Sleep: Restorative of Tired Body and Mind
Sleep is one of nature’s greatest inventions and
blessings of life. It is a periodic rest of the body which is absolutely
essential for its efficient functioning. It has been called "most cheering restorative of tired
bodies." Sleep is the indispensable condition to the recuperation of
energy. We go to bed fatigued and get up refreshed. Sleep repairs the wear and tear of
the body and mind incurred during waking hours. Nothing is so restorative to
the nerves as sound and uninterrupted sleep. Sleep is thus a vital element in a
total way of life. It is a basic need in man’s mental as well as physical life.
During sleep most of the functions of the body are carried on at the lowest
level possible in health. Heat production is from 10 to 15 per cent below the
basal level. The mechanism regulating the body temperature are less sensitive
than in the waking state and are depressed by 0.5 to 1.0 degree F. The rate of the heart is
reduced by 10 to 30 beats per minute and a decline in blood pressure of about
20 mm occurs in quiet restful sleep. The urine volume is considerably reduced,
but its concentration in solids is increased. The tone of all the skeletal muscles
is lessened. The eyes are usually rolled upward and the pupils constricted. Loss
of sleep exerts seriously detrimental effects upon the nervous system. Long
periods of wakefulness may cause profound psychological changes such as loss of
memory, irritability, hallucination and even schizophrenic manifestations.
During the last World War, prisoners in Nazi concentration camps were kept
awake for days by strong lights and blaring wireless sets, collapsed.
Sleep versus rest
For correct living, it is essential to differential
between sleep and rest. At rest the body is disturbed by all exterior noises;
but in sleep it is screened from them by partial loss of consciousness and also
by what is called "dream protection". One useful purpose of the dream
is to convert outside noises that might awake the sleeping person, into
fantasies that do not disturb him. During rest the limbs are normal, but in
sleep they swell. Blood flows from the brain, distends the arteries, and makes
the limbs bigger. in sleep more muscles are relaxed than in rest, though the sleeping
person changes his position about 35 times in one night, without knowing it.
Many organs which work during rest suspend their activities in sleep. Thus the
recouping value of sleep is much more than that of rest or simple lying down.
Theories of sleep
Many theories of sleep have been advanced to explain
the temporary loss of consciousness which we know as sleep. The oldest theory
is that sleep is induced by a reduction in the blood supply to the brain or at
least to conscious centers. This is known as ischemic theory. Even the ancient
Greek physicians were aware that the carotid artery was in a way concerned with
the onset of sleep. The name itself expresses this belief. The Greek word ‘Karotides’
for carotid arteries is derived from karoo which means ‘put to sleep.’ In
modern times, the drowsiness after a meal, presumably due to the diversion of
blood from the brain to the digestive organs, is cited in support of the
ischemic theory.
Another important theory about sleep is the chemical
theory. As a result of experiments in the metabolism of sleeping subjects, it
is considered that the fatigue inducing sleep may be a mild form of blood
poisoning or toxemia. This "poisoning" is believed to be brought on
by the expenditure of energy during the waking hours. According to this theory,
every contraction of a muscle and every impulse passing through the brain or
the nerves breaks down a certain amount of tissue. The debris from broken down
tissue is then thrown into the bloodstream. In the waking state, much of the
waste from broken down tissue is got rid of through the natural eliminating
processes of lungs, kidneys, bowels and skin. But there comes a saturation
point when there is such an accumulation of waste that it cannot be disposed of
by these processes and it then invades the grey matter of the brain. In such an
eventuality, mental and physical alertness are impaired. It is nature’s warning
that the waste product must be reduced to replenish the lost energy. So we get
tired and the urge to get sleep becomes irresistible. During sleep, the cells
and tissues that break down to produce toxic waste become less active and the
production of toxic waste is vastly reduced. Simultaneously, constructive
activities take place within the body during sleep, which rebuild the broken
down tissue. Another theory places a sleeping centre in the hypothalamus. Many
of the bodily changes in sleep such as constriction of pupils, reduced
frequency of heart beat, increased gastric tone and secretion are
manifestations of the activity of hypothalamus nuclei, especially
parasympathetic
centers. Perhaps some of the sleeping pills affect
this centre in the brain. Although the various theories have certain amount of
experimental evidence to support them, none has really solved what is the most
mysterious process in our lives. All we know is that sleep substitutes
constructive measures for the destructive processes of our waking hours. We cannot
live without sleep.
