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45 Cards in this Set
- Front
- Back
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whats a sensory receptor?
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cells that detect various stimuli and produce receptor potentials
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5 types of sensory receptors
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chemoreceptors
thermoreceptors mechanoreceptors photoreceptors noniceptors |
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chemoreceptors
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smell
taste pH metabolite concentrations |
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thermoreceptors
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respond to temperature and its changes
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mechanoreceptors
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respond to physical deformation
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photoreceptors
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visual receptors of the retina
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noniceptors
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pain
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somatosensation
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mechanical, chemical, and thermal changes are detected
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sensations are transduced by receptors in the _________ and conveyed to _________
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PNS
CNS targets |
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wheres somatic sensation come from
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dendritic processes in skin and muscles
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where are cell bodies of the body and face sensory neurons located?
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ganglia alongside the SC and BS
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sensory neurons are ______ polar
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pseudounipolar
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transduction
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conversion of 1 form of energy into another
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sensory transduction
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conversion of pressure, touch, heat, etc. into neural impulses
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receptor potential
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depolarizing current
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afferent fiber endings
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receptor cells at peripheral endings
-mechanoreceptors |
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largest afferents supply
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sensory receptors in muscles
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intermediate diameter fibers mediate _________
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touch
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smallest fibers convey
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temperature and pain
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C fibers for slow pain are __________
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unmyelinated
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A delta fibers are for
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pain, temperature
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Receptive fields
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area of skin where stimulation results in a change in AP rate
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what does each receptive field correspond with?
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a single afferent fiber
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how do you test for receptive field size
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2 pt. discrimination using calipers
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peripheral processes are called ______.
Because? |
Free nerve endings
-they lack a receptor structure |
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2 general types of free nerve endings
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A delta
C fiber nonciceptors |
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A delta receptors respond to:
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dangerously intense mechanical and/or thermal stimuli
"first pain" |
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Unmyelinated C fibers are polymodal because they:
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respond to thermal, mechanical, and chemical stimuli
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what mediates the sharp first pain?
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A delta nociceptors
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the second pain is mediated by:
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C fibers
-delayed, diffuse, and longer lasting |
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pain pathways have their cell bodies where?
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Dorsal root ganglia
CN ganglia |
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pain pathways:
1st neuron does what? |
enters SC
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Pain pathways:
2nd neurons go where? |
decussate in the SC and ascend in ventrolateral part of SC and carries it to the medulla
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nonciceptors only begin to respond when ______________
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the stimulus reaches intensive levels
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when does chronic neuropathic pain occur?
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when central pathways change to constantly produce pain, even tho peripheral areas heal and thresholds normalize
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where do primary afferents carrying tactile and proprioceptive information synapse?
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the posterior column nuclei of the ipsilateral medulla
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2nd order neurons that carry tactile and proprioceptive information cross the midleine and form the _________, then ______
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medial lemniscus
ascend to ventral posterolateral nucleus of the thalamus |
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3rd order of neurons carrying tactile and proprioceptive information project to the _________
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somatosensory cortex of the POSTcentral gyrus
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spinothalmic tract has what?
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pain, temperature, and some touch and pressure afferents
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in the spinothalmic tract, the 2nd order fibers cross the midline, form the spinothalmic tract, and ____________
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ascend to the ventral posterolateral nucleus of the thalamus
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spinothalmic tract:
thalmic cells project to the _______________ of the ___________ _________ and ___________ |
somatosensory cortex
POSTcentral gyrus insula other cortical areas |
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Mechanoreceptive afferents from the lower extremities ascend thru the _______ to reach __________, whose cells give rise to the _________.
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Fasciculus gracilis (FG)
Clarke's nucleus ipsilateral posterior spinocerebellar tract (PST |
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fibers from the PREcentral gyrus, and other nearby cortical areas descend thru the:
(3) |
cerebral peduncles
pons medullary pyramids |
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Fibers from the PREcentral gyrus cross in the pyramidal decussation to form the:
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lateral corticospinal tract
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Fibers that don't cross in the pyramidal decussation form the ______________
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anterior corticospinal tract
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