Sleep is divided into two parts: rapid eye movement and non-eye movement sleep speed. Human sleep is divided into two very important parts. When the eyelids sleep, the bottoms of the eyes swing from side to side. This special sleep is called rapid eye movement sleep. Another kind of sleep with very quiet eyes is called non-rapid eye movement sleep. These two kinds of sleep cover a variety of health care functions and are regularly staggered at night. Sleep medicine is called sleep cycle. There will be 4-5 sleep cycles in one night. Non-REM sleep maintains more sleep, rarely in the first half of the night and the second half of the night, but REM sleep becomes more and more in the second half of the night.
Non-rapid eye movement sleep is more common in the first half of the night, which is mainly made by ordinary people after a day's tempering. However, cats with great wisdom, brain cells and brain tissues are under pressure and damage, and the biological clock will prompt us to enter a sleep state, and the brain temperature will drop to a maintenance stage, which is very important for maintaining life. Rapid eye movement sleep will sleep more in the middle of the night, which is related to work and study. When you experience many good or bad scenery in a day, it includes memory, speed and eye movement sleep, including learning new things and integrating the mood of the day.
After people go to sleep, the body shows muscle relaxation, and some behaviors and physiology will change accordingly. When sleeping, the temperature will drop, the growth hormone will increase, and the adrenocortical hormone will decrease. Once there is a problem with sleep, these hormones will change, which will affect the body to varying degrees. Similarly, when the hormones change, they will also affect sleep.
During sleep, blood flow generally decreases, breathing is slow, muscles relax, and the body rotates unconsciously. This is a kind of non-rapid eye movement, and eye movements also move. About 3/4 of the time in one night is a period of full rest. When a person is sleeping in rotation, this stage is a dream, which is a rapid eye movement period. At this time, except for muscle relaxation, the rest of the state will be the same as when awake during the day, such as hypertension and penile erection.
Sleep structure will change with age. From infancy to 10 years old, the ratio of non-rapid eye movement sleep to eye movement sleep is about 50:50, which means that the baby's brain matures very quickly, with a high level of activity and strong learning, while the speed of learning and memory will account for more eye movement sleep. After 10 years old, the proportion of sleep between them tends to be stable. Rapid eye movement sleep accounts for about a quarter of one day's sleep, and it accounts for three quarters in the second half of the night. By the age of 60, the rate of eye movement sleep began to decrease. In addition to representing the physiological aging of the brain, learning activities also began to weaken, which also meant that the motivation of the elderly to learn became less and gone. Different age groups have different sleep needs. When a certain part has problems, it may expose the inherent physical and mental diseases of the individual, or because sleep problems will have an impact on the body and mind for a long time after they start.
Doing at sunrise, resting at sunset, sleeping at a fixed time and waking up at a fixed time are part of the body's biological clock. The central body temperature of human activity represents the brain: from 6 o'clock in the morning, the temperature of the human brain will gradually increase, relax in the afternoon, then continue to increase, reach the highest point in the evening, and then begin to decrease in the darkness for 2 or 3 hours at night until the temperature of the brain reaches the lowest value in the morning, which is called central body temperature. This temperature change in the brain is actually a manifestation of brain activity, just like a clock, which can tell people when to sleep and when to wake up. The human brain is external, and internal command is important. As long as you are awake, you can't stop brain activity. And brain temperature.
After the brain wakes up from morning activities, the body temperature gradually rises, indicating that there are more and more activities. At night, when the brain is most excited, it reminds humans that it is time to enter the brain to adjust. If the brain cannot get proper rest, it may cause many physical and psychological problems.
What time should someone sleep enough? As for the duration of sleep, it changes naturally with age, from sleeping more at night in infancy to sleeping nearly 16 hours a day; In youth, it takes 8 to 9 hours to study at night in order to meet a series of exams; On average, I slept six hours less when I woke up than when I was old.