Exam 2 Nociception, Analgesics, Audition Flashcards
alpha2
location
function
central nociceptive pathways
Local dilation of blood vessels & degranulation of mast cells
mu receptor
location
function
CNS
Brainstem intrinsic analgesic centers (mu1)
mediate respiratory depression/dorsal horn analgesia (mu2)
kappa receptor
location
function
CNS
hallucinations and delirium in people
AMPA receptor
location
function
CNS
glutamate receptors that are Na channels
dynorphin
location
function
kappa receptors
Inhibit transmission in spinal cord pain pathways, endogenous ligands for kappa receptors
endorphins
location
function
PAG axons
anti-nociceptive pathways
enkephalin
location
function
dorsal horn interneurons
inhibit transmission in spinal cord pathways
glutamate
location
function
WDR neurons
sustained augmented post-synaptic potential
NMDA receptor
location
function
WDR neurons
admits Ca and Na to bring closer to threshold
norepinephrine
location
function
nucleus raphe magnus
mood, attention, sleep wake cycles
serotonin
location
function
nucleus raphe magnus
mood, attention, sleep wake cycle, cardiovascular function
substance P
location
function
central nociceptive pathways
local dilation of blood vessels and degranulation of mast cells
pharmacological approaches for analgesics
opoids
alpha 2 agonists
local anesthetics
NSAIDs
ketamine
adjunct methods for analgesics
sedation
good nursing care (hold small animals)
ice packs
support bandages
complementary techniques (e.g. acupuncture)
is Acepromazine an analgesic?
NO
order of neuro-anatomic pain
perception
projection
modulation
transmission
transduction
conduction deafness
disease affects ability of tympanic membrane or auditory ossicles to transmit vibrations to the vestibular window
sensorineural deafness
disease affects spiral organ or more proximal components of auditory system (including the cochlear nerves, brainstem, and auditory cortices)
the most inherited deafness in domestic animals is ______ due to _______
sensorineural
degeneration of cochlear hair cells
why is bilateral deafness almost invariably peripheral in origin
very hard for central lesions to affect both sides of the pathway
lesion to left auditory cortex
not deaf
lesion to axon going to right auditory cortex
not deaf
lesion to right lateral lemniscus
not deaf
lesion to left primary afferent of cochlear n.
deaf in left ear
bilateral brainstem lesion to caudal colliculi
complete deafness in either or both ears
ototoxicity
toxicity to neural elements of inner ear; irreversible
common class of Abx that are associated with ototoxicity
aminoglycoside Abx
what can infections of the middle ear (otitis media) be associated with
dysfunction of parasympathetics: taste rostral 2/3 tongue, salivary glands, nasal glands
dysfunction of sympathetics to eye –> horner’s syndrome
diseases of gutteral pouch affect dysfunction in which cranial nerves and fibers
VII, IX, X, XI, XII
post sympathetic fibers from cranial cervical ganglion
nociception
- definition
- fibers
activation of nociceptors that detect noxious stimulus
naked nerve endings, Adelta and C fibers
pain definition
conscious perception of noxious stimuli
reflex to noxious stimuli
mydriasis
increased resp and heart rate
activation of HPA axis
reaction to noxious stimuli
voluntary behavior - whining, biting, vocalizing, withdrawal, escape
hypalgesia, analgesia, anesthesia
reticular formation
what is ARAS
nuclei in brainstem (medulla –> diencephalon)
regulates heart and resp rates, certain visceral functions, some postural motor systems and maintain wakefulness
ARAS - rostral components, regulates level of consciousness (coma)
spinocervicothalamic tract
modality:
location of tract in cord:
axons:
decussation:
somatotopy:
degree of connectivity to RF:
clinical testing:
degree of descending modulation:
superficial
lateral cervical nucleus
Adelta
C2-caudal medulla
good
some
light pinch of skin
little
spinoreticular tract
modality:
location of tract in cord:
axons:
decussation:
somatotopy:
degree of connectivity to RF:
clinical testing:
degree of descending modulation:
deep
lateral and ventral funiculi, associated with gray matter
C
throughout spinal cord
poor
robust
pinch across nailbed
robust
which fibers are more susceptible to damage
large, thick myelinated fibers
superficial > deep
hyperalgesia
increased sensitivity to painful stimuli
allodynia
non-noxious stimulation activates nociceptors (clothes after sunburn)
wind up
glutamate AMPA receptors
glutamate NMDA receptors
other NT (substance P, BDNF)
increases sensitivity
AMPA - ligand-gated, fast, causes depolarization
NMDA - ligand-gated, requires depolarization, allows conductance of Ca, more sensitive, hours-days
substance P, BNDF - GPCR, slow, long term change in genetic expression, chronic - months+
referred pain
noxious stimuli originating in viscera
WDR neurons
gate control theory
decreases sensitivity
primary afferent (noxious) C fiber synapse on WDR neuron
primary afferent (non-noxious) synapses on WDR neurons and inhibitory interneuron
leads to inhibition of pain
periaqueductal grey (PAG)
release endorphins & opioids
stimulates dorsal horn interneurons to release enkephalin & dynorphin
descending brainstem pathways involved in the endogenous control of pain
periaqueductal grey (PAG)
nucleus raphe magnus
nucleus raphe magnus
release serotonin & NE
stimulates dorsal horn interneurons to release enkephalin & dynorphin
preemptive analgesia
nerve blocks or other analgesics pre- or intra- operatively as a preemptive strike against development of wind up in surgery
neuropathic pain
characteristics
pain results from trauma, vascular injury, endocrinopathy, infection
hyperalgesia, allodynia, dysethesia
modulate or prevent transduction at the nociceptor/ inflammatory effects on sensitivity of nociceptors (increase nociception)
NSAIDs
recruit neuroanatomical substrate of gate control theory (decrease nociception)
acupuncture
TENS
massage
prevent spinal cord sensitization “spinal facilitation of pain (“wind up”)” (increase nociception)
nerve blocks
NMDA antagonists
augment descending modulator pathways
opoids
alpha2 agonists
reduce the cortical perception of pain
sedatives
opoids and opoid receptors
mu - brainstem intrinsic analgesic
delta - bind enkephalins
kappa - dynorphin
gabapentin
GABA - inhibitory; blocks Ca channels
subalbinism deafness linked to a lack of ______
what is its functions
stria vascularis (vascularized epithelium responsible for healthy survival of hair cells, neurotrophic substances produced by melanocytes & production of endolymph)
the most effective analegsic protocols combine several approaces, a so-called _________ apprach to pain relief
multimodal
