Circadian rhythm (redirected from Sleep cycle)

circadian rhythm

n.

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

---

Circadian rhythm

Any body rhythm that recurs in 24-hour cycles. The sleep-wake cycle is an example of a circadian rhythm.

Mentioned in: Phototherapy, Sleep Disorders

---

circadian rhythm,

n person's biological patterns within a 24-hour cycle, circa a day. See also chronobiology.

---

circadian rhythm Diurnal rhythm, ultradian rhythm Physiology An innate, daily, fluctuation of physiologic and behavioral functions–eg sleep waking, generally tied to the 24 hr day-night cycle; the diurnal cadence in humans without cyclical cues provided by natural light, is 25.4 hrs; CR affects drug metabolism, serum levels of various substances–eg, ACTH, physiologic activities–eg, BP, myocardial blood flow and O₂ demand, psychosomatic disease and sleep cycles, cell division, hematopoiesis, NK cell activity. See Biorhythm, Circadian pacemaker, Insomnia, Jet lag, Melatonin, Shift work.