Sleep is the vital part of the life of every organism including humans. The time of the sleep varies with the species. The cat is expected sleep more than 18 hours per day and us human sleep around 8 hours per day. Among the mammals, humans are claimed to sleep less. Sleep is the vital aspect of organism life cycle. The building or the anabolic state that is vital for repair of the body occurs during sleep.
The compulsion of sleep is great debate among the scientific community. There are many hypotheses to justify the essence of sleep. One claims that sleep is essential to conserve energy in the body. Other states that it is essential to get rid of the noisome waste (1). Further, another emphasis that sleeps the vital aspect of survival. Sleeping causes the organism to disguise from the predator.
The recent hypothesis points out the necessity of sleep for the purpose to forget. There is no widely accepted theory to claims the essence of sleep in the organism life cycle.
Types of Sleep
There are two types of sleep one is the rapid eye movement and the other is nonrapid eye movement. The rapid eye movement is the dreaming state and uses more energy than nonrapid eye movement.
Sleeping Time in Humans
Sleeping time in humans is the greatly debated topic. Sleeping time varies with individuals the series of parameter like age, sex, physical condition, diet, etc. There is strong argument that 8 hours of the sleep is the ideal time. But, this is not always the truth.
There is the need of refreshment after awakening from the sleep. Individuals need to estimate their own sleeping time.
In every organism the timing of the sleep is governed by the circadian rhythm commonly refers to as the biological clock. The circadian rhythm is governed by rising and setting of the sun.
Awakening after the sleep is marked by the electrical activation of the brain (2). Electrical activation starts in thalamus and moves towards the cortex.
Insomnia is the condition marked by the lack of the sleep. The common effect of the insomnia is the confusion. Lack of sleep interferes with the hormone production within the body that can trigger several diseases. The major cause of car accident around the globe is due to lack of sleep.
There are various cures available for Insomnia and it depends on the severity of the condition. Modern sedentary habits are accelerating insomnia. In my experience, the best way to combat is the brisk walking at least one hour in a day.
Anyone who falls sleep before fifteen minutes after lying in the bed is considered to have chronic sleep deprivation.
1. Lulu Xie, et al., (2013). "Sleep Drives Metabolite Clearance from the Adult Brain". Science. 342 (6156): 373–377.
2. Åkerstedt Torbjorn; et al., (2002). "Awakening from Sleep". Sleep Medicine Reviews. 6 (4): 267–286