—summational, adj./seuh may"sheuhn/, n.1. the act or process of summing.2. the result of this; an aggregate or total.3. a review or recapitulation of previously stated facts or statements, often with a final conclusion or conclusions drawn from them.4. Law. the final arguments of opposing attorneys before a case goes to the jury.5. Physiol. the arousal of impulses by a rapid succession of stimuli, carried either by separate sensory neurons (spatial summation) or by the same sensory neuron (temporal summation).[1750-60; < ML summation- (s. of summatio), equiv. to summat(us) (ptp. of summare to SUM; see -ATE1) + -ion- -ION]
* * *in physiology, the additive effect of several electrical impulses on a neuromuscular junction, the junction between a nerve cell and a muscle cell. Individually the stimuli cannot evoke a response, but collectively they can generate a response. Successive stimuli on one nerve are called temporal summation; the addition of simultaneous stimuli from several conducting fibres is called spatial summation.
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