absolute refractory period


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Related to absolute refractory period: Relative refractory period

period

 [pēr´e-od]
an interval or division of time; the time for the regular recurrence of a phenomenon.
absolute refractory period the part of the refractory period from phase 0 to approximately −60 mV during phase 3; during this time it is impossible for the myocardium to respond with a propagated action potential, even with a strong stimulus. Called also effective refractory period.
blanking period a period of time during and after a pacemaker stimulus when the unstimulated chamber is insensitive to avoid sensing the electronic event in the stimulated chamber.
effective refractory period absolute refractory period.
ejection period the second phase of ventricular systole (0.21 to 0.30 sec), between the opening and closing of the semilunar valves, while the blood is discharged into the aorta and pulmonary artery. Called also sphygmic period.
gestation period see gestation period.
incubation period see incubation period.
isoelectric period the moment in muscular contraction when no deflection of the galvanometer is produced.
latency period
latent period a seemingly inactive period, as that between exposure to an infection and the onset of illness (incubation period) or that between the instant of stimulation and the beginning of response (latency, def. 2).
refractory period the period of depolarization and repolarization of the cell membrane after excitation; during the first portion (absolute refractory period), the nerve or muscle fiber cannot respond to a second stimulus, whereas during the relative refractory period it can respond only to a strong stimulus.
relative refractory period the part of the refractory period from approximately −60 mV during phase 3 to the end of phase 3; during this time a depressed response to a strong stimulus is possible.
safe period the period during the menstrual cycle when conception is considered least likely to occur; it comprises approximately the ten days after menstruation begins and the ten days preceding menstruation. See the section on fertility awareness methods, under contraception.
sphygmic period ejection period.
supernormal period in electrocardiography, a period at the end of phase 3 of the action potential during which activation can be initiated with a milder stimulus than is required at maximal repolarization, because at this time the cell is excitable and closer to threshold than at maximal diastolic potential.
vulnerable period that time at the peak of the T wave during which serious arrhythmias are likely to result if a stimulus occurs.
Wenckebach's period a usually repetitive sequence seen in partial heart block, marked by progressive lengthening of the P–R interval; see also dropped beat.

ab·so·lute re·frac·to·ry pe·ri·od

the period following excitation during which no response is possible regardless of the intensity of the stimulus.

absolute refractory period

Absolute Refractory Period

The period immediately after an electrical event, during which a new discharge cannot occur, given that the ions integral to a new event have not yet repolarised across an ionic gradient.

ab·so·lute re·frac·to·ry pe·ri·od

(ab'sŏ-lūt' rĕ-frak'tŏr-ē pēr'ē-ŏd)
Period after the firing of a nerve fiber during which it cannot be induced to fire again by any stimulus, no matter how strong.

absolute refractory period

The period during which no stimulus, however strong, is able to evoke a response from an excitable tissue. The absolute refractory period follows immediately after a prior response and is brief.

absolute refractory period

the brief period after the discharge of a nerve impulse when the neuron cannot fire again.

absolute

in mathematical terms, the magnitude of a number regardless of sign.

absolute refractory period
extends from the onset of the action potential as the nerve impulse is generated to the stage where the fiber is repolarized and susceptible to the transmission of another impulse.