Sleep physiology Flashcards
Motion sensor used to measure sleep wake patterns and movement disorders during sleep
Actigraphy
Typical dreams during non-REM sleep
Thought-like
Typical dreams during REM sleep
Illogical and bizarre
Comprehensive assessment of sleep including EEG, electromyogram and electrooculogram
Polysomnography
Time from attempting to go to sleep to actually sleeping
Sleep latency
Time from sleep onset to first REM period
REM latency
Normal REM latency
Around 90 minutes
Calculation for sleep efficiency
Sleep time/time in bedx100
Objective test to measure how long someone takes to fall asleep in controlled conditions
Multiple sleep latency test
Average length of sleep for adults
7.5 hours
Measurement tool for brainwaves during sleep
EEG
Measurement tool for eye movements during sleep
Electrooculography
Measurement tool for skeletal muscle movement during sleep
Electromyography
Percentage of sleep which is REM
25%
Number of stages of sleep
4-5
Normally 3 NREM plus REM
Previously stage 3 divided into stage 3 and 4
Percentage of time in stage 1 sleep
5%
EEG findings in stage 1 sleep
Theta waves
Alpha waves
Characteristics of stage 1 sleep
Easily woken
Sleep starts
Percentage of time in stage 2 sleep
45%
EEG findings in stage 2 sleep
Sleep spindles
K-complexes
Theta waves
V waves
Physical characteristics of stage 2 sleep
Drop in body temperature
Eyes stop moving
Percentage of time in stage 3 (3+4) sleep
25%
EEG findings in stage 3 (3+4) sleep
<50% delta waves in stage 3
>50% delta waves in stage 4
Characteristics of stage 3 (3+4) sleep
Deepest stage of sleep
Night terrors and sleepwalking can occur
Slowest heart rate and breathing
EEG findings in REM sleep
Low voltage mixed frequency similar to EEG when awake
Sawtooth waves
Features of REM sleep
Increased HR, BP, RR Penile erection Occasional myoclonic jerks Memory of dreams when they occur Rapid eye movements Loss of muscle tone Deafness
Pattern of REM and non-REM sleep
Stage 1 Stage 2 Stage 3 (3+4) Stage 2 REM Through the night more time is spent in REM sleep
Typical number of REM cycles per night
5
Length of sleep spindles
<1 second
Frequency of sleep spindles
Upper alpha or lower beta frequency - 12-16Hz
Stage of sleep sleep spindles most commonly seen
Stage 2
Frequency of K complexes
Delta
Part of the brain sleep spindles are most commonly seen
Parasagittal regions
Part of the brain K complexes most commonly seen
Frontal regions
Trigger for K complexes to occur
Partial wakening
Sharp waves that occur during sleep
V waves
Area of the brain that manages circadian rhythms
Suprachiasmatic nucleus in the anterior hypothalamus
Signals that synchronise the suprachiasmatic nucleus
Signals of light from the retina
Number of hours of a natural sleep-wake cycle in the absence of light
26 hours
Part of the brain which induces sleep by stopping arousal nuclei
Ventrolateral preoptic nucleus
Disorder caused by damage to the ventrolateral preoptic nucleus
Chronic insomnia
Neurons which reinforce the arousal system during the day
Orexin/hypocretin
Condition characterised by a reduced number of orexin neurons
Narcolepsy
Average hours of sleep a day for newborns
16 hours
Proportion of REM sleep in newborns
> 50%
Sleep changes in older adults
Less REM and NREM sleep
Neurotransmitters involved in the ascending reticular activating system which affect sleep and wakefulness
Cholinergic Noradrenergic Dopaminergic Serotonergic Histaminergic
Function of cholinergic neurotransmitters in sleep
Activation induced REM sleep
Function of noradrenergic neurotransmitters in sleep
Activation reduces REM sleep
Effect of alcohol on sleep
Short term - increases slow wave sleep
Long term - decreases slow wave sleep
Reduced initial REM and increased second half REM
Effect of alcohol withdrawal on sleep
Loss of slow wave sleep
Increased REM
Effect of anxiety on sleep
Increased stage 1 sleep
Reduced REM sleep
Reduced slow wave sleep
Effect of benzodiazepines on sleep
Reduced sleep latency Increased sleep time Reduced stage 1 sleep Increased stage 2 sleep Reduced slow wave sleep Reduced REM sleep Prevention of transition from stage 2 sleep to slow wave sleep
Effect of cannabis on sleep
Increased slow wave sleep
Decreased REM
Effect of dementia on sleep
Increased sleep latency
More fragmented sleep
Reduced sleep time
Effect of depression on sleep
Loss of slow wave sleep in the first half
Increased REM leading to early morning wakening
Reduced REM latency
Effect of lithium on sleep
Increased REM latency
Loss of REM
Increased slow wave sleep
Effect of opiates on sleep
Decreased slow wave sleep
Decreased REM
Effect of SSRIs on sleep
Generally alerting
Effect of TCAs on sleep
Loss of REM
Increased slow wave sleep
Increased stage 1 sleep
TCA which causes the biggest loss of REM sleep
Clomipramine
Likelihood of family history in cases of night terrors
Infrequent
Amnesia experienced after night terrors
Complete amnesia
Most consistent changes to sleep seen in people with PTSD
Increased eye movements in REM
Increase in stage 1 sleep
Decrease in slow wave sleep
Usual stage of sleep for night terrors to occur
Stage 4