The human body is an organic whole, composed of the viscera, the meridians and many other tissues and organs, The relationships between the zang-organs and the fu-organs are a component part in the theory of zangxiang. The zang-organs and the fu-organs are connected with each other through the meridians in structure, coordinate with each other and differ from each other in physiology as well as affect each other and transmit to each other in pathology.
The relationships among the five zang-organs
1. The relationship between the heart and the lung
The relationship between the heart and the lung is signified by the inter-dependence between qi and blood. Physiologically, the lung dominates qi and assists the heart to propel blood circulation; the heart governs blood and blood nourishes the lung and maintains the respiratory function of the lung. Since the pectoral qi accumulates in the chest, by means of flowing in the heart vessels to propel qi and blood and running in the respiratory tract to regulate respiration, to warm the heart and the lung, it can strengthen the coordination between the heart and the lung in propelling blood circulation and governing respiration.
Pathologically, deficiency of lung-qi and disorder of the lung in dispersing and descending will affect the function of the heart to propel blood; insufficiency of heart-yang will weaken blood circulation, leading to disorder of lung in respiration with the symptoms of cough, asthma, chest oppression and palpitation.
2. The relationship between the heart and the spleen
The relationship between the heart and the spleen includes two aspects. On the one hand the heart governs blood and promotes blood circulation while the spleen commands blood to circulate in the vessels. The coordination of the heart and the spleen ensures the normal circulation of blood. On the other hand, the heart nourishes the spleen if there is sufficient blood in the heart and regulates the function of the spleen because the heart governs the mind; the spleen absorbs food nutrients and transforms them into blood for the heart if it functions well. So clinically insufficiency of heart-blood or disorder of heart-spirit affects the function of the spleen; dysfunction of the spleen or failure of the spleen to command blood also leads to disorder of the heart, bringing on simultaneous disorder of both the spleen and the heart with the symptoms of palpitation, insomnia, poor appetite and loose stool, etc.
3. The relationship between the heart and the liver
The relationship between the heart and the liver is signified by circulation of blood and regulation of mental activities. The heart governs blood and is the motivation of blood circulation; the liver stores blood and is a very important factor in the storage and regulation of blood. So the heart and the liver coordinate with each other in blood circulation. The heart governs the mind and regulates mental activities; the liver governs dredging and dispersing and adjusts emotional activities. They are closely related to each other in maintaining mental and emotional activities.
Clinically insufficiency of liver-blood and deficiency of heart-blood may affect each other, leading to deficiency of both liver-blood and heart-blood with the symptoms of pale complexion, palpitation and dizziness. Disorder of heart-spirit and failure of the liver to dredge and disperse and emotional upset frequently affect each other, leading to dysphoria, insomnia, irritability and susceptibility to rage due to exuberance of heart-fire and liver-fire.
4. The relationship between the heart and the kidney
The relationship between the heart and the kidney is mainly signified by inter-dependence between heart-yin / heart-yang and kidney-yin / kidney-yang. The heart pertains to fire in the five elements and is located in the upper energizer; the kidney pertains to water in the five elements and is located in the lower energizer. Heart-fire (heart-yang) has to descend to the kidney to warm kidney-yang and prevent abnormal flow of water; kidney-water (kidney-yin) has to ascend to nourish heart-yin and prevent hyperactivity of heart-yang. Such a coordination between the upper and the lower is called "coordination between the heart and the kidney" or "coordination between water and fire". If kidney-yin fails to nourish heart-yin due to insufficiency, it will lead to deficiency of heart-yin and hyperactivity of heart-yang, bringing on dysphoria, insomnia, tinnitus and weakness of the waist and knees. If heart-fire fails to descend, it will cause heat in the upper and cold in the lower, leading to dysphoria, insomnia and cold sensation below the waist and knees. Such pathological cases are called "disharmony between the heart and the kidney".
Besides, the heart governs blood and the kidney stores essence. Blood and essence can transform into each other. So insufficiency of heart-blood will cause deficiency of kidney-essence and deficiency of kidney-essence, in turn, will result in insufficiency of heart-blood, consequently leading to disorder of both blood and essence with the symptoms of pale complexion, palpitation, tinnitus and weakness of the waist and knees.
