Phases of human sleep. Sleep disturbance. Causes, types of disorders and methods of treatment, structure of normal sleep How long does slow and fast sleep last?

Sleep is one of the most mysterious processes that occur in the human body. And one of the most significant, since we spend almost a third of our lives sleeping. And complete sleep deprivation, even for a relatively short period of time of a few days, can lead to neurotic disorders and imbalance of the entire body. Sleep is a very complex process in which brain activity changes and vital important functions body. Scientists were able to identify the phases of slow and fast sleep, which have their own characteristics and purposes.

A little history

They tried to study sleep back in Ancient Greece. True, the explanation of what was happening at that time was more mystical than scientific. It was believed that during sleep, the immortal soul could rise to higher spheres and even descend to the kingdom of the dead. Slightly modified, this interpretation of sleep lasted in scientific circles until the mid-19th century.

But even after scientists established that sleep is caused by the functioning of the human nervous system and brain and has nothing to do with the immortal soul, it was impossible to conduct full-fledged research due to the lack of suitable equipment. It was only in the second half of the 20th century that it became possible to record nerve impulses emanating from muscles and the brain, which made it possible to determine the level of their activity.

A lot of things have been done with the help of electrical appliances in the field of sleep. important discoveries. Rapid and slow-wave sleep were discovered, various types of insomnia were studied, and the processes occurring in the body during lethargic sleep were studied.

Scientists were able to reveal that human activity is regulated by circadian rhythms - daily alternations of periods of sleep and wakefulness, which continue to work even if it is impossible to navigate in time due to the lack of clocks and sunlight.

Computed tomography and magnetic resonance imaging have made it possible to study in more detail the brain activity that occurs during fast and slow sleep looks completely different. Interesting processes happen to a person when falling asleep, when the body and brain begin to slowly switch off and plunge into a state of deep relaxation, but at the same time certain parts of the brain continue to work.

But the most ambitious discovery was that the reactions of the brain and body to a vivid dream that a person sees in the REM phase are practically no different from reactions to real events. This means that a person literally “lives” his dream physically and mentally. But first things first.

Falling asleep

A person who wants to sleep is always easy to recognize, even if he tries to somehow hide his condition. Signs of drowsiness include:

A sleepy person begins to stretch, rub his eyes, and turn around in search of a position comfortable for falling asleep. This condition is associated with an increase in the concentration of a special hormone in the blood - melatonin. It gently inhibits the activity of the nervous system, promoting deeper relaxation and speeding up the process of falling asleep.

The hormone has virtually no effect on the quality of sleep itself. Melatonin is only a natural regulator of circadian rhythms.

The process of falling asleep in a healthy adult lasts from 20 to 40 minutes. If it takes more than an hour to fall asleep, we can talk about the presence of one of the many forms of insomnia and it is better to take measures to eliminate it before it becomes chronic. Natural products can help with this sedatives, taking additional doses of melatonin or proven folk remedies.

Slow phase

Having gone through the stage of falling asleep, a person plunges into slow-wave sleep. It gets its name from the slow rotation of the eyeballs that can be observed in a sleeping person. Although it's not just them. During slow-wave sleep, everything vital functions the body is slowed down - the body and brain relax and rest.

As they studied this phase, scientists made more and more new discoveries. As a result, it was discovered that in infants slow sleep has only two stages, and in children over 1-1.5 years old and adults - as many as four, through which the body sequentially passes:

All four stages slow phase It takes about an hour and a half, plus or minus 10 minutes. Of this, approximately a fifth of the time is occupied by deep and very deep sleep, and the rest is superficial.

Moreover, a person usually goes through the first stage of slow-wave sleep only after falling asleep, and when slow and slow sleep alternate during the night REM sleep, she “falls out”.

Fast phase

Scientists have not fully figured out what REM sleep is, how such strange processes can occur in the body, and what significance it has for humans. If everything is more or less clear with slow sleep - this is a period of active recovery of the body and complete relaxation, then the reactions of the brain and the vital functions of the body during REM sleep are completely different.

During REM sleep eyeballs under closed eyelids, people begin to move quickly along a chaotic trajectory. From the outside it seems that a person is closely watching something. In fact, this is so, since it is in this phase that dreams appear. But eye movement is not the only and far from the main difference between REM sleep.

What was seen on the encephalogram, and later on the brain tomogram during fast phase scientists were so amazed that it received another name “ paradoxical dream" All readings during this period may be practically no different from those taken in a state of active wakefulness, but at the same time the person continues to sleep:

In fact, the entire body is “turned on” in the dream as if it were a real event, and only the person’s consciousness is turned off. But if you wake him up at this moment, he will be able to tell the plot of the dream in great detail and at the same time will experience emotional experiences.

Interestingly, it is during REM sleep that changes occur hormonal levels. Some scientists believe it is necessary for emotional "reset" and balancing endocrine system.

Having experienced exciting events again during sleep, a person then sends these memories to the subconscious, and they stop bothering him.

REM sleep also helps in regulating the level of sex hormones. Nocturnal erections, wet dreams and spontaneous orgasms occur during this phase. Moreover, they are not always accompanied by dreams of an erotic nature.

At the same time, most heart attacks or strokes occur, due to the fact that the relaxed heart and blood vessels are subjected to sudden stress.

At the beginning of the night, the fast phase does not last long - from 5 to 10 minutes, and most A person spends time after falling asleep in slow-wave sleep. But in the morning the phase relationship changes. The periods of REM sleep become longer and longer, and the periods of deep sleep become shorter and shorter, and at one point the person wakes up.

