Phases of human sleep - the influence of slow and fast sleep. Study of sleep phases and their influence on proper rest Sleep phases slow, fast, paradoxical

Night rest is a natural component of every person’s life, both for adults and children. When people get adequate sleep, they not only improve their mood and well-being, but also show significant improvements in mental and physical performance. However, the functions of night sleep do not end only with rest. It is believed that it is during the night that all information received during the day passes into long-term memory. Night rest can be divided into two phases: slow-wave sleep and fast sleep. Particularly relevant for humans deep dream, which is part of the slow phase of night rest, since it is during this period of time that a number of important processes occur in the brain, and disruption of this phase of slow sleep leads to a feeling of lack of sleep, irritability and other unpleasant symptoms. Understanding the importance of the deep sleep phase allows us to develop a number of tips for normalizing it for each person.

Sleep includes a number of stages that regularly repeat throughout the night.

Periods of night rest

The entire period of human dreams can be divided into two main phases: slow and fast. As a rule, falling asleep normally begins with the slow-wave sleep phase, which in its duration should significantly exceed the fast phase. Closer to the awakening process, the relationship between these phases changes.

How long do these stages last? The duration of slow-wave sleep, which has four stages, ranges from 1.5 to 2 hours. REM sleep lasts from 5 to 10 minutes. It is these numbers that determine one sleep cycle in an adult. In children, the data on how long the nightly rest cycle should last differs from in adults.

With each new repetition, the duration of the slow phase continues to decrease, and the fast phase, on the contrary, increases. In total, during a night's rest, a sleeping person goes through 4-5 similar cycles.

How much does deep sleep affect a person? It is this phase of rest during the night that ensures our recovery and replenishment of physical and intellectual energy.

Features of deep sleep

When a person experiences slow-wave sleep, he sequentially goes through four stages, which differ from each other in the features of the pattern on the electroencephalogram (EEG) and the level of consciousness.

In the first phase, a person notices drowsiness and half-asleep visions, from which one can easily awaken. Typically, people talk about thinking about their problems and looking for solutions.
The second stage is characterized by the appearance of sleepy “spindles” on the electroencephalogram. The sleeping person has no consciousness, however, he easily awakens under any external influence. Sleepy “spindles” (bursts of activity) are the main difference between this stage.
At the third stage, sleep becomes even deeper. On the EEG, the rhythm slows down, slow delta waves of 1-4 Hz appear.
The slowest delta sleep is the deepest period of night rest, which is required for the rest of sleeping people.

The second and third stages are sometimes combined into the delta sleep phase. Normally, all four stages should always be present. And each deeper phase must come after the previous one has passed. “Delta sleep” is especially important, since it is it that determines the sufficient depth of sleep and allows you to move on to the REM sleep phase with dreams.

The stages of sleep make up the sleep cycle

Changes in the body

The norm for deep sleep for an adult and a child is about 30% of the total night's rest. During delta sleep, significant changes occur in work internal organs: heart rate and breathing rate decrease, skeletal muscles relax. There are few or no involuntary movements. It is almost impossible to wake a person - to do this you need to call him very loudly or shake him.

According to the latest scientific data, it is during the deep sleep phase that normalization of metabolic processes and active restoration occur in the tissues and cells of the body, allowing the internal organs and brain to be prepared for a new period of wakefulness. If you increase the ratio of REM sleep to slow-wave sleep, the person will feel unwell, experience muscle weakness, etc.

The second most important function of the delta period is the transfer of information from short term memory into the long term. This process occurs in a special structure of the brain - the hippocampus, and takes several hours. With chronic disturbance of night rest, people experience an increase in the number of errors when testing the efficiency of memory, speed of thinking, and others. mental functions. In this regard, it becomes clear that it is necessary to get enough sleep and ensure a good night's rest.

Duration of the deep phase

The average amount of sleep a person gets usually depends on numerous factors.

When people ask how many hours a day you need to sleep to get enough sleep, this is not a completely correct question. Napoleon could say: “I sleep only 4 hours a day and feel good,” and Henry Ford could argue with him, since he rested for 8-10 hours. Individual values for night's rest vary significantly between different people. As a rule, if a person is not limited in the recovery period at night, then on average he sleeps from 7 to 8 hours. The rest of most people on our planet fits into this interval.

REM sleep lasts only 10-20% of the entire night's rest, and the rest of the time the slow period continues. It’s interesting, but a person can independently influence how long he will sleep and how much time he needs to recover.

Increasing delta sleep time

Every person should strictly adhere to the regime of falling asleep and waking up. This allows you to normalize the duration of night rest and make it easier to wake up in the morning.

It is very important to maintain a sleep-wake schedule

Eating before rest is not recommended, just as you should not smoke or drink energetic drinks etc. It is possible to limit yourself to a light snack in the form of kefir or an apple a couple of hours before going to bed.
In order for the deep phase to last longer, it is necessary to give the body physical activity of adequate intensity 3-4 hours before falling asleep.
Provide more falling asleep quickly and quality sleep is possible with using easy music or sounds of nature. For example, cricket singing is known to be very beneficial for deep sleep. This means that listening to music while relaxing is recommended by doctors, however, it is very important to choose it wisely.
Before going to bed, it is best to ventilate the room well and eliminate any possible sources of noise.

Sleep disorders

Woman suffering from insomnia

What percentage of people experience sleep disorders? Statistics in our country show that every fourth person experiences certain problems associated with night rest. However, the differences between countries are minimal.

All violations in this area of human life can be divided into three large groups:

Problems falling asleep;
Violations of the process of night rest;
Problems with well-being after waking up.

What are sleep disorders? These are temporary disorders of any phase of night rest, leading to disorders in various areas human psyche during the waking period.

