AP PSYCHOLOGY

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: -Action potentials are triggered when an initial depolarization reaches threshold. This threshold potential varies, but generally is about 15 millivolts above the cell’s resting membrane potential, occurring when the inward sodium current exceeds the outward potassium current.

Detailed explanation-3: -1.21 Action Potentials When threshold is reached, an action potential is fired. As the axon rapidly depolarizes during the rising phase of the AP, the membrane increases its K+ conductance, which then allows efflux of K+ to counter the rapid depolarization and bring the membrane potential back toward its resting level.

Detailed explanation-4: -Conclusion: Both depolarization and hyperpolarization caused by an electrical field can prevent action potentials.