PSY3320 Lecture Notes - Lecture 4: Sleep Deprivation, Circadian Rhythm Sleep Disorder, F.Lux
15 Oct 2018
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Document Summary
Circadian rhythm a biological rhythm that exhibits a period of 24hours, endogenously generated. Organising appropriate timing for physiology (sleep, metabolism) Evolved this to be able to anticipate events in our environment. Tau/period = the time elapsed for one complete oscillation or cycle of a rhythm e. g. minimum body temperature to minimum body temperature the next day is 1 period. E. g. hamster running on wheel even without external cues such as light/lack of light, occurs even with the absence of changes in the environment (constant darkness for example) Melatonin > a hormone secreted by pineal gland and released during the human biological night (when our bodies anticipate night). Provides the body"s internal signal of darkness, higher secretion at night. Hamsters have high melatonin at night but they have lots of activity at night. Release of melatonin controlled by the scn. Light exposure both resets the circadian rhythm of melatonin and acutely inhibits melatonin synthesis.