All three types of sleep disorders lead to general manifestations: during the day there is lethargy, fatigue, decreased physical and mental performance. A person has Bad mood, lack of motivation for activity. Over a long period of time, depression may develop. At the same time, it is very difficult to identify the main cause of the development of such disorders, due to their large number.

Sleepiness during the day, insomnia at night

Causes of deep sleep disorders

Within one or two nights, a person’s sleep disturbances may not have any serious cause and will go away on their own. However, if violations persist long time, then there may be very serious reasons behind them.

Changes in the psycho-emotional sphere of a person, and, first of all, chronic stress lead to persistent sleep disturbance. As a rule, for such psycho-emotional overstrain there must be some kind of psycho-traumatic factor that led to disruption of the process of falling asleep and the subsequent onset of the delta sleep phase. But sometimes it's mental illness(depression, bipolar affective disorder etc.).
Diseases of the internal organs play an important role in the disruption of deep sleep, since the symptoms of diseases can prevent a person from fully resting during the night. Various pain sensations in patients with osteochondrosis, traumatic injuries cause constant awakenings in the middle of the night, causing significant discomfort. Men may have frequent urination, leading to frequent awakening to go to the toilet. It is best to consult your doctor regarding these issues.

However, most often the cause of problems falling asleep is related to the emotional side of a person’s life. It is the causes of this group that occur in the majority of all cases of sleep problems.

Emotional disorders and night rest

Sleep and stress are interconnected

People with emotional disorders have difficulty sleeping because they experience increased levels of anxiety and depressive changes. But if you manage to fall asleep quickly, then the quality of sleep may not suffer, although usually the delta sleep phase in these cases is reduced or does not occur at all. Intrasomnic and post-somnic disturbances may additionally appear. If we talk about major depression, then patients get up early in the morning and from the very moment they awaken, they are immersed in their negative thoughts, which reach a maximum in the evening, leading to disruption of the process of falling asleep. As a rule, deep sleep disorders occur together with other symptoms, however, in some patients they may be the only manifestation of the disease.

There is another category of patients who experience the opposite problem - the initial stages of slow-wave sleep can occur during wakefulness, leading to the development of hypersomnia, when a person constantly notes high drowsiness and can fall asleep in the most inappropriate place. If this condition is hereditary, a diagnosis of narcolepsy is made, which requires special therapy.

Treatment options

Identifying the causes of deep sleep disorders determines the approach to treatment for a particular patient. If such disorders are associated with diseases of internal organs, then it is necessary to organize appropriate treatment aimed at full recovery patient.

If problems arise as a result of depression, then the person is recommended to undergo a course of psychotherapy and use antidepressants to cope with disorders in the psycho-emotional sphere. Typically, use sleeping pills limited due to their possible negative influence on the quality of recovery itself at night.

Sleeping pills should only be taken as prescribed by a doctor.

Accept medicines to restore the quality of night's rest, it is recommended only as prescribed by the attending physician.

Thus, the deep sleep phase has a significant impact on a person’s waking period. In this regard, each of us needs to organize optimal conditions to ensure it. adequate duration and complete restoration of the body. If any sleep disturbances occur, you should always seek help from your doctor, since complete diagnostic examination allows you to detect the causes of disorders and prescribe rational treatment that restores the duration of delta sleep and the patient’s quality of life.

Every night we all go through phases of sleep: rapid and slow sleep. Physiologically, sleep is a complex various processes, during which we can experience several cycles of these two phases.

For a long time it was believed that there was no way to study a person’s dreams and their influence on his physiology and psyche in any way. Initially they were studied on the basis of purely physical description processes - it was possible to determine the sleeper’s pulse, his arterial pressure and his body temperature. But about assessing the influence of sleep on mental and physical activity there wasn't even any talk.

With the advent of encephalography in the twentieth century, the possibilities for understanding the processes occurring during sleep have expanded significantly.

Every night's rest is necessary for a person; to some extent we can say that sleep is for a person more important than nutrition. A person deprived of sleep for only two or three days becomes irritable, loses emotional stability, and begins to experience memory loss. Against the background of fatigue and mental retardation due to lack of sleep, a person falls into depressive state. It is believed that the maximum time a person can live without sleep is 11 days, after which irreversible changes occur in the brain, leading to death.

The main purpose of sleep for the body is to rest all its systems. For this purpose, the body “turns off” all senses and is almost completely immobilized.

Modern science represents sleep as a special period that has behavioral characteristics of the motor sphere and the autonomic nervous system. A feature of sleep is the alternating change of two states with almost opposite manifestations. They are called slow and fast sleep.

The surprising thing is that only together both phases - fast and slow sleep - can restore both the physical and mental strength of the body. If you interrupt the night cycle at a stage when only one of the cycles is completed, the body will not receive proper rest. The combination of fast and slow sleep renews the brain's performance and fully processes the information received during the past day. It is the complete completion of sleep cycles that facilitates the transfer of information from short-term memory to long-term memory.

In fact, a full sleep is the final stage in solving the problems of the past day and a kind of “summing up” of its results.

Also, complete and proper rest during sleep improves the health of the whole body.

The following physiological processes occur only during night rest:

fluid balance is restored and the body is cleansed by removing excess moisture;
collagen protein is synthesized, which plays a major role in strengthening joints, blood vessels and skin;
The body absorbs calcium, which is necessary for bone and dental tissue.

These processes take quite a long time, so to feel normal you need to sleep about eight hours.

The duration of slow-wave sleep is equal to almost three-quarters of the total time of night rest, its features are as follows:

The slow phase is characterized by a general slowdown in metabolism, a significant decrease in the brain's response to external factors, relaxation of the entire body and general lethargy. Waking up is a very difficult time and leaves unpleasant sensations for quite a long time.

