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circadian rhythm
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circadian rhythm Article

circadian rhythm summary

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Below is the article summary. For the full article, see circadian rhythm.

circadian rhythm , Inherent cycle of approximately 24 hours in length that appears to control or initiate various biological processes, including sleep, wakefulness, and digestive and hormonal activity. The natural signal for the circadian pattern is the change from darkness to light. The controlling mechanism for these cyclic processes within the body is thought to be the hypothalamus. Any change in the circadian cycle (such as jet lag and other conditions associated with travel) requires a certain period for readjustment.

jet lag
jet lag Summary
Jet lag, physiological desynchronization caused by transmeridian (east-west) travel between different time zones. The severity and extent of jet lag vary according to the number of time zones crossed as well as the direction of travel—most people find it difficult to travel eastward (i.e., to adapt