A biological science that studies time-related phenomena in living organisms
Chronobiology is a branch of biology concerned with biological rhythms, i.e. the time-related phenomena in living organisms. Biological rhythms are synchronized cyclic patterns observed in organisms. Examples of biological rhythms are circadian rhythms, diurnal rhythms, ultradian rhythms, and infradian rhythms. These cyclic patterns are driven by the so-called biological clock. A biological clock is one that synchronizes biological rhythm. It helps regulate the biochemical and physiological activities such as sleep and wakefulness cycle, body temperature, patterns of hormone secretion, blood pressure, digestive secretions, alertness levels, reaction times, etc.1 The biological clock that drives these cyclic patterns may be endogenous (internal) or exogenous (external). External cues involved in biological rhythms are particularly referred to as zeitgebers. Examples of these external cues are light, temperature, eating or drinking patterns, etc.
Chronobiology encompasses other fields of study such as anatomy, genetics, physiology, and behavior. Understanding biological rhythms is essential in predicting physiological and behavioral patterns of a biological system. An expert in this field is called a chronobiologist.
Word origin: chrono– + G. bios, life, + logos, study
1 Hedge, A. (2013). Biological Rhythms. Retrieved from ://ergo.human.cornell.edu/studentdownloads/dea3250pdfs/biorhythms.pdf