dictionary help| refractory period | medical dictionary |
<neurology, physiology> most commonly used in reference to the interval (typically 1ms) after the passage of an action potential during which an axon is incapable of responding to another. This is caused by inactivation of the sodium channels after opening. The maximum frequency at which neurones can fire is thus limited to a few hundred Hertz. An analogous refractory period occurs in individuals of Dictyostelium discoideum, which are insensitive to extracellular cyclic AMP immediately after a pulse of cAMP has been secreted.
The term can be applied to any system where a similar insensitive period follows stimulation.
This entry appears with permission from the Dictionary of Cell and Molecular Biology
(11 Mar 2008)
refractory cast, refractory flask, refractory lining < Prev | Next > refractory period of electronic pacemaker
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