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The property of cardiac muscle in which stimulation from a single myocyte travels to the atrium and ventricle before contracting, resulting in a coherent and co-ordinated pump activity.
A rule applied to the activation of individual muscle or nerve cells, where the response to stimuli (depolarisation) only occurs above a certain threshold, usually –55 mV, after which a complete action potential occurs that is maximum in intensity—i.e., the strength of the nerve impulse is not dependent on, or a function of, the strength of the stimulus.
A “soft” rule in behavioural studies, which refers to the observation that a behavioural stimulus will produce either a complete response or none at all.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
all-or-none lawThe property in muscle and nerve fibres of either responding wholly to a stimulus or not at all. The strength of the stimulus must exceed a particular threshold or there will be no response, but when the response occurs it is total. The law applies to individual fibres and a graded response is obtained by a variation in the number of fibres activated.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
all-or-none lawa law stating that certain tissues respond in a similar way to stimuli no matter how strong the stimuli are, i.e. they either react by giving a response (all), or do not react and give no response (none). Nerve fibres normally act in this way.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005