Duration
Another mystery about sleep is that no two persons
need the same amount of sleep. Dr. Nathaniel Kleitman, Associate Professor of
Physiology at the University of Chicago, who conducted years of extensive
experiments at the University’s "Sleeping Laboratory" says that there
is no more a normal duration of sleep than there is normal height and weight. A
study of 25 subjects spread over thousands of nights showed that the average
amount of sleep needed to feel well rested is seven-and-a-half hours, though
individuals varied from six to nine hours. According to Dr. Demmis Williams, a
noted authority on sleep, the amount of sleep needed for an individual’s
well-being, is determined by what he feels he needs, not by what other people, including
the doctor, think is reasonable. On the whole, women sleep from 45 minutes to
one hour more than men. The amount of sleep required varies at different ages
as follows:
New Born: 18
to 20 hours
Growing children: 10 to 12 hours
Adults: 6
to 9 hours
Aged persons: 5 to 7 hours
The depth of ordinary restful sleep fluctuates
throughout the sleep. In most adults, sleep deepens through the first hour,
after which it lightens rather sharply and then more gradually until morning or
until the usual time of wakening. IN growing children, however, sleep deepens a
second time for a little while. According to Dr. Lindlahr, a famous naturopath,
two hours before and two hours after midnight are the most valuable for sleep
of all the twenty-four hours of the
day. In these four hours, mental and physical vigor
are at their lowest ebb and sleep is soundest and most natural. It is believed
that three-quarters of our sleep consists of what is called ‘slow wave sleep’.
The restorative processes occur during this time. The remaining quarter is
taken by what is called ‘rapid eye movement (REM) sleep.’ It is also called
paradosical or dreaming sleep and it comes in episodes of about 20 minutes
duration about five times in a night. It involves dreaming, irregular heart
rates, raised blood pressure and erection of the penis. It is in this phase of
sleep that normal healthy young men may have wet dreams. Both forms of sleep
are considered equally important, being normal sleeping rhythms.
Sleeping positions
There are many theories about good and bad sleeping
positions. Practically everyone changes positions several times during sleep.
Hence how one starts out is of no consequence. It is a good thing we do turn
about in our beds. If we did not, we would awake in the morning stiff, having
maintained the same position all night. For proper sleep, however, one should
not sleep on one’s back but on the side with one or both legs brought well up
and the head and the shoulder slightly forward. Sleeping pills are no remedy
for sleeplessness. They are habit-forming and become less effective when taken
continuously. They lower the I.Q. dull the brain and can prove fatal if taken in
excess or before or after alcohol. The side-effect of sleeping pills include
indigestion, skin rashes, lowered resistance to infection, circulatory and
respiratory problems, poor appetite, high blood pressure, kidney and liver
problems and mental confusion.
Sleeping well is an art. It needs a perfect blend of
healthy habits and control of mind. A clean body and mind, relaxed mood,
physical exercises, and perfect dietary control are some of the basic
sleep-inducing methods. Unpleasant situations at bed time such as arguments,
quarrels, watching a horror movie, listening to loud music which would create anxiety,
fear, excitement and worries should be avoided. Such situations stimulate the
cerebral cortex and tend to keep one awake. The sleeping place should be well
ventilated, with balanced temperature and free from noises. The bed should be
neither too hard nor too soft, but comfortable. The pillow should not be too hard
or too high. The bed clothes should be loose-fitting and light colored. Another
important rule is not to have heavy food shortly before bed time.
Source: www.healthlibrary.com through
www.scribd.com
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