Term
| scanning braille: mechanoreceptors respond differently |
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Definition
| -merkels disk and meissner corpuscle almost exactly mimic braille pattern |
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Term
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Definition
-perception of unpleasant sensations
-does not require activation of nociceptors
-highly individual and subjective |
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Term
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Definition
activation of nociceptors and associated neural pathways
does not necessarily lead to the perception of pain |
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Term
| nociceptors are not the same as thermoreceptors |
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Definition
-thermoreceptor axons do not increase firing rate as stimulus becomes noxious
-nociceptor axons start responding when stimulus beomes noxious, firing rate increases as stimulus intensity increases |
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Term
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Definition
=free nerve endings of a-delta fibers and unmyelinated C fibers
-Most are polymodal (mech,chem,AND thermal)
-some respond to ONE stimulus (mechanical, chemical, OR thermal) |
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Term
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Definition
| smallest diameters, slowest conduction (low to no myelination) |
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Term
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Definition
-made by enzyme released from damaged cells
-directly activate nociceptors via depolarization thourhg g-protein receptors |
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Term
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Definition
-made by enzyme released from damaged cells
-directly affects P2x receptors |
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Term
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Definition
released from damaged cells
depolarizes nociceptors |
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Term
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Definition
| following injury, injury site and surrounding area has increased perception of pain |
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Term
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Definition
| exposure of nociceptors to products of tissue damage increases their activity and their sensitivity to stimuli |
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Term
| substances that sensitize nociceptors |
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Definition
1. bradykinin-increases sensitivity of ion channels (e.g. TRPV1)
2. Prostaglandins-made by enzyme released from damaged cells, aspirin inhibits this enzyme
3. Substance P - released from nociceptors, causes swelling of capillaries, causes release of histamine which causes depolarization |
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Term
| First pain vs. Second pain |
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Definition
First Pain= a-delta fiber (fast,sharp)
Second Pain= C fiber (long lasting, dull) |
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Term
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Definition
| information from two different pain receptors (e.g. organ and skin) can converge on same pain neuron |
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