What Are The Stages Of Sleep
By: Mark ShowalterTotal Views: 318, Word Count: 518,
A session of sleep consists of two stages, REM (rapid eye movement) and NREM (non rapid eye movement). During sleep there are several cycles that comprise of 5 stages. A sleep cycle is followed by another. Generally, in the initial stages of sleep the duration of REM is less while the NREM is longer in length. As the person is about to get up from the sleep the time period of REM increases and the period of deep sleep decreases. If you are thinking what are the stages of sleep, you may take a look at the following information on the sleep cycle.
What are the Stages of Sleep
Stage one – The stage sleep lingers for about 5 to 10 minutes and is characterized by drowsiness. In this stage the eyes of the person tend to close and if awakened from this stage of sleep the individual might feel that he or she might have not gone to sleep. According to polysomnography, there is a cut down of mental and physical activities of up to 50%.
Stage Two –This is the stage when the body gets ready to enter the stage of deep sleep. This stage consists of a combination of toning ad relaxation of muscular tissues. Often the variances of the muscular tension depend upon the activation of auditory nerve stimuli. Polysomnography reveals that the graph of the depth of sleep is characterized by high and low waves or peaks and valleys. During this time the rate of the heart beat slows down and the temperature of the body decreases.
Stage Three – The third stage is the stage of deep sleep. The graph shows even curves of slow waves.
Stage Four – The stage four of sleep is the phase of sound sleep. During this phase an individual experiences more deep sleep than phase three. The electromyogram records show waves of very high amplitude that are of a continuous rhythm.
The cycle of Non REM sleep consists of stages 1 to 4 with an average duration of about 90 to 120 minutes and each stage taking about 15 to 20 minutes. Before entering into the lighter phase of sleep, i.e. the REM stage, there is a repetition of the stages two and three.
Though the graphical representation of the REM is some what similar to that of NREM, certain physiological changes between the two forms of sleep differentiate them. It is during this stage of sleep that the individual is likely to be dreaming. The stage is characterized by short movements of limbs and facial muscles while the brain and respiratory activities heighten. Studies reveal that most of the sleep disorders like sleep walking and sleep paralysis, take place in the REM stage.
To know what are the stages of sleep you may consult a physician or search the net for authentic sleep related information. If you are suffering from sleep disorders, you may take up medical sleep promoters like the Melatrol. The medicine would be an effective help for you to fight against sleep abnormalities by promoting sound sleep.
About the Author
Mark Showalter is an expert in treating various types of sleep disorders. He has carried out series of research works that deal with the various mysteries of sleep and its associated disorders. If you find yourself to be too stressed out during the day or suffer from disorders caused by improper sleep, you may take a good medical sleep aid. You must be prudent enough to select the right one for you that would keep you away from any form of harmful side effects.
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