PHYSIOLOGY
SYNAPTIC PHYSIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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When there is resting potential, the outside of the axon is negative relative to the inside.
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During an action potential, sodium ions diffuse into the axon.
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The axon is depolarized when potassium ions diffuses out of it.
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Depolarization occurs when potassium ions diffuses into the axon.
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Detailed explanation-1: -Voltage-gated sodium channels at the part of the axon closest to the cell body activate, thanks to the recently depolarized cell body. This lets positively charged sodium ions flow into the negatively charged axon, and depolarize the surrounding axon.
Detailed explanation-2: -Action potentials travel down neuronal axons in an ion cascade. Positive ions (mostly sodium ions) flow into the cell body, which triggers transmembrane channels at the start of the axon to open and to let in more positive ions.
Detailed explanation-3: -In response to a signal from another neuron, sodium-(Na+) and potassium-(K+)–gated ion channels open and close as the membrane reaches its threshold potential. Na+ channels open at the beginning of the action potential, and Na+ moves into the axon, causing depolarization.
Detailed explanation-4: -When the neuron receives a stimulus, voltage-gated sodium ion channels open and sodium ions flood into the cytoplasm down their concentration gradient. As sodium ions diffuse into the cytoplasm, it causes more voltage-gated sodium ion channels to open, which changes the potential difference to a positive 40 millivolts.