Sleep Cycle Flashcards
How many stages?
4
Describe order of events (5)
- starts at stage 1
- progresses to stages 2, 3 and 4
- stage 2 and 3 repeated
- REM sleep
- Returns to stage 2
How many sleep cycles do we have a night?
4-5
When do we enter REM sleep?
approx. 90 mins after falling asleep
What kind of sleep is stage 1?
relatively light
What is stage 1 a transition period between?
Wakefulness and sleep
What is produced during stage 1? What are these?
Hight amplitude theta waves=very slow brain waves
How long does stage 1 last?
5-10 mins
How long does stage 2 last?
approx. 20 mins
What does the brain start producing during stage 2? What are these?
Sleep spindles-bursts of rapid rhythmic brain wave activity
What 2 things start to decrease during stage 2?
- Body temp
- Heart rate
What is produced in stage 3? what are these?
Delta waves- deep, slow brain waves
What is stage 3 a transitional period between?
light and very deep sleep
what is stage 4 aka? why?
delta sleep because of the slow delta brain waves produced during it
how long does stage 4 last?
approx. 30 mins
when does most dreaming occur?
stage 5
what kind of sleep is stage 5?
rapid eye movement (REM)
What increases during stage 5? (2)
- respiration rate
- brain activity
how many REM episodes a night?
3-5
what becomes more active during stage 5?
brain and body systems
what becomes relaxed during stage 5?
muscles
what becomes paralysed during stage 5?
voluntary muscles
what does stage 5 make up? (percentage and total times)
- 20-25%
- 90-120 mins
