Also found in: Dictionary, Thesaurus, Legal, Encyclopedia, Wikipedia.
rap·id eye move·ment sleep, REM sleep
that state of deep sleep in which rapid eye movements, alert EEG pattern, and dreaming occur; several central and autonomic functions are distinctive during this state.
A period of sleep during which dreaming takes place, characterized by rapid periodic twitching movements of the eye muscles and other physiological changes, such as accelerated respiration and heart rate, increased brain activity, and muscle relaxation. REM sleep is the fifth and last stage of sleep that occurs in the sleep cycle, preceded by four stages of non-REM sleep. Also called paradoxical sleep.
REM sleepRapid eye movement sleep, desynchronized sleep, paradoxical sleep Neurology A 5 to 20 min segment of a normal sleep cycle, characterized by irregular heart rate and respiration, BP, EEG similar to awake and alert state, involuntary or jerky muscle movement, and higher threshold for arousal; the usual high-amplitude slow brain waves seen by EEG are replaced by rapid eye movement and rapid, low-voltage irregular EEG activity. See Insomnia, Sleep disorders.
REM sleepRapid eye movement sleep. This occurs during about 20% of the sleeping time and features constant movement of the eyeballs, twitching of the muscles and erection of the penis in men. REM sleep is deep and is associated with dreaming. It is necessary for health.
Rapid Eye Movement phase of sleep, a mentally active period during which dreaming occurs.
Mentioned in: Night Terrors