia

How well did you know this?

Not at all

Perfectly

exaggerated response to noxious stimuli, even without sensory input

hyperalgesia

How well did you know this?

Not at all

Perfectly

noxious insult depolarizes sensory ending membrane to produce action potential

transduction

How well did you know this?

Not at all

Perfectly

activated by extremes in temperature (<45 and <5 degrees C)

thermal

How well did you know this?

Not at all

Perfectly

TRP

transient receptor potential (TRP) ion channels expressed selectively on nociceptive neurons

How well did you know this?

Not at all

Perfectly

activated by ~45C temp and capsaicin

TRPV1

How well did you know this?

Not at all

Perfectly

activated by cold (<20C) and menthol, may mediate cold sensitivity to chemotherapeutics

TRPM8

How well did you know this?

Not at all

Perfectly

activated optimally by intense pressure

mechanical

How well did you know this?

Not at all

Perfectly

activated by high intensity, mechanical, chemical, thermal (both hot AND cold) stimuli

polymodal

How well did you know this?

Not at all

Perfectly

not normally activated by noxious stimuli, but inflammation and various chemical agents

what might it contribute to

silent

may contribute to the emergence to the emergence of hyperplasia and sensitization to pain, features of chronic pain

How well did you know this?

Not at all

Perfectly

a voltage gated ion channel: encoded for by the SCN9A gene, not found in CNS. Has been found to be a key player in the perception of nociception by humans

Nav 1.7

How well did you know this?

Not at all

Perfectly

loss of fxn can cause patient to be sensitive to pain, can also be hyperexcited and hypersensitive to pain

Nav 1.7

How well did you know this?

Not at all

Perfectly

nociceptors transduce pain, but perception of pain in determine by

conducting nerves

How well did you know this?

Not at all

Perfectly

small diameter, thinly myelinated, fast. small receptive field

what is the activation associated with

A-delta, fast, sharp, pricking pain

How well did you know this?

Not at all

Perfectly

small -diameter, unmyelinated, slow, large receptive fields

c fibers

How well did you know this?

Not at all

Perfectly

larger, faster, carry non-pain touch data

A alpha A beta

How well did you know this?

Not at all

Perfectly

bradykinin released from

damaged tissues

How well did you know this?

Not at all

Perfectly

histamine released from

immune mast cells

How well did you know this?

Not at all

Perfectly

(I + V) relay sensory data to brain
neurons
high density in lamina 1 project directly up to the midbrain and thalamus
wide dynamic range neurons (may be difficult to treat)
lamina V project to brain stem and talamus projection neurons (visceral organ) heart attack, referred pain

projection neurons

How well did you know this?

Not at all

Perfectly

(lamina 2) relay data to projection neurons, enhancing nociceptive signaling

local excitatory interneurons

(lamina 2) regulate/suppress flow of nociceptive information to projection neurons - target of descending inhibitory pathway resulting pain

local inhibitory interneurons

activated by ATP released from peripheral cells after tissue damage

ionotropic purinergic receptor, PTX3

activated by peptide ligands, sensitize nociceptors

mas-related G protein-coupled receptor (Mrg) family

target of lidocaine

voltage-gated sodium ion channels (Nav 1.7)

tissue damage and reduced pH sensitize nociceptors, enhancing sensation of pain in response to stimuli by

-sensitizing nociceptors lowers threshold for action potential on nociceptor-bearing neurons -increasing frequency of action potentials, increasing magnitude of pain evoked by superthreshold stimuli -sensitization results from the release of chemical mediators that produce EPSPs

results from direct injury to nerves in the peripheral or central nervous system

neuropathic pain -can result from loss of inhibitory control (loss of impairment of interneurons; injured Abeta "sprouting" -may be exacerbated by activation of microglia and their release of inflammatory agents

primary sensory neurotransmitter, release triggers mild pain

glutamate

where does glutamate work

NMDA receptors

____ is stored in small clear vesicles and refilled quickly

glutamate

glutamate is used primarily by

both Adelta and C fibers for fast excitatory synaptic potentials

a tachykinin, activation of neuroinin receptors excites and prolong EPSPs

substance P

all neuropeptides are used ___ fibers for ___ synaptic potentials

C, slow

when released neuropeptides are released with glutamate, this triggers

a strong pain

local dorsal horn interneurons modulate nociception with

GABA and endorphins -GABA inhibition of projection neurons -endorphins act at all three opioid receptors

delta mu gaba

-enkephalin -B endorphin -dynorphin

endorphins reduce the perception of pain by

acting at opioid receptors to - decrease Ca, increase K influx -decrease duration of action potential -hyperpolarize dorsal horn neurons -decrease amplitude of evoke EPSP located at key points in the pain modulatory system

Gate theory

spinal cord areas that receive messages from pain receptors also receive input from other skin receptors and from axons descending from the brain. these outer inputs sometimes activate inhibitory interneurons, closing the "gates" for the pain messages by inhibiting projection neurons

