Human Sensory Physiology Flashcards
(18 cards)
stimulus
something that triggers a reaction in organ or tissue
modality
nature of type of stimulus (light, sound), indicated by type of sensory neuron activated
quality
differences in modality (diff freq. of sound, sweet and sour taste)
intensity
number of receptors activated, frequency of action potentials generated
duration
coded by pattern of action potential generation. some neurons generate action potentials for duration of stimulus, some generated ap at on-offset of stimulus
location
which group of neurons is active, ear and nose neurons have no location sensor. uses timing to compute location
receptor
organ or cell responding to stimuli
characteristics of stimulus
modality, intensity, duration, location
characteristics of receptors
sensitivity, threshold, density
sensitivity
varies with type of receptor
5 main types of receptors
chemoreceptor-respond to chemical ligans binding to receptor
mechnaoreceptors- mechnical energy-vibration, sound, pressure
thermoreceptors-temp
electromagnetic receptors- electromagnetic energy, eg light
nociceptors-noxious stimuli (tissue damage interpreted as pain)
threshold
min stimulus strength that receptor responds, depends on circumstances
density
how many receptors in a given area
non-neural receptors
lens, cornea of eye, hairs on arm, tastebuds
sensory pathway characteristics
receptive field, specificity of the pathway
receptive fields
all the sensory receptors that influence neuron’s activity
specificity of the pathway
intensity of stimulus, duration are coded in pattern of action potentials reaching cns
stimulus location and modality coded according to receptors that are activated or timing of activation
each pathway projected to region of cerebral cortex dedicated to a particular receptive field
other factors influencing the integration of info and perception
alertness, muscle fatigue, age, experience, adaptation and habituation
