circadian rhythm clock definition
A circadian rhythm /sÉËrËkeÉªdiÉn/ is any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria. The term circadian comes from the Latin circa, meaning around (or approximately), and diÄm, meaning day. The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.
Although circadian rhythms are endogenous (built-in, self-sustained), they are adjusted (entrained) to the local environment by external cues called zeitgebers (from German, time giver), which include light, temperature and redox cycles.he term circadian comes from the Latin circa, meaning around (or approximately), and diÄs, meaning day. The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology.