AP PSYCHOLOGY

Detailed explanation-1: -If depolarization reaches −55 mV, then the action potential continues and runs all the way to +30 mV, at which K+ causes repolarization, including the hyperpolarizing overshoot. Also, those changes are the same for every action potential, which means that once the threshold is reached, the exact same thing happens.

Detailed explanation-2: -An action potential is a transient, electrical signal, which is caused by a rapid change in resting membrane potential (-70 mV). This occurs when the threshold potential (-55 mV) is reached, this causes a rapid opening in the voltage-gated sodium channels leading to an influx of sodium ions into the cell.

Detailed explanation-3: -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-4: -The action potential has three main stages: depolarization, repolarization, and hyperpolarization. Depolarization is caused when positively charged sodium ions rush into a neuron with the opening of voltage-gated sodium channels.

Detailed explanation-5: -Membrane Repolarization results from rapid sodium channel inactivation as well as a large efflux of potassium ions resulting from activated potassium channels. Hyperpolarization is a lowered membrane potential caused by the efflux of potassium ions and closing of the potassium channels.