In the slow phase, muscle tissue is regenerated. It is also during this phase that the “reboot” occurs. immune system. Thus, its normal and complete completion is a guarantee of improved well-being.

Slow sleep promotes rehabilitation and healing of the body: cell renewal occurs and the functioning of all body systems improves. REM sleep is different in that it does not have such abilities.

In fact, slow-wave sleep is divided into four components, each of which has various characteristics. Let's look at the components of slow-wave sleep.

A person who falls into a state of drowsiness, despite the decrease in physiological processes, continues to work with the brain and he thinks about and improves some of the most important ideas that he dealt with during the day. The brain receives sufficient quantity oxygen and works somewhat beyond its capabilities: various options for solving certain situations are searched for, and optimal options are selected. Often it is during the dozing phase that dreams appear that have positive and pleasant results. The final decisions of some known issues came to humanity precisely during this phase. Mendeleev, Descartes, Bohr and many other scientists admitted that the final processing of their theories occurred precisely during dozing.

Sleep spindles

This stage is also called the sigma rhythm due to the characteristic impulses observed on the encephalogram. Her distinctive feature is an almost complete blocking of consciousness, similar to that observed during anesthesia. The duration of this stage is half of the entire slow phase. It takes a very long time for the brain to prepare for deep sleep.

Notable is the fact that this activates special cells that separately block the channel of sound transmission to the brain

Delta sleep

A kind of “prelude” to the deep, it happens relatively quickly. During delta sleep, the amplitude of impulses in the brain decreases significantly, the impulses themselves become shorter - brain activity approaches its minimum.

From this stage, which begins about an hour and a half after the start of napping, we are already completely asleep. Brain activity is minimal, there is practically no reaction to any stimuli. It is almost impossible to wake up a person in this stage: even loud sounds, braking and quite strong pain are not able to interrupt it.

Dreams are present at this stage, but it is almost impossible to remember them - only fragments of images remain in memory. If it is possible to wake a person during this stage, the rise will be extremely difficult and the final restoration of the body may not occur until the next period of sleep.

Another name for this phase is paradoxical or fast wave. There is a significant activation of life processes, primarily occurring in the brain. The transition from slow-wave sleep to fast sleep occurs quickly, and serious changes occur throughout the body.

Features of the REM sleep phase include:

Increased breathing and heart rate.
Frequent arrhythmias in the heart.
Decreased muscle tone.
A significant decrease in the activity of the muscles of the neck and diaphragm.
Promotion motor activity eyeballs with closed eyelids.
Clear memories of dreams seen during REM sleep, down to the smallest details, which is completely uncharacteristic of the slow-wave sleep phase.

With each subsequent cycle, the phases of slow and fast sleep alternate, which means that the latter has a longer and longer duration, however, its depth decreases. This happens to make it easier to get out of sleep cycles when you wake up. The prejudice that sleeping better in the morning than at night is wrong. By the third or fourth change of cycles of alternating sleep phases, it is much easier to wake a person.

The REM stage of sleep is unique in its own way. It is here that the exchange of data between consciousness and subconscious takes place, and what was thought about during dozing again enters consciousness, but now supplemented by various options that can happen.

REM sleep is usually divided into two stages: emotional and non-emotional. During the REM sleep phase, they can alternate several times, with the first phase always being slightly longer.

During REM sleep there is a significant change hormonal levels. According to researchers, it is REM sleep that promotes daily readjustment. endocrine system.

Thus, REM sleep seems to sum up all the mental activity of the brain for the whole day. Rest at this stage is necessary for a person so that he can adapt to possible options developments of yesterday's events.

This is why interrupting this phase sometimes leads to more undesirable consequences than interrupting slow-wave sleep. In this case, we are faced with the problem of not physical, but mental fatigue, leading to possible violations psyche. There is an opinion in the scientific community that if a person is deprived of REM sleep too often, it will undermine his psyche to such an extent that it can lead to death.

For the body, the fast phase is to some extent small stressful situation. The changes taking place in it are quite radical and can lead to some undesirable consequences. For example, most heart attacks, strokes and seizures occur during REM sleep. This is due, first of all, to the fact that the relaxed cardiovascular system is subjected to a sharp and sudden load.

It is impossible to say for sure which of the sleep phases - slow or fast - is better or more important, since each of them performs its own functions. If you try to imagine the entire dream in the form of a curved line, it will look like several “dives” into deep and slow sleep, followed by “ascents” into superficial, fast sleep. The time between such ascents and descents will be approximately one and a half to two hours.

According to physiologists, this one and a half hour time period is the main biorhythm of the human body; it manifests itself not only during rest, but also during wakefulness.

In an adult, the stages of night rest are distributed approximately according to the following ratios:

drowsiness - 12%;
sleep spindles - 38%;
delta sleep - 14%;
deep delta sleep -12%;
REM sleep - 24%.

The first four belong to the phase of slow-wave sleep, the last - to fast sleep. In addition, the phases of sleep are very different and do not replace each other immediately, but over the course of an intermediate state similar to drowsiness. It lasts about 5 minutes.

During the entire sleep period, 5-6 cycles of complete changes of all stages occur. The duration of the stages may vary slightly from cycle to cycle. At the end of the last cycles, the intermediate state is the most sensitive and leads to normal awakening.

Awakening is an individual process and lasts from several tens of seconds to three minutes. At this time, the final restoration of normal organ functions and the appearance of clarity of consciousness occurs.

The main differences between NREM and REM sleep

NREM and REM sleep are performed different functions. During each phase, the human body behaves differently. Often, the behavior of a sleeping person is purely individual, however, there are characteristics that are characteristic of all people, which are presented in the table.

