gestation period


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gestation

 [jes-ta´shun]
the period of development of the young in viviparous animals, from the time of fertilization of the oocyte (ovum) to birth; see also pregnancy.
gestation period the duration of pregnancy; in the human female, the average length, calculated from the first day of the last normal menstrual period, is 280 days, or 6 lunar months. The normal limits of the human gestation period are from 37 weeks (259 days) to 42 weeks (293 days); days and weeks are counted as completed days and weeks. If one counts from the moment of conception, the length of time is 266 days (280−14 days).

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.

gestation period

Etymology: L, gestare, to bear; Gk, peri, near, hodos, way
the time span between conception and labor. In humans the period is approximately 38 weeks.

gestation period

The period from fertilization of the egg (ovum) to the birth of the child. The human gestation period is 40 weeks, plus or minus 2 weeks.

gestation

the period of development of the young in viviparous animals, from the time of fertilization of the ovum to birth. See also pregnancy.

gestation period
the duration of pregnancy in the domestic animal species are: cow—273 to 292 days (Bos taurus), 271 to 310 days (Bos indicus); mare—333 to 346 days; ass—365 to 375 days; ewe—143 to 147 days (meat sheep), 147 to 155 days (merino); goat doe—146 to 155 days; sow—111 to 116 days; bitch—58 to 68 days; queen—61 to 70 days.
In laboratory and quasi-pet animals: guinea pig 59-72 days, gerbil 24-26 days, hamster 15.5-16 days, mouse 19-21 days, rat 21-23 days, rabbit 29-35 days.
perpetual gestation chart
a table based on the average gestation period of the particular species, e.g. 63 days for bitches, that plots the anticipated date of parturition against the breeding (conception) date. Designed to be independent of the year so it is valid indefinitely.
prolonged gestation
References in periodicals archive ?
A female of 194 cm TL recorded in September had nine uterine eggs, mating scars, the third membrane remaining in the oviducal glands and 15 vitellogenic oocytes, which indicates that this female had been fertilized and was starting the gestation period.
In addition, I later heard wind of European and Turkish versions of this gestation period that led to an unprecedented high level of multi-religious cooperation to protest the Vietnam War in particular and the Cold War in general.
After a gestation period of a hundred thousand years our human ancestors began to think like we do.
Bonn, the potent warning for any potentially prolonged gestation period on such projects, started life as a competition win that year at the height of the Cold War, only to be declared redundant with the destruction of the wall less than two years after its completion.
Three to four years is the standard gestation period.
Also, the longer the child spent living near a petrol station, the higher the risk of contracting leukaemia became, by approximately three per cent per month, including the gestation period.
Kerry included, agrees that the moral obligation to reverence life arises early in the gestation period, and is thus substantively pro-life.
Condon found that the concentration of SPA in the amniotic fluid around a mouse fetus rises sharply at the end of the rodent's 19-day gestation period.
Like most worthwhile memoirs, a lengthy gestation period will increase the quality of insight these yet-unwritten memoirs have to offer.
This need was recognized a while ago by the school board and the gestation period for this project has been almost four years," says Dawes.
This work benefits from its long gestation period, for only someone so conversant with archives, printed sources, visual materials, and literary works could have produced such a wide-ranging, but concise, study.
Moreover, planning such a project requires seven years gestation period.