PHYSIOLOGY
SYNAPTIC PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Na+ (sodium) voltage channels open allowing Na+ to diffuse inward, depolarizing the membrane
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K+ (potassium) diffuse outward, repolarizing the membrane
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Neuron is hyperpolarized and enters a refractory period
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All of the Na+ channel proteins and and most of the K+ channel proteins are closed and resting membrane potential has been reestablished
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Detailed explanation-1: -The Channels of an Action Potential More Na+ influx depolarizes the membrane which opens more channels which depolarizes the membrane more. This channel has only two states, closed and open. Open to closed: The channel will close when the membrane becomes hyperpolarized or repolarized.
Detailed explanation-2: -To reestablish the appropriate balance of ions, an ATP-driven pump (Na/K-ATPase) induces movement of sodium ions out of the cell and potassium ions into the cell.
Detailed explanation-3: -Depolarization is caused when positively charged sodium ions rush into a neuron with the opening of voltage-gated sodium channels.
Detailed explanation-4: -As voltage-gated Na+ channels begin to inactivate, the membrane potential stops becoming more positive This marks the end of the depolarization phase of the action potential. Then, as voltage-gated K+ channels open, K+ ions rush out of the neuron, following their electrochemical gradient.