Proper awakening

An interesting fact is that a person’s activity and condition, especially in the first half of the day, depends on how he woke up. If he is awakened by external stimuli (alarm clock, bright light, sharp sounds, shock) during the slow phase of sleep, he still needs some time to “come to his senses.” In the first seconds, he may not even understand where he is, some parts of the brain are still so inhibited.

It is a completely different matter if the awakening occurs during REM sleep. The body is already alert and active, you just need to turn on your consciousness. A person who wakes up in this phase feels great, can quickly get out of bed and go about his business. At the same time, he perfectly remembers the last dream and can write it down or retell it.

The modern rhythm of life places high demands on the level of physical activity. Perhaps this is why recently so-called “smart alarm clocks” have become increasingly popular, which read the body’s readings and send a signal just in the stage of REM sleep.

The advantage of such a device is that it greatly facilitates awakening, but the disadvantage is that it can wake a person up 20-30 minutes before the set time, since it begins to track sleep phases in advance, calculating the appropriate moment.

But even if you woke up easily, doctors do not advise jumping out of bed right away. Give the body 5-10 minutes for all organs and systems to smoothly start working. Stretch, lie down, tune in to the new day, go over your plans in your head again. And when you feel that you are completely ready for active actions, get up and move on to your morning routine.

Prevention of insomnia

Healthy quality sleep is considered to be a state in which a person quickly falls asleep and smoothly moves from one phase to another, waking up at the end of the night at his usual time on his own, without an alarm clock. Unfortunately, few people can boast of this today. Chronic fatigue, stress, poor nutrition, negative emotions greatly reduce the quality of sleep and are becoming increasingly common causes of chronic insomnia.

To avoid this problem and the multiple troubles associated with it - from neuroses to serious psychosomatic diseases, try to take at least basic measures that can ensure normal quality of sleep:

And most importantly, do not reach for sleeping pills even if you have been unable to fall asleep for several nights in a row. Similar drugs They quickly become addictive and in most cases deprive a person of the rapid phase of sleep.

Under the influence of a sleeping pill, a “heavy”, very deep sleep without dreams occurs, which is very different from normal - after it the person still feels broken.

If problems with falling asleep or frequent awakenings at night have become protracted, you are often tormented by nightmares, or your loved ones talk about you walking at night, go to the doctor. The problem cannot be solved without finding out the cause that provoked it. And this can only be done after examination and consultation with several specialists: a neurologist, an endocrinologist, a somnologist.

But in most cases, temporary insomnia occurs as a result of stress or severe fatigue and can be easily dealt with using folk remedies: warm baths, milk at night, relaxing massage, aromatherapy. No less important is positive attitude. You can significantly improve the quality of your sleep simply by weaning yourself from thinking about problems in the evenings.

2013-03-05 | Updated: 2018-05-29© Stylebody

Scientists have long proven that good sleep, which includes two main phases - slow and fast - is extremely important for human health and well-being. And this fact must be taken into account when creating a daily routine. There is an old folk saying that states that “the morning is wiser than the evening.” And indeed, to accept important and complex solutions It's much easier in the morning than at night. In addition, each of us has noticed how lack of sleep affects well-being and performance. A sleepless night can lead to not only a sharp decline mental activity, but also headache, weakness, weakness and other unpleasant symptoms.

Physiology of sleep

The human body is designed in such a way that all processes occurring in it are tied to a certain daily time and largely depend on the change of day and night. Sleep and wakefulness constantly alternate between each other and occur at approximately the same time. And if normal rhythm sleep-wakefulness is suddenly disrupted, this has the most negative impact on the work of various human systems and organs. From chronic lack of sleep First of all, the nervous and immune system, which can lead to the gradual disabling of the entire organism.

Wakefulness and sleep are two opposite and, at the same time, interconnected states. When a person does not sleep, he actively interacts with the environment: he eats, exchanges information, and so on. During sleep, on the contrary, there is an almost complete disconnection from the outside world, although important processes in the body itself do not stop. It is estimated that sleep and wakefulness are in a 1:3 ratio, and any deviation from this norm is dangerous to health.

Scientists have been able to record changes that occur in the human brain during sleep using a research method such as electroencephalography. It allows you to make a graphic recording in the form of waves, the decoding of which provides information about the quality of sleep and the duration of its different phases. This method is mainly used for diagnosis various violations sleep and to determine their degree negative influence on the body.

When the mechanism that regulates the frequency of sleep and wakefulness is disrupted, various pathological conditions, such as narcolepsy (an irresistible desire to fall asleep that occurs during the day), as well as hypersomnia (an exaggerated need for sleep when a person sleeps much more than normal).

Sleep is characterized by a quality called cyclicity. Moreover, each cycle lasts an hour and a half on average and consists of two phases - slow and fast. For a person to get enough sleep, four to five such cycles must pass. It turns out that you need to sleep at least eight hours a day.

The main differences between the phases are:

Duration The predominant phase is the slow phase. It takes up approximately 80% of the time of the entire sleep process and, in turn, is divided into four stages. The fast phase takes significantly less time, and its duration increases in the morning, closer to awakening. Purpose The purpose of sleep phases is different. During the slow phase they are restored internal organs, the body grows and develops. The fast phase is needed to activate and regulate the nervous system, to organize and process accumulated information. During REM sleep, children develop the most important mental functions - which is why in childhood we so often see vivid, memorable dreams.

Brain activity The differences between the slow and fast phases in terms of brain activity. If during slow-wave sleep all processes in the brain slow down significantly, then in the REM sleep phase they, on the contrary, are extremely activated. That is, a person is sleeping, and his brain is actively working at this time - that’s why REM sleep is also called paradoxical. Dreams People see dreams throughout the entire cycle, but those dreams that occur during the fast phase are better remembered. The dynamics of dreams also strongly depend on the phase - the slow phase is characterized by restrained dreams, during the fast phase they are more vivid and emotional. Therefore, it is morning dreams that most often remain in memory after waking up.

