Sleep and other good stuff
Biological Rhythms Annual cycles- migration, hibernation 28 day cycles- menstruation hour cycles- body temp., hormone secretion 90 minute cycles- cycle through sleep stages
Circadian Rhythm Regular body clock that operates on a 25 hour cycle People’s clocks vary… night owls vs. early birds Can be disturbed by many external factors
Sleep Stages While awake, and in twilight, alpha waves Stage 1 –Lasts about 5 minutes –May experience hallucinations
Sleep Stages cntd. Stage 2 –Lasts about 20 minutes –Characterized by sleep spindles (rapid bursts of brain-wave activity) –Sleep talking can occur –People are clearly asleep at this point
Sleep Stages cntd. Stages 3 & 4 –Beginning of slow wave sleep (Delta waves) –At this point, it’s very hard to wake people up –Lasts about 30 minutes –End of stage 4 marked by bed wetting or sleep walking (somnambulism) in children
Sleep Stages Information Ascend from stage 4 up through stage 2 Spend about ½ the night in stage 2 Instead of going back to stage 1, REM occurs Time spent in stage 4 decreases until no longer exists
Rapid Eye Movement Heart rate rises Breathing becomes rapid & irregular Eyes dart about even though lids are shut Most vivid dreams occur during this stage
Eight Hours a Day??? NOT TRUE!!! Babies spend 2/3 of their time sleeping Adults spend less than 1/3 sleeping If left to sleep, most will sleep 9 hours
Sleep Debt Brain keeps track of how many hours you sleep about every 2 weeks Brain isn’t satisfied by 5 hours, 5 hours, 5 hours, 13 hours It wants consistency
Sleep Deprivation 2 nd leading cause of fatal car accidents Can also lower your immune system Accidents increase immediately after daylight saving (spring ahead) –Canada – 7% higher on the Monday after –U.S. – 17% higher on the Monday after
Why do we need sleep? Sleep protects us from the dangers of night Restores body tissues, especially the brain May play a role in growth process – during sleep, pituitary gland releases growth hormones