What is a dream and why should we sleep? Phases of sleep. Sleep disturbances.
What is a dream?
One third of our life we spend in a dream. Sleep is necessary for man just like water and food. Without food, a person can live about a month, and without sleep a person will not live for two weeks.
As a result of the experiment conducted in the 1960s on volunteers, it was found that a person deprived of sleep on the fifth day, vision, hearing, memory worsen, visual and auditory hallucinations occur, and there are violations in the coordination of movements. Many of the people lost weight, although the subjects were heavily fed. Eight days later, the experiment was suspended. Experiments conducted on dogs showed that in two weeks the dogs deprived of sleep died.
What is a dream? Sleep is a natural physiological process that occurs in living beings in humans and animals, in fish and birds, in insects. This is the rest of the nerve cells of the cerebral cortex, this is the state when motor and mental activity decreases. Sleep is the rest of the whole organism.
If a person is not allowed to sleep, the immune system is harmed and the body is exposed to harmful microorganisms and substances and becomes ill.
All over the world, research is conducted on how a person's condition changes during sleep. It turns out that our life is divided into three phases - wakefulness, dreamless sleep and dreaming. Dreams are necessary for our body. Dreams fulfill, as it were, a protective function.
When we sleep, we get irritable signals from the external environment, for example: stuffiness, heat, cold, turned on light, soft music and sounds - they are included in our dreams,( we dream about a hot desert or cold snow, disco with bright lights andmusic, etc.), but they do not wake us up, and we continue to sleep.
It turned out that during sleep, a person is closed not only eyes, but also ears. The muscles that control the auditory ossicles are relaxed during sleep, and our ears do not catch a soft sound. Therefore, we do not wake up from every rustle, only louder sounds interrupt our sleep.
Sleep fast and sleep slow. Phases of sleep.
To find out what happens to a person during sleep, an electroencephalograph is used for research. With the help of an electroencephalograph( EEG), oscillations of the brain wave are recorded. Brainwaves have different indicators for wakefulness, with drowsiness, with slow sleep and deep sleep.
It turns out that during the dream the human brain continues to work, the activity of the brain changes with a periodicity of 1.5 hours and the person's dream passes from 4 to 6 periods-phases.
Scientists have found out that every person has two sleeps - sleep is slow and sleep is fast. A quarter of the time a person sleeps in a fast sleep, the rest of the time in a slow sleep.
Rapid sleep
During rapid sleep, a person has a rapid eye movement, jerks the muscles of his face, he moves his hands and feet, breathing becomes more frequent, blood pressure rises and heart rate changes. The brain during a fast sleep is actively working. Rapid sleep lasts 10-20 minutes, followed by a slow sleep, and repeats 4-5 times a night.
During a fast sleep a person sees dreams - bright, colorful, memorable. If you wake him up at this moment, he will tell you what he dreamed.
The phase of fast sleep is simply necessary for our body - the brain processes information and stores it in memory for "long storage".It is believed that during a fast sleep, the brain and nervous activity develop.
The phase of fast sleep is also called the "paradoxical phase", since the brain is active at this time, and the body is asleep, or the phase of BDG( Fast Eye Movement).
Slow sleep
Most of the sleep falls on a slow dream, a slow sleep is divided into four phases.
During a slow dream, dreams are also dreamed, but they are less bright and more often than not we do not remember them. During a slow sleep a person can talk in a dream, make various sounds, cry, laugh, sometimes walk( sleepwalking).
Sleep phases
The first phase-nap in a healthy person lasts very little time about 5 minutes. During drowsiness, the person slows down breathing and heartbeat, reduces pressure and body temperature, eyeballs are immobile, and the brain continues its work, digests the information received for the day, completes thoughts and ideas, seeks answers to unresolved issues.
Then comes the second phase - about 20 minutes. As in the first phase, life processes slow down, eyes are also immobile. At this time, a person has a strong sleep, and brain activity decreases.
The third phase is a deep sleep. Life processes also continue to slow down. During the third phase, the person has slow rotations of the closed eyes.
The fourth phase is characterized by a deeper slow sleep. In humans, the heart beats more slowly, the respiratory rate and body temperature decrease, and the pressure decreases. The fourth phase lasts 20-30 minutes. It is believed that during the fourth phase of sleep a person grows, his immune system is restored, and damage to organs is eliminated.
The phases of slow sleep proceed alternately, from the first to the fourth phase, then the sleep returns to the second phase, followed by the fast-sleep phase. This sequence lasts all night from 4 to 6 times. During the morning sleep, the fourth phase is skipped and the sequence of phases is as follows: the second phase is replaced by the third, then the second comes again, followed by the fast sleep phase, the time of the fast sleep phase with each cycle is lengthened.
Why should we sleep?
For a day a person manages to do a lot of things, by the night his body gets tired and requires rest. Muscles that help the work of the heart and blood vessels, just get tired, slow down their work. This reduces blood flow to the organs, and we experience fatigue and a desire to sleep.