Characteristic		Fast phase
State of the autonomic nervous system	Active work of the pituitary gland. Accelerated synthesis of most hormones	Inhibition of spinal cord reflexes. The appearance of fast brain rhythms. Increased heart rate. The emergence of a “vegetative storm”
Brain temperature	Decrease by 0.2-0.3°С	Increase of 0.2-0.4°C due to blood flow and increased metabolism
Breathing Features	Loud and deep, there is a lack of rhythm	Uneven, often rapid breathing with delays due to dreams
Eyeball movements	At the beginning of the phase - slow, at the end - almost absent	There is constant rapid movement
Dreams	Dreams are rare; if they exist, they are calm character. It's hard to remember them	Bright and rich pictures and dreams, as a rule, contain a lot of active actions. Well remembered
Awakening	Associated with a depressed state, a feeling of fatigue. Severe waking up due to incomplete chemical processes during the slow phase	Waking up at the beginning of the phase causes mental fatigue. In the end - light and fast, the body wakes up rested. In this case, the state is cheerful, the mood is good

Despite the rather large difference in the nature of the phases of slow and fast sleep, both have a deep physiological, functional and biochemical relationship and are the result of the joint work of the sympathetic and parasympathetic nervous systems.

Regulates slow-wave sleep internal rhythms brain areas and structures, fast contributes to their synchronization and harmonious functioning.

A dream, like all beautiful things, ends sooner or later. The physical and psycho-emotional state of a person depends on at what stage of sleep the awakening occurred.

The most unpleasant thing will be waking up in the slow phase, when she has entered deep stage. The best time awakening will be the interval between the end of REM sleep and the end of the first stage of the next cycle. Get up while active fast phase Not recommended.

If a person has slept well, then he is full of energy, cheerful and in high spirits. This often happens at the end of the dream.

During this period, his senses are activated, and the person responds well to external irritating factors that contribute to awakening:

Light from the window.
Sounds from the street or music.
Changes in ambient temperature.

If you wake up immediately, you will feel excellent. But, if you skip this time and take a nap a little more, the body can “drag” into another slow cycle.

We often wake up shortly before the alarm clock. This is not surprising: the body itself adjusts its “ internal clock“under the daily routine and the cycles occur in such a sequence that the fast phase ends at a time close to the moment the artificial clock operates.

If at this moment you tell yourself that such an awakening occurred ahead of schedule, then you can fall asleep again and wake up in a deep stage, ruining your entire next day.

Therefore, the best awakening is one that occurs independently, without any external factors. It doesn't matter what time it is. If the body symbolizes to us that it has had enough sleep, we cannot be deaf to such a message.

However, recently “ smart alarm clocks”, which are connected via wireless sensors to the human body. They read the body parameters and use them to determine the time of awakening - at the end of REM sleep or during the transition from it to an intermediate state.

In any case, even if waking up was easy, do not rush to jump out of bed. The body needs to be given a few minutes to adapt all its systems to the new day. The main thing in this process is not to fall asleep again, think about some idea, get ready for the new day and go ahead!

One of the most mysterious and significant processes occurring in our body is sleep. We spend a third of our lives in this state. Moreover, if you are deprived of night rest even for a short period of time, this is fraught with the development of neurotic disorders and disruption of important body functions.

Today, thanks to the colossal work of scientists, it has been possible to isolate and study in detail REM and NREM sleep. Each of these phases is accompanied by certain features, which we will discuss further.

Rest is the most important component of every person’s life. During this state, the body relaxes, and the brain processes the information received during the day. When the slow-wave sleep phase begins, the material received and studied is better consolidated in memory.

And the fast stage models upcoming events on a subconscious level. In addition, a long night's rest restores the immune system and activates lymphocytes to fight viral infections.

If you interrupt the rest, only one of the cycles will be realized, and accordingly the human body will not rest. This means that the performance of the brain will not be updated.

In addition, physiological processes such as:

fluid balance is restored;
the process of cleansing the body begins by removing excess moisture;
collagen protein is synthesized, which helps strengthen skin and joints;
the body absorbs calcium.

Each of these processes is characterized by duration. For this reason, the question arises of how long it takes for the body to fully recover. If you sleep 8 hours daily, a person will feel rested.

Physiology of human sleep

Daily night's rest is vital for the human body. Moreover, sleep in some situations is much more important than food. Just a couple of sleepless days provoke the appearance of the following symptoms:

irritability;
emotional instability;
a person develops memory lapses;
lack of sleep provokes mental retardation;
depression develops.

Important: If a person spends about 11 days without a night's rest, irreversible processes begin in his body, leading to death.

Normally, an adult should sleep from 4 to 8 hours. Moreover, such data are comparative, since it is necessary to take into account the ratio of human fatigue. If a large amount of physical activity is received during the day, it is recommended to increase the time of physiological rest.

Features of the slow phase

NREM sleep is classified into 4 stages, such as:

nap;
sleep spindles;
delta sleep;
Delta sleep is deep.

Nap

When a person enters a state of drowsiness, he revises ideas and replays current situations that appeared during the day. In addition, the brain looks for the right solutions to the current situation. In most cases, a person has dreams in which he sees a definition of the current problem.

Sleep spindles

After the drowsiness phase comes sleep spindles. This stage is characterized by alternating subconscious shutdown and auditory receptivity.

Delta sleep

This phase is called transition to deep sleep.

Delta sleep deep

This stage is characterized by the following factors:

dullness of energy;
heavy lifting;
inability to wake up a sleeping person.

The deep phase in question begins an hour and a half after going to bed.

Important: Slow sleep is important for the human body. It regulates the rhythms of brain areas and structures. And fast, helps to synchronize and promotes their harmonious work.

When immersed in a slow cycle, the body's activity slows down and it is difficult to wake a person. And with the onset of the deep stage, rapid heartbeat and breathing are observed. At the same time, the pressure drops.

A slow night's rest is important because significant processes occur during this time, such as:

cells are restored;
the condition of internal organs improves;
the human body becomes healthier.