How does the sleep process proceed?

When a person becomes drowsy and falls asleep, the first stage of non-REM sleep begins, lasting a maximum of ten minutes. Then, as the second, third and fourth stages occur, sleep becomes deeper - all this lasts approximately 1 hour 20 minutes. It is the fourth stage of the first phase that is characterized by such well-known phenomena as sleepwalking, talking in sleep, nightmares, and childhood enuresis.

Then, for a few minutes, there is a return to the third and second stages of slow-wave sleep, after which the fast phase begins, the duration of which in the first cycle does not exceed five minutes. At this point, the first cycle ends and the second cycle begins, in which all phases and stages are repeated in the same sequence. In total, four or five such cycles change per night, and each time the REM sleep phase becomes longer and longer.

In the last cycle, the slow phase may be exceptionally short, while the fast phase is predominant. And it’s not for nothing that nature intended it this way. The fact is that waking up during REM sleep is very easy. But if a person is woken up when slow-wave sleep is in full swing, he will feel exhausted and sleep-deprived for a long time - one can say about him that he “got off on the wrong foot.”

NREM sleep phase (4 stages)

Stage	Description	Duration
Nap	The pulse and breathing slow down, the eyes move slowly under closed eyelids. Consciousness begins to float away, but the mind still continues to work, so at this stage people often come to interesting ideas and solutions. In a state of drowsiness, a person wakes up relatively easily.	No more than 5-10 minutes.
Sleep spindles	The name of the second stage of slow-wave sleep is associated with the encephalogram graph. During this period, the human body relaxes, but the brain still remains sensitive to everything that happens around it and reacts to the words and sounds heard.	Approximately 20 minutes.
Delta sleep	This stage precedes deep sleep. Characterized by a slight increase in heart rate, breathing is also rapid, but shallow. Blood pressure drops, eye movements become even slower. At the same time, active production of growth hormone is observed, blood flows to the muscles - thus the body restores energy costs.	About 15 minutes.
Deep dream	At this stage, consciousness is almost completely turned off, the eyes stop moving, breathing becomes slow and shallow. A person sees dreams of neutral, calm content, which are almost never remembered. Waking up in time deep sleep can only be forced and occurs with great difficulty. A person awakened at this stage feels overwhelmed and lethargic.	From 30 to 40 minutes.

REM sleep phase

When a person enters the REM phase of sleep, it can be seen even from the outside. His eyeballs begin to move actively, his breathing either quickens or slows down, and facial movements may be noticeable. The devices record a slight increase in body and brain temperature, increased cardiovascular activity. During this phase, the process of exchanging information accumulated during wakefulness between consciousness and subconscious occurs, and the energy that the body managed to accumulate during slow sleep is distributed. A person sees colorful dreams that he can remember and retell after he wakes up. Waking up during REM sleep is the easiest and fastest.

How much sleep do you need to get enough sleep?

According to scientists, a person needs to sleep from 8 to 10 hours a day, which equals 4-6 sleep cycles. It should be borne in mind that the duration of the sleep cycle varies from person to person and, depending on the individual characteristics of the nervous system, can vary from 1.5 to 2 hours. And for the body to get proper rest, there should be at least 4-5 such complete cycles. How much sleep a person should have is largely determined by his age.

Here are the approximate sleep norms for different age groups:

• Most long sleep for unborn babies in the mother's womb - about 17 hours a day.
• Newborn babies spend 14 to 16 hours sleeping.
• Babies aged 3 to 11 months need to sleep 12-15 hours.
• One- and two-year-old children sleep 11-14 hours a day.
• It is advisable for preschoolers to sleep at least 10-13 hours.
• The body of primary school children under 13 years of age requires 10 hours of rest at night.
• Teenagers are recommended to sleep between 8 and 10 hours.
• Sleep duration of an adult from 18 to 65 years, depending on personal characteristics body, is 7-9 hours.
• The need of people after 65 years decreases slightly - they need to sleep from 7 to 8 hours.

How to sleep less and get enough sleep

The quality of sleep is very dependent on what time a person goes to bed. Sleeping until midnight from 19.00 to 24.00 is extremely beneficial. People who are accustomed to falling asleep early feel refreshed and well-rested, even if they get up at dawn. In this case, a person can sleep less, but still get enough sleep. And the trick is that the value of sleep in a certain period of time is different.

Sleep value table by hour

Sleep period	The value of rest
19.00 — 20.00	7 hours
20.00 — 21.00	6 hours
21.00 — 22.00	5 hours
22.00 — 23.00	4 hours
23.00 — 24.00	3 hours
24.00 — 01.00	2 hours
01.00 — 02.00	1 hour
02.00 — 03.00	30 min
03.00 — 04.00	15 minutes
04.00 — 05.00	7 min
05.00 — 06.00	1 min

What time is best to get up in the morning?

It is believed that the best time to wake up is from 4 to 6 am. People who rise with the sun are not afraid of fatigue, and they manage to do a lot during the day. But, of course, in order to get up early, you need to develop the habit of going to bed early. In addition, people have different biological rhythms. As you know, people are divided into “night owls” and “larks”. And if a person is a night owl, then it is better for him to wake up around 8-9 in the morning.

How to correctly calculate your wake-up time

It is very difficult to independently calculate the time for which you need to set an alarm clock in order to wake up in the REM sleep phase. As mentioned above, each person's sleep phases have an individual duration. Therefore, before carrying out such calculations, you must first contact medical Center so that specialists can determine your personal sleep rhythm using special devices.

