circadian rhythm

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Related to Sleep-wake cycle: circadian rhythm

circadian rhythm

n.
A daily rhythmic activity cycle, based on 24-hour intervals, that is exhibited by many organisms.

cir·ca·di·an rhythm

(sər-kā′dē-ən)
A daily cycle of biological activity based on a 24-hour period and influenced by regular variations in the environment, such as the alternation of night and day.
Did You Know? Why do you sometimes wake up on time even if your alarm clock doesn't ring? How do nocturnal animals know when it is time to wake up? It's because you—and most other animals—have a kind of internal clock that controls the cycle of the day's biological activities, such as sleeping and waking. These daily biological activities are known as circadian rhythms because they are influenced by the regular intervals of light and dark in each 24-hour day. While the process underlying circadian rhythm is not completely understood, it is mainly controlled by the release of hormones. The brain regulates the amount of hormone released in response to the information it gets from light-sensitive cells in the eye, called photoreceptors. Circadian rhythms can be disrupted by changes in this daily schedule. For example, biologists have observed that birds exposed to artificial light for a long time sometimes build nests in the fall instead of the spring. In humans who travel long distances by air, the local time of day no longer matches the body's internal clock, causing a condition known as jet lag.

circadian rhythm

The regular recurrence of life activities in 24-hour cycles.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.circadian rhythm - a daily cycle of activity observed in many living organisms
biological time - the time of various biological processes
Translations

cir·ca·di·an rhythm

n. ritmo circadiano, ref. a variaciones rítmicas biológicas en un ciclo de 24 horas.
References in periodicals archive ?
Cirelli and colleagues wanted to see how alterations to the sleep-wake cycle affected the anatomy of the developing adolescent brain.
It is expressed in regions of the brain associated with the sleep-wake cycle.
Washington, Mar 11 (ANI): Researchers have known for decades that fat production by the liver runs on a 24-hour cycle, the circadian rhythm, and is similar to the sleep-wake cycle.
They have discovered that the loss of a certain gene, dubbed "twenty-four," messes up the rhythm of the common fruit fly's sleep-wake cycle, making it harder for the flies to awaken.
In addition to its role in regulating the sleep-wake cycle, melatonin has been shown to lower blood pressure and body temperature and has also been explored as a treatment option for insomnia, hypertension and cancer.
She cautioned parents to not look at a child's sleep-wake cycle in isolation, but to also look for evidence of "withdrawing", such as quitting their team sport or not seeing as much of their friends or poorer school grades.
To track the sleep-wake cycle, the children wore accelerometers continuously for 24 hours a day for a period of at least five days.
A new study finds that, in older people who show no signs of cognitive impairment, those with a sleep-wake cycle that is subtly off-kilter are more likely to have amyloid protein deposits in their brains, writes Melissa Healy A fitful night's sleep and a habit of daytime catnapping may be an early-warning sign of Alzheimer's dementia, according to new research conducted in humans and mice.
This rhythm dictates both physiological and behavioral activities, including the sleep-wake cycle, body temperature, metabolism, eating schedules, hormone secretion, glucose control (homeostasis), and cell reproduction.
Studies have shown that light from smartphones and tablets can disrupt the body's natural sleep-wake cycle.
2002) assessed premature infants and the impact of KC on the sleep-wake cycle.
With children, it probably occurs more frequently because the body and brain's ability to regulate the sleep-wake cycle is still immature.