Sleep Physiology, Hypersomnolence, Parasomnias Flashcards
what is sleep?
normal, recurring, reversible state where there is loss of ability to respond to external environment
what makes sleep not a conscious state?
not fully aware of self and environment
what makes sleep not an unconscious state?
can respond when stimulated
when do you have more non REM sleep?
start of night (3/4 of sleep for young adults is NREM)
what occurs to the body during non REM sleep?
synchronised, rhythmic EEG activity
partial muscle relaxation
reduced cerebral blood flow
what is heart rate during non REM sleep?
reduced heart rate
do you dream during non REM sleep?
yes - get some non-narrative images
when do you have more REM sleep?
end of night
what happens to body during REM sleep?
EEG shows fast activity
fMRI shows increased brain activity - similar to awake
atonic muscles (except diaphragm and extraocular muscles)
increased cerebral blood flow
impaired thermal regulation
do you dream during REM sleep?
yes - narrative dreaming
what type of sleep is more important?
non REM sleep (deep sleep)
why is non REM sleep more important?
allows cortex to recover after a busy day
what is the main role of REM sleep?
early brain development in children
what type of drugs suppress REM sleep?
tricyclics
how many hours per day do neonates spend seeping?
what kind of sleep?
16
50% REM sleep, shorter cycles
what is the trend of REM sleep during 1st decade?
percentage REM sleep falls
REM latency increases
what kind of sleep habits do elderly experience?
increased awakenings
reduced REM latency and total sleep time
daytime napping
what are the three critical processes of sleep onset?
homeostatic response - regulated need for sleep
emotional response - brain has to be ready to go to bed
circadian rhythm - body clock
do adolescents have an advanced or delayed sleep pattern?
delayed
do elderly have advanced or delayed sleep pattern?
advanced
how long does normal circadian rhythm last?
25 hours
how does light entrain body clock?
using retinal ganglion cells (non-rod and non-cone cells) projecting to suprachiasmatic nucleus
(why dark room = cant get up in morning)
can the cortex rest when awake?
no - only during sleep
when awake it stays in “quiet readiness”
most effects of sleep deprivation and prefrontal - what are these?
no psychoses but become irritable and suspicious
visual illusions
microsleeps and concentration lapses