REM sleep
REM sleep is the portion of sleep when there are rapid eye movements (REMs). Dreams occur during REM sleep. We typically have 3 to 5 periods of REM sleep per night. They occur at intervals of 1-2 hours and are quite variable in length. An episode of REM sleep may last 5 minutes or over an hour. About 20% of sleep is REM sleep. If you sleep 7-8 hours a night, perhaps an hour and half of that time, 90 minutes, is REM sleep. REM sleep is characterized by a number of other features including rapid, low-voltage brain waves detectable on the electroencephalographic (EEG) recording, irregular breathing and heart rate and involuntary muscle jerks.
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REM sleep n a state of sleep that recurs cyclically several times during a normal period of sleep and that is characterized by increased neuronal activity of the forebrain and midbrain, by depressed muscle tone, and esp. in humans by dreaming, rapid eye movements, and vascular congestion of the sex organs
called also desynchronized sleep, paradoxical sleep, rapid eye movement sleep compare SLOW-WAVE SLEEP
Medical dictionary.
2011.