Rhythms Of The Body Flashcards
Biological Rhythms
periodic and regular fluctuations in a biological systems such as body temp, sleep, activity, …
Circadian rhythm -.
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a biological rhythm with a period of about 24 hours - latin ‘circa’ about ‘dies’ day and are affected by all sorts of environment cues
Entrainment
occurs where biological rhythms are synchronized with external cues, such as daylight.
-Studies in bunkers or caves (living without time cues) lead to “free-running” rhythms. Usually get 18 to 36 hours.
Cycle is normally controlled by SCN suprachiasmatic nucleus of hypothalamus- information from eyes. Leads to changes in levels of melatonin from pineal gland. Secreted during dark hours and keeps sleep-wake cycle going…
-Melatonin also affects sexual activity cycle in hamsters.
Blind people
often have disrupted sleep-wake cycles, insomnia.
Internal desynchronization
Interoften occurs with (jet lag or daylight savings time - where it’s easier to shift west or late)
-affects energy level, mental skills, motor coordination
-use bright lights or melatonin to ‘reset clock.’
Mistleberger (1991) found genetic differences
- night owls vs. early birds
Melatonin supplements .
Metreat insomnia as in older people who have a decline in levels of melatonin and sleep.
Sleep Deprivation).
Can function on sleep deprivation for 1 day, but 4 days is unbearable. Yet, don’t need to make up all of deprived sleep. ?
Mental flexibility, attention, and creativity are affected by sleep loss. Eg., several days - irritable, hallucinations, and delusions (car accidents)
Seems to play a role in learning & memory, ‘mental housekeeping’ and consolidation of memory & creativity. Reinforcement of daily activities.
Without sleep fall back on skill maintenance and development and gain weight through metabolism changes (ghrelin and cortisol increase and leptin decreases).
The various types of sleep
The
1950’s - started to study electrical activity of the brain during sleep and discovered REM using EEG (now several measures) Chart
