Sleep

When sleep relaxes the body and restores energy. After all Sleep is a state actor affect the survival of physical and mental health in good condition. The good sleep during the night is the best way to counter stress and tension and solve problems or recover from the disease.
What happens during sleep
Sleep occurs in response to natural changes in brain activity and includes two main phases
- Rapid eye movement sleep (REM)
- Sleep is rapid eye movement (NREM), which in turn includes four stages.

During sleep the body passes the previous two phases alternately. As the model starts with eye movement sleep phase of slow and then enter the person in the process of rapid eye movement (REM) for a short period

Dreams occur primarily during rapid eye movement.

Sleep non-rapid eye movement
And includes four stages. The duration of each stage of the ten to fifteen minutes. And complete sleep cycle through traffic in all these stages before entering the phase of rapid eye movements to begin after the episode of the new

Sleep stages non-rapid eye movement:
Phase I: shows the reader a measure sleep decrease in activity when the drowsiness and before the first stage of sleep. The eyes were closed and can awaken a person easily. And if the person is alert at this stage Vsazn he had not slept yet.
This phase may last from five to ten minutes. And at this stage, many people feel that they fall, where there is reflex contraction of the muscles of the body (muscle contraction during sleep and is a defensive reaction)

The second stage: it is a state of light sleep, and waves appear on the reader sleep tops and Tqarat or negative and positive waves. These changes occur because of muscle tension and punctuated by periods of relaxation. It also reduced heart rate and body temperature. And then prepares the body to enter into a phase of deep sleep

Third and fourth phases: two phases and deep sleep and sleep is deeper in the fourth stage. This is known as phase: slow wave sleep or delta waves, and the person is not directed (to the place and time) for several minutes if you wake up at this stage

During the two previous stages (deep sleep), the body repairs tissue and bone and muscle building and strengthening the immune system (which increases the secretion of growth hormone during this phase).
When people age, reduce the period of deep sleep and increase sleep duration or light surface. As aging is accompanied by a lack of sleep periods, although the need for sleep does not decrease with increasing age


Rapid eye movement sleep
Occur the first period of rapid eye movement sleep after about ninety minutes from start to sleep and lasts for about ten minutes and goes on this period with frequent occurrence of the term of the last period (before getting up) at about
Shows the reader to sleep at this stage, brain waves similar to those recorded in the waking state
In people who do not suffer from sleep disorders get them in the acceleration of heart rate and respiratory rate had been coordinated with the disorder as the eye moves rapidly in all directions
Violent dreams occur as a result of high efficiency of the brain's cerebral cortex, but in this case there is paralysis of facilities in most large groups of voluntary muscles in the body
Include rapid eye movement sleep on the effectiveness of stroke (cortical) High with Ahrkih muscle (functional)
For this reason, sometimes called paradoxical sleep

Increase the percentage of paradoxical sleep (rapid eye movement) of the total sleep in infants and young children, where the baby spends about fifty percent of his sleep at this stage, while this percentage drops in adolescents and adults up to about twenty percent.

What is the amount of sleep needed by the human
Different amount of sleep needed by the human person to another. And this need is determined by several factors including the age and.
An infant's need about 16 to 18 hours a day, while teenagers need about nine hours and adults from 7 to 8 hours.

And an increased need for sleep in the case of a person deprived of it for a while. Nor does it appear that people adapt to the less sleep than they need the usual.


What are the effects of severe lack of sleep
May cause lack of sleep:
- Disturbance in memory and thinking process
- Depression
- Weak immune
The sleep deprivation increases the effect of alcohol on the body and so the weary man of his lack of sleep getting worse by the alcohol more than the average person.
Lack of sleep also increases the pain during the test induction of pain. Can the rest of caffeine and stimulants to overcome temporarily the symptoms of severe lack of sleep, but not for long