We know that sleep is essential to maintain a good health, as chronically poor sleep hygiene or shift work have been correlated with a poorer health and greater risk of diseases, including cardiovascular diseases.
At Vitónica we have discussed on some occasions certain tips that can help improve sleep hygiene, such as avoiding blue lights Before going to sleep, keep the room at a temperature between 15 and 20º C, listening to relaxing music 5-10 minutes before going to sleep, etc.
Different phases of sleep
The human body It goes through two phases of sleep , rapid eye movement ( REM ) sleep and non-rapid eye movement ( NREM ) sleep, which is divided into three stages, N1, N2 and N3, although some researchers disagree and separate the stages. of NREM sleep in N1 and N2.
Each phase and stage of sleep includes variations in muscle tone, brain wave patterns, and eye movements. The body goes through all of these stages approximately 4 to 6 times each night, averaging 90 minutes per cycle.
The dream It occurs in five stages: wakefulness, N1, N2, N3 and REM. Stages N1 through N3 are considered non-rapid eye movement (NREM) sleep, with each stage being progressively deeper sleep. Approximately the 75% of sleep remains in the NREM stages , and NREM sleep remains, most of the time, in the N2 stage.
The typical night's sleep consists of 4-6 sleep cycles, with the progression of sleep stages in the following order: N1, N2, N3, N2, REM. A complete sleep cycle lasts approximately 90 to 110 minutes. The first REM period is short and, As the night progresses, longer periods of REM occur and decreased deep sleep time (NREM).
Vigil
During the waking state, especially when we are with our eyes open, beta waves predominate in the brain, involved in conscious thought and logical thinking, and tend to have a stimulating effect.
As people become drowsy and close their eyes, alpha waves become the predominant pattern, which are waves that have the opposite effect of beta waves.
N1 (LIGHT SLEEP)
This is the lightest stage of sleep and begins when more than 50% of alpha waves are replaced with low-amplitude mixed-frequency activity (theta waves, which allow for greater flow of ideas). Muscle tone is present in skeletal muscle and breathing It tends to occur at a regular pace. This stage lasts about 1 to 5 minutes , which represents 5% of the total sleep time.
N2 (DEEP SLEEP)
This stage represents deeper sleep as the heart rate and body temperature. It is characterized by the presence of sleep spindles, K complexes, or both.
The sleep spindles are short, powerful bursts of neuronal activation . This mechanism is believed to be integral to synaptic plasticity. Several studies suggest that sleep spindles play an important role in the consolidation of memory, specifically in declarative memory.
K complexes are long delta waves that last about a second and are known to be the longest and most distinctive brain waves. HE have demonstrated that K complexes work to maintain sleep and memory consolidation.
N3 (DEEPER NREM SLEEP)
This is considered the deepest stage of sleep and is characterized by signals with much lower frequencies and higher amplitudes, known as delta waves. This stage is the most difficult to wake up and for some people, even loud noises (more than 100 decibels) will not wake them up.
This is the stage in which the body repairs and regenerates tissues , develops bones and muscles, and strengthens the immune system. This is also the stage in which sleepwalking, night terrors, and nocturnal enuresis (involuntary urination) occur.
REM PHASE
The REM phase is associated with dreaming and is not considered a stage of restorative sleep . When an EEG is performed on a person in REM sleep, brain activity is similar to that of an awake individual. Additionally, skeletal muscles are atonic and motionless, except for the eyes and diaphragmatic respiratory muscles, which remain active. However, the respiratory rate becomes more erratic and irregular.
This stage It usually starts 90 minutes after you fall asleep, and each of your REM cycles lengthens throughout the night. The first period usually lasts 10 minutes, and the last lasts up to an hour. During the REM phase is when dreams, nightmares, and tumescence of the penis and clitoris occur.
PRONAPRESA
"Because prevention is better than cure"
