Chapter 14 - Sleep, Dreaming & Circadian Rhythms Flashcards
delta waves
the largest and slowest EEG waves, with a frequency of 1 to 2 Hz
initial stage 1 EEG
the period of the stage 1 EEG that occurs at the onset of sleep; it is not associated with REMs
emergent stage 1 EEG
all periods of stage 1 sleep Egg except initial stage 1; each associated with REMs
REM sleep
the stage of sleep characterized by rapid eye movements, loss of core muscle tone, ad emergent stage 1 EEG
slow-wave sleep (SWS)
NREM 3 is often referred to as slow-wave sleep (SWS), after the delta waves that characterize it
activation-synthesis hypothesis
the theory that the information supplied to the cortex by the brain stem during REM sleep is largely random and the resulting dream is the cortex’s best effort to make sense of those random signals
recuperation theories of sleep
theories based on the premise that being awake disturbs the body’s homeostasis and the function of sleep is to restore it
adaptation theories of sleep
theories of sleep based on the premise that sleep evolved to protect organisms from predation and accidents and to conserve their energy rather than to fulfill some particular physiological need
circadian rhythms
circadian means “lasting about a day”
zeitgebers
Environmental cues, such as the light–dark cycle, that can entrain (control the timing of) circadian rhythms
free-running rhythms
Circadian rhythms in constant environments, and their duration is called the free-running period
internal desynchronization
the cycling on different schedules of the free-running circadian rhythms of two or more different processes
circadian clock
internal timing mechanism
suprachiasmatic nuclei (SCN)
nuclei of the medial hypothalamus that control the circadian cycles of various body functions
melanopsin
photopigment found in certain retinal ganglion cells that responds to changes in background illumination and plays a role in the entrainment of circadian rhythms
Hypnotic drugs
drugs that increase sleep
antihypnotic drugs
drugs that reduce sleep
benzodiazepines
diazepam, clonazepam), which are GABAA agonists, were developed and tested for the treat- ment of anxiety, yet they are some of the most commonly prescribed hypnotic medications
chronobiotic
a substance that adjusts the timing of inter- nal biological rhythms
Insomnia
includes all disorders of initiating and maintaining sleep
Hypersomnia
includes disorders of excessive sleep or sleepiness
sleep apnea
patient with sleep apnea stops breathing many times each night. Each time, the patient awakens, be- gins to breathe again, and drifts back to sleep
Periodic limb movement disorder
characterized by periodic, involuntary movements of the limbs, often involving twitches of the legs during sleep
> Most patients suffering from this disorder complain of poor sleep and daytime sleepiness but are unaware of the nature of their problem.
restless legs syndrome
aware of their problem, They complain of a hard-to-describe tension or uneasiness in their legs that keeps them from falling asleep
Narcolepsy
persons with narcolepsy experience severe daytime sleepiness and repeated, brief (10- to 15-minute) daytime sleep episodes,
> typically sleep only about an hour per day more than average; it is the inappropriateness of their sleep episodes that most clearly defines their condition
Cataplexy
characterized by recurring losses of muscle tone during wakefulness, often triggered by an emotional experience
Sleep paralysis
is the inability to move just as one is falling asleep or waking up
Hypnagogic hallucinations
dreamlike experiences during wakefulness
REM-sleep behavior disorder
a disorder where the individual experiences REM sleep without core-muscle atonia
sleep inertia
left them unrefreshed, or too much, which left them groggy for several minutes when they awoke
polyphasic sleep cycles
regularly sleep more than once per day
monophasic sleep cycles
they sleep once per day
