An action potential is an "all-or-nothing" event. explain what is meant by this phrase.

An Action Potential is an "All or Nothing" phenomenon. It was first described in 1871 by a Physiologist Henry Pickering Bowditch.

Explanation:

The action potential is always a full response, there is no such thing as a strong or weak potential. This means that when a stimulus is given, a neuron either does not reach the threshold or a full action potential is fired.

STATEMENT OF LAW:

The all or none law states that , the strength of a response of a nerve cell or a muscle fiber do not depends upon the strength of a stimulus. If a stimulus is above a certain threshold, the nerve cell will send the information down the axon towards the synapse and the signal is being propagated.

SIGNIFICANCE:

The significance of this law is that it minimizes the possibility of information to be lost along the way.

This law was initially applied to the muscles of heart but later it was found to be true for neuronal cells and other muscle fibers too.

Thus an action potential is all or nothing event.  

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