Sleep is a part of our day to day activity. A person requires an average of 7 hours of sleep a day for a sound and healthy body. While we are awake, our brain is fully functioning, like
- Seeing
- Hearing
- Talking
- Laughing
- Smelling
- Calculating
- Tasting
- Thinking
- Playing
- Crying
- Feeling
- Getting angry
So sleep is very important for us, as it helps the brain get some rest. Each body has its own body clock. The body has a cycle for going to sleep and waking up, that it follows everyday. This is called the CIRCADIAN RHYTHM.
There are two patterns of sleep. They are 1) REM sleep 2) non REM sleep.
*REM Sleep*
REM refers to - Rapid Eye Movement.We dream during the REM sleep. Our eyelids will be moving because our pupil will be moving too, even if the eyelids are open. REM sleep is also called as "BODY'S SLEEP". Each phase of the REM sleep lasts for 10 to 20 minutes, about five times each night. REM sleep is very important for us as it is said that, the brain works out its memory during the REM sleep.
*Non REM Sleep*
During a non REM sleep, the eyeballs do not move even if the eyelids are opened. Non REM sleep is also known as "SLEEP FOR THE BRAIN" .A healthy person first enters into a non REM sleep only. After which, REM sleep and non REM sleep are repeated one after the other.
An experiment conducted showed that, one REM sleep and non REM sleep cycle lasts for about 90 minutes. People having non REM sleep only are found to be - Cranky, while people having REM sleep alone are found to be - Lethargic.
