SLEEP:
Luxury or Necessity
To some people, sleep is a waste of time. This set of people prefers very busy schedule and social engagements, and only surrender to sleep when extremely tired. In contrast, others would give anything for a good night sleep.
Researchers have established that sleep is a complex process regulated by the
brain and it obeys a 24-hour biological clock. They also assert that some adults appear to need only three hours of sleep a day; others need up to ten hours. As one gets older, the
sleeping habits changes. A newborn sleeps for frequent short periods that total about 18 hours a day.
The biological clock is regulated by chemical substances such as
melatonin – a hormone that trigger sleepiness. Melatonin is produced in the brain, and some scientists believe that it is responsible for the slowdown of the body’s metabolism that occurs prior to falling asleep. As melatonin is released, body temperature and blood flow to the brain are reduced, and the muscles gradually loose their tone ad become flaccid.
Approximately two hours after one falls asleep, the eyes begin to quiver quickly back and forth. This observation led scientists to divide sleep into 2 basic phases:
rem (Rapid Eye Movement) sleep and non-REM sleep. Non-REM sleep can be sub-divided into four stage of progressively deeper sleep. During a healthy night’s sleep, REM sleep occurs several times, alternating with non-REM sleep.
Most dreaming occurs during REM sleep. The body also experiences maximum muscle relaxation, which allows the sleeper to wake up feeling physically refreshed. In addition, some researchers believe that newly acquired information is consolidated as part of one’s long-term memory during this sleep. Also, during deep sleep, the blood pressure and heart rate reach lower ranges providing rest for the circulatory system. In addition, the production of growth hormone peaks during non-REM sleep.
Sleep also seems to affect one’s appetite. The brain interprets lack of sleep as lack of food. During sleep, leptin – the hormone that notify the body that one has eaten enough – is secreted. Staying awake for a long period leads to reduction in the production of leptin.
Today, millions of people have difficulty sleeping well. Sleep specialists posit that an estimated 35 percent of the world’s population suffer from insomnia – the inability to enjoy normal and sufficient sleep. They assert described sleeping badly as “one of the most serious epidemics of the turn of the century.” Many insomniacs suffer in ignorance. They simply accept sleeping badly as part of life and resign themselves to spending their waking hours feeling irritated and drowsy. To these, sleep is neither a luxury nor a necessity.
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