BIOLOGICAL BASES OF BEHAVIOR
THE NERVOUS AND ENDOCRINE SYSTEMS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The movement of sodium and potassium ions across the membrane creates an action potential
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Neurotransmitters are released from the dendrites
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The absolute refractory period of the neuron prevents it from responding
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The neuron’s equilibrium potential is reached
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Detailed explanation-1: -In neurons, the rapid rise in potential, depolarization, is an all-or-nothing event that is initiated by the opening of sodium ion channels within the plasma membrane. The subsequent return to resting potential, repolarization, is mediated by the opening of potassium ion channels.
Detailed explanation-2: -A stimulus from a sensory cell or another neuron causes the target cell to depolarize toward the threshold potential. If the threshold of excitation is reached, all Na+ channels open and the membrane depolarizes. At the peak action potential, K+ channels open and K+ begins to leave the cell.
Detailed explanation-3: -When the nerve cell is sufficiently stimulated, sodium channels in the cell membrane open and sodium ions flood into the cell, depolarizing the cell membrane (the charge reverses: inside becomes positive relative to the outside).
Detailed explanation-4: -When the membrane potential of the axon hillock of a neuron reaches threshold, a rapid change in membrane potential occurs in the form of an action potential. This moving change in membrane potential has three phases. First is depolarization, followed by repolarization and a short period of hyperpolarization.