Short Description
A person goes through five stages while going to sleep.The background activity of the brain is called the electroencephalogram (EEG) and can be recorded by the use of scalp electrodes.
Allah (all glory be to Him) tells us in the Holy Quran about Ramadan that, “(He wants you) to complete the prescribed period (of fasting), and to glorify Him in that He has guided you; and perchance ye shall be grateful.” (Surat Al Baqarah: 2:185).
Many benefits, in addition to the spiritual, result from completing this prescribed period of fasting. This article attempts to explain those related to our biological rhythms.
Sleeping Stages
A person goes through five stages while going to sleep.The background activity of the brain is called the electroencephalogram (EEG) and can be recorded by the use of scalp electrodes.
The dominant frequency and amplitude characteristic of the surface EEG varies with states of arousal.
Calm wakefulness is accompanied by alpha waves 8-12 Hz (cycles per second) and low voltage fast activity of mixed frequency. This is called stage one. Alpha waves disappear when we open our eyes.
As sleep deepens into stage two, bursts of 12-14 Hz (sleep spindles) and high amplitude slow waves appear.
The deep sleep of stages three and four is featured by an increasing proportion of high voltage slow activity. Breathing is regular in slow-wave sleep or non-REM (Rapid Eye Movements) sleep.
Delta activity (very slow waves, 0.5-4 Hz, high amplitude) is unusual in a normal record and accompanies deep sleep i.e. stages three and four sleep.
After about 70 minutes or so mostly spent in stages three and four, the first REM period occurs, usually heralded by an increase in body movements, and a shift in the EEG pattern from stage four to stage two.
These rapid low-voltage irregular waves resemble those seen in alert humans; sleep, however, is not interrupted.
This is called stage 5 or REM sleep, when the EEG activity gets desynchronised. There is marked muscle atonia despite the rapid eye movements in REM sleep, and the breathing is irregular.
Theta activity with a pattern of large regular waves occurs in normal children and is briefly seen in stage one sleep and also in REM sleep.
Non-REM (NREM) sleep passes through stages one and two, and spends 60-70 minutes in stages three and four. Sleep then lightens and a REM period follows.
This cycle is repeated three or four times per night, at intervals of about 90 minutes throughout the night, depending on the length of sleep. REM sleep occupies 25% of total sleeping time.
When the eyes are opened, the alpha rhythm is replaced by fast irregular low voltage activity with no dominant frequency, called the alpha block.
Any form of sensory stimulation or mental concentration such as solving arithmetic problems could produce this break-up of the alpha rhythm. This replacement of the regular alpha rhythm with irregular low voltage activity is called “desynchronisation”.
To be continued........
http://www.onislam.net/english/health-and-science/faith-and-the-sciences/419648-your-circadian-rhythm-while-fasting.html
Comments
Send your comment