Deep sleep is a part of sleep, accounting for only 25% of the whole sleep time. Deep sleep is also called "golden sleep". During deep sleep, the human body sleeps best and soundly. There is no noise outside at this time, so it is difficult to be awakened by others. When you wake up, you will feel refreshed. Deep sleep is a child's physical growth and intellectual development; Young people are full of energy; Middle-aged people are physically strong; The guarantee of health and longevity for the elderly.
During deep sleep, the cells in the cerebral cortex are at rest, so some people call it "brain sleep" because deep sleep is extremely important for stabilizing emotions and balancing mentality.
During deep sleep, all life activities of the human body are reduced to a minimum: breathing is slow and steady, blood pressure drops, heartbeat slows down ... the body's metabolism is maintained at a low basic level, and energy consumption is reduced; At the same time, the anabolism of related tissues and organs in the body is strengthened under the control of parasympathetic nerve, and the energy production is increased, which is also helpful to eliminate fatigue and restore physical strength.
Deep sleep can promote the secretion and release of growth hormone from pituitary gland, which can not only promote bone growth and physical development, but also enhance protein synthesis in various tissues of the body, promote fat decomposition, and keep the metabolism of adults in a "young" state. Therefore, people who have enough sleep generally look rosy, while those who have poor sleep for a long time will look haggard.
Experiments have proved that some antibodies will be produced during deep sleep, which will enhance the body's disease resistance and promote the self-healing of various tissues and organs. Therefore, people pay more and more attention to the relationship between sleep and physical rehabilitation, and lack of sleep may induce or aggravate the original disease. Therefore, patients with cold and fever especially want to sleep, which is actually a self-protection mechanism.