5. The relationship between the lung and the liver
The relationship between the lung and the liver is signified by the regulation of qi activity. On the one hand, the lung and the liver coordinate with each other in regulating qi activity. The lung governs qi in the whole body, controls respiration and regulates qi activity; the liver governs dredging and dispersing and promotes qi to flow in the whole body. On the other hand, the lung and the liver adjust the movement of qi through the activities of ascent and descent. Lung-qi functions to descend and depurate while liver-qi functions to elevate and disperse. The liver and the lung, by means of ascent and descent, restrain each other and depend on each other so as to maintain the normal flow of qi in the whole body and avoid hyperactivity, adverse flow or sinking tendency. That is to say that the normal ascending and descending movement of qi depends on the coordination of the lung and the liver.
Besides, the lung and the liver affect each other pathologically. For example, fire transformed from liver stagnation may lead to disorder of the lung in depuration and descent; lung-heat may invade the liver and lead to disorder of the liver in dredging and dispersing. In both cases simultaneous disorder of the liver and the lung will be caused, clinically leading to reddish complexion, redness of eyes, irritability, susceptibility to rage, cough and pain in the chest and hypochondria due to simultaneous appearance of fire-heat and adverse flow of qi.
6. The relationship between the lung and the spleen
Physiologically, two aspects are involved in the relationship between the lung and the spleen. One is the production of the pectoral qi. The lung is responsible for inhaling fresh air and the spleen for absorbing food nutrients through transportation and transformation. The accumulation of the fresh air and food nutrients in the chest eventually transforms into the pectoral qi. Thus the normal functions of the lung and the spleen are prerequisite to sufficient production of the pectoral qi. The other is the metabolism of fluid. The spleen absorbs and transports water and the lung distributes water to all parts of the body, both of which are important to the metabolism of water. If deficiency of spleen-qi or insufficiency of lung-qi affects the production of the pectoral qi, it will lead to shortness of breath, no desire to speak, chest oppression, poor appetite and loose stool. If it affects the metabolism of fluid, it will bring on cough, asthma, profuse phlegm, edema and oliguria.
7. The relationship between the lung and the kidney
The relationship between the lung and the kidney is signified by respiration and fluid metabolism. The lung regulates water passage and the kidney controls water. The coordination of the lung and the kidney maintains the normal distribution and excretion of water. Besides, the lung governs respiration and the kidney receives qi. The lung and the kidney work together to accomplish respiratory activity and ensure air exchange between the internal and the external. Pathologically, disorder of the lung in regulating water passage and weakness of the kidney in transforming qi affect each other and cause disturbance in water metabolism, leading to edema and oliguria; failure of the lung to disperse and descend and failure of the kidney to receive qi also affect each other and causes disorder in respiration, bringing on symptoms of cough, chest oppression, shortness of breath and frequent dyspnea, etc.
8. The relationship between the liver and the spleen
The relationship between the liver and the spleen involves two aspects: digestion and blood circulation. The liver governs dredging and dispersing and regulates the ascending and descending activities of spleen-qi and stomach-qi, which is beneficial to the transportation and transformation of the spleen. The spleen governs the transportation and transformation of food nutrients that are transformed into blood to nourish the liver, which is beneficial to the dredging and dispersing functions of the liver. If the liver fails to dredge and disperse and invades the spleen, it will cause dysfunction of the spleen, clinically leading to hypochondriac pain, abdominal distension and loose stool, etc.
9. The relationship between the liver and the kidney
The liver and the kidney depend on each other. That is why it is said that "the liver and the kidney share the same origin" and "yi and kui share the same origin". "Yi" pertains to wood in the five elements and refers to the liver here; and "kui" pertains to water in the five elements and refers to the kidney here.
There are two reasons to explain why "the liver and the kidney share the same origin". One is that essence and blood come from the same source. The liver stores blood and the kidney stores essence. Sufficient blood in the liver makes it possible for the kidney to store the essence and abundant essence in the kidney provides necessary nourishment for the liver. So blood and essence promote each other and transform into each other. The other is mutual promotion between yin-fluids. The kidney pertains to water and the liver to wood. Thus kidney-water nourishes liver-wood and liver-yin invigorates kidney-yin. The mutual promotion and transformation between liver-yin and kidney-yin maintain the coordination between them and the superabundance of them.