PAG neuron activation releases endorphins, which ____ inhibitory GABA pathway interneurons

inhibits

both the ___ and ____ inhibit pain pathways in the spinal cord and brainstem

PAG and medulla

processes precise location of pain, relays to somatosensory cortex and consciousness as acute pain (lamina 1 and 5-7)

spinothalamic tract ( major ascending nociceptive pathway)

extensive collateral to mesencephalic reticular formation & periaqueductal gray matter, activating descending control (why pain stops) parabrachial neurons project to amygdala, controlling affect (emotion) (lamina 1 and 5)

spinoparabrachial tract (major ascending nociceptive pathway)

projection neurons of lamina 7 and 8 ascend with spinothalamic tract, terminating in both reticular formation and thalamus -- large bilateral receptive field: implicated in diffuse, unlocalized pain

spinoreticular tract (major ascending nociceptive pathway)

contains axons of projection neurons form lamina 1 5 and 7. projects to hypothalamic nuclei -- influences autonomic control, triggers, neuroendocrine, and cardiovascular response to pain

spinohyothalamic tract (major ascending nociceptive pathway)

lateral thalamus sends data to the medial thalamus and from there to the angular cingulate cortex to affect

cognition and mood, associated with the anticipation of pain

what are the key components in the descending inhibitory pathway regulating pain

serotonin norepinephrine GABA endorphins

descending inhibitory pathway starts in the ___

PAG

descending inhibitory pathway is an _____ pathway that synapses with the 5-HT neurons in the ______

excitatory, nucleus raphe magnus (medulla)

5-HT neurons project to the spinal cord (from nucleus raphe magnus), making _____connections with neurons in lamina ______ of the dorsal horn, including neurons of the ____ tract that carry noxious stimulation signals

inhibitory 1 2 and 5 spinothalamic

5-HT neurons project to the spinal cord (from nucleus raphe magnus), making _____connections with neurons in lamina ______ of the dorsal horn, including neurons of the spinothalamic tract that carry noxious stimulation signals

inhibitory

______ released from this pathway (descending inhibitory pathway) inhibits spinothalamic tract input, blocking pain

serotonin

_____ in the PAG, inhibits the excitatory pathway. they are constantly firing at a hihg rate and theyre used by the body to suppress that excitatory serotonergic pathway

GABA **THIS EFFECT IN ONLY IN PAG**

-initial response to tissue injury, usually preceded the immune response -cell damage associated with inflammation acts on cell membranes to cause the release of lysosomal enzymes, triggering cellular decay, arachidonic acid and eicosanoid synthesis -mediated by release of ______ which have specific overlapping effects

acute inflammation autocoids

-occurs when immunologically competent cells are activated in response to either foreign organisms or antigenic agents liberated during the acute or chronic response -outcome beneficial when invading organisms are neutralized -outcome deleterious if it leads to chronic inflammation without resolution of injury

immune inflammation

activity of _____ can also produce all the cardinal signs of inflammation (what are they)

peripheral nociceptors calor, rubor, swelling

______ and _______ released from c fibers at the site of injury provokes plasma extravasation and edema (__) and vasodilation (__)

substance P and CGRP SP CGRP

Spread of histamine and bradykinin to otherwise healthy nearby tissue contributes to secondary _____ and _________

hyperalgesia increased repetitive firing of C fibers

_____ acts of mast cells in the vicinity of sensory endings, evoking degranulation and the release of histamine _____ induced vasodilation leads to further inflammation that causes additional liberation of bradykinin

substance p gcrp

effect of substance p and cgrp induced hyperalgesia and increased firing of c fibers is to ______ what is this called?

enhance the sensitivity of dorsal horn neurons to nociceptor signals central sensitization

gradual enhancement of excitability or "wind up" of dorsal horn neurons thought to involve ___ long term potentiation causes prolonged ____

NMDA-R excitation

nerve growth factor and brain derived neurotrophic factor upregulated in inflamed peripheral tissues may also contribute to _____ (blocked by growth factor inhibitors)

persistent pain

nerve growth factor and brain-derived neurotrophic factor upregulated in inflamed peripheral tissues may also contribute to _____ (blocked by growth factor inhibitors)

persistent pain

sources and primary selective effects of interleukins (IL-1 through 17) GM-CSF

S: macrophages, t lymphocytes p: lymphocyte activation, prostaglandin production

sources and primary selective effects of TNF-alpha

s: macrophages p: prostaglandin production

sources and primary selective effects of interferons (IFN alpha and beta)

s: macrophages, endothelial cells, t lymphocytes p:many

sources and primary selective effects of PDGF

S: macrophages, endothelial cells, fibroblasts, platelets p: fibroblast chemotaxis, proliferation

chronic inflammation may produce severe__

disability, including systemic changes decreasing lifespan

chronic inflammation destroys bone, cartilage, produces severe pain, may be an autoimmune disease driven by excessive secretion of IL 1b and TNF alpha by t cells

rheumatoid arthritis

the interleukins, specifically 1 and TNF alpha both work to produce an increase in ____ production that can produce an acceleration in the _____ and ___responses

prostaglandins inflammatory pain

TNF alpha IL 1beta and IL 8liberate prostaglandins and bradykinin to induce _____

hyperalgesia -this is pain

tnf alpha IL 1beta and IL6 increase PGE, levels thereby causing the hypothalamus to elevate body temperature through increased heat generation and decreased heat loss

fever

increased sleepiness is thought to be IL beta acting through ___ release

prostaglandin

____ is thought to be a principal mediator of the response to infection and endotoxins

IL 1

______are increasingly important mediators in immunopharmacology with many applications: some may have antiproliferative, antimicrobial, and antitumor effects

cytokines

cytokines operate in ___, many different cytokines working sequentially or simultaneously

cascades

cytokines mediate their effects via ___ on relevant target cells

cell surface receptors

the condition where nerves in the somatosensory, PNS or CNS are diseased or damaged

neuropathy

results from this nerve injury, although results vary based on the specific nerves damaged,

neuropathic pain

tingling, pricking senation

paresthesia

numbness, impairment of senses, especially touch

dyesthesia

burning pain

causalgia

1.1.1 Flashcards

(85 cards)