PHYSIOLOGY
SLIDING FILAMENT MODEL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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This is the largest charge achieved during an action potential
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This is the threshold required to complete an action potential
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This is the resting charge of a neuron
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This is the charge when all the sodium is inside the cell
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Detailed explanation-1: -When the depolarization reaches about-55 mV a neuron will fire an action potential. This is the threshold. If the neuron does not reach this critical threshold level, then no action potential will fire.
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: -Threshold potential is the minimum potential difference that must be reached in order to fire an action potential. For most neurons in humans, this lies at-55 mV, so a signal to a resting cell must raise the membrane potential from-70 mV.
Detailed explanation-4: -The threshold is the value of the membrane potential which, if reached, leads to the all-or-nothing initiation of an action potential. The initial or rising phase of the action potential is called the depolarizing phase or the upstroke.
Detailed explanation-5: -Voltage-gated channels open when the cell’s membrane potential reaches a specific value, called threshold. The neuron reaches threshold after enough EPSPs summate together.