Chapter 28 Section 4 Understanding of Human Biological Rhythm

The "Nei Jing" already has the concept of rhythmic and periodic changes in the physiological activities of the human body. More than 2,000 years ago, people have realized that the physiological activities of the human body are closely related to the circadian cycle changes in nature. "Su Wen·Jin Kui Zhen Comments" says: In nature, there is yin within yin, and yang within yang.During the period from morning to noon (6-12 o'clock), the yang energy in nature is the yang of yang, and from noon to dusk (12-18 o'clock), the yang energy in nature is the yang of yang. Negative.During the period from dusk to cock crowing (18-24 o'clock), the yin energy in nature is the yin within yin.During the period from cock crowing to Pingdan (0-6 o'clock), the yin qi in nature is the yang within yin.The yin and yang qi in nature is like this, and so is the yin and yang qi in the human body.This concept of periodic yin and yang rhythm changes is quite similar to the modern "approximate circadian rhythm" (day clock). The "Nei Jing" specifically talked about this rhythm of the human body. "Su Wen Qi Tong Tian Lun" said: The Yang Qi of the human body belongs to the outside throughout the day.At dawn, a person's yang energy begins to grow, and at noon, the yang energy is at its strongest; at sunset, the yang energy declines, and the valves of the qi are closed.In traditional Chinese medicine, "Wei Qi" has the function of nourishing and warming the body and resisting external pathogens. The "Nei Jing" has recognized that the operation and function of "Wei Qi" in the body is closely related to the periodic rhythm of falling asleep and waking up. "Lingshu Jing·Wei Qi" says: Yang is during the day and Yin is at night, so the movement of Wei Qi is as regular as the circle of celestial bodies.In one day and one night, it is necessary to go through the whole body 50 times.25 cycles in the yang branch during the day and 25 cycles in the yin branch at night. "Lingshu Jing Dahuolun" also said: The sequence of Wei Qi circulation throughout the body is that it always moves in the Yang part during the day and in the Yin part at night.Therefore, when the yang energy is gradually exhausted at night, one must sleep; when the yin energy is gradually exhausted, one will wake up.It is clearly pointed out here that the operation of "Wei Qi" has a "circadian rhythm", which is quite correct.Modern medicine believes that when waking up in the daytime, the sympathetic nerves are excited and dominant, and the basal metabolism is strong; on the contrary, the parasympathetic nerves are excited and the basal metabolism is relatively reduced when sleeping at night.

Not only that, but the "Internal Classics" also pointed out that when the human body is sick, the severity of the symptoms will also show changes in the "circadian rhythm". "Lingshu Jing Shunqi Four Hours a Day" says: The changes of various diseases often feel refreshed in the morning and quiet during the day; while the disease becomes worse in the evening and more serious at night.What is the reason for this?The answer is: this is caused by the change of seasons.Spring growth, summer growth, autumn harvest, and winter storage are the normal conditions of the climate throughout the year.Human physiology corresponds to it.A day is divided into four o'clock, spring in the morning, summer in the noon, autumn in the evening, and winter in the middle of the night.In the morning, the human body's righteousness becomes active, and the pathogenic factors temporarily decline, so I feel refreshed.At noon, the body's righteousness tends to be strong, and the evils are overcome by righteousness, and the diseases and evils tend to decline, so I feel calm.By midnight, the righteous energy of the human body has entered the viscera, and the evil energy is absolutely dominant in the body, so the disease becomes more serious. The understanding of the physiological circadian rhythm of the human body in the "Internal Classics" is summed up from a large number of practices and has a certain scientific basis.

In addition to "circadian rhythm", there are also descriptions about "tidal rhythm", "weekly rhythm" and "annual rhythm" in "Nei Jing", which are also worthy of study.