Sleep is the most common human activity. We sleep everyday and it rejuvenates us but have you wonder what is sleep? Sleep is the most interesting human activity as it is not just absence of wakefulness but has its own internal structure. The interesting part is during the 7-8 hours of your sleep you go through several sleep cycles . It is not one continuous stretch of sleep but sleep cycles each of about 90-110 minutes.
Now, according to science during these sleep cycles the sleeper crosses 4 stages and then reaches REM(rapid eye movement) sleep .REM is basically the 20 min stage in which you DREAM!
Stage 1 : Light sleep In this stage of sleep we are neither awake nor in sleep. Our muscles actively slow down and one can we awakened easily at this stage.
Stage 2 : True sleep Within 10-15 minutes of light sleep we enter into stage 2, which lasts about 20 minutes. The breathing rate and heart rate starts to slow down in this stage
Stage 3 and 4 : deep sleep During stage three the brain begins to produce delta waves, a type of wave which is high in amplitude and low in frequency. breathing and heart rate are at their lowest level.
In stage four rhythmic breathing and limited muscle activity is observed.
Does is happen that you feel groggy and disoriented for several minutes after waking up?
It is so because you have been awakened during deep sleep . Some people also experience bed wetting , night terrors or sleepwalking in this stage. the irritated feeling arises due to the same reason. so to feel fresh when you wake up one should wake up during the light sleep mode . This is what we are here for. to help you in waking up happy and fresh very morning
REM sleep: Rapid eye movement sleep is the period when DREAMS occur!
During this period our eyes dart around(hence the name) , our breathing rate and blood pressure rises and though are mind are very active more than when we are awake our bodies are effectively paralyzed.