biological rhythm
Internal timing cycle
A biological rhythm is any recurring cycle in a living organism's functions—sleeping and waking, hormone fluctuations, seasonal breeding, migration patterns.
The most familiar is the circadian rhythm, the roughly 24-hour cycle governing sleep, alertness, and metabolism.
Other biological rhythms operate on shorter cycles (heartbeat, breathing) or longer ones (menstrual cycles, hibernation).
- diurnalActive during daylight
- menstrual cycleMonthly female reproductive process
- seasonal affective disorderLight-linked recurring depression
- chronotypeInnate daily rhythm preference
- heartbeatRhythmic cardiac contraction
hibernation · melatonin · light exposure · nocturnal · sleep-wake cycle · sleep cycle · jet lag · body temperature · ocean tides · body clock · hormonal fluctuations · REM sleep · night owl · early bird · lunar phases · migration patterns · internal clock · ovulation
biological rhythmmechanical clock
Gear-operated time device
digital clock · electronic timer · clockwork · atomic clock · metronome
biological rhythmarrhythmia
Abnormal cardiac rhythm
randomness · chaos · irregularity · unpredictability · dysrhythmia
biological, biology, biologic, biologically, biologist, biologists, biomes, biotic, abiotic