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1. the level that must be reached for an effect to be produced, as the degree of intensity of stimulus that just produces a sensation.
2. that value at which a stimulus just produces a sensation, is just appreciable, or comes just within the limits of perception.
3. renal t.
auditory threshold the slightest perceptible sound.
threshold of consciousness the lowest limit of sensibility; the point of consciousness at which a stimulus is barely perceived.
defibrillation threshold DFT; the minimum amount of energy in joules that will consistently terminate ventricular fibrillation.
fibrillation threshold the least intensity of an electrical impulse that will cause cardiac tissue to begin fibrillation.
pacing threshold the minimal electrical stimulus required to produce consistent cardiac depolarization.
renal threshold that concentration of a substance (threshold substance) in plasma at which it begins to be excreted in the urine.
concentration of plasma substance above which the substance appears in the urine.
re·nal thresh·old(rē'năl thresh'ōld)
The plasma concentration level of a substance below which none appears in urine.
the level that must be reached for an effect to be produced, as the degree of intensity of stimulus which just produces a sensation.
a theory explaining pruritus which states that some degree of pruritus is tolerated by a patient, but a small increase from an additional source raises the patient above their threshold and causes clinical signs.
that concentration of a substance in plasma at which it begins to be excreted in the urine.
heritable traits which have specific thresholds, e.g. four rather than three toes on a guinea pig's hindfeet, alive or dead at a specific age.
the distance between two thresholds when an inherited abnormality can occur at a number of levels, e.g. completely patent ductus arteriosus, through partial closure (ductus diverticulum) and complete closure. See also threshold traits (above).