Sleep forms part of human’s biological need to
rest. As a person sleeps, the various physiological processes of a human body
figuratively put into an apparent arrest and some parts of our system that were
mostly exploited can be replenished for future use.
However, imagine a system so disrupted that our
normal scheduling for sleeping and waking is totally altered. Some people tend
to sleep early and wake up early in the morning and some cannot sleep early and
as a consequence, wakes up late.
These and other sleep-related problems are
manifestations of a malfunctioning biological circadian clock and characterize
several forms of Circadian Rhythm Syndrome. Circadian activity is a unique by
24-hour period or cycles in which our body is physically patterned.
24-hour vs. 25-hour cycle
Earth rotates around the sun in a 24-hour cycle, so
as our body functions in this 24-hour time schedule. All living organisms
charismatically subscribe to this cyclic resting and activity patterns so that
their body could function in sync with the environment in which they live.
Although humans externally operate under a 24-hour
environment, research found that our body clocks evidently works significantly
different than what we see in the environment.
It shows that the human body closely behaves as if
it were under a 25-hour environment. Convincingly, humans’ reluctance to wake
up at a required time and sleeping late at night probably explains this theory.
To compensate for this discrepancy, the body uses
time “cues” to effectively counter-manage this asynchronous rhythmical. Setting
an alarm helps us wake up at a designated time of the day and allows us to
function as if it were under the 24-hour rhythmic schedule.
Dark vs. Light
Light and temperature provides the determining
factor by which the body responds to the 24-hour activity period. The presence
or absence of light mainly affects the part of the brain, which paces your
bodily activities.
It was understood that the fundamental locus or
location of our biological clock is the brain specifically in the
suprachiasmatic nucleus (SCN) of the hypothalamus.
In complex animals like humans, hypothalamus forms
part of the autonomous nervous system, which in part, controls the functions of
organs that are not voluntarily controlled, hence involuntary. Involuntary,
meaning, they are not governed by conscious will to act. These include
breathing, heartbeat and intestinal digestion.
Eyes, Light and SCN
One interesting point to make is that the location
of SCN is just above the optic chiasma (cross). Optic chiasma can is described
as a location where optic nerve fibers meet and cross (chiasma-cross).
It is fitting to say that; the perception of light
through the opening in the eyes triggers the wake/sleep patterns in humans
since this is one way the organism receives such physical message.
As retina (a portion of the eye where initial image
of an object is stored) traps light rays, an optic fiber relays the image to
the brain via characteristic electrical pulses.
This unique sensory impulse is carried along the
optic fibers to the occipital lobe (rear part) of the brain and is perceived as
images. The proximity of the optic chiasma to the SCN perhaps provides the
opportunity for the hypothalamus to “sense” the referred electrical impulses.
Forms of Circadian Rhythms Syndrome/Disorders
Circadian Rhythm defects can come many distinct
forms depending on the amount and timing of waking up and sleeping. Others, as
in the case of Seasonal Affective Disorder (SAD), result in the changes in the
length of day and night.
People who tend to sleep at a later time of the day
and wake up late as well are said to be exhibiting Delayed Sleep Phase Syndrome
(DSPS). These people tend to develop insomnia, an abnormal inability to take
adequate amount of sleep due to not being able to sleep at the right time of
the night.
Still, other people, especially the elderly, are
more likely to sleep early around
The amount of a substance called melatonin is also perceived
as a motivating factor in sleep-related disorders in humans. In a study among
vertebrate mammals, melatonin is secreted in response to the absence of light.
This means more melatonin is secreted in the period
of darkness and less in the presence of light. It presupposes the idea that
melatonin is related to the 24-hour sleep/wake cycle of every human being.
Recommendations
With the knowledge gained in the preceding
discussion, it can be assumed that the presence and absence of light affects our
sleeping/waking schedule. With these in mind, keep yourself committed to your
schedule to rest and sleep and set aside things, which are not really
important.
Keep your room as dark and gloomy as possible, to
make it easy for you to sleep. Colorful objects stimulate your senses and
disrupt sleep. Keep it ventilated and air-conditioned.
Studies show that as we sleep, our body temperature
drops and allows the neurotransmitter melatonin to be produced at a rapid pace.
Keep those things in mind and do not forget to seek
medical help should your condition progresses.
Nishanth Reddy is an author and publisher of many health related websites. Visit his website to know more about other Sleep Disorders like insomnia, sleep apnea, snoring, restless legs, narcolepsy.
Sleep Disorders Guide
Article Source: Infonexus.org Free Articles
