U5 lecture 37 Flashcards
define general senses
receptors distributed throughout body (particularly on body surfaces)
where are general senses not collected
within specialized ‘sense organs’
what are the 4 types of general senses
- pain (nociceptors)
- temperature ( thermoreceptors)
- touch, presuure, body position (mechanoreceptors)
- chemical stimuli (chemoreceptors)
where are somatic general senses
body surface
-surface temp, touch, pain and muscle soreness
where are visceral general senses
internal organs
-stomach ache, cramps
define special senses
receptors congregated in specialized ‘sense organs’
what are the 5 types of special senses
- smell (olfaction)-nose
- taste (gustatory)-tongue
- sight( vision)-eye
- balance/equilibrium- ear
- sound (hearing)- ear
why can’t we discriminate between different types of stimuli
because different receptor types respond preferentially to different stimuli
is a mechanoreceptor more sensitive to touch or light
touch
is a photoreceptor more sensitive to touch or light
light
regardless of stimulus ‘modality’, all sensation is read in the CNS as what
electrical signals
what is discrimination between two similar stimuli dependent on
the number of receptors within an area of sensory surface
what does stimulation anywhere within the receptive field result in
a signal from the same sensory afferent
what are the steps of sensory transduction
- stimulus arrives at receptor and alters membrane potential of receptor
- receptor potential influences rate of AP production in a sensory neuron
- APs travel to CNS along afferent pathway
- CNS interprets/processes these incoming signals
the brain assumes that any signals coming in along a sensory afferent from a particular receptor reflects stimulation by what
the appropriate stimulus
