circadian rhythm

(redirected from Circadian cycles)
Also found in: Dictionary, Thesaurus, Medical.

circadian rhythm:

see rhythm, biologicalrhythm, biological,
or biorhythm,
cyclic pattern of physiological changes or changes in activity in living organisms, most often synchronized with daily, monthly, or annual cyclical changes in the environment.
..... Click the link for more information.
.

circadian rhythm

[sər′kād·ē·ən ′rith·əm]
(physiology)
A self-sustained cycle of physiological changes that occurs over an approximately 24-hour cycle, generally synchronized to light-dark cycles in an organism's environment.
References in periodicals archive ?
Furthermore, variation in circadian cycle for individual rats also makes comparisons of heart rate or blood pressure difficult.
mutations) in two of the genes influencing circadian cycles (i.
Further, by injecting fluorescently labeled dead bacteria into flies at different points in their circadian cycle, the investigators could see increased phagocyte function at night for those two pathogens: there was an increase in the number of bacteria ingested by phagocytes in flies infected during resting versus active phases.
It is interesting that all of these genes are transcribed in 5-day-old planulae, the source of the RNA used in sequencing the Acropora transcriptome, as this indicates that circadian cycles are established very early in larval development.
Then, biologists found they could throw the eyes' rhythms out of sync with other circadian cycles.
As reported in Science in June, researchers were repeatedly able to readjust the biological clocks of 14 men (age 18 to 24) by exposing them to light (equal to sunlight in brightness) for three five-hour sessions at various stages of their circadian cycles over the course of three days.