BioScience Dictionary

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Found All-or-nothing phenomenon 1 time.

Displaying results 1 to 10.

1. All-or-nothing phenomenon
* Refers to the phenomenon where the strength of a nerve impulse is not dependent on the strength of the stimulus. Instead, there is a threshold level of stimulus strength that must be reached before the nerve will fire an impulse (at full capacity). Below the threshold, the nerve will not fire at all. * In cardiology, it refers to the same phenomenon observed in the heart muscle, which will either contract fully or not at all. * In studies of behavior, it refers to the same phenomenon where a behavioral stimulus will either produce a complete response or no response at all. Also called all-or-nothing principle, all-or-none law, all-or-none responsiveness, etc.