The exact definition of sleep has different connotations with the changes of the times. At first, French scholars thought that sleep was a state in which sensory activities and motor activities were temporarily stopped due to internal needs of the body, and it could be awakened immediately by giving appropriate stimulation. Later, people realized the EEG activity, and thought that sleep was the low physiological activity of animals caused by the functional activity of the brain, and proper stimulation could make them fully awake. After research in recent years, modern medicine generally believes that sleep is an active process, sleep is a necessary rest to restore energy, and there is a special center to manage sleep and awakening. When sleeping, the human brain only changes the working mode, so that energy can be stored, which is conducive to the recovery of spirit and physical strength; Proper sleep is the best rest, which is not only the basis for maintaining health and physical strength, but also the guarantee for achieving high productivity. I don't think so completely.
According to my experience and understanding, sleep means that the brain needs to distribute and solidify stimuli and stimulus connections to the corresponding nerve cells (reorganization information), and temporarily transfer the excitement point (attention) to nerve cells with weak original excitement intensity, which take over most of human life activities, while nerve cells with high excitement that have previously received internal and external stimuli and responded to them prevent the stimulation connections from interfering with each other (information overload). (It can also be understood that biochemical energy is limited, and these nerve cells mainly receive and process stimuli when they are awake, and mainly organize, filter and solidify stimuli when they sleep), so most of them must shield the necessary life processes of these nerve cells from internal and external stimuli. Mental fatigue is manifested in that too many stimuli are processed or solidified, and people instinctively feel uneasy, nervous and anxious about stimuli. Sleep plays a role in digesting these stimuli, which is manifested in relieving fatigue. Poor sleep quality refers to the phenomenon that the shielding degree is not enough or the sleep time is not enough to fully digest the stimulus connection. Sleepiness is a pathological mask for too long. These are all manifestations of insufficient nerve control. During sleep, due to the weakening of active activities, people's physical strength has also been restored accordingly.
Sleep is often an unconscious state of happiness, which usually happens when we are lying in bed and when we allow ourselves to rest at night. Compared with the awakening state, when people sleep, their contact with the surrounding environment stops, their conscious consciousness disappears, and they can no longer control their words and deeds. Sleeping people relax muscles, weaken nerve reflex, lower body temperature, slow heartbeat, slightly lower blood pressure, slow metabolism and obviously weaken gastrointestinal peristalsis. At this time, it seems that the sleeping person is static and passive, but it is not. If we give a person an EEG during sleep, we will find that the electrical pulses emitted by brain cells during sleep are not weaker than when they wake up. This proves that the brain has no rest. Just like a hive at night, it looks as if all the bees have returned to their nests to rest, but in fact all the bees are busy making honey all night.
Improve sleep quality:
Just as everyone's appetite is different, everyone needs different sleep time. You can't judge whether a person has enough sleep by the length of sleep. As long as you wake up energetic, energetic and quick-thinking, you will sleep well. Some people have poor sleep quality, either dreaming more or waking up early. This kind of sleep is very long and they are still listless during the day.
References:
Sleep is the function of the brain
We can control our sleep.
If consciousness is the function of the human brain, then sleep is also the function of the human brain. We talk, walk and eat, which are the functions of specific motor centers in our brains. We feel cold, hot, painful and itchy, which are the functions of specific sensory centers in our brain. Also for sleep, it is still an active function of the central nervous system. Sleep is not a passive process as many of us think. Now we think it is an active behavior, and it is controlled very accurately, not simply not awakening. But people have not found a fixed sleep center so far.
Sleep mechanism is related to extensive brain activity. There is a structure in human midbrain called reticular ascending excitation system, which is of course much more complicated than our computer network. If the reticular ascending excitation system is inhibited by the cerebral cortex, it will enter a sleep state. The cerebral cortex is the highest command of our human body, so sleep is controlled by our consciousness. In other words, if sleep happens, we must want to sleep. If we don't want to sleep, we can also control ourselves from sleeping. Just like a guy in our village who played computer games for three days and nights, his eyes are wide open and he is tireless. Of course, the ability of the cerebral cortex to control the reticular ascending excitation system varies from person to person, and the disorder of control leads to various sleep disorders, such as insomnia.
After falling asleep, if there are no special circumstances, we will wake up, because of course we will not sleep forever. So, how did sleep end? This is because there is a biological clock in our brain, which may be related to a nerve nucleus called pineal gland. This is the natural clock in the human body. Taking 24 hours as a cycle, its accuracy can reach 1%, and the daily error is less than 5 minutes. This is why many people wake up before the alarm clock rings. In addition to the biological clock to wake up sleep, external or internal strong stimulation also has the same effect. Such as strong light, strong sound, defecation and so on, can make people awake.
Everyone's sleep time varies greatly, with an average of about 8 hours. Some people may need 4 to 5 hours, and about 10% of healthy people belong to this situation. 15% of them slept more than 8 hours or more. Sleep time is different at different stages of a person's life. Newborn babies need to sleep 16 hours or more every day. As time goes by, the sleep time decreases with the growth of children, and puberty takes about 8 hours, which is relatively longer than that of adults. In adulthood, everyone is stable in their own unique sleep habits; Generally, after entering old age, sleep time gradually decreases. For example, if an adult or an elderly person sleeps more than 10 hour or less than 4 hours, it is necessary to consider whether this person has any problems and needs to go to the hospital for examination. In addition, due to the change of physiological state, the sleep time required by the same person in different periods will also increase or decrease. For example, women may sleep more during menstruation, and pregnant women often need more than 10 hours of sleep every day. After heavy physical labor or physical exercise, sleep time will generally be prolonged, while excessive mental labor will often reduce sleep. So we can't generalize how much sleep people need.
What is sleep?
Sleep is what everyone needs every day, and most people sleep more than 1/3 in their lifetime. But the exact definition of sleep has different connotations with the changes of the times. At first, French scholars thought that sleep was a state in which sensory activities and motor activities were temporarily stopped due to internal needs of the body, and it could be awakened immediately by giving appropriate stimulation. Later, because people knew the EEG activity, they thought that sleep was the low physiological activity of animals caused by the functional activity of the brain, and proper stimulation could make them fully awake. In recent years, the research thinks that sleep is an active process, and there is a special center to manage sleep and awakening. When sleeping, the human brain only changes the working mode, so that energy can be stored, which is conducive to mental and physical recovery; Proper sleep is the best rest, which is not only the basis for maintaining health and physical strength, but also the guarantee for achieving high productivity.