灵枢经·营卫生会 The Generation and Meeting of Nutritive and Defensive Qi

Huangdi asked Qibo: 'From where does a person receive qi? Where do yin and yang meet? What qi becomes nutritive qi, and what qi becomes defensive qi? Whence is nutritive qi generated, and where does defensive qi converge? The qi of the old differs from that of the vigorous, and yin and yang occupy different positions — I wish to hear of their meeting.' Qibo replied: 'A person receives qi from grain. Grain enters the stomach and is transmitted to the lung, and the five viscera and six bowels all receive qi from it. Its clear portion becomes nutritive qi, and its turbid portion becomes defensive qi. Nutritive qi travels within the vessels, and defensive qi travels outside the vessels. Nutritive qi circulates ceaselessly, and after fifty circuits it once again meets in a great convergence; yin and yang are strung through one another like a ring without end. Defensive qi travels twenty-five circuits through the yin and twenty-five circuits through the yang, dividing into day and night; thus when the qi reaches yang it rouses one to wake, and when it reaches yin it brings one to rest. Hence it is said that at midday yang is at its height, and this is called double yang; at midnight yin is at its height, and this is called double yin. Thus the Taiyin governs the interior and the Taiyang governs the exterior, each traveling twenty-five circuits, dividing into day and night. At midnight yin is at its height; after midnight yin begins to decline, and at dawn, when yin is exhausted, yang receives the qi. At midday yang is at its height; as the sun moves westward yang declines, and at sunset, when yang is exhausted, yin receives the qi. At midnight the great convergence occurs, when the myriad people all lie asleep — this is called the closing of yin. At dawn, when yin is exhausted, yang receives the qi once more, and so it continues without cease, following the same order as Heaven and Earth.'

Huangdi said: 'What qi causes old people to be unable to sleep soundly at night? What qi causes the young and vigorous to be unable to sleep during the day?' Qibo replied: 'In the vigorous, qi and blood are abundant, the flesh is smooth and supple, and the pathways of qi are open and unobstructed, so that the movement of nutritive and defensive qi does not lose its normal course; hence they are alert by day and sleep soundly by night. In the aged, qi and blood have declined, the flesh has withered, and the pathways of qi have become rough and impeded; the qi of the five viscera contends within, the nutritive qi has grown scant and weak, while the defensive qi assails the interior — hence they are not alert by day and cannot sleep soundly by night.'

Huangdi said: 'I wish to hear by what pathway nutritive and defensive qi travel, and whence they come.' Qibo replied: 'Nutritive qi emerges from the middle burner, and defensive qi emerges from the lower burner.' Huangdi said: 'I wish to hear whence the triple burner emerges.' Qibo replied: 'The upper burner emerges from the upper opening of the stomach; it runs alongside the throat and ascends, passes through the diaphragm, and spreads through the chest; it courses to the armpit, follows the division of the Taiyin, and travels along, then returns to reach the Yangming; it ascends to the tongue and descends to the Foot Yangming. It constantly travels together with nutritive qi twenty-five circuits through yang and twenty-five circuits through yin, completing one full cycle; thus after fifty circuits it once again meets in the great convergence at the Hand Taiyin.'

Huangdi said: 'When a person has heat, and food and drink descend into the stomach before its qi has become settled, sweat will issue forth — sometimes from the face, sometimes from the back, sometimes from half the body — failing to follow the pathway of defensive qi as it emerges. Why is this?' Qibo said: 'This occurs when one is injured by wind from without, so that the interstices of the flesh open within; the body hair steams and the interstices leak, and defensive qi rushes toward the opening, and so cannot follow its proper pathway. This qi is swift, fierce, slippery, and rapid — wherever an opening appears, it escapes through it, and so cannot follow its regular course. This is called "leakage" (louxie).'

Huangdi said: 'I wish to hear whence the middle burner emerges.' Qibo replied: 'The middle burner likewise lies alongside the stomach, emerging just after the upper burner. What it receives of qi, it separates out the waste and dregs, steams the body fluids, and transforms their refined essence, sending it upward to pour into the lung vessel, where it is transformed into blood, in order to nourish and sustain the body. Nothing is more precious than this; hence it alone is able to travel through the channel passageways, and it is called nutritive qi.'

Huangdi said: 'Now, blood and qi have different names yet belong to the same category — what does this mean?' Qibo replied: 'Nutritive and defensive qi are the essential qi; blood is the spirit qi. Hence blood and qi, though differently named, belong to the same category. Thus one who has lost blood should not be made to sweat, and one who has lost sweat should not be depleted of blood; hence in human life there are two ways to die from their loss, but no way to gain twice from preserving them.'

Huangdi said: 'I wish to hear whence the lower burner emerges.' Qibo replied: 'The lower burner branches off at the coiled intestine, pours into the bladder, and seeps into it. Water and grain ordinarily reside together within the stomach; they form waste and dregs, which together descend into the large intestine and become the lower burner, seeping downward together. The clear fluid is filtered and separated out, and follows the lower burner to seep into the bladder.'

Huangdi said: 'When a person drinks wine, the wine also enters the stomach; yet even before the grain has been digested, the urine is passed first — why is this?' Qibo replied: 'Wine is the fluid of digested grain. Its qi is fierce and clear; hence, although it enters after the grain, its fluid is discharged before the grain's.' Huangdi said: 'Excellent. I have heard it said that the upper burner is like a mist, the middle burner is like a froth, and the lower burner is like a drainage ditch — this is precisely what is meant.'