Although it is possible to calculate the approximate time When is the best time to wake up? To do this, you need to take the average duration of the slow sleep phase (120 minutes), as well as the average duration of the fast phase (20 minutes). Then you should count 5 such periods from the moment you go to bed - this is the time you set the alarm clock. For example, if you fell asleep at 23:00, then best time Your wake-up time will be from 7:20 to 7:40 am. If you decide to sleep longer, for example on Sunday, then the time to get up correctly will be between 09:00 and 09:20.

The importance of sleep for the body

• The main purpose of sleep is to allow the body to rest and recover. Prolonged insomnia is fraught with serious health problems. Animal experiments have shown that complete absence sleep after a certain time causes hemorrhages in the brain. People who are chronically sleep deprived soon experience increased fatigue, and then problems with the cardiovascular system join.
• Sleep affects metabolic processes in the body. While a person is in slow-wave sleep, growth hormone is produced, without which protein synthesis cannot occur - therefore, lack of sleep is especially dangerous for children. In people who are sleep deprived, the cleansing system is also impaired. recovery processes in the body, since during sleep, organ cells are actively supplied with oxygen, and the work of the liver and kidneys, which are responsible for neutralizing and removing harmful substances, is activated.
• During the fast phase, the distribution, processing and assimilation of accumulated information occurs. By the way, as it turned out, you can’t learn or remember anything while you sleep (learning method foreign languages sleeping people did not justify itself), but the information that entered the brain immediately before sleep is actually better remembered.
• REM sleep promotes the activation of all neurohumoral processes - nervous system a person is tuned to active work. It has been noticed that a lot of nervous diseases appear from lack of sleep.

The effect of sleep on the cardiovascular system

Many of us are accustomed to regularly invigorate ourselves with tonic drinks - strong tea, coffee. Yes, this way you can really cheer yourself up for a short period of time. But then, when caffeine stops working, the person feels even more tired, drowsiness and weakness appear. Therefore, there is nothing better for vigor than normal sleep. People who systematically cut down their sleep time, thereby force their body to work under overload and lead it to exhaustion, as a result of which such problems arise. serious illnesses like ischemia, chronic, and so on.

The effect of sleep on appearance

Medical scientists unanimously claim that lack of sleep provokes oxygen deficiency in the body and inevitably leads to early aging and a significant deterioration in appearance. A well-rested person, as a rule, can boast not only of vigor, but also a fresh appearance, good color faces. By the way, metabolic disorders, which can lead to chronic insomnia, often entail increased appetite and... Therefore, athletes and actors, for whom it is vital to always be in good physical fitness, strictly adhere to the sleep-wake schedule.

Sleep and human behavior

It has been noticed that in people who do not get enough sleep, such negative character traits as capriciousness, short temper, irritability, and aggressiveness become more acute. And all because their nervous system is not ready for stress and is constantly on edge. But those who sleep well have an excellent mood and full psychological readiness to overcome life's problems. Therefore, if your work involves night shifts, be sure to compensate for the lack of sleep during the day. Drivers should never get enough sleep. A huge number of accidents occurred due to the fact that a sleep-deprived driver was distracted or fell asleep at the wheel.

And finally, we should remember one more function of sleep - through dreams, our subconscious often sends us hints and insights that help us solve important life problems.

Falling asleep

Immediately before bedtime, a state of drowsiness occurs, a decrease in brain activity, characterized by:

1. decreased level of consciousness;
2. decreased sensitivity of sensory systems;
3. a decrease in heart rate, a decrease in the secretory activity of the glands (salivary → dryness of the oral mucosa; lacrimal → burning of the eyes, sticking of the eyelids).

Sleep structure

The REM sleep phase lengthens from cycle to cycle, and the depth of sleep decreases. REM sleep is more difficult to interrupt than slow-wave sleep, although REM sleep is closer to the threshold of wakefulness. Interruption of REM sleep causes more severe violations mental health compared to slow-wave sleep disorders. Some of the interrupted REM sleep must be replenished in subsequent cycles.

It is assumed that REM sleep provides the functions of psychological protection, information processing, and its exchange between consciousness and subconsciousness.

Sleep deprivation is a very difficult experience. Over the course of several days, a person’s consciousness loses clarity, he experiences an irresistible desire to fall asleep, and periodically “falls” into a borderline state with confused consciousness. It was not without reason that this method of psychological pressure was used during interrogations; currently it is considered as sophisticated torture.

Notes

see also

• Flying in a dream

• Hypersomnia
• Syndrome sudden death children (SVS in infants)
• Dream dictionary

Links

In Russian

In English

• It's the Little Things: Daily Routines. The Whole Child - For Early Care Providers. Public Broadcasting Service (PBS).

Literature

In Russian

• Vein A. M. Pathology of the brain and the structure of night sleep. Materials of the symposium. "Sleep Mechanisms" - L.: Science, 1971.
• International Classification of Diseases (ICD-10). Classification of mental and behavioral disorders: clinical descriptions and diagnostic instructions / Transl. from English (WHO, 1992). - St. Petersburg: Overlayd, 1994.
• Rottenberg V.S. Adaptive function sleep, causes and manifestations of its disturbance. - M.: Nauka, 1982.
• E. R. Dodds. Images of dreams and images of culture // Dodds E.R. Greeks and the irrational. St. Petersburg, 2000, pp. 152-197.
• I. A. Protopopova. About dreams in ancient Greece // Russian Anthropological School. Proceedings Vol. 2. M.: RSUH, 2004, p. 163-190

