Sleep Flashcards

Any 24-hour periodicity in the behavior or physiology of animals or plants. Examples are the sleep/activity cycle in many animals and the growth movements of plants.

Try it for free as part of the Oxford Advanced Learner's Dictionary app. [intransitive, transitive] to imagine and think about something that you would like to happen dream of/about something She dreams of running her own business.

​a medical test that measures and records electrical activity in the brain.

Hypersomnia is a state of excessive sleepiness that can result in decreased functioning and affect performance adversely. Hypersomnolence is defined as an inability to stay awake and alert during major waking episodes, resulting in periods of irrepressible need for sleep or unintended lapses into drowsiness or sleep.

inability to fall asleep or to remain asleep for an adequate length of time

a hormone produced by the pineal gland in darkness but not in bright light. Melatonin is a derivative of serotonin, with which it works to regulate the sleep cycle

to sleep for a short time, especially during the day.

a condition in which somebody falls into a deep sleep when they are in a relaxing environment.

a sudden awakening in dazed terror that occurs in children during slow-wave sleep, is often preceded by a sudden shrill cry uttered in sleep, and is not remembered when the child awakes. Usually used in plural. called also pavor nocturnus.

A terrifying or extremely upsetting dream

An abnormal disruption of sleep, such as sleepwalking, sleep talking, nightmares, bedwetting, sleep apnea (problems with breathing that cause loud snoring), or nighttime seizures.

a nervous disorder characterized by aching, crawling, or creeping sensations of the legs that occur especially at night usually when lying down (as before sleep), and cause a compelling urge to move the legs.

the natural state of rest in which your eyes are closed, your body is not active, and your mind is not conscious

a condition in which someone stops breathing temporarily while they are sleeping.

A disruption and reduction in the number of hours of sleep normally needed by a person.

A terrifying inability to move or speak while remaining fully alert.

Polysomnography, known as a sleep study, is a test used to diagnose sleep disorders. Polysomnography records your brain waves, the oxygen level in your blood, and your heart rate and breathing during sleep. It also measures eye and leg movements.

the act of breathing noisily through your nose and mouth while you are asleep; the noise this makes.

Stage 1 NREM sleep is the first sleep stage you enter when nodding off. This sleep stage is when heartbeat, eye movements, brain waves, and breathing activity begin to taper down.

Stage 2 is still light sleep, but deeper than stage 1. During this stage, your brain waves slow down and have noticeable pauses between short, powerful bursts of electrical activity. Experts think those bursts are your brain organizing memories and information from the time you spent awake.

lowest frequency, highest amplitude. N3 is also known as slow-wave sleep (SWS). This is considered the deepest stage of sleep and is characterized by signals with lower frequencies and higher amplitudes, known as delta waves.

As your body progresses through the four sleep cycle stages—stages 1 through 3 (non-rapid eye movement, or NREM) and stage 4 (rapid eye movement, or REM), it transitions through different biological processes that affect your temperature, breathing, cells, and muscles.

the act of walking around while you are asleep.

​the condition of not sleeping or being unable to sleep.