Key Points of the video
The overall sleep cycle is comprised of two broad alternating cycles, REM (rapid eye movement), and NREM (non-rapid eye movement), which consists of three individual phases-N1, N2, and N3.
Stage 1 NREM is the “drifting off” stage, characterized by lowered brain activity, blood pressure, and muscle tone. During this 10-minute period, a sleeper may experience twitches and may even deny having slept at all.
Stage 2 NREM is characterized by sleep spindles and K-complexes. During this stage, muscular activity decreases, and conscious awareness of the external environment disappears.
Stage 3 NREM (formerly considered two stages, 3 and 4) is the deepest stage of NREM sleep. It is characterized by delta waves, and is also called slow-wave sleep or SWS. It occurs 30-45 minutes after falling asleep, and many environmental stimuli no longer produce any reactions.
REM sleep is characterized by partial paralysis, vivid dreaming, and an EEG that resembles waking brain activity. It is also referred to as paradoxical sleep because the sleeper, although exhibiting waking-state EEG waves, is harder to arouse than at any other sleep stage.
Key Terms
Electroencephalography: The recording of electrical activity along the scalp; it measures voltage fluctuations resulting from ionic current flows within neurons.
Parasomnia: Category of sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that occur during sleep.
#Psychoinformative
#Stagesofsleep
#REMsleep
#NREMsleep
#SleepCycle
28 авг 2024
