SLEEP PART 2 Flashcards
what are the two types of sleep
NREM + REM sleep
describe the four stages of NREM sleep
stage 1: eyes closed, relaxed, lasts 1 -7 minutes, easily awakened
stage 2: light sleep, dream fragments, harder to wake
stage 3: moderately deep sleep, HR & body temp fall
stage 4: deep sleep, body temp & HR low
when do the first two stages of NREM sleep occur
within 30 - 45 minutes of lying down
describe the second two stages of NREM sleep
slow wave sleep, important for restoration, neural activity at basal levels
describe REM sleep
very alert; only occurs after NREM sleep; every 90 min; most dreaming occurs; short periods at first, but gradually gets longer; important for processing day’s events and emotional problems; appearance of alpha waves at onset
what occurs because of REM sleep deprivation
confusion, paranoia, affective disorders, memory impairs, decrease in motor performance, loss of balance, decreased immune function
how do the sleep stages work
begin with NREM and then goes through four stages; REM begins after ~90 minutes
how does the REM timing work
at first, only spend like 5 - 10 minutes in it and then as you sleep, you spend more time in REM
how does the sleep cycle continue throughout the night
cycles between REM and NREM continuously with final REM stage racing between 20 - 50 minutes, and our longest dreams occur right before we wake up
what are orexins
chemicals released from the hypothalamus that wake us up
describe infant sleep
about 16 hours with REM sleep accounting for 50% of the time
how does REM sleep change throughout childhood
declines until age 10 when it stabilizes at 25% of sleep time; total sleep time decreases to 7 hours in young adults
how does stage 4 sleep change throughout life
declines steadily and often disappears in those over 60
when is it easiest to wake up
during REM sleep
when does spontaneous arousal occur
during REM sleep