In English

• Chapter 3 // Dynamics of Complex Systems. - 2003.
• Foldvary-Schaefer N, Grigg-Damberger M (Feb 2006). "Sleep and epilepsy: what we know, don't know, and need to know." J Clin Neurophysiol 23 (1): 4-20. J Psychiatr Res. 1974;10:283-306.
• Tamar Shochat and Sonia Ancoli - Specific Clinical Patterns in Aging - Sleep and Sleep Disorders
• Zepelin H. Normal age related changes in sleep. In: Chase M, Weitzman ED, eds. Sleep Disorders: Basic and Clinical Research. New York: SP Medical; 1983:431-434.
• Morrissey M, Duntley S, Anch A, Nonneman R (2004). "Active sleep and its role in the prevention of apoptosis in the developing brain." Med Hypotheses 62 (6): 876-9. PMID 15142640.
• Marks G, Shaffery J, Oksenberg A, Speciale S, Roffwarg H (Jul-Aug 1995). "A functional role for REM sleep in brain maturation.". Behav Brain Res 69 (1-2): 1-11. PMID 7546299.
• Mirmiran M, Scholtens J, van de Poll N, Uylings H, van der Gugten J, Boer G (Apr 1983). "Effects of experimental suppression of active (REM) sleep during early development upon adult brain and behavior in the rat." Brain Res

  The electroencephalogram is highlighted with a red frame, the REM sleep phase is underlined. REM sleep phase (synonym: REM phase or REM phase, from REM rapid eye movements, English ... Wikipedia

Electroencephalogram, REM sleep phase is highlighted with a red frame REM sleep phase (synonym: REM phase, from REM rapid eye movement) sleep phase characterized by increased activity brain. One of the signs... ... Wikipedia

"SLOW" SLEEP PHASE- one of the two main phases of sleep, during which tonic (persistent) changes in vegetative and motor indicators are observed: muscle tone decreases, breathing and heart rate slow down. At the stage of “slow” sleep, behavioral thresholds... ... Psychomotorics: dictionary-reference book Wikipedia

DREAM - – mental condition, characterized by a person’s detachment from the world around him. Physiologically, sleep is a condition for restoring vitality and energy reserves in the human body. Psychologically, sleep is... encyclopedic Dictionary in psychology and pedagogy

- (σ rhythm, sleep spindles, fusiform activity, explosive or bursting activity, fusiform bursts, α-like rhythm of animals, barbiturate spindles) one of the main and most clearly expressed elements of spontaneous EEG, ... ... Wikipedia

The request "Sleepwalking" is redirected here; see also other meanings. Somnambulism ... Wikipedia

Contents of the article

A third of human life is spent sleeping. This is a complex and necessary process for health. Deprivation of night rest for just 3 days can lead to disruption of many functions - loss of appetite, apathy. At night, physical strength is restored, immunity is strengthened, brain activity changes, and daytime information is taken into account. To perform all these functions, a person goes through phases of rapid and slow sleep during the night.

Physiology of sleep

During the night, the phases of slow and fast sleep alternate more than once. First comes the slow one, then comes the fast one. Each has its own goals. During slow periods, the body rests. When the fast phase begins, the body prepares to wake up, the heart begins to work actively, blood pressure increases, and vivid dreams occur.

The phases of slow and fast sleep are contained in a single cycle. It lasts from one and a half to two hours. For the whole night physiological standards 4 to 6 cycles should occur, then the person will wake up with the feeling that he has slept, rested, and gained strength.

In each subsequent cycle, the duration of the slow phase is shorter, and the duration of the fast phase is longer. In order for the full restoration of all systems to go well, you need to complete the cycles before 4 a.m. (for this you need to go to bed at about 10 p.m. the previous day). After this, the person will continue to sleep, but without the slow phase, because the recovery processes have already passed. It is better to wake up after the fast phase, as all systems are activated and ready to start working.

Although during the slow stage the speed of many physiological processes, but at the same time protein synthesis is accelerated and hormones are produced. Sweating increases, blood supply to the brain increases, hair and nail plates continue to grow. During the slow phase, tissue and organ restoration actively occurs.

The fast phase is also necessary for the body. It allows a person to experience the emotions of those events that happened in life. This makes it possible for a person not to change over time, to remain emotionally stable, and to adapt to a changing world. For newborn children, the fast phase helps the rapid development of the brain and strengthens it with special impulses. This lasts until the age of two, then personality formation occurs.

Numerous examinations help to understand what slow and fast sleep is, the most common of which are tomography, electroencephalography, ultrasound studies, and others. modern techniques studying.

Alternation of stages

During slow-wave sleep and REM sleep, different functions are performed. Throughout the entire cycle, there are five stages with their own physiological characteristics:

• Stage 1 – takes 4-5% of the time, light sleep, the process of basic actions in the body slows down, blood pressure decreases;
• Stage 2 – 45-55%, there is a decrease in body temperature, slowing of breathing, decreased heart rate;
• Stage 3 – from 4 to 6% of the time, the beginning of deep, sound sleep;
• Stage 4 – 12 – 15%, rhythmic, unhurried breathing is observed;
• Stage 5 – 20 – 25% of the time, a person dreams peaceful dreams, the brain relaxes, the heartbeat quickens.

It takes from 15 to 40 minutes to fall asleep. If this takes 1 hour, then this is a sign of insomnia, which means it is necessary to take measures to eliminate it. The first cycle, that is, alternating slow and fast sleep, takes 1 hour, then the slow phase of another cycle begins again. Each time the sleep will be deeper. In the ratio of fast and slow sleep, the latter remains up to 80% of the total night time.

After passing through all the cycles, awakening occurs. It usually takes up to 3 minutes. During this time, consciousness is connected.

The alternation of stages does not change in a healthy person. The following factors can disrupt the sequence:

• emotional instability;
• age-related changes;
• prolonged stress, depression;
• mental disorders;
• long-term chronic diseases;
• injuries.

