Stages of Sleep Essay

951 WordsNov 28, 20124 Pages
Wakenya Ruffin Professor Smedley ENGL 1301 21 November 2011 Stages of Sleep Sleep is a natural reoccurring state of reduced consciousness that allows the body to rest and restore the energy that is lost throughout the daily activities. Studies of human sleep proved that sleep gradually occurs through a series in stages, but does not progress through the stages in sequential order . There are two types of sleep: NREM (Non Rapid Eye Movement- stages one through four) and REM (Rapid Eye Movement- paradoxical sleep). Sleep begins in stage one, then flows into stages two, three, and four. After stage four sleep, stage three and stage two sleeps are repeated before going into REM sleep. When REM sleep is over, the body usually returns to stage two sleep. The sleep cycle may go through these stages about four or five times throughout the night; however, most people cannot get through stage one successfully. In stage one, the body enters into a light sleep. The heart rate slows down and breathing becomes irregular. This is known as a transitional stage between being fully awake and sleep. The brain produces four to seven hertz of theta waves which are the second slowest frequency of brain waves. The muscles in the body become very relaxed; however, one may feel sudden twitches and hypnic jerks. A hypnic jerk is an involuntary twitch which occurs during hypnagogia, often causing a person to awaken suddenly resembling a “jump” experienced by a person who is startled and is accompanied what one would describe as a “falling sensation”. A hypnic jerk can make a person slightly aware of their surroundings and will often say that they were not sleep. They are not dreaming nor do they have rapid eye movement during this stage. This phase only lasts about five to ten minutes. During stage two, the brain starts moving into

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