A person must sleep to restore strength, give rest to the muscles of the body. During sleep, not only the strength is restored, but also vital processes( blood circulation, blood pressure, blood sugar, immune and nervous systems, hormonal background) are normalized.
The brain, as well as other organs, needs rest. Our brain is constantly at work. During the day he works hard, learns, learns new information, receives various impressions. And at night, when a person falls asleep, the brain also continues its work - recycling all the information received for the day, discarding unnecessary information from memory, and leaving important information, deferred in memory.
If a person sleeps a little, the brain does not have time to do all of its night work and rest, gain new strength. Not a sleepy person feels broken and tired from the morning, his working capacity goes down, he is in a sleepy, depressed state all day, because his brain has not rested properly.
In order not to overwork the brain during the day, you need to alternate work, doing different things, rather than doing the same thing all day. And the brain needs to be trained( to become smarter) - solve problems, examples, guess crossword puzzles, memorize and learn poems, text and play logic games, chess, checkers. Sleeping night and sleeping daytime.
When is it better to sleep - at night or in the daytime? People who are nocturnal( night work, night dives on the Internet, nightclub lovers and others who prefer to stay awake at night and sleep during the day) put their bodies at great risk. As stated above, we must sleep in order to restore strength and normalize the work of internal organs.
And it is night sleep that contributes to the pineal gland of the brain to produce a hormone melatonin that regulates daily rhythms. The maximum production of melatonin is observed at night - from midnight to 4 am.
Melatonin has antioxidant properties. It slows down the aging and aging process of the body, helps fight seven types of cancer cells, improves the digestive tract and brain function, works on the immune and endocrine systems, reduces anxiety and helps fight stress, regulates blood pressure and sleep frequency, helps to adapt betterwhen changing time zones.
The lack of melatonin in the body leads to premature aging, obesity, colds and oncologic, cardiovascular and other diseases. The use of night sleep is obvious.
Do we need a day's sleep? Many people believe that daytime sleep is necessary only for young children and those who work in the night shift, but adults do not need a day's sleep. And scientists and doctors believe that a person simply needs a short-term sleep during the day. It favorably affects the body, the cardiovascular system and reduces the occurrence of diseases of the blood vessels and heart, allows you to quickly restore strength.
What time is best for sleeping during the day? We all know that after a hearty meal, we feel relaxed and we tend to sleep. Why is this happening? The stomach is filled with food to be processed into the stomach receives more blood and oxygen. And the supply of blood and oxygen to the brain decreases, the work of the brain slows down and we want to sleep. According to research, a person wants to sleep in a period when the body temperature goes down. These periods are at night from 3 hours to 5 am and from 13 to 15 hours in the afternoon. This is the most suitable time for a day's sleep.
After a day's sleep, the mental activity of a person rises, and work capacity increases. The body relaxes, stress is removed, and mood improves. As well as daytime rest improves memory, information is quickly and easily remembered, imagination increases and new ideas come to the person.
So if you can sleep a little during the day, use it. You will get a boost of energy and avoid fatigue. But much sleep is not recommended, you need to sleep no more than half an hour. If you sleep, then instead of freshness and vivacity, you will get lethargic and irritable, or even a headache.
How long does it take for a person to sleep depends on the person and the environment. It's enough for one person to sleep for 5-6 hours, and they are full of energy, others and 9 hours too little to restore strength and be cheerful. How much you need to sleep will prompt your body, each person has his own biological clock and rhythms and you just need to listen to the needs of your body.
Sleep disorders.
Every person faces such a problem as sleep disturbance. Sometimes you can not sleep for a long time, digesting all kinds of impressions in your head, often waking up from noise outside the window, from loud sound of a working TV set or from bright light, from heat and stuffiness, from cold, and sometimes an empty stomach does not let you fall asleep. Periodically, almost all people face this. But when this happens constantly, then such sleep disorders should be considered as a painful sleep disorder.
Insomnia is the most common sleep disorder. Insomnia itself is not a disease, but it can be a symptom of many diseases( endocrine, nervous, cardiovascular systems, the brain). It can be caused by stress, alcohol and psychotropic drugs.
Narcolepsy is another disease associated with sleep disorders. Excessive bouts of sleepiness can occur at any time of the day, anywhere( at work, at home, on the street, in the store), in any situation. As a rule, they last not for long( from several seconds to several minutes), but can be life-threatening. A person can fall asleep at the wheel of a car or crossing the road. Another symptom of narcolepsy is a sudden loss of muscle tone and a drop. Night sick nightmares, he often wakes up, fall asleep do not give him auditory hallucinations - he hears that someone calls him, it seems to him that insects, snakes, mice crawl on his body. Headaches, double vision, loss of memory are often noted.
Lethargic sleep
Another known sleep disorder is lethargic sleep. A person who has fallen asleep with a lethargic sleep is often mistaken for a deceased person. His breathing slows down, his pulse is not probed, and his heart almost does not beat. The cause of lethargic sleep can be brain tumors, head injuries, cardiovascular insufficiency, lethargic encephalitis and even a strong mental shock.
A person who has persistent sleep disorders needs medical examination and treatment.
Strong sleep and pleasant dreams!