senses Flashcards
define sensory transduction
the conversion of energy in a stimulus to action potentials in a nerve
what are sensory receptors
cells that transmit signals to sensory neurons
what is receptor potential
an initial response of a receptor cell to a stimulus, consisting of a change in voltage across the receptor membrane
what is a sensation
when sensory receptors and nervous system receive and represent stimulus energies from the environment
what is perception
the process of organizing and interpreting sensory information. allows us to recognize meaningful objects and events
what are the two main types of receptor cells in senses
those that are separate cells vs those that are free nerve endings on an afferent neuron
what is the difference between a receptor cell and a cell surface receptor
receptor cells are found in the cytoplasm or on surface that receive signals
cell surface receptors are embedded in the plasma membrane and receive signals
classification of sensory receptors and their stimulus that they detect
chemoreceptors detect chemicals
mechanoreceptors detect touch, stretch, etc
photoreceptors detect light
thermoreceptors detect temperature
nociceptors detect pain
define modality
specific type of sensation felt (light, touch, sound)
define quality of sense
distinct characteristics within a modality (pitch of noise, soft or hard touch)
what are the main types of information that needs to be sent to the brain about a stimulus
type of stimulus, location, magnitude, and duration
what is the labeled line theory
that the CNS determines the type of stimulus based on receiving input from all sensory cells activated by that stimulus
how does the sensory system encode stimulus intensity
frequency of action potentials, number of receptors activated a stimulus
define receptive field (location of stimulus)
a specific region of sensory space in which an appropriate stimulus can drive an electrical response in a sensory neuron
define sensory projection
any areas of the cerebral cortex to which information is transmitted by the afferent fibers from sensory receptors
define projection pathways
connect the cerebral cortex to the thalamus, brainstem, cerebellum, and spinal cord
what is phantom pain
pain experienced in the area of a body part that has been surgically removed
what does the frog experiment tell us about sensory projection
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define phasic receptor (duration)
rapidly adapting receptors. they respond quickly to stimuli but stop responding upon continuous stimulation.
define tonic receptors (duration)
they are slow adapting. they will respond to the stimulus as long as it persists and produce a continuous frequency of action potentials
what info does tonic receptor provide
they convey stimulus duration and intensity
what info do phasic receptors provide
convey information about the changes to the stimulus such as intensity
define adaptation
the change in sensation intensity with a continued stimulus, due to adjustments of the receptors sensitivity
define interoreceptor
sensory receptor which receives stimuli from within the body