Circadian Rhythms

The timing and rhythmicity of the sleep-wake cycle is matched to the solar day-night cycle in humans. This rhythmical pattern is generated internally but is modified by environmental factors, in particular the light-dark cycle. The endogenous nature of the circadian rhythm is verified by the persistence of these rhythms when environmental conditions are held constant. For example, a human kept in isolation without access to a clock or a periodic light-dark cycle will maintain a regular sleep-wake cycle. Although the rhythm is maintained, the periodicity of the sleep wake cycle under this free-running condition is approximately 25 hours. However, under the influence of the environmental light-dark cycle, this rhythm is entrained to 24-hour solar day. The environmental cues that are able to entrain the internal clock mechanism are called Zeitgebers. The most potent Zeitgeber for sleep-wake rhythms in most organisms is light.

Was this article helpful?

0 0
Hearing Aids Inside Out

Hearing Aids Inside Out

Have you recently experienced hearing loss? Most probably you need hearing aids, but don't know much about them. To learn everything you need to know about hearing aids, read the eBook, Hearing Aids Inside Out. The book comprises 113 pages of excellent content utterly free of technical jargon, written in simple language, and in a flowing style that can easily be read and understood by all.

Get My Free Ebook


Post a comment