The duration of slow-wave sleep is about 75% of the total rest. And about 25% comes from a quick night's rest.

Below will be presented comparison table fast and slow sleep, where you can clearly see how the phases change and compare these data with your own.

Features of the fast phase

The fast phase is also called fast-wave or paradoxical, and it has a number of distinctive features:

the dream seen is clearly remembered;
good respiratory rate;
muscle tone decreases;
the muscles located in the neck area stop moving.

Important: When a new cycle begins, a quick night's rest has a longer duration. However, its depth is less.

In addition, a quick night's rest has two cycles:

emotional;
unemotional.

During a quick night's rest, information received the day before is processed and exchanged between the subconscious and the mind. This type of sleep is necessary for the brain to adapt to all changes occurring in the surrounding space. Moreover, if this phase of night rest is interrupted, a violation of the human psyche may occur.

Differences between cycles

What is the difference between slow-wave sleep and REM sleep? As mentioned above, the slow resting phase has 4 stages, and the fast resting phase has only two. In addition, there are a number of other differences. We invite you to familiarize yourself with them in the comparative table below:

during slow-wave sleep, at the beginning the eye movements are smooth, and at the end they freeze, when during the fast phase the eyes move constantly;
during slow cycle human body grows faster because growth hormone is produced during this period;
dreams have a different character;
during the fast phase, he wakes up easier and feels well-rested in contrast to the slow phase;
breathing in the phase of slow night rest may be delayed, but during REM sleep a person breathes frequently, because this is how he reacts to dreams;
Temperature indicators of the brain decrease with a slow degree; with a fast degree, the opposite happens: blood flow increases and the temperature rises.

Despite the differences, REM and NREM sleep are interconnected and are considered one balanced system. For comparison, during the slow phase the functioning of the structures of internal organs is regulated. And during the fast cycle, a harmonious establishment of relationships between the cells of the human body occurs.

Best time to wake up

Sooner or later, rest ends and the need to awaken comes. However, it is important to emphasize that a person’s condition directly depends on at what stage of the night’s rest the awakening occurred.

As a rule, the deep stage of slow-wave sleep is considered a negative time to wake up. And the most optimal time for awakening is considered to be the interval between the end of the rapid stage of sleep moving into the first stage of the next stage.

Important: If a person is fully rested, he is full of energy and will be in a good mood. As a rule, such a state is guaranteed if you wake up after the end of your dreams.

When the REM sleep phase begins, at this moment all senses are activated, and accordingly a person responds well to external factors that contribute to his awakening, such as:

light coming through the curtains;
extraneous sounds coming from outside;
changes in ambient temperature indicators.

If you wake up at this moment, the health of both the man, woman, and child will be excellent. But, it’s worth taking a little nap and the person already gets up exhausted. This happens when the body enters another slow cycle.

Important: Even if awakening happened easily and positively, do not rush to jump out of bed. Give your body some time to adapt its systems to the coming day. At the same time, be careful not to fall asleep again.

As a rule, all people wake up before the alarm clock rings. This is because the body has The biological clock, which adapt to a person’s daily routine. Therefore, if you wake up before the scheduled time, do not rush to fall asleep again, otherwise you will plunge into a deep stage and ruin your entire day.

The optimal time to wake up is considered to be the period when you woke up on your own and the body itself signaled that you had enough sleep. Then there will be no need to calculate when it is better to wake up.

What are the consequences of insomnia?

Often both sleep cycles are disrupted for certain reasons. Moreover, many people, having a similar problem, do not even realize that the duration of their night's rest is insufficient. But lack of sleep has a negative impact on general condition body with the following symptoms:

a person is worried about fatigue, apathy and lethargy appear;
mood has frequent changes, attacks of irritability and tearfulness often occur;
the immune system decreases;
memory is impaired;
body weight increases;
the endocrine system malfunctions.

The human body gradually starts the process of self-destruction. In addition, mental disorders are becoming more pronounced. And if you don’t start in a timely manner curative therapy, the consequences can be catastrophic.

How to get rid of insomnia

If your rest at night is disturbed, you should not self-medicate. First you need to identify the reason that provoked this failure, then direct efforts to eliminate it. Sometimes our body gives signals in the form of insomnia about the development of pathology.

Therefore, consultation with a doctor and examination is mandatory. Moreover, sometimes such a violation is even useful. After all, with its help it is possible to promptly identify the development of a dangerous pathology.

As for treatment methods, there are several of them:

drug treatment;
eliminating the problem with special gymnastics or sports;
surgical intervention;
visiting a psychotherapist;
nutrition correction;
maintaining sleep hygiene;
competent planning of the daily routine.

Having eliminated the true cause of sleep disturbance, slowly and fast cycle will come back to normal.

And in conclusion, it is worth noting that a healthy night's rest is of great importance in a person's life, regardless of his age. At this time, you calm down nervous system and gain positive emotions for the coming day. And remember, it doesn’t matter how long the rest lasts. The main thing is to feel energized in the morning.

Night rest is divided into periods that differ in the processes taking place. Deep sleep is important, and an adult's rate determines how deeply a person sleeps. From the article you will learn the features and duration of the slow phase.

Night rest is cyclical and is divided into 2 phases: slow and fast. Slow is a deep period from which a healthy person begins to fall asleep. The functioning of organs slows down, they go into a state of rest, the body partially switches off, rests and recovers. Then comes the fast phase, during which the brain works and the sleeper dreams. Muscle contractions, spontaneous movements of the limbs, and movements of the eyeballs are observed.

Night rest includes several cycles, each consisting of a slow and a fast period. Total cycles – 4-5, depending on the total duration of sleep. The first slow phase lasts maximum amount time, then it begins to shorten. Fast period, on the contrary, increases. As a result, the percentage at the time of awakening changes in favor of the fast phase.

