Types of Sleep and Characteristics

The sleep is a state of unconsciousness from which a person can be aroused by proper stimuli.
Exist 2 types of sleep that alternate with each other:

1.NON REM sleep:Slow wave sleep which is the first to occur when the person falls asleep.
2.REM sleep.

1.Non REM Sleep:
-occurs at the start of sleep
-takes 80% from the sleep time
-has a duration cycle around of 90 min
-non-rapid eye movement,eyes deviate up
-hypotonic (decreased) muscle tone
-the dreams are present nut not remembered
-talking and wlking can be present
-easy awaked

2.REM Sleep:
-occurs after 4th stage of non REM sleep
-takes 20% of the sleep time
-has a duration around of 20 min
-rapid eye movement
-marked hypotonia
-dreams are present and remembered
-the talking and walking are absent
-difficult to awaken.

Non REM sleep have 4 stages:
According to the brain waves registration during sleep:
-low amplitude-high frequency
-light sleep
-high amplitude-low frequency (moderate sleep)
-few frequency (deep sleep).

For REM Sleep:
-small rapid irregular waves like an alert person.