These disorders require treatment, as they can lead to complications. Deficiency of night rest or certain stages leads to the appearance of serious diseases.

The main differences between NREM and REM sleep

When comparing, it is difficult to answer which sleep is better - fast or slow sleep. Each phase performs its own function and is therefore needed by the body. The comparison is presented in the table, where slow and fast sleep are analyzed according to individual parameters.

Sleep characteristics	Slow	Fast
Vegetative system	There is a rapid, enhanced synthesis of hormones produced by the pituitary gland of the brain. Active growth of nails, eyelashes, hair, bones.	The heartbeat quickens, breathing becomes deeper and more active, and the pupils move faster.
Dreams	I rarely have dreams. But if this happens, then the dreams are characterized by calm content without temperamental turns.	Dreams with vivid storylines, intense experiences, strong emotions and color effects.
Subtleties of breathing	It can be rare, superficial, deep, there may be no rhythm, which occurs in the delta stage.	Uneven, sometimes delayed, frequent. This is how the reaction to dreams manifests itself.
Awakening	Upon waking up, a person feels tired and depressed. The sprinkling process will be difficult. This is the result of incomplete processes in the slow phase of sleep.	He wakes up easily, on his own. You feel freshness, vivacity, energy.
Brain temperature	Decreases.	Increased due to the influx of plasma and enhanced metabolic processes.
Eye movement	Smooth, leisurely, lasting until the end of this phase.	There is continuous, chaotic movement.

The stages of REM and NREM sleep differ from each other, but are mutually dependent and in harmony. They are equal in importance and take part in the single action of rest and restoration.

Main stages of slow-wave sleep

When falling asleep, a person finds himself immersed in a slow phase. It received this name because of the leisurely movement of the pupils at this stage. In this phase everyone calms down natural processes in body. Blood pressure decreases, the brain begins to rest, relaxes, and the heartbeat becomes less frequent.

The night's rest cycle consists of four stages slow-wave sleep and two stages of fast sleep. With the onset of night, slow-wave sleep has an advantage; towards the end of the rest, the share of fast sleep increases.

Wakefulness - NREM sleep (stages 1 and 2) - Delta sleep (stages 3 and 4) - REM sleep

In slow-wave sleep there are stages of drowsiness, then there are “sleep spindles”, then delta sleep follows. Real deep sleep will occur during the deep delta stage of sleep. These stages differ from each other in physiological parameters and actions occurring in the body.

When falling asleep, physiological categories change. The heartbeat decreases, blood pressure decreases, and blood moves more slowly through the vessels. When the last stage is reached, the heartbeat becomes faster and blood pressure begins to rise. At the same time, the body prepares to move on to the next fast phase. During the slow-wave sleep stage, the events of the past day are replayed in the memory, so a special rhythm of breathing and twitching of the limbs is possible.

During deep sleep, damaged cells are restored, which is why this stage is so important for maintaining youth and healing.

For an adult, the norm for slow-wave sleep is 118 minutes per night.

In difficult situations, the body independently prolongs this stage. So a person who adheres to a strict diet will feel weak and begin to sleep a lot. This body requires more time to recover. This happens in diseases of the thyroid gland, in professional athletes, and in people engaged in heavy physical labor.

The norm of deep sleep in adults should not be disturbed. If you don't get enough sleep, it will be difficult to compensate for the deficit in the slow stage of sleep. The shortage will constantly accumulate and negatively affect well-being and performance. With a prolonged disruption in the sleep schedule, for example, during a night work schedule, disturbances in the endocrine system begin. Growth hormone stops being produced, which means that a person’s fat layer on the stomach. Tissues cease to renew themselves steadily, new pathologies develop, and chronic diseases worsen.

Nap

The first stage is the slow phase, lasts up to 10 minutes. In this case, slow movements of the pupils under closed eyelids are noted. The body is in a soft, sleepy state, in which the physiological indicators of pulse, respiration, and pressure decrease. But it’s still easy to wake a person up. The brain is not resting yet, but is actively working. In this state, you can find answers to unsolvable problems. One has only to remember about them. In the morning it will not be possible to restore the chain of decisions, but the conclusion will remain in memory. If you constantly wake a person up during the slow phase, he will gradually become irritable and nervous.

Sleepy spindles

This stage lasts up to 20 minutes. It got its name from the characteristic pattern on the EEG graph. The heart rate slows down, muscle activity decreases, and the reaction to external stimuli remains. A person can wake up from a small, extraneous noise. For example, crying small child Mom will hear. Regular awakenings at the sleep spindle stage lead to scattered attention.

Delta

The stage lasts from 10 to 15 minutes. There is a gradual decrease in blood pressure, loss of consciousness, shallow, slow breathing. Most people don't dream, but people with depression may have nightmares. Data is transferred from short-term to long-term memory. With constant lack of sleep, there is an increase in errors in mathematical calculations, a decrease in memory, reaction and speed of thinking.

Deep delta sleep

This stage lasts from 25 to 40 minutes. Represents real sound deep sleep. There is no reaction to odors or other external stimuli. At this time, it is difficult to wake up a person; you need to shake him by the shoulders and loudly call him by name. During sleep, metabolism is restored and renewed at the cellular level. There are calm dreams, manifestations of sleepwalking and sleep talking are possible in people prone to such pathologies.

According to scientists, the less delta sleep, the faster the body aging. To increase the duration of this stage, you must follow the following rules:

• before leaving for the night's rest, do hiking or perform simple physical exercises;
• correctly alternate work and rest;
• do not overeat in the evening, do not drink alcohol, caffeinated drinks, or energy drinks;
• sleep in a ventilated room, preferably in darkness and silence.

