sleep physiology Flashcards
which sleep stage is towards the end of the night and has similar characteristics to wakefulness?
REM sleep
Which muscles are NOT profoundly atonic during REM sleep?
extra ocular muscles and diaphragm
What is the main function of REM sleep?
mainly for early brain development (important in childhood)
Why is thermal regulation impaired during REM sleep?
increased cerebral blood flow
Which type of sleep occurs at mainly at the start of the night and is a profound state of relaxation?
non-REM sleep
What are the findings during NREM?
synchronised, rhythmic EEG activity
partial relaxation of muscles
reduced cerebral blood flow
reduced HR, BP and tidal volumes
You can only dream during REM sleep. T/F?
FALSE - can dream in both types
NREM -> strong emotional link but can’t remember what happened; prominent single image occurs before you wake up.
REM -> illustrative-narrative dream
Name the 3 critical processes for sleep onset.
- “homeostatic” response
- emotional response
- circadian rhythm
The effects of sleep deprivation are mostly prefrontal… what does this affect?
Impairs alertness but not old and well-rehearsed tasks, routine behaviour, logic tasks.
become irritable, suspicious
Visual hallucinations are a common sign of sleep deprivation. T/F?
FALSE - visual illusions can occur but no psychoses
Which cellular process peak during sleep?
cell division; skin mitoses
Sleep helps with tissue repair and muscle recovery. T/F?
FALSE
Helps with tissue repair
but no evidence of muscle recovery during sleep
What is the suggested minimum acceptable length of sleep?
7-7.5 hrs
What is parasomnia?
a disturbance of sleep
What kind of parasomnia is sleep walking, sleep paralysis and bruxism?
non-REM parasomnia
Describe REM parasomnias.
dreaming, much simpler behaviour, usually latter 1/3 of night
Parkinson’s is associated with which type of parasomnia?
REM
when are the 2 peaks of onset of narcolepsy?
15 and 36
What is cataplexy and how common is it in narcolepsy?
loss of muscle tone with strong emotions e.g. anger, laughing
Present in 70% of patients
what are hypnagogic hallucinations?
seeing things as you fall asleep
Give an example of daytime sleepiness.
embarrassing situations, e.g. falling asleep into meals
Describe the multiple sleep latency test.
4x 35-min naps scheduled 2hrs apart.
Record EEG, muscle activity & eye movements.
Measure time from start of daytime nap to the 1st signs of sleep (sleep latency).
Faster patient falls asleep, the more tired they are.
What investigation can you do in narcolepsy but it isn’t sensitive or specific?
CSF hypocretin
