The sleep

The sleep

One speaks about refreshing sleep, of paradoxical or major sleep. A thing is certain, the sleep which represents a third of our life, contributes to our good health.
In addition to this card, read our files:
> The sleep… and its disorders,
> In finishing with insomnia,
> My newborn wants to never go to lie down.

For what is used the sleep?

Obviously, the sleep is essential for our good health, for the storage capacities, physical recovery… To sleep allows a better repair of the muscles and bones in the adult, and a reinforcement of the immune system. In the child, the deep sleep would support the development of the brain and the training. It also takes part in the growth. It is especially during the night that the growth hormone is secreted.

Various phases of the sleep.

During the sleep, the majority of the functions of the organization slow down their activity: cardiovascular, respiratory, cerebral…
The sleep is normally cut out in four stages which are determined by the amplitude of the waves of the cerebral electric activity recorded by an electroencephalogram (EEG).
Stage 1 corresponds to the phase of drowsiness in a very light sleep.
Arrived at the stage 2, the sleep starts to deepen. At the end of several tens of minutes, the cerebral activity still slows down and one reaches the deep sleep (stage 3). This deep sleep especially occupies an important place during the first hours of the sleep, much less over the morning. With the age, the phases of deep sleep are curtailed and rarefy.
Another particular stage: the paradoxical sleep during which the ocular spheres move in all the directions. The person sleeps deeply whereas its brain is near to a stage of drowsiness. Here is the paradox!
In fact, these stages follow one another according to 4 to 6 cycles during the night. Generally the first cycle is longest. Each one of them is repeated but not exactly in the same way during all the time of sleep.
Somebody who sleeps awakes several times in the night during a short moment and without remembering it.

Needs for each one, at each age.

• The adults on average need seven hours thirty of sleep per night. Nevertheless, there exist the “small ones” (six hours) and “large” (nine to ten hours) sleepers. A reduction of the time of one hour sleep or two over one prolonged period can involve a productivity reduced in the course of the day and of uncontrolled drowsinesses,
• The elderly sleep a little less and especially of a lighter sleep, and little the morning,
• The newborn needs 16 to 17 hours of sleep per day,
• Between three and six years, the child requires 12 hours,
• Between six and twelve years, 10 hours,
• During adolescence, 9 hours.

Principal sleep disorders.

> Insomnia appears by a bad quality of cut sleep of many alarm clocks and by difficulties of drowsiness. This disease is very current, and can be occasional when it is related to an event or a change in the life. Its chronic form often concerns psychological causes.
> The syndrome of apnea of the sleep can be dangerous on the long run, in particular with cardiovascular consequences. The sleep is split up by respiratory pauses which can last several seconds. The muscles of walls of the pharynx are slackened and prevented the air from passing. It can even occur tens of the hundreds of followed apnea by microphone-alarm clocks per night. They are generally the specialists in the sleep or the lung specialists who deal with these patients
> The syndrome of the legs without rest results in feelings very particular to the lower extremities, often the evening, with the pressing desire to move. During the night, periodic movements in the legs generally can cause sleep disorders.
> The cases of narcolepsy remain rather not very frequent. The narcolepsy appears by a somnolence during the day, of the crises of cataplexie (muscular relaxation suddenly which can involve a fall). The organization of the various stages of the sleep is disturbed.