summation

summation /sum·ma·tion/ (su-ma´shun) the cumulative effect of a number of stimuli applied to a muscle, nerve, or reflex arc.

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sum·ma·tion (s-mshn)

n.

The process by which multiple or repeated stimuli can produce a response in a nerve, muscle, or other part that one stimulus alone cannot produce.

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summation,

n the phenomenon in which similar actions of more than one drug result in a total action that may be expressed as the arithmetical sum of the effects of the individual drugs.

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summation

accumulate, add up, aggregate a series of numbers or quantities or events.

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summation of effects

a theory explaining clinical pruritus as the additive effects of pruritus from several causes which may raise the individual above the threshold, but pruritus from any single cause would be unlikely to do so.

summation gallop

see gallop rhythm.

neurological summation

physiological summation in synapses is a characteristic of the mammalian nervous system. It may be spatial, with additional synaptic junctions participating, or temporal, when succeeding stimuli catch up with the as-yet undischarged neurotransmitter. Seen in the retina of the cat, as an example of a nocturnal animal, where many millions of photoreceptors are connected to only one million axons, resulting in maximal sensitivity to light.

weighted summation

the sum obtained by adding the numerical value for individual clinical signs, each weighted to express their importance, when making a diagnosis. The total, as a fraction or a percentage, provides an estimate of the probability of each diagnosis being the correct one.