circadian rhythm


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Related to circadian rhythm: melatonin, Circadian rhythm sleep disorder

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 ?
Biologists survey some of the recent research on the daily, or circadian rhythm of life.
Certain diseases and natural aging affect that circadian rhythm or are linked to disruptions in it, but (https://nccih.
PARIS--Converging evidence suggests that attention-deficit/hyperactivity disorder and sleep difficulties share a common underlying etiology involving circadian rhythm disturbance, J.
The circadian rhythm guides these animals through a daily migration, to deep waters during the day to hide from predators and shallow waters at night to feed.
With all the artificial illumination we now have, nights can be like days and this disturbs the body's biological clock, called the circadian rhythm.
New information about how vision regulates circadian rhythm could be used to develop an eye drop that treats jet lag.
This is not the first time that pathogens have been seen to 'game' our body clocks: the malaria parasite, for example, is known to synchronise its replication cycle with the host's circadian rhythm, producing a more successful infection.
Continuous work in night shift and rotation shift disrupts the normal circadian rhythm and disturbances in the psycho-physiological function.
However, because her eyes cannot perceive the normal daily cycle of light and darkness, she suffers from a circadian rhythm disorder known as non-24 sleep-wake disorder or, simply, non-24.
Manfredini and colleagues (18) reported that optimal timing in the circadian rhythm can result in as much as a 10% increase in athletic performance.
Melatonin regulates circadian rhythm and plays a role in the transduction of the chronobiological actions of multiple hormones.

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