The lungs are situated in the thorax, one on each side. They are compared to the roof of a carriage due to their uppermost location among all of thezang - fu organs. They are also known as “delicate visceral organs” because their lobes are very delicate and tender, intoler-ant of cold and heat, and predisposed to invasion by pathogenic agents.
The lungs, equivalent to “metal” of the five elements, are the house of the soul and the dominator ofqi . Their main jobs are to dominateqi and respiration, fulfill the dispersing and descending functions, partici-pate in regulating water metabolism, and communicate with numerous vessels to achieve coordination of functional activities of the whole body.
In this way, they assist the heart in maintaining normal circulation of qi -blood. The lungs, which extend upward toward the larynx and lead out through the nose, are related outward to the skin and its hairs. They are responsible for melancholy and have their associated secretion in nasal discharge. The lungs and the large intestine are related due to the interconnection of the lung channel ofhand -taiyin and the large intes-tine channel ofhand - yangming .
Qi and Respiration Dominated by the Lungs.The primary function of the lungs involves two aspects: the regulation ofqi through-out the body and the control of respiration. The latter denotes that the lungs are visceral organs where interchange ofqi inside and outside the body takes place, i.e., the exchange of gases between the body and its environment occurs through the breathing movements of the lungs. By continuously exhaling stale gas and inhaling fresh air instead, the lungs promote the formation of pectoral-qi and regulate the lifting-lowering and entering-exiting movements ofqi and thereby maintain normal metabolism of the human body. This function is described in the chapter in the “Treatise onYin -Yang Classification of Natural
Phenomena” of the book by Su Wen: “The atmosphere communicates with the lungs.”
Dispersing and Descending Functions of the Lungs. Literally,
“dispersing” here means the upward diffusion and outward sending of
Chapter 4: Phase of Viscera
lung-qi and the descending or lowering of lung-qi to keep the respirato-ry tract clean. The dispersing function of the lungs consists mainly in the following:
1. Discharging the stale gas from the body and its functional activities.
2. Distributing the food essence and body fluids transported by the spleen to all parts of the body and to the skin and its hairs externally.
3. Spreading defensiveqi so as to control the open-and-close action of the striae of skin and muscles, thereby converting the metabolized body fluids into sweat to be removed from the body.
The descending function of the lungs, on the other hand, lies in:
1. Inspiring fresh air from the external environment.
2. Sending down the fresh air inspired and the body fluids as well as food essence transported from the spleen.
3. Purifying the foreign bodies in the lungs and the respiratory tract in order to keep the latter clean.
Water Metabolism Regulated by the Lungs.Water metabolism, here, refers to a physiological process by which body fluids are pro-duced, distributed, and discharged. The lungs can regulate this process by maintaining normal flow, distribution and discharge of body fluids due to their dispersing and descending functions. Via their dispersing function, the lungs not only spread body fluids and food essence to all parts of body, they also control the discharge of sweat as well as the opening-closing action of the striae of skin and muscles. Via their descending function, the lungs send down fresh air into the kidneys.
They also continuously send the part of the body fluids that was con-verted into urine to be excreted from the body via the kidneys and urinary bladder.
Convergence of Blood Vessels in the Lungs.The phrase, “con-vergence of blood vessels in the lungs” means that all blood flows along the vessels to all parts of the body through the lungs where the
exchange of gases takes place. The circulation of blood relies upon the impulsion ofqi and, with the lifting-lowering ofqi , the blood flows to all parts of the body. Since the lungs control respiration and dominate theqi of the whole body, the circulation of blood depends to a certain extent on the spread and coordination of lung-qi .
The Lungs Are in Charge of Coordination of Functional Activities.This lung function may be summarized as follows:
The Lungs
1. The lungs make rhythmic breathing movements.
2. By means of their breathing movements, the lungs regulate the way thatqi functions throughout the body (the lifting-lower-ing and enterlifting-lower-ing-exitlifting-lower-ing movements of qi ).
3. The lungs assist the heart in promoting and regulating blood circulation.
4. They help to maintain normal flow, distribution and discharge of body fluids.
The Lungs Are Responsible for Melancholy. Melancholy and sorrow as two modes of emotion, though slightly different from each other, exert roughly the same influence on physiological functions of the human body. Therefore, they both belong to the emotions of the lungs.
After all, melancholy and sorrow are the emotional responses to unfavor-able stimuli, bringing about a consuming effect on theqi of the body.
As the lungs dominateqi , melancholy and sorrow are apt to impair the lungs. On the other hand, when the lungs are deficient, the body’s tolerance to unfavorable stimuli is diminished and melancholy or sorrow is likely to occur.
The Lungs Connect with the Skin and Their Condition Is Ref lected on Vellus Hairs. Here the skin and vellus hairs refer to the entire body surface including the skin, sweat glands, pili, etc. The skin with its hairs must be nourished by warmth and replenished moisture.
These functions are accomplished by defensiveqi and body fluids, respectively and thus form a protective barrier against external pathogens. Since the lungs dominateqi and perform the functions of dispersing outward defensiveqi and sending the essence to the skin and vellus hairs, they are closely related to the skin and its hairs.
When the lungs function normally, the skin becomes compact and body resistance is enhanced. Otherwise, body resistance against foreign pathogens becomes weakened and such phenomena as hyperhidrosis and predisposition to common cold, wan, dry and lusterless skin and hairs, etc. are likely to occur. Conversely, the invasion of the skin and its hairs by foreign pathogenic agents causes closure of the striae of the skin and muscles. This results in the stagnation of defensiveqi , frequently followed by failure of lung-qi to disperse and descend, which, in turn, leads to such pathological changes as occlusion of the striae of skin and muscles, stagnation of defensiveqi and so on.
Nasal Discharge Derived from the Lungs. Nasal discharge is the mucuos secreted from mucous membrane of the nose, which moisten the nasal passage. The nose is the orifice of the lungs, and, under
Chapter 4: Phase of Viscera
normal circumstances, its discharge moistens nasal lining instead of running out. In the case of an attack of the lungs by pathogenic cold, the lucid nasal discharge flows from the nose; in the case of an attack by heat, the nasal discharge becomes yellowish and thick; and in the case of an invasion by dryness, the nasal cavity becomes dry.
The Nose as the Window of the Lungs.The nose connects with the larynx and the larynx with the lungs; the nose and larynx are the passageway of respiration. “The nose is the external orifice of the lungs.
The larynx is the gateway of the lungs.”
Lung-qi governs both the sense of smell and the pronunciation in the larynx. Sound lung-qi with smooth breathing is accompanied by a keen sense of smell and sonorous voice. If foreign pathogens invade the lungs and come mostly from the nose and larynx, such symptoms as stuffy nose, running nose, sneezing, itching of the throat, and hoarse-ness may occur.