Biological Rhytms and Sleep - Psychology4A.com.
Biological rhythms are cyclical patterns within biological systems that have evolved in response to environmental influences, e.g. day and night. There are two key factors that govern biological rhythms: endogenous pacemakers (internal), the body’s biological clocks, and exogenous zeitgebers (external), which are changes in the environment.These are rhythms with a period of greater than a day. The menstrual cycle is an example of an infradian rhythm. Infradian rhythms that occur as a result of seasonal changes, for example, migration and hibernation are called circannual rhythms. The menstrual cycle has a period of about 28 days, although the timing can vary according to environmental factors.Biological rhythms allow organisms to adapt to the cycle of day and night and they appear to control nearly all behaviours and physiological processes. In this topic we consider the three main categories of biological rhythms and the extent to which they are controlled by internal and external factors.
A biological rhythm is defined as a “period, more or less regular fluctuation in a biological system; it may or may not have psychological implications” (p.143). Our bodies go through multiple ups and downs in physiological functioning and this is known as biological rhythms.Study on how timing affects drug treatment, Circadian rhythms affect digestion, heart rate, hormone secretions and other functions, medications acting on hormones may not have an effect if taken when hormones are low and fully effective when high.
Circadian rhythm is exhibited by, body temperature cycle, secretion of hormone; mood and cognitive performance and most apparently by sleep and wake cycle and circadian rhythms are influenced by the external environmental and social cues.
