Which of the following changes during an action potential?Action Potential ConductionInitiation of the Action PotentialSlide 4What effects the rate of propagation?What effects the rate of propagation?What effects the rate of propagation?Slide 8SummaryWhich of the following changes during an action potential?1. Vm2. ENa3. Vm and ENa4. Neither Vm nor ENaAction Potential Conduction•How is an action potential conducted down an axon?•What properties affect the speed of action potential conduction? How?Initiation of the Action PotentialPropagation of the Action PotentialWhat effects the rate of propagation?•Axon diameterWhat effects the rate of propagation?•Membrane resistanceleak channelsV-gated Na+ channelsWhat effects the rate of propagation?•MyelinationDoes the action potential decay (decrease in amplitude) as it travels down the axon?a) Yesb) NoSummary•When the membrane at the axon hillock reaches threshold, an action potential is initiated and is propagated down to the axon terminal•Membrane depolarization during the rising phase of the action potential spreads and opens voltage-gated Na+ channels further down the axon, resulting in the propagation of the action potential•The conduction of an action potential down an axon is faster when:–The axonal diameter is larger, so current can move more freely–The axonal membrane has fewer channels (higher membrane resistance), so that charge is not lost–The axon is myelinated because it creates patches of very high resistance membrane through which the action potential can passively
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