Duration and norms

How long should a person sleep deeply at night? Average duration within one cycle can range from 60 minutes to 1.5-2 hours. The normal duration of the slow phase is 40-80 percent rest. The fast period will last 20-50%. The longer the slow phase goes on, the better man If he manages to get enough sleep, he will feel more rested and alert.

It’s clear how long deep sleep lasts, but how to calculate the duration? It will not be possible to take measurements with a watch or other usual measuring instruments, even for a person next to the sleeper: it is difficult to determine when the slow phase begins and ends. An electroencephalogram, which detects changes in brain activity, will allow you to get accurate results.

The rate of deep sleep depends on the person’s age. Average indicators for different age categories It’s easy to estimate if you make a table:

Age	Length of night rest	Duration of the slow deep phase
Newborn, one month old baby	16-19 hours	10-20%
Infant age (2-6 months)	14-17 hours	10-20%
One year old child	12-14 hours	20%
Child of two or three years old	11-13 hours	30-40%
Children 4-7 years old	10-11 o'clock	Up to 40%
Teenagers	At least 10 hours	30-50%
Adult aged 18-60 years	8-9 hours	Up to 70%
Elderly man over 60 years old	7-8 hours	Up to 80%

Good to know! In children, the brain goes through a formative stage, so biological rhythms and processes differ from those characteristic of adults. In infants, the duration of the slow period is minimal, but gradually it begins to increase. Global changes occur until approximately two or three years of age.

Slow Phase Stages

The slow-wave period of sleep, called deep sleep, is divided into four stages:

Drowsiness – the beginning of falling asleep, followed by severe drowsiness, obvious desire to sleep. The brain functions and processes the information received. Dreams are possible, intertwined with reality, repeating events seen during the day.
Falling asleep, shallow sleep. Consciousness gradually turns off, brain activity decreases, but it continues to respond to external stimuli. At this stage, it is important to provide a comfortable, calm environment, since any sound can provoke awakening and prevent you from falling asleep and staying asleep.
Deep sleep stage. Brain activity is minimal, but weak signals pass through electrical impulses. Reactions and processes occurring in the human body slow down and fade away, muscles relax.
Delta sleep. The body is relaxed, the brain does not react to external stimuli, the temperature drops, breathing and blood circulation slow down.

Features and significance of the slow phase

How important is the slow phase? When a person falls asleep deeply, he is fully rested. Night is the time for the body to recover, which takes place in a slow phase. The energy resources and reserves necessary for full life activity are replenished. The muscles relax and rest after prolonged work, tension and intense exercise. The brain practically turns off, which allows you to systematize the information received during the day and record it in memory. Cell regeneration occurs, which slows down the natural aging process.

If there is deep sleep, the brain stops responding to stimuli, including sounds. It is not easy to wake a person, which is important for proper rest. If the duration of the fast phase begins to increase, the sleeper will wake up from sounds, his own involuntary sleepy actions, or the movements of the person lying next to him.

A complete, healthy and normally occurring deep period of rest helps strengthen the immune system and improve the functioning of the immune system. This is important for a frequently ill child, a weakened elderly person, during illness and during the recovery stage.

Important! The state of the human body, health and intellectual abilities depend on the duration of deep sleep. Therefore, a good night's rest becomes necessary before important events, during illness or during the rehabilitation period.

Changes occurring in the body

During deep good sleep A number of changes are observed in the human body:

Restoration of body tissue cells. They are regenerated, renewed, damaged organs strive for a physiologically correct state.
Synthesis of growth hormone, which triggers catabolism. During catabolism, protein substances are not broken down, but are formed from amino acids. This helps restore and strengthen muscles, form new healthy cells, for which proteins are building elements.
Restoration of intellectual resources, systematization of information received during the waking period.
Reducing the frequency of inhalations. But they become deep, which avoids hypoxia and ensures oxygen saturation of the organs.
Normalization of metabolic processes, stabilization of reactions occurring in the human body.
Replenishment energy reserves, restoration of the necessary performance.
Reducing heart rate, helping the heart muscle to recover and contract actively during the next day.
Slowing of blood circulation due to decreased heart rate. The organs are at rest and the need for nutrients decreases.

Causes of deep sleep phase disorders and their elimination

Changes in the duration of deep sleep are possible. It lengthens with rapid weight loss, after intense physical activity, with thyrotoxicosis. The period is shortened in the following cases:

mild or moderate condition alcohol intoxication(heavy things make sleep deep, but disrupt it: it is difficult to wake up a drunk person, although rest is not complete);
stress experienced during the day;
emotional and mental disorders: depression, neuroses, bipolar disorder;
overeating, eating heavy food at night;
diseases that are accompanied by discomfort and painful sensations, worse at night;
unfavorable rest conditions: bright light, sounds, high or low humidity, uncomfortable room temperatures, lack of fresh air.

To eliminate sleep disorders, identify the causes and act on them. Sometimes a change in daily routine, a change in the area of activity and normalization is enough emotional state. In case of illness, the doctor must prescribe treatment after a comprehensive examination. For severe mental disorders Antidepressants and psychotherapy are recommended.

To increase the duration of the slow phase and make deep sleep long, sound and healthy, somnologists recommend following the following tips:

You will achieve an increase in the slow phase if you establish and follow a daily routine and maintain a balance of rest and wakefulness.
Try increasing your physical activity. Light exercise before bed would be a good idea.
To increase the slow phase, give up bad habits.
Provide comfortable conditions in the bedroom: ventilate it, cover the windows with thick curtains, close the door and protect yourself from extraneous sounds.
To increase the duration of the slow phase, do not overeat before bed, limit yourself to light snacks.

