EMBRYOLOGY
NERVOUS SYSTEM
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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is the minimum hyperpolarization needed to prevent the occurrence of action potentials.
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is the peak amount of depolarization seen in an action potential.
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is the lowest frequency of action potentials a neuron can produce.
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is the point of separation from a living from a dead neuron
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is the minimum depolarization needed to operate the voltage-gated sodium and potassium channels
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Detailed explanation-1: -The critical depolarization value is about 32 mV. Generally speaking, the threshold value is the difference between the resting membrane and threshold potential; that is, the threshold value is in direct proportion to the critical depolarization, and it will change with relative changes of the two potentials.
Detailed explanation-2: -Most often, the threshold potential is a membrane potential value between –50 and –55 mV, but can vary based upon several factors. A neuron’s resting membrane potential (–70 mV) can be altered to either increase or decrease likelihood of reaching threshold via sodium and potassium ions.
Detailed explanation-3: -K(A) channels were activated by depolarization with a threshold near-45 mV, suggesting that K(A) channels function in both repolarization and timing of APs.