Compare and Understand the "All-or-None" Characteristic of Action Potentials
When the first domino pushed all of the other dominoes compared to when the first domino did not move, what characteristic of action potentials does this represent?
When the first domino is pushed and it causes all the other dominoes to fall, this represents the "all-or-none" characteristic of action potentials. When the first domino is pushed, it creates a chain reaction causing all of the other dominoes to fall. This represents the characteristic of action potentials known as "all-or-none." Just like how the first domino either falls completely or not at all, action potentials in neurons are either triggered fully or not at all. If the stimulus is strong enough, it will trigger an action potential that will propagate down the entire neuron, much like how the chain reaction of falling dominoes is triggered by the first one being pushed. However, if the stimulus is not strong enough to trigger an action potential, it will not propagate down the neuron just as the chain reaction of dominoes will not occur if the first one is not pushed. In this scenario, once the threshold is reached, the action potential is generated and propagates along the neuron without losing strength. If the first domino does not move, this represents a sub-threshold stimulus, meaning that the stimulus was not strong enough to initiate an action potential. In this case, the signal does not propagate, similar to how the dominoes do not fall if the first one is not pushed with enough force.