In the slow phase, sleep disorders appear: nocturnal enuresis(involuntary urination), sleepwalking, sleep talking.
If a person who is fast asleep and in a deep sleep phase is suddenly awakened, he will not remember his dreams and will feel drowsy and lost. This is confirmed by people's reviews. At the same time, dreams can be dreamed, but it will not be possible to reproduce them and interpret them with the help of a dream book.
Experiments have proven that artificially eliminating the slow-wave sleep phase is tantamount to a sleepless night.
Each person has individual norms and sleep characteristics. So, Napoleon needed 4-5 hours, and Einstein slept for at least ten hours.
A relationship has been established between deep sleep, the functioning of the endocrine system and body weight. When the slow phase is shortened, the level of growth hormone responsible for growth decreases, which provokes a slowdown in muscle development and an increase in fat (mainly in the abdominal area).

The norms for deep sleep depend on age and lifestyle. But following some recommendations and an optimal nighttime routine will allow you to sleep soundly and feel refreshed after waking up.

Is physiological process, in which a person (as well as mammals, fish, birds and some insects) is in a state radically different from the waking state. This condition characterized by altered consciousness, decreased level brain activity and reactions to external stimuli. Natural sleep is significantly different from such similar states as coma, suspended animation, fainting, sleep under the influence of hypnosis and lethargic sleep. Along with sleep in the usual sense of the word (i.e. sleep at night), certain cultures allow the existence of the so-called daytime rest or siesta. Short naps during the day are part of the traditions of many peoples. According to the results of ongoing research, regular afternoon naps can significantly reduce (by almost 40%) the risk of a heart attack. In a word, sleep is the most important element of human life and, at the suggestion of researchers, since 2008, every 3rd Friday of the first month of spring is celebrated as Sleep Day.

Basic functions of sleep

Thanks to sleep, the body receives the necessary rest. During sleep, the brain processes the information accumulated during the day. The so-called slow sleep allows you to better assimilate the studied material and consolidate it in memory. REM sleep provides the ability to simulate upcoming events at the subconscious level. Important function sleep is also the restoration of the human immune system by activating the activity of T-lymphocytes that resist viral infections and fight colds.

Physiology of the sleep process

Healthy sleep can last from 4 to 8 hours. However, these indicators are quite subjective, since the duration of sleep depends on physical fatigue person. A significant amount of work done during the day may require a longer night's rest. Normal sleep is cyclical and required to the human body at least once a day. Sleep cycles are called circadian rhythms. Every 24 hours, circadian rhythms are redefined. The most important factor during sleep, illumination is considered. The concentration of photodependent proteins in the body depends on its natural cycle. Usually, circadian cycle correlates with the length of daylight hours. Just before sleep sets in, a person feels drowsy and brain activity decreases, and a change in consciousness is also noted. In addition, a person who is in a sleepy state has a decrease in sensory sensitivity, a reduction heart rate, yawning, and also a decrease in the secretory function of the lacrimal and salivary glands. One more physiological feature sleep is a process called “vegetative storm”, i.e. when various forms of arrhythmias are observed, an increase or decrease in blood pressure, increased blood supply to the brain and secretion of the adrenal glands, erection of the clitoris and penis.

Structure of the sleep process

Any sleep is divided into several stages, which are repeated with a certain pattern throughout the night (naturally, provided that the daily schedule is absolutely normal). Each stage of sleep directly depends on the activity of one or another brain structure. The first stage of sleep is slow-wave sleep (Non-REM). The duration of Non-REM sleep is 5 to 10 minutes. This is followed by the second stage, lasting approximately 20 minutes. Over the next 30-45 minutes, another 3 and 4 stages of sleep are observed. Next, the person again falls into the second stage of slow-wave sleep, at the end of which rapid REM sleep occurs (episode 1). This is approximately 5 minutes. All of the above stages are the first sleep cycle, which lasts from 90 to 100 minutes. After this, the cycle repeats again, but at the same time the stages of slow-wave sleep are reduced, and REM sleep, on the contrary, increases. Typically, the last sleep cycle ends with an episode of REM sleep, lasting in some cases about 1 hour. Full sleep includes 5 full cycles. The sequence in which one stage of the sleep cycle follows another, as well as the duration of each cycle, is usually presented in the form of a hypnogram. The sleep cycle is regulated by certain areas of the cerebral cortex, as well as the locus coeruleus, located in its trunk.

What is slow wave sleep?

NREM sleep (also called orthodox sleep) lasts 80 to 90 minutes and occurs immediately after a person falls asleep. The formation and development of slow sleep is ensured by the anterior parts of the hypothalamus, raphe nuclei, nonspecific nuclei of the thalamus and middle part bridge (the so-called Moruzzi brake center). At the first stage of slow-wave sleep, the alpha rhythm decreases, transforming into slow low-amplitude theta rhythms, equal in amplitude to the alpha rhythm or exceeding it. The person is in a state of drowsiness (half-asleep), and dream-like hallucinations are observed. Muscle activity decreases, heart rate and breathing decrease, metabolic processes slow down, and the eyeballs move slowly. At this stage of sleep, solutions to problems that seem unsolvable during wakefulness are intuitively formed. By at least, the illusion of their existence may arise. The first stage of slow-wave sleep may also include hypnogogic jerks.

In the second stage of Non-REM sleep (this is usually light and shallow sleep), a further reduction in muscle activity occurs, the heart rate slows down, body temperature drops, and the eyes become motionless. The second stage is approximately up to 55% of the total sleep time. The first episode of the second stage lasts approximately 20 minutes. The electroencephalogram shows at this moment the predominant theta rhythms and the emerging sigma rhythms (the so-called “sleep spindles”), which are essentially rapid alpha rhythms. At the moment of the appearance of sigma rhythms, consciousness turns off. However, during pauses between sigma rhythms, which occur at a frequency of 2 to 5 times per minute, a person can be easily awakened.

