Final answer:
An action potential is either generated to its maximum amplitude or not produced at all. That is referred to as its all-or-none property. All action potentials achieve the same peak voltage, and their frequency can increase with stronger stimuli. Following an action potential, a refractory period prevents the immediate generation of a new one.
Step-by-step explanation:
An action potential is either generated to its maximum amplitude or not produced at all. This characteristic is referred to as its all-or-none property. The threshold level of an action potential is a critical point: if depolarization reaches -55 mV, then the action potential continues and runs the full course up to +30 mV, at which K+ causes repolarization. No action potential is 'bigger' than another; they all reach the same peak voltage. Therefore, stimuli that exceed the threshold don't result in a more intense action potential, but they can cause more frequent action potentials.
During this electrical event, an action potential travels down the axon without diminishing in strength, much like a lit fuse of a firecracker. This propagation ensures that signals are transmitted effectively over long distances within the nervous system. After an action potential occurs, the neuron enters a refractory period during which a new action potential cannot be initiated, ensuring orderly transmission of nerve impulses.