By increasing the deep phase of delta sleep, it will be possible to fully restore cells. This will have a positive effect on your appearance. First of all, this will affect the condition skin. Good sleep affects the smoothing of wrinkles, a healthy skin tone is acquired, and puffiness under the eyes goes away.

Fast cycle its features

Dreams that occur during the fast phase are remembered very well

During REM sleep, unusual actions begin; it is no coincidence that it is called the paradoxical cycle. Scientists do not fully understand the significance of this night phase cycle for humans. If during the slow stage there is active recovery, then in the fast phase other processes take place.

The pupils move chaotically under closed eyelids, as if they are watching some events. All indicators of a person (muscle tone, brain activity, blood pressure, heartbeat) indicate that he is awake, only his consciousness is turned off. A person often participates in his dreams. When he is woken up during the rapid phase, he remembers small details and talks about everything in detail and with emotion.

During this period, hormonal changes occur. The functioning of the organs of the endocrine system is adjusted. In the fast phase, the genital area is adjusted. During this stage, nocturnal erections, wet dreams, and orgasms occur, even in the absence of erotic dreams. Often heart attacks and strokes also occur at this time. A relaxed heart and blood vessels receive a huge load and cannot cope with it.

2 cycles included in the fast stage:

• unemotional;
• emotional.

They change each other throughout the night. The emotional cycle is always longer. IN fast period daily information and data are being processed, the brain adapts to the changing situation. People who do not have the opportunity to get a good night's sleep during this phase lose the ability to restore mental protection. Over time, they become irritable, whiny, absent-minded, and develop nervous disorders.

Features of awakening in each phase of sleep

Vigor and ability to work in the first half of the working day depend on the person’s awakening. If this happened from external irritating phenomena (a sharp ringing of an alarm clock, a scream, a jolt, a bright flash of light), then a certain time is needed to put the body in order. Some people do not even realize after such an awakening where they are, what they need to do. It is difficult for people with chronic low blood pressure. They are forced to accept medicines after such a morning rise.

When you wake up on your own in the fast phase, you have a chance to feel cheerful and fresh even early in the morning. The body is ready to work, all that remains is to turn on the consciousness. A person remembers his dreams and can retell them in detail.

It is important to consider the subtleties of awakening in different phases so as not to feel overwhelmed and unable to work. A good invention for taking into account the stages of sleep is “”. They are able to read the body’s readings, determine the necessary phases of REM sleep, and send a signal to wake up at exactly this time. The disadvantage of this device is the likelihood of hearing the call ahead of schedule. The alarm clock performs its functions ahead of schedule.

A smart alarm clock will help you wake up on time

We have invented a special calculator that helps calculate the phases of a person’s night rest by defining algorithms. You just need to enter your bedtime time, the program will perform the full calculation. A time will be determined when you need to get up in order to feel freshness, strength and vigor.

It is better to calculate the time of awakening through experiment. Determine the time of the fast phase, wake up and determine whether it is easy to get up, whether there is cheerfulness and activity. If you liked the sensations, then you should try to maintain this regime, it is optimal for this age and type of activity. The slow stage takes about 120 minutes, the fast stage lasts 20 minutes. After falling asleep, 4 cycles must pass to complete recovery and final awakening. If you go to bed at 22 o'clock, then 4 cycles will pass from 4:40 to 5:00. If it is too early to get up, then the next cycle will end from 7:00 to 7:20.

The time you fall asleep matters. The optimal time interval is from 19 to 20 hours. Our ancestors went to bed around this time, with the end of daylight. With the invention of electricity, life changed. People began to go on vacation much later. This has increased the number of neurological diseases, chronic fatigue, depression, oncology.

The best time to wake up will be the first or second stage after the end of the fast phase. It is important to wake up and get up and not doze off a little more. In this case it will begin new cycle, will go again slow stage, during which it is difficult to wake up, there will be no former vigor. REM sleep is different from slow sleep, but it is better to wake up on your own when the body is ready for it.

You can go out onto the balcony with coffee - it will wake you up / Photo nickned.livejournal.com

In order not to fall asleep again after waking up, you can have a snack to finally restore consciousness. It is useful to go for a walk or to the balcony. The morning air will invigorate you, you will have strength and vigor for a new day. After 3-4 days of such a rise, the body will get used to getting up without getting enough sleep, which only spoils the morning awakening.

To maintain good health and good appearance, you need REM and REM sleep. They have a mutual influence on the human body. One should not intrude unnecessarily into the well-established structure of nightly recovery. On the part of a person it is required to maintain the correct night sleep, avoid frequent lack of sleep, interruption of sleep in in the wrong place. Following the rules for night rest will help you maintain your health for a long time.

NATALIA EROFEEVSKAYA

Duration and quality of sleep– criteria that influence many factors: mood, well-being, feeling of cheerfulness. In preparation for a new day, we try to go to bed early, but in the morning we wake up exhausted and lethargic. On another day, on the contrary, after a short sleep, we wake up on our own, feeling cheerful and strong. Why does this happen and how to learn to get enough sleep? To answer these questions, we will analyze the phases of human REM and NREM sleep in time and their characteristics.

Discoveries of scientists

Today, sleep is an understandable physiological state. But it was not always so. For a long time, scientists could not track what changes occur in a person during rest. The topic was closed and difficult to study. In the 19th century, they assessed a person’s posture, measured blood pressure and temperature, and took other indicators. For detailed study, sleepers were awakened and changes were recorded.

Hand turns off alarm clock early in the morning

Early attempts at sleep intervention have yielded results. Scientists have found that sleep goes through stages of varying duration rapid and deep sleep of a person, and their importance is great, since it affects all indicators of the body. The German physiologist Köllschutter found that deep sleep occurs in the first hours of rest, and then it turns into superficial sleep.

