11 Sensory Receptor Mechanisms and Central Processing Flashcards Preview

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Flashcards in 11 Sensory Receptor Mechanisms and Central Processing Deck (30):
1

exteroreceptors

convey information about the external environment

2

interoreceptors

convey information about the internal environment

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sensory modality

differentiates one type of sensation from the others

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the receptor for pain is

naked nerve endings

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this sensation (modality) responds to mechanoreceptors, thermoreceptors, and nocioceptors

pain

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sensory unit

a single sensory nerve and the receptor/receptors to which it responds

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receptive field

area of response for the receptor(s) in each separate sensory unit

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transduction

converting energy of the stimulus into electrical energy in the nervous system

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adequate stimulus

the specific stimulus that normally activates a particular type of sensory receptor (i.e. the visual spectrum); it produces a graded electrical potential in the receptor

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generator potential

when the receptor is the sensory nerve ending itself

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receptor potential

when the receptor cell is non-neural

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all or none action potential

generator potential depolarizes sensory nerve beyond threshold

13

pacinian corpuscle consists of

free nerve surrounded by layers of connective tissue

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pacinian corpuscle responds to

touch and pressure

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deforming a pacinnian corpuscle causes___

Na+ channels to open, influx of Na+, depolarization

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receptor potentials may be ____ or _____

hyperpolarizing or depolarizing

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sensory adaptation/accommodation

when receptor potential declines due to continued pressure

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phasic/velocity receptors

quickly adapting; identify the rate at which a stimulus changes

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the pacinian corpuscle is a ____ receptor

phasic

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tonic/intensity receptors

slowly adapting; fire for as long as the stimulus is applied, show slow adaptation; i.e. pain signals, proprioceptors in muscles, tendons, and ligaments

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the amplitude of the generator or receptor potential is proportional to the ____ of the stimulus strength

logarithm
(the receptor can respond to a very wide range of stimuli)

22

intensity of stimulus is determined by

the frequency of firing of nerve action

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population code says

the stronger the stimulus, the more receptors activated

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e.g. first order neuron

DRG (dorsal root ganglion)

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e.g. second order neuron

dorsal column nuclei

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receptive field first order neuron

area on skin where applied pressure excites the neuron

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second order neuron

dorsal column nuclei - receptive field changes shape and now has an excitatory center with inhibitory surround

28

lateral inhibition

to enhance the boundaries of contrast between incoming sensory signals; a region of excitation surrounded by a inhibition

29

third order neuron

thalamus

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generator potential

may generate a train of action potentials