why do we dream and sleep what happens in the brain Flashcards
what is sleep?
motivation to sleep forces us to sleep. physical state of postural recumbency close eyes.
what happens when you sleep
heart rate lowers blood pressure decreases , decreased breathing rate
why do we sleep
inactivity theory (Webb, 1974) sleep to avoid danger. vital for health , cell regrowth , removes toxins from brain
who said there was a correlation between sleep duration and risk of danger ?
Allison & Cicchetti, 1976)
energy conservation theory
sleep allows us to conserve energy
how many biological internal mechanisms are there
2
what are the biological internal mechanisms.
circadien rythem biological clock signals when to be alert and when not to be alert. homeostatic sleep drive longer you stay awake sleep load increases.
there are two stages of sleep
non rem and rem
what happens in non rem sleep
3 stages 75% of night takes up predominant in 1st half of sleep.
what happens in rem sleep
25% of night predominant in second half of sleep
sleep stages?
wakefulness 7 minutes duration
how long does non rem sleep last for? stage one stage 2?
1-5 minutes
stage 2 - 10 minutes to 1 hour
non rem stage 3
deep sleep 20 to 40 mins
stage 4 rem sleep
90 mins into sleep , lasts 10 mins to 60 getting progressively longer with each passing cycle.
