how is a stimulus converted into and electrical AP?
specific sensory receptors
how are AP’s transmitted?
specific sensory pathways
what is a receptive field?
each neuron has a cluster of peripheral nerve branched, each with a nerve ending (receptor), the distribution of these defines the receptor field- vary
describe the receptive fields in the arm
small in the periphery
large in trunk
what is 2 point discrimination?
the ability to discern 2 separate mechanical stimuli
- measure of spatial resolution
- indication of receptive field size
describe the transduction of a stimulus
stimulus -> change in receptor membrane permeability
- > influx of cations
- > depolarisation:receptor potential
- > AP
how is stimulus intensity coded?
frequency of AP discharge
^ stimulus intensity= ^ AP frequency
(limit to max)
different receptors have dif thresholds depending on number of neurons activated
how us stimulus duration coded?
duration of AP firing
how is location coded?
receptor -> neural pathway -> brain location