After the discovery of electric waves, scientists took a complete picture of what was happening to the sleeper. An electroencephalogram helped to understand what was happening to a person during rest. In this case, the subject did not have to be woken up. Thanks to new technologies, it has become known that sleep goes through 2 phases: slow and fast sleep.

Stages of slow-wave sleep

Orthodox sleep is divided into stages. The stages differ in the duration and depth of rest. Let's look at the stages of slow-wave sleep:

First. Occurs after a person closes his eyes. The first stage is called napping. A person is not yet falling asleep; the brain is in an active stage. Within 10–15 minutes. the vacationer processes information that happened during the day. During this period, solutions are found to the questions that tormented a person.
Second. At this stage, “sleep spindles” appear. They occur at intervals of 3–5 minutes. During their passage, consciousness is completely switched off. In between sleep spindles, a person is sensitive to what is happening around him. He hears voices or sounds. This feature allows the mother to hear the baby’s cry at night. If you call a sleeping person by name, he will immediately wake up. Physiological changes come down to a decrease in muscle activity and a slower heart rate.

During the second slow phase of sleep, a person hears sounds

Third. Stage of delta sleep or transitional. “Sleep spindles” are preserved and become longer lasting. Delta oscillations are added to them. The third stage is called preparatory stage before deep sleep.

Fourth. At this stage, the pulse quickens and blood pressure rises. The person falls into deep sleep. Dreams during this period are unclear and blurry. If the vacationer wakes up during the fourth stage, he will not remember what he dreamed.

People who sleepwalk or talk in their sleep do not remember anything the next morning. This is due to the fact that all events take place in deep stage sleep. Even if you interrupt the sleepwalker, he will not understand why he is not in bed and how he ended up in another room. It is at this stage that people have nightmares.

Duration of deep sleep directly depends on the person’s age and physical condition his body. For example, the duration of a child's deep sleep phase is 20 minutes, but the quality of sleep is completely different than that of most adults: it is much stronger, children may not respond to external stimuli (sound, light, touch). Thus, even the smallest ones restore energy, “reboot” the body’s systems, and charge the immune system.

How long does the deep sleep phase last? The deep sleep phase, the duration of which varies depending on the specific stage, generally lasts one and a half to two hours. Of these, 5-10 minutes are “allocated” for dozing, for the second stage (slowing breathing and heart rate) – 20 minutes, for the third and fourth phases – 30-45 minutes each.

The girl sleeps sweetly, hugging a pillow

Features of REM sleep

After deep sleep ends, REM sleep begins. The fifth stage was discovered by Kleitman in 1955. The recorded indicators made it clear that the indicators of the body during REM sleep in humans are similar to the state of wakefulness. The REM sleep phase is accompanied by:

constant movement of the eyeballs;
significant decrease in muscle tone;
emotionally charged and action-packed dreams;
complete immobility of a person.

How long does REM sleep last? In total, shallow sleep makes up 20-25% of the average night's rest time, i.e. one and a half to two hours. One such phase lasts only 10-20 minutes. The most vivid and memorable dreams come during the REM sleep stage. If a person is awakened during this period, he will fully tell what he dreamed.

Baby is sleeping

Why are sleep phases needed?

A person’s well-being is inextricably linked with rest and sleep. No wonder. In the first months of life, a little person has a strong connection with nature and obeys its laws. As adults, we make decisions about how much sleep we need. Often untrue, so the mental is disturbed, emotional condition person - that is why it is important to know the frequency of fast and deep stages in night sleep and be able to calculate the stages of sleep for the time of awakening.

Scientists calculated sleep phases and after a series of studies came to the conclusion that 4–5 cycles pass per night. During this period, the person is restored. During slow-wave sleep, energy expended during the day is replenished. REM sleep is short in the first cycles, then lengthens. During the fifth phase, a person processes information and builds psychological protection, adapts to environment. Knowing how to calculate the sleep cycle, it is possible to learn how to regulate the body’s energy capacity and its vital functions as a whole.

Studies done on rats have shown that Lack of REM sleep leads to death. The rodents were deliberately awakened, preventing the rats from entering the fifth stage. Over time, the animals lost the ability to fall asleep, after which they died. If the sleeper is deprived of the fast phase, the person will become emotionally unstable, prone to irritation, mood swings, and tearfulness.

Girl sleeping with hand on alarm clock

How to calculate sleep phases to know when is the best time to wake up?

Let's take as a basis that one cycle lasts for 90 minutes. Long REM sleep is required for proper rest. Therefore, at least 4 cycles should pass overnight. Waking up during slow-wave sleep makes a person groggy and lethargic. So, we need to calculate how to wake up during REM sleep: the fifth phase is characterized active work brain, so awakening occurs softly and painlessly.

Let's summarize. To feel cheerful in the morning, the duration of sleep and awakening after the completion of the fifth phase are important. For an adult, the ideal sleep time is 7.5–8 hours. The best option- This self-awakening, no alarm or phone signal.

If during the day you feel weak and want to take a nap, then allow this luxury. To avoid harm, record your rest time. If you have slept enough time at night, close your eyes for 15–20 minutes. This is how long the first stage of slow-wave sleep lasts. You will not have time to fall asleep, but you will feel that fatigue has been relieved. If the night's sleep was short, then go through one cycle during the day. Sleep for 1–1.5 hours.

Conclusion

The data given is approximate, but the essence is clear. For normal life human body phase sleep is necessary. It is important to wake up after completing 4–5 cycles. It’s ideal when you wake up on your own. Daytime nap It won’t do any harm if you prevent the second phase from entering or if you go through one full cycle.

January 20, 2014, 11:36