TopicMemory Foam Mattresses Are Great For Overall Health
Stage 4 of sleep produces almost exclusively delta waves. To wake someone during stages 3 and 4 becomes Melatolin-plus very difficult. These combined stages are also known as a deep sleep. You do not see eye movement, nor muscle activity. Awakened during deep sleep, people have a problem of immediate adjustment. The often feel dizzy and disoriented for a few minutes after they wake up. Some children experience, nightmares, or during deep sleep.
The most unusual portion during our sleep is a REM sleep. It could be identified by our breathing, which becomes more irregular, rapid, and shallow. Our eyes moves rapidly in various directions, with our limb muscles staying temporarily immobilized. During REM sleep the heart rate increases and blood pressure rises. Some males develop penile erections. Awakening during REM sleep often allows to describe recent dreams, mostly illogical and bizarre.
REM sleep happens several times during the night. It is usually related to dreams people see. However, if we are not awakened immediately after the REM sleep, we do not remember those dreams. The first REM sleep period usually happens between 70 to 90 minutes after we fall asleep. In average, a full sleep cycle normally takes 90 to 110 minutes. The first sleep cycle consists of relatively short REM periods with a long period of deep sleep. After the first sleep cycle is over, the REM sleep periods have tendency to be increasing in length. Deep sleep cycle is decreasing. By the morning, our sleep time is slowing down towards Stages 1, 2, and REM.