At the third stage of slow-wave sleep, the total number of delta rhythms is no more than 50%. At the fourth stage this figure exceeds 50%. The fourth stage is slow and deep sleep. Quite often stages III and IV are combined and called delta sleep. It is extremely difficult to wake a person during delta sleep. Dreams usually appear at this stage (up to 80%). A person may begin to talk, sleepwalking is possible, nightmares may occur and enuresis may develop. At the same time, a person usually does not remember any of the above. The third stage lasts from 5 to 8% of the total sleep time, and the fourth stage takes from 10 to 15% of the entire sleep period. The first four stages of slow-wave sleep normal person last from 75 to 80% of the total duration of this physiological process. According to researchers, Non-REM sleep provides full recovery energy expended per day. In addition, the slow-wave sleep phase allows you to record conscious memories of a declarative nature in your memory.

What is REM sleep?

Rapid eye movement sleep is also called REM sleep, paradoxical sleep, or rapid wave sleep. In addition, the generally accepted name is the REM (rapid eye movement) stage. The REM stage lasts 10 to 15 minutes and follows non-REM sleep. REM sleep was discovered in 1953. The centers responsible for REM sleep are: the superior colliculus and the reticular formation of the midbrain, the locus coeruleus, as well as the nuclei (vestibular) of the medulla oblongata. If you look at the electroencephalogram at this moment, you can see quite active fluctuations in electrical activity, the values of which are as close as possible to beta waves. During REM sleep, the electrical activity of the brain is almost identical to the waking state. However, at this stage the person is completely motionless, since his muscle tone is zero. At the same time, the eyeballs actively move under closed eyelids, moving quickly with a certain periodicity. If you wake up a person in the REM stage, there is a 90% chance that he will report an exciting and vivid dream.

As noted above, the electroencephalogram of REM sleep reflects the activation of brain activity and is more reminiscent of the EEG of the first stage of sleep. The first episode of the REM stage lasts from 5 to 10 minutes and occurs 70-90 minutes after the person falls asleep. Throughout the entire sleep period, the duration of subsequent episodes of REM sleep becomes increasingly longer. The final episode of REM sleep can last up to 1 hour. The duration of REM sleep in a healthy adult is approximately 20-25% of the total sleep time. From one cycle to the next, the REM sleep phase becomes longer and longer, and the depth of sleep, on the contrary, decreases. Disturbances of slow-wave sleep are not as severe for the psyche as interruption of the REM phase. If any part of REM sleep is interrupted, it must be replenished in one of the subsequent cycles. Experiments conducted on mice have proven the detrimental effect of the missing REM phase on these mammals. After 40 days, the mouse deprived of REM sleep died, while the rodents deprived of slow-wave sleep continued to live.

There is a hypothesis that during the REM phase, the human brain works to organize the information received during the day. Another theory is that REM sleep is especially important for newborns, providing neural stimulation that promotes the formation and development of the nervous system.

Sleep duration

Duration normal sleep can vary from 6 to 8 hours per day. However, this does not exclude large deviations in one direction or another (4-10 hours). If sleep disturbances are observed, then its duration can be equal to several minutes or several days. When the duration of sleep is less than 5 hours, this is considered a violation of its structure, which can lead to the development of insomnia. If you deprive a person of sleep, then within a few days his consciousness will lose clarity of perception, an irresistible urge to sleep will appear, and “dips” into the so-called borderline state between sleep and wakefulness will be observed.

Dreams

Along with the corresponding physiological process, the word “sleep” also means a sequence of images that arise in the REM sleep phase and, in some cases, are remembered by a person. A dream is formed in the consciousness of a sleeping person, consisting of a variety of subjectively perceived tactile, visual, auditory and other images. Usually the person who is dreaming is not aware that he is in a dream state. As a result, the dream is perceived by him as an objective reality. An interesting type of dreams are lucid dreams, in which a person understands that he is dreaming and therefore can control the development of the plot in the dream. It is believed that dreams are inherent in the REM sleep phase, which occurs once every 90-120 minutes. This phase is characterized by rapid movement of the eyeballs, increased heart rate and breathing, stimulation of the pons, as well as short-term relaxation of skeletal muscles. According to the results of recent research, dreams may also be characteristic of the slow-wave sleep phase. At the same time, they are less emotional and do not last as long as REM dreams.

Sleep pathologies

All kinds of sleep disorders are quite common. For example, the cause of insomnia (insomnia) can be psychosis, depression, neurosis, epilepsy, encephalitis and other diseases. Apnea is a breathing disorder of a sleeping person, the causes of which can be mechanical or psychogenic in nature. Parasomnias such as sleepwalking, nightmares, epilepsy and teeth grinding are formed and develop on the basis of neurosis. Pathologies such as lethargic sleep, narcolepsy and sleep paralysis are among the most severe disorders sleep. In case of any alarming factors associated with obvious deviations in the structure of sleep, you should seek help from a specialist.

Pharmacological hypnotics

Sleep regulation using pharmacological agents must be carried out under the supervision of a physician. Along with this, it should be remembered that long-term use of sleeping pills reduces the effectiveness of the latter. Relatively recently, the group of sedatives even included drugs - morphine and opium. Barbiturates have also been used as sleeping pills for quite a long time. One of the most progressive this moment melatonin is considered a drug. An equally effective treatment for insomnia is taking magnesium supplements, which improve sleep and promote the production of melatonin.

Sleep Study

According to prominent researchers of the past and present, sleep plays a more important role for the human body than food. In the second half of the 20th century, technologies for recording the activity of muscles (EMG), brain (EEG) and eyes (EOG) were developed, after which it was possible to formulate ideas about the structure of sleep and its nature, which no one has yet refuted .