Receptors Flashcards
what are receptors?
transducers that change physical and chemical stimuli into electrical nerve impulses
what is afferent (sensory) information used for?
sensation- conscious, must be perceived
control of movement (e.g. flexor reflex)
maintaining arousal
protection- pain, reflexes
for sensation you must have a ____?
cerebral cortex
sensory receptors go to ____?
autonomic effectors
what are the 4 receptor qualities?
receptors mediate 4 stimulus qualities that can be quantified
1: modality
2: intensity
3: duration
4: location
modality:
labeled line code- modality specific
vision hearing touch taste smell
intensity:
frequency- increase # of receptors; threshold
temporal - how fast
spatial- how many
duration:
relationship between stimulus intensity and perceived intensity
discharge patterns of RA & SA
location:
location of receptor, types of discharges
modalities and qualities of sensation depend on:
1: temporal and spatial patterns of activation
2: specificity of sensory endings
(lowest threshold for a receptor is the “novel stimulus” (i.e. lowest threshold for eye receptors is light))
3: central connections
(where it goes in the cerebral cortex determines the type of stimulus detected (a touch sensory put in the eye would sense touch as sight)???
(primary sensory cortices- go along with modalities; input goes to certain areas; central connections
what is the quality for the sensory modality vision?
color, motion
what is the quality for the sensory modality hearing?
pitch
what is the quality for the sensory modality smell?
> 20 odors
what is the quality for the sensory modality taste?
sweet sour salt bitter "umami" (MSG, other amino acids)
what is the quality for the sensory modality somatic?
touch-pressure warm-cold flutter-vibration pain, itch, tickle postion and movement senses
rate coding:
the greater the response the greater the stimulus
spike in AP
the more AP, the higher the intensity
Topographic (somatotopic) map
slide 7 of receptors????
occipital-seeing
temporal- hearing
parietal- somatostatic
primary sensory cortices to go with modalities. go to certain areas of cerebral cortex. this is what is meant by central connections
what are the 3 anatomic classifications of receptors?
exteroceptor
proprioceptors
interoceptors
what are exteroceptors?
located on external body surfaces
touch pressure pain temperature smell vision hearing
what are proprioceptors?
located in tendons, joints, ligaments, fascia
position sense
movement sense
what are interoceptors?
(visceroceptors)
visceral sensations digestion excretion circulation respiration taste pain
what are the 6 physiologic classifications of receptors?
**based on novel stimulus
1: mechanoreceptors- physical or mechanical stimuli
2: thermoreceptors- temperature
3: photoreceptors- light
4: chemoreceptors- chemicals
5: pain receptors
6: nociceptors- damage (pain & damage info)
what is habitutation?
decrease in response to a constant/repeated stimulus
what is adaptation?
stops working because it is used to the response
phasic/dynamic
fast adapting
will respond when you touch it and stops when you stop touching it; only sees change (when stimulus is turned on or off, not in between)
more time detection
tonic/static
slow adapting
will respond when you touch it and then there is a slow decay when you remove the stimulus
receptor fields- individual neurons
slide 11 receptors ????
