Why Do We Sleep?

The secrets of sleep, what happens in our brain when we sleep?

We spend a third of our life sleeping, but do we know what our organism and our brain do while sleeping that it cannot do awake? Why do we sleep? What are the sleep cycles and how do they affect us?

Let's start at the beginning: what is the use of sleeping ?. The reality is that

there are countless hypotheses about the functions of sleep, but among all those possible functions, we have an acceptable level of scientific evidence on the following.

Replenishment and management of the body's chemical energy.
Memorization and consolidation of what we learned during the vigil.
Regulation of brain temperature.
Elimination of harmful substances produced by the brain during wakefulness.
Repair of body tissues.
Brain plasticity (brain modeling) during the embryonic phase.

All living beings with nervous systems need sleep, the human being is no exception, but what happens in our brain when we sleep ?. If we study the electrical activity of a subject's brain while sleeping, we will observe 5 well-defined phases:

Phase I: Drowsiness. As soon as we close our eyes and fall asleep, the brain enters the first stage, this first phase is a kind of intermediate zone between being awake and asleep. Muscle tension decreases and breathing softens. It usually happens during these moments that if the sleeping person is awake during this stage, he will react quickly and deny having fallen asleep.

Phase II: Superficial sleep. The brain waves lengthen and regularize. All our senses are blocked, although the dream at this stage is still not completely reparative.

Phase III: Moderately deep sleep. Brain waves increase in size and slowness. The functions of the whole organism as a whole are increasingly slow. If we wake up in this phase, we would certainly find ourselves disoriented.

Phase IV: Deep sleep. You enter total unconsciousness. An electroencephalogram would reveal extremely long and smooth brain waves. It is where we achieve the deepest sleep, and therefore, where our body can recover both physically and psychically. If there are dreams during this stage, they will not be like watching a movie, but games of shapes and lights.

While a person falls into sleep, and progressively goes through these phases, brain activity is drawing a pattern of slow waves. But after moving forward in phase IV something fascinating happens. The dream meaning of drawing suddenly returns to draw a storm of nonsense lines, a chaotic plot that indicates that the patient is awake, but if we look at the person, we see them completely asleep, and not only asleep, if we try to wake them it will cost us even more than in phase IV. It is the deepest dream, and if we can wake her up, she will probably tell us that she was dreaming. If you look at your closed eyes, we will notice that under the eyelids the eyes dance with rapid movements. It is phase V: the REM (rapid eye movement) dream. REM sleep is so characteristic that the rest of the phases are usually called non-REM sleep. REM is accompanied by intense dreams and rich in content, color and sensations.

During REM, the blood flow of the brain accelerates and breathing also becomes faster and more choppy. The brain stops emitting signals to the spinal cord and our muscles are still, preventing dreams from taking action. REM is the stage of vivid dreams, where if a person wakes up, he probably remembers fragments of his fantasies. After 10 minutes of REM it descends again in the stages of the Quiet Dream (the first four phases). Which will be cyclically taking turns with the REM phases throughout the night. Find out dream interpretation