Sleep Flashcards
EEG
recording of the electrical activity of the cerebral cortex
EEG is caused by
graded potentials and electrochemical signaling between neurons
EEG and Diagnosis
damaged cortical tissue, brain death
Alpha wave
rhythmic, 8-13 Hz, low voltage, awake but resting
Beta waves
low voltage, higher frequencies 14-50 Hz, awake and concentrating
Theta waves
low frequency, higher voltage, children and frustrated adults or sleep stage 2-4 slow wave and bursts in REM
Theta wave location in children
parietal and temporal areas
Delta waves
low frequency, HIGH voltage, coma, Sleep 3-4 slow wave
The waking state
behaviorally: relaxed inactive to very active
EEG: alpha to beta waves depending on attentiveness
Stage 1 of sleep
transitional stage between drowsy and light sleep; alpha waves predominate and transition to mixed frequency waves
Stage 2 of sleep
theta low voltage and mixed frequency waves, sleep spindles and K complexes; light sleep
Sleep spindles
bursts of alpha rhythms during sleep stage 2
K complex
single large biphasic deflection during sleep stage 2
Stage 3 of sleep
Delta waves 20-50%; deep sleep
Stage 4 of sleep
Delta waves 50%; deep sleep
Slow rolling movement of eyes
occurs during stage 1, relatively motionless for remainder of stages
REM
deepest sleep, beta waves predominate, rapid-eye movements, irregular HR and RR, dreaming
New Sleep Nomenclature
W, N1/N2, N3, R (wake, light sleep, deep sleep, REM)
Sleep Architcture
patterns of sleep cycles
Stages 3-4 are most likely during
first few hours of sleep
REM is most likely during
morning hours of sleep
Age and sleep architecture
sleep time decreases, REM percentage decreases from 50% in newborns to 20% adults
Skeletal muscle
activity declines during slow-wave sleep, during REM, eye movements are rapid but most muscles are inhibited, occasional escape from inhibition results in twitching and altered RR
CV system
decrease in BP, HR, and RR occurs in slow-wave sleep, REM is associated with large oscillations and increases
Heart attacks are most common during what time
5-6 am during REM
Growth Hormones
pulsatile release during slow-waves, primarily stage 3-4
Prolactin
entirely during sleep, in morning hours
Cortisol
minimum in early sleep, peaks at end of sleep
TSH
peaks at onset of sleep and declines during sleep
LH
increases during sleep
FSH
increases during sleep
Body temperature
lowest at slow wave sleep in early morning hours
REM importance
physical changes necessary for memory consolidation
Suprachiasmatic nucleus of hypothalamus
basic circadian rhythm based on inputs from the retina producing melatonin
Arousal
Cholinergic neurons –> thalamic nuclei and adrenergic neurons –> cerebral cortex
Arousal
peptidergic neurons of the hypothalamus (orexin and melanin) activate thalamic nuclei
Reticular Activating System
arousal system in the brainstem (Raphe Nucleus)
Amphetamines act on
Reticular Activating System to promote arousal and decrease sleep
Sleep center
preoptic nucleus; inhibitory GABA containing neurons
Orexin
neurons in the lateral hypothalamus activate arousal areas
Histamine
posterior hypothalamus project to RAS and promote wakefulness
Anti-histamines
drowsy due to inhibition of histaminergic neurons
REM promoting areas
pontine tegmentum and ventrolateral periaqueductal gray matter
Sleep promoting factors
PGD2, VIP, DSIP, CCK, ADH, Melatonin
Wakeful promoting factors
PGE2, Hypocretins, orexins
DIMS
disorders initiating or maintaining sleep common in children
Insomnia
difficulty falling asleep, staying asleep, going back to sleep
DOES
Disorders of excessive somnolence
Narcolepsy
DOES; sudden shift from awake to REM accompanied by cataplexy; loss of hypocretin producing cells
Cataplexy
a sudden loss of muscle tone or paralysis
Dysomnias
disturbance to normal circadian rhythm
Parasomnias
behaviors that occur during sleep (nightmares, sleep walking)
Nightmares
Nightmares occur during REM
Night terrors
scared “FEELING” that occurs during slow-wave sleep, wakens abruptly screaming and incoherent
Sleepwalking
complex motor behaviors during slow-wave
REM Sleep Disorder
Skeletal muscle inhibition is absent so dreams are acted out
Pseudoinsomnia
sleeps okay, but dreams they cannot sleep
Snoring
inhaled air vibrates relaxed tissue of the throat
Sleep Apnea
frequent periodic breathing pauses during sleep
Obstructive sleep apnea
physical blockage of airway due to collapse of soft tissue at rear of throat
Central sleep apnea
skeletal muscle inhibition during REM extends to inhibition of respiratory muscles
Restless Leg Syndrome & Periodic Limb Movement Disorder
pins and needles around bedtime leading to vigorous movement of limbs; repetitive movements of the toe/foot/knee
Effect sof sleep deprivation
weight gain, cognitive decline, mood swings, depression
Sleep promoting
Alcohol, hypnotics (sleeping pills), antihistamines, DSIP
Sleep Inhibiting
Caffeine, Steroids, opiates, Vitamin B, Cocaine/amphetamines, narcolepsy drugs
