The Consequences of Disrupting Biological Rhythms
All living organisms experience rhythmic changes, which tend to coincide with seasonal or daily environmental changes. These rhythms are known as biological rhythms, which include circadian, ultradian and infradian types.
All biological rhythms are controlled by two different factors - internally (endogenous) through nature, and externally (exogenous) through nurture. Most organisms have internal biological clocks,
called endogenous pacemakers. The main endogenous pacemaker in circadian rhythms is the suprachiasmatic nucleus (SCN), a small bundle of nerves in the hypothalamus, as suggested by Morgan (1995), and Kalat (1998). Kalat ...view middle of the document...
He documented problems of a young man who was blind from birth. The subject was exposed to a variety of zeitgebers such as alarm clocks and radios, but results showed that he had a strong 24.9
hour circadian rhythm. The subject had problems resetting his biological clock and had to use stimulants and sedatives to co-ordinate his sleep-wake cycle with the rest of the world. This
shows that the absence of light can disrupt biological rhythms and Miles et al. therefore concluded that light is a dominant time-giver.
Shift work and jet lag have also shown to disrupt biological rhythms. Shift working involves regular changes to the hours of work, it is a feature of our industrialised society. It is a concern because records show that more accidents occur at nights between 1 and 4am or on night shifts, leading to impaired performance and therefore potentially dangerous situations. Frequent shift changes (weekly) are the hardest to readjust to, so longer periods of readjustment (every three weeks/month) are better for the workforce and, consequently, production (Czeisler et al....