latency period


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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.

la·ten·cy phase

in psychoanalytic personality theory, the period of psychosexual development in children, extending from about age 5 to the beginning of adolescence at age 12, during which the apparent cessation of sexual preoccupation stems from a strong, aggressive blockade of libidinal and sexual impulses in an effort to avoid oedipal relationships; during this phase, boys and girls are inclined to choose friends and join groups of their own sex.
Synonym(s): latency period

latency period

n.
1. The fourth stage of psychosexual development in psychoanalytic theory, from about five years to puberty, during which a child apparently represses sexual urges and prefers to associate with members of the same sex. It is preceded by the phallic stage and followed by the genital stage.
2. A latent period.

latency period

Epidemiology A period of subclinical or inapparent pathologic changes following exposure to a noxious agent, ending with the onset of Sx of disease. Cf Incubation period Psychology See Psychosexual development Virology
1. A period in which a virus–eg, EBV, HSV, HIV present in the body is undetectable or asymptomatic; viral LPs are attributed to a lack in host factors critical for expressing early viral gene products; during latency the virus absconds itself in certain cells–eg, EBV in epithelial cells and B lymphocytes; activation of specific cellular–host transcription factors in response to extracellular stimuli may induce the expression of viral regulatory proteins. leading to a burst of lytic viral replication.
2. The period that follows the 1º infection–chickenpox in Pts infected with varicella-zoster virus. See Herpes zoster.

la·ten·cy phase

, latency period (lā'tĕn-sē fāz, pēr'ē-ŏd)
1. psychiatry According to psychoanalytic personality theory, the period of psychosexual development in children, extending from about age 5 to the beginning of adolescence around age 12, during which the apparent cessation of sexual preoccupation stems from a strong, aggressive blockade of libidinal and sexual impulses in an effort to avoid oedipal relationships; during this phase, boys and girls are inclined to choose friends and join groups of their own sex.
2. biowarfare Interval during which an organism lies dormant.
References in periodicals archive ?
The plaintiffs argued that the statute was not intended to apply to cases involving diseases with extended latency periods, alleging that this would eliminate claims before they even arose.
260, 2B, "can be applied to bar personal injury claims arising from diseases with extended latency periods, such as those associated with asbestos exposure, where defendants had knowing control of the instrumentality of injury at the time of exposure."
Since 2008, additional cases have been ascertained, reflecting the identification of previously missed cases and the occurrence of new cases with longer latency periods (interval from exposure to symptom onset) for dCJD (up to 30 years), underscoring the importance of maintaining surveillance for dCJD.
As stated in the epidemiological literature [16], the retrospective analysis of collected cases--as usual for an incidence surveillance system--could "miss" the cases with the shorter latency thereby overestimating the mean latency period. In addition, the possible presence of competitive causes of death (e.g., asbestos related lung cancer and asbestosis) and the incomplete cohort analysis (our study population comprised cases collected in recent years and, hence, cases with relevant past exposure and short latency could be missing) induce a possible bias in the statistical inference about differences in latency.
absorbable thread Authors Position Latency period Kostopoulos Mandibular ramus 0 days and Karring Schmidt et al.
This case emphasises that rabies can have an unusually long latency period (20 years).
Initially 21 rabbits were included, but 3(14%) were excluded before the end of the latency period. Of them 2(66%) removed the pins of the distractors, and 1(33.3%) rabbit underwent unexpected weight loss.
However Australia's mining union, the CFMEU told local media on Wednesday the return of the disease, which has a long latency period, caused by long term exposure to coal dust in areas with poor ventilation, has sent shockwaves through the industry.
The latency period (the period from the start to the onset of cough) and the coughing frequency in 2 min were recorded by a trained observer.
Dust from asbestos can trigger the deadly lung disease, mesothelioma, but the long latency period means many victims are unaware of asbestos exposure until decades later.
Additionally, in PSReA the latency period is about 1-2 weeks, shorter than ARF and cardiac/kidney involvement is also rare.
Hence, they often fail to capture events that only become apparent once a drug is used in a large population, including both rare events and those with a long latency period.