Sleep occupies about a third of our existence! It consists of a succession of cycles, which are linked throughout the night. Healthmagazinehouse takes stock of these different phases, to help you understand how your “sleep disorder”.
Sleep cicle has long remained a mystery. In the late 50s, Dr. Michel Jouvet discovered the existence of sleep disorder, allowing the current understanding of the electrical phenomena that occur in our brain when we sleep.
Sleep cycles, kesako?
Sleep has several cycles that are repeated several times in the night. A cycle consists of several phases and is preceded by a period of awakening quiet, long or short, preparing sleep.
A sleep cycle, with an average duration of 90 minutes, includes:
A quiet phase of sleep slow wave (slow activity on brain recordings) during 60 to 75 minutes and comprising four stages:
Stage I: sleep, including two sub-stages – stage IA: IB and drowsiness
Stage II: light sleep
Stage III: deep sleep (sleep established)
Stage IV: very deep sleep (deep sleep).
A sleep disorder, shorter, where brain activity is more intense: this period is accompanied by rapid eye movements caused by brain waves, associated by most authors with dreams. Sleep disorder lasts 15 to 20 minutes;
An intermediate phase of sleep, brief, with micro-awakenings leading to a new cycle or at the end of the night, on full awakening.
A succession of cycles … Moreover, the periods of sleep disorder, with dreams, gradually lengthens during the night. Thus, the first part of the night sees sleep disorder, deep and physically restorative, while the second part is more conducive to mental and nervous recovery.
Sleep will revive if the cycles follow harmoniously. There is no absolute rule on the number of cycles needed for a good recovery: some people feel good with 3 cycles per night, for others it will take 6 or 7.
Register his sleep
If sleep problems, for example in cases of chronic fatigue or doubt about sleep apnea, an electrical recording can be performed. This is the polysomnogram, barbaric term for a collection of electrical data from:
Brain sensors electroencephalogram
A motion detector of the eyes
A sensor attached to the muscle contraction chin.
The electromyography, respiratory rate, electrocardiogram and blood oxygen saturation are also recorded and studied, for example to highlight sleep apnea.
This examination is carried out in certain specialized services or in the laboratory in conditions of comfort that should make optimal; sometimes overnight in required. So be specified hours of sleep and awakenings, total sleep time, the sequence of stages, and especially any anomalies.
Even if you never remember your dreams and you like sleeping in one go, so your sleep is complex, made of alternating quiet periods and other more fertile … What this obviously prevents you not sleep well!