PHYSIOLOGY
CENTRAL NERVOUS SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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+30 mV
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0mV
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-45mV
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-80mV
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Detailed explanation-1: -During this period, that part of the membrane becomes hyperpolarized – more negative than resting potential. At the hyperpolarization phase or overshoot phase, the inside surface of the neuron membrane reaches a voltage of approximately-70 to-75mV.
Detailed explanation-2: -Action potentials are “all or none.” Either the membrane reaches the threshold and everything occurs as described above, or the membrane does not reach the threshold and nothing else happens. All action potentials peak at the same voltage (+30 mV), so one action potential is not bigger than another.
Detailed explanation-3: -The relative refractory period is the interval of time during which a second action potential can be initiated, but initiation will require a greater stimulus than before.