Zyklusarten

Zyklusarten describes the different recurring processes or patterns that repeat over time and across fields. The term is used to distinguish how often a cycle occurs, how regular it is, and what system it affects.

In biology and physiology, cycles organize bodily functions and behavior. Examples include the circadian cycle, which follows roughly a 24-hour day and governs sleep-wake rhythms; infradian cycles, such as the menstrual cycle, with a longer period; and physiological cycles like the cardiac cycle, which encompasses the heartbeat and its phases of systole and diastole. These cycles help coordinate metabolism, activity, and homeostasis.

In nature and climate, cycles range from the visible to the subtle. The lunar cycle tracks phases of the Moon over about a month; solar activity exhibits cycles that influence space weather and possibly climate patterns; Milankovitch cycles describe long-term variations in Earth’s orbit and tilt that affect glacial and interglacial periods. Ecological cycles, such as predator–prey population oscillations, illustrate how interactions between species create periodic fluctuations.

In economics and chemistry, Zyklusarten include business cycles—periods of expansion and contraction in economic activity—and seasonal cycles tied to yearly demand. In chemistry and catalysis, catalytic cycles describe a sequence of steps that repeat in a catalyst-driven reaction, returning to the initial state after each turnover. Cycles can be regular and predictable or irregular, and their study helps understand timing, regulation, and system dynamics across disciplines.