chapter 10: Biological rhythms and sleep Flashcards
biological rhythms
are regular fluctuations in any living process
circadian rhythms
about 24 hours
free-running
a rhythm of behavior shown by an animal deprived of external cues about time of day
phase shift
a shift in the activity of a biological rhythm, typically provided by a synchronizing environmental stimulus, such as light
entrainment
the process of synchronizing a biological rhythm to an environmental stimulus
zeitgeber
the stimulus that entrains circadian rhythms (usually the light-dark cycle)
suprachiasmatic nucleus (SCN)
small region of the hypothalamus that is the location of a circadian clock for drinking, locomotion, behavior, and of hormone secretion
retinohypothalamic pathway
carries light information from the eye to the SCN
electroencephalographs (EEG)
record electrical activity in the brain that can be used to classify levels of arousal and sleep
Rapid-eye-movement (REM)
stage of sleep characterized by small-amplitude, fast EEG waves, no postural tension, and rapid-eye movements
non-REM sleep
presence of distinctive EEG activity that differs from that seen in REM sleep
desynchronized EEG
(beta activity) pattern of EEG activity comprising a mix of many different high frequencies with low amplitude
alpha rhythm
8-12 hz that occurs during relaxed wakefulness
vertex spike
sharp-wave EEG pattern that is seen during stage 1 sleep
stage 1 sleep
initial stage of non-REM sleep, small amplitude EEG waves of irregular frequency, slow heart rate, and reduced muscle tension
stage 2 sleep
bursts of EEG waves called sleep spindles
sleep spindles
12-14 hz wave in EEG in stage 2 sleep
K complexes
sharp, negative EEG potential in stage 2 sleep
stage 3 sleep (slow wave sleep)
stage of non-REM with the presence of large-amplitude, slow delta waves
delta waves
slowest type of EEG wave; about 1 per second
nightmares
long, frightening dreams that awaken the sleeper
night terror
sudden arousal from stage 3 sleep that is marked by intense fear and autonomic activation
sleep deprivation
partial or total prevention of sleep
sleep recovery
process of sleeping more than normally after a period of sleep deprivation, as though in compensation
fatal familial insomnia
inherited disease that causes people in middle age to stop sleeping, which after a few months results in death
4 functions ascribed to sleep
- energy conservation
- niche adaptation
- body and brain restoration
- memory consolidation
ecological niche
unique assortment of environmental opportunities and challenges to which each organism is adapted
4 interacting neural systems during sleep
1) forebrain system that generates SWS
2) brainstem system that activates the sleeping forebrain into wakefulness
3) pontine system that triggers REM sleep
4) hypothalamic system that coordinates the other three brain regions to determine what state we’re in
basal forebrain
where constant SWS activity in the forebrain is generated
reticular formation
region of the brainstem, extending from the medulla through the thalamus that is involved in sleep and arousal
narcolepsy
frequent, intense attacks of sleep that lasts 5-30 minutes and can occur at any time during usual waking hours
cataplexy
sudden loss of muscle tone, leading to collapse of the body without loss of consciousness
orexin
neurons of the hypothalamic appetite system that promote feeding behavior
sleep paralysis
temporary inability to move or talk either just before dropping off the sleep or just after waking up
sleep enuresis
bed wetting
somnambulism
sleepwalking
REM behavior disorder (RBD)
organized behavior by a person who appears to be asleep
sleep-onset insomnia
difficulty in falling asleep
sleep-maintenance insomnia
difficulty in staying asleep
sleep apnea
respiration slows or stops periodically, waking the sleeper
SIDS
might be caused by sleep apnea
