What is sleep
To date, no one knows what exactly is sleep. People used to think that sleep was a time when everything in our functioned slowly or not. Today we know that that is definitely not the case. When we sleep things happen in our brains. At times our brain is even more active during sleep than when we are awake.
How does our sleep Works?
Everyone has more or less the same sleep patterns. Our sleep consists of two parts, namely:
– NREM non-rem sleep
– REM sleep
REM sleep stands for Rapid Eye Movement sleep. Rapid Eye Movement means rapid eye movements.
NREM is the Non Rapid Eye Movement sleep.
NREM sleep occupies most of the time we sleep. About 75 to 80% of the time we sleep we are in the NREM stage.
If we follow sleep NREM sleep and REM sleep alternate. We start with the NREM sleep and then REM sleep follows.
NREM sleep is divided into four phases
The first stage of NREM sleep is light sleep. During this phase, we are half awake and half asleep. You may find yourself moving occasionally involuntarily. During this time you wake up easily.
After about ten minutes of light sleep, we enter the next phase, the actual sleep. This part of sleep usually lasts twenty minutes. During this phase, the rhythm of our heartbeat and our breathing down.
Then we enter the third stage of NREM sleep. Our brains start to produce the so-called delta waves. Our heart rate and breathing now reach their slowest pace.
The fourth stage of the NREM sleep is characterized by rhythmical muscular movements and small breaths. When we wake up we feel sleepy and weak and we know a few minutes is not where we are at this stage. This is the period of sleep in which some children bedwetting or sleepwalking.
After NREM sleep we enter the stage of REM sleep. Normally, this phase begins somewhere between 70 and 90 minutes after we fall asleep.
Although we are not conscious during REM sleep phase, the brain is very active. Often more active than when we are awake. Closed our eyes dart back and forth. There is also the name of this phase, REM Rapid Eye Movement from.
Our breathing quickens and our blood pressure increases. But otherwise we are paralyzed and we do not move us. This is the stage of sleep in which we dream our.
After the REM sleep is over NREM sleep begins again and the cycle repeats.
On average we have three to five periods of REM sleep during the night. The NREM and REM alternate in a cycle of about 90 to 110 minutes.
But relations between NREM and REM sleep are different in the course of the night. By REM sleep cycle gets an increasingly important role and so we dream more at the end of our sleep than at the beginning.
During REM sleep we dream the most.
Everyone dreams to sleep. Some people remember their dreams and some people do not know that they are dreaming.
We even dream a lot and have about five to seven dreams per night. Dreams do not all have the same length. Some dreams take five minutes while others probably can take twenty minutes or more.
Want to know more about dreams please check the page Dreams.