refractory period (redirected from Refractory period (biology))

period /pe·ri·od/ (pēr´e-od) an interval or division of time.

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ejection period  the second phase of ventricular systole, being the interval between the opening and closing of the semilunar valves, during which the blood is discharged into the aortic and pulmonary arteries; it is divided into a p. of rapid ejection followed by a p. of reduced ejection.

gestation period  the duration of pregnancy, in humans being about 266 days (38 weeks) from the time of fertilization until birth. In obstetrics, it is instead considered to begin on the first day of the woman's last normal menstrual period prior to fertilization, thus being about 280 days (40 weeks).

incubation period 

1. the interval of time required for development.

2. the interval between the receipt of infection and the onset of the consequent illness or the first symptoms of the illness.

3. the interval between the entrance into a vector of an infectious agent and the time at which the vector is capable of transmitting the infection.

latency period 

1. latent p.

2. see under stage.

latent period  a seemingly inactive period, as that between exposure to an infection and subsequent illness, or that between the instant of stimulation and the beginning of response.

menstrual period , monthly period the time of menstruation.

pacemaker refractory period  the period immediately following either pacemaker sensing or pacing, during which improper inhibition of the pacemaker by inappropriate signals is prevented by inactivation of pacemaker sensing.

refractory period  the period of depolarization and repolarization of the cell membrane after excitation; during the first portion (absolute refractory p.), 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.

safe period  the period during the menstrual cycle when conception is considered least likely to occur; it is approximately the ten days after menstruation begins and the ten days preceding menstruation.

sphygmic period  ejection p.

Wenckebach period  the steadily lengthening P–R interval occurring in successive cardiac cycles in Wenckebach block.

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refractory period

n.

The period that follows effective stimulation, during which excitable tissue fails to respond to a stimulus of threshold intensity.

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refractory period,

the time from phase 0 to the end of phase 3 of the action potential, divided into effective and relative. In pacing terminology, the period during which a pulse generator is unresponsive to an input signal of specified amplitude. The effective refractory period is from phase 0 to approximately -60 mV during phase 3 of the action potential, a time during which it is impossible for the myocardium to respond with a propagated action potential, or even to a strong stimulus. The relative refractory period is from approximately -60 mV during phase 3 to the end of phase 3 of the action potential, the time during which a depressed response is possible to a strong stimulus. Also called refractory phase, refractory state.

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refractory

not readily yielding to treatment.

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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.

myocardial refractory state

the myocardium is refractory to stimulation during the action potential period, excitability returning in the repolarization phase; initially there is a period of supernormality.

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refractory period

Cardiac pacing The time during which a pacemaker's sensing mechanism is nonresponsive–in full or in part to cardiac activity–eg, to a retrograde P-wave in a DDD pacemaker. See Pacemaker Sexuality A post-orgasm recovery period lasting from mins to hrs during which the penis is unerectable. See Erection.