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30 Cards in this Set
- Front
- Back
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difference between sensation and perception |
sensory inputs get transduced into signal that goes to brain as sensation where we make judgments about it = perception |
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what's the purpose of smell and taste? |
protect from harm- eating poisons or breathing them in
makes you feel nice |
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what do you call the best stimulus type for eliciting response of sense receptor |
adequate stimulus |
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what are the dendritic endings like for different sense types
pain pressure sight smell taste temp touch |
free: pain temp
encapsulated pressure touch
rods cones sight
modified epithelial cells- chemoreceptors- taste smell |
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how is smell taste transduced |
go to receptor cell which sends msg to afferent neuron. intensity relayed by AP frequency
pain temp it hits neuron directly |
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what all receptors are cutaneous and which are special sense |
touch pressure temp pain
sight hearing equilibrium taste smell |
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what are fast and slow receptors for |
tonic are slow for showing what the status is
phasic fast are to show changes. Sense the change and adapt quickly. |
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what ways can adaptation happen for a sensor? |
fatigue/accomodation peripheral- at lvl of receptor central- at level of processing in CNS |
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how specific are these nerves
what other ways do we discriminate? |
each sensor can only send one kind of message- CNS integrates to determine what is happening
texture/temp/pain changes perception (some learned) |
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how do smell and taste compare in sensitivity?
what changes relative sensitivity? |
smells parts per trillion tastes part per million- best at bitter, baseline Na in mouth
background conditions- so like the salt |
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the higher the background, the level the stimulus has to be at increases ___. this is known as |
exponentially- not linearly Stevens power law |
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how does signal get transduced comparatively in phasic and tonic sensory nerves |
generator potential (like EPSP) to reach a threshold. In phasic: as stimulus continues the generator potential size diminishes
for tonic the generator potential is just proportional to intensity of stimulus (no or very slow adaption) |
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four taste structures |
filiform- abundant but no taste cells fungiform foliate circumvalate (last three have taste cells) |
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what are the taste cells like |
rapid turnover - 10 days channels or receptor proteins- G protein coupled
leads to depolarization -> Ca++ -> NT release
not neurons modified epithelial cells that depolarize upon stimulation and put out NT for neurons
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what is the sensation of taste called?
what is it called if you can't taste? |
gustation
dysguesia |
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a given sensory neuron can be stimulated by |
more than 1 taste cell in several different taste buds- convergence already happening |
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what is the kind of transduction for each taste time |
sweet and bitter use g proteins- gustducin
closes K or Ca channels respectiviely |
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what's the innervation of the different tongue parts |
ant 2/3 CN VII posterior 1/3 IX pharynx and larynx X trigeminal nerve innervates tongue and mouth for thermal pain and tactile |
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what's the chain of neurons for taste |
first order synapse onto second in nucleus tractus solitarius
go to thalamus for third order neurons
which go to gustatory cortex |
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why do you need saliva |
molecules dissolve in saliva to be sensed
has enzymes to break foods down
note- it has sweet salty and bitter components so thresholds come into play |
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what situations can alter taste sensation |
oral product or meds changing chemoreception (abx)
loss of saliva- decreases sweet esp since amylase and changes concentration available for taste cells
fungus/bacteria/background |
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olfaction- what cells |
receptor cells, supporting cells and basal (Stem) cells. 1-2 month turnover of neurons
supporter cells have enzymes to oxidize hydrophobic volatile odorants
sensory neurons are psueduostratified and bipolar with axon up to olfactory bulb and dendrite down to nasal cavity |
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olfactory how does it signal |
molecule binds -> g protein -> cAMP -> membrane channels -> AP |
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about __% of taste is actually ___ |
80% is olfaction |
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what's it called if you can't smell |
anosmia |
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why does smelling matter |
well being- mental dz in anosmia emotional trigger pheromones- mother/child learning aromatherapy |
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general secretion- there is a ...
what is end day net value like |
continuous flow of fluid through the gut, even in the fasted state
intake and secretion = reabsorption and excretion
excretion is 100 mL/day from gut |
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what are the purposes for secretions in GI system? |
it has electrolytes water mucus enzymes and hormones so
lubricates and protects mucosa
enzymatic function
acidification and neutralization |
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how do you regulate secretion in GI |
local myenteric reflexes- distention, irritation, motility, chemicals
PNS and SympNS coming in
GI hormones secretagogues - specific senses
MOST from blood flow to gland! plasma filtrate so.. if plasma coming in, have more to secrete so SNS PNS and vasoactive substances |
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what is a vasoactive substances that is an example of secretion regulation in GI |
kallikrein- protease released from salivary acinar cells- breaks down kininogen into bradykinin which causes local vasodilation and blood flow to actively secreting glands |
