Sleeping. During sleep many changes occur fisológicos used to recover.
Sleep and dreams have always been a fundamental part of human existence. Wrote E. Goode “any second grader knows why humans need food and water, but even the most reputable scientists in the world could explain why we sleep.”
Indeed, sleep is a complex whose function is not limited only to the need to break from the agencies. Its scientific study is performed at multiple levels. The thousands of sleep laboratories all over the world are meant to respond basically three questions: what is the dream, what are its mechanisms and what are their functions. The rapid progress of research has been possible thanks to the development of polysomnography, a technique that allows recording multiple physiological changes that occur during sleep, which has allowed a deeper understanding.
Thanks to this and other recent techniques signal analysis, it has been established that sleep has five cyclical stages, which are: drowsiness, light sleep, deep sleep, slow-wave sleep and rapid eye movement (REM sleep or REM) .
Almost 50% of time spent asleep corresponds to a light sleeper, approximately 20% with REM (REM) and the remaining 30% is distributed in the other stages. Usually, to sleep, you go through all stages. These progress cyclically from the first to the REM and then begins again with the first.