Chapter 10 (Part 2) Flashcards
the process whereby a sensory receptor converts a stimulus modality into a change in membrane potential is called
sensory transduction
a sensory unit is composed of ?
all receptors in receptive field and the associated afferent neuron
what is the receptive field?
region in which all the receptors are / can respond in order to activate a sensory unit
how does the nervous system determine stimulus strength?
stim. strength is determined by AP frequency
what is population coding?
when multiple receptors activate 1 afferent neuron
in a sensory afferent neuron:
___ stimulus = ___ potential = ___ potential frequency
increased stimulus = increased graded potential = increased AP frequency
in a sensory afferent neuron:
___ AP frequency = ___ ion influx at axon terminal = ___ release = ___ postsynaptic ___ potential in a _____
increased AP frequency = increased Ca ion influx at the axon terminal = increased NT release = stronger postsynaptic graded potential in second order neuron
how is the size of a receptive field used in stimulus localization?
bigger RF = stimulus is harder to detect
smaller RF = stimulus is easier to detect
how is the degree of overlap between sensory units used in stimulus location?
if detected by two afferent neurons, signal must lie within the overlap region (draw the picture of areas one, two, and three)
what is lateral inhibition?
draw picture
when you eat a salty pizza, you drink a lot of water. how are your osmoreceptors and baroreceptors responding throughout this time?
why would it be important to be able to respond to change in osmolarity differently from dehydration vs. trauma?
respond more quickly to the more serious event
what is the mechanism behind referred pain?
two regions, such as the viscera of the heart and the skin of the shoulder, both communicate with the brain through the same secondary interneuron
draw out the gate-control hypothesis
okay
what accounts for different AP transmission rates among pain receptor neurons?
myelinated or unmyelinated
