Mysteries Of Sleep

Our bodies are synchronized with the 24 hour cycle of day and night through a biological clock known as the circadian rhythm. Our body temperature rises as it dawns and drops as it approaches dusk.
Altering one’s sleeping schedule throws the biological clock out of phase and the circadian rhythm is interrupted causing insomnia and a sort of jet lag.
There’s a biological rhythm during our sleep-a cycle of five distinct sleep stages we pass through during the night.
Stage 1 sleep which lasts about 2 minutes and in which you experience fantastic images. One can easily be awakened from this sleep.
Stage 2 sleep is characterized by a more relaxed state and periodic bursts of brain wave activity-it lasts about 20 minutes.
Stage 3 sleep lasts up to 30 minutes and it is hard to be woken from this sleep.
Stage 4 sleep is usually characterized by a deep sleep where we may talk or walk in our sleep and children are seen to wet their beds. After one hour of deep sleep you go back up the ladder through stage 3 to stage 2 and for some 10 minutes your brain waves become active, your heart rate rises, your breathing becomes rapid and your eyes dart around in momentary bursts of activity under your closed eye lids. This episode is the rapid eye movement sleep usually referred to as REM.
Although the motor cortex is active during REM sleep, it’s neural messages don’t reach your muscles, which are very relaxed-except for an occasional finger twitch, you are essentially paralysed.You can’t be easily awakened .REM is usually referred to as “paradoxical sleep”, since internally your body is aroused but externally your body appears calm.
The rapid eye movement announces the beginning of a dream. The common morning erection stems from the last REM period of the night which occurs before one awakens.
As the night wears on, this sleep cycle repeats itself and the REM sleep becomes progressively longer. An average night sleep consists of 100 minutes of REM sleep.
WHY DO WE SLEEP?
Sleep commands about a third of our lives. The major effect of sleep deprivation is sleepiness. Other effects are diminished immunity to disease, irritability, misperception and inattention.
In a few rare cases, brain diseased people have lost their ability to sleep and consequently died.
Sleep restores body tissues-during deep sleep the pituitary gland releases a growth hormone .As adults advance in age they release less of this hormone and spend less time in deep sleep.
It is recommended that a healthy human being should sleep for at least 8 hours.However, not every one needs 8 hours of sleep. Age is usually a determining factor in the amount of sleep one requires. Infants spend at least two thirds of their day asleep whereas the elderly barely sleep for more than 4-5 hours.
SLEEPING DISORDERS
1.Insomnia-a natural and adaptive response to stress characterized by an abnormal lack of sleep. The two common sought after remedies for insomnia are pills and alcohol and they aggravate the problem by reducing REM sleep.Moreover, when the use of pills or alcohol is discontinued, the insomnia worsens.
2. Narcolepsy-people with this disorder suffer periodic overwhelming sleepiness at the most inopportune times.
3. Sleep Apnea-a disorder where you stop breathing while sleeping. After an airless minute or so the sleeper begins to snort in the air for oxygen. This sequence is repeated all night. Children who don’t resume breathing suffocate and die of “sudden infant death” (SIDS).
4. Night Terrors-The person -often a child- might sit up or walk around, talk incoherently, experiencing a doubling of heart and breathing rates and suffer frightening images which are not remembered the following day.
TIPS TO AVOID INSOMNIA
-Relax before bed time.
-Avoid rich foods around bed time. Milk is good as it aids in the manufacture of serotonin, a neurotransmitter that facilitates sleep.
-Sleep on a regular schedule i.e. rise at the same time and go to sleep at the same routine time.
-Avoid naps.
-Reassure yourself that temporary loss of sleep causes no great harm-most of those who suffer insomnia, tell how they stay all night without shuttering an eyelid when they actually don’t remember falling asleep.