Question

Give a definition for the all or none rule as a response of a nerve or muscle fibre to a stimulus.

Answer 1

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The all-or-none law is a principle that states that the strength of a response of a nerve cell or muscle fiber is not dependent upon the strength of the stimulus. If a stimulus is above a certain threshold, a nerve or muscle fiber will fire. Essentially, there will either be a full response or there will be no response at all for an individual neuron or muscle fiber.

How Does the All-or-None Law Work?
If a stimulus is strong enough, an action potential occurs and a neuron sends information down an axon away from the cell body and toward the synapse. Changes in cell polarization result in the signal being propagated down the length of the axon.