noun, plural: biological rhythms
Biological rhythms pertain to the synchronized cyclic pattern demonstrated by an organism as its response to a particular stimulus. It accords with the biological clock. This clock helps regulate the body’s chemicals and functions such as sleep and wakefulness cycle, body temperature, patterns of hormone secretion, blood pressure, digestive secretions, alertness levels, reaction times, etc.1
Biological clock that synchronizes with biological rhythm may be endogenous or exogenous. An endogenous type is one in which the internal biological clock is the one that controls it. An example of it is the body temperature cycle. An exogenous type is one that which involves an external cue (i.e. zeitgeber). An example is the sleep and wakefulness pattern.
There are the different types of biological rhythms: circadian rhythms, diurnal rhythms, ultradian rhythms, and infradian rhythms. Circadian rhythms involve a 24-hour cycle. Ultradian rhythms involve a shorter period than circadian rhythms. Infradian rhythms are biological rhythms lasting more than 24 hours.1
Understanding biological rhythms is essential in predicting physiological and behavioral patterns of a biological system.
1 Hedge, A. (2013). Biological Rhythms. Retrieved from []