Pathologically, insufficiency of liver-blood may lead to deficiency of kidney-essence and deficiency of kidney-essence will, in turn, bring on insufficiency of liver-blood, consequently resulting in dizziness, tinnitus and weakness of the waist. Besides, insufficiency of kidrtey-yin may lead to deficiency of liver-yin or prolonged deficiency of liver-yin may cause insufficiency of kidney-yin, usually resulting in deficiency of both liver-yin and kidney-yin.
10. The relationship between the spleen and kidney
The kidney is the congenital base of life while the spleen is the acquired base of life. The relationship between the spleen and the kidney is in fact the inter-dependence between the congenital and acquired bases of life. Kidneys store innate essence, and get nourished and supplemented by acquired essence to be prosperous; the spleen generates acquired essence, and get stimulated by kidney qi to perform its function of transportation and transformation. Therefore, the relationship between kidneys and the spleen is the innate promoting the acquired and the acquired nourishing the innate.
Pathologically, weakness of spleen-qi and dysfunction of the spleen in transportation and transformation will not provide the kidney with enough food nutrients, leading to insufficiency of kidney-essence with the manifestations of abdominal distension, loose stool, weakness of the waist and tinnitus. Failure of insufficient kidney-yang to warm spleen-yang causes deficiency of spleen-yang, leading to deficiency of both spleen-yang and kidney-yang with the manifestations of cold pain in the abdomen, diarrhea with undigested food or morning diarrhea and edema, etc.
The relationship among the six fu-organs
The relationships among the six fu-organs mainly involve the coordination in the process of digesting, absorbing and excreting food. After primary digestion in the stomach, food is transmitted to the small intestine where the chyme is further digested by separating the lucid from the turbid. At the same time the gallbladder excretes bile into the small intestine to promote digestion. After absorption, the small intestine transports food nutrients upwards to the heart and the lung to nourish the whole body. The rest of water is transformed by the kidney into urine and transmitted to the bladder. Food dregs are transported to the large intestine, and water in the dregs is absorbed by the large intestine to become stool i. e. discharged through the anus.
The six fu-organs mainly function to transport and transform food and water. So they constantly receive, transmit and excrete. When food and water are transmitted from the upper to the lower, the stomach and the intestines alternate with the states of fullness and emptiness so as to keep an unobstructed condition. That is why it is said that "the six fu-organs function well when they are not obstructed" and that "the disorder of the fu-organs can be treated by dredging therapy". Clinically disorders of the six fu-organs tend to affect each other. For example, failure of the gallbladder to dredge and disperse will affect the stomach, leading to hypochondriac pain, jaundice, poor appetite and vomiting due to dysfunction of both the gallbladder and the stomach. Consumption of fluid by excess-heat in the stomach will obstruct the large intestine, causing constipation.
The relationship between the five zang-organs and the six fu-organs
The relationship between the five zang-organs and the six fu-organs, though complicated, can be summarized as "mutual internal and external relationship". The zang-organs pertain to yin while the fu-organs to yang. Yin controls the internal and yang manages the external. Such a coordination between yin and yang as well as the internal and external makes up a special mutual internal and external relationship between the zang-organs and the fu-organs.
This special mutual internal and external relationship between the zang-organs and fu-organs covers five aspects: the heart and the small intestine, the lung and the large intestine, the spleen and the stomach, the liver and the gallbladder as well as the kidney and the bladder. But no organ is internally and externally related to the triple energizer. That is why the triple energizer is called "a solitary fu-organ. However, it is said in Huangdi Neijng that "the kidney is externally and internally related to the triple energizer and the bladder. "
The internal and external relationship between the zang-organs and the fu-organs is signified by mutual association with the meridians, mutual coordination in functions and mutual affection in pathology. The mutual association between the zang-organs and the fu-organs with the meridians is introduced in the chapter of the meridians and collaterals. The following discussion only focuses on the mutual coordination in functions and mutual affection in pathology.
1. The internal and external relationship between the heart and the small intestine
The heart governs blood vessels and propels blood to circulate in the whole body, also nourishing the small intestine. The small intestine receives chyme, absorbs food nutrients and transforms them into blood to enrich the heart. Physiologically they depend on each other; pathologically "the heart shifts heat to the small intestine" (that is to move exuberant heart-fire downward to the small intestine along the meridian) , leading to dysphoria, reddish tongue, sores in the mouth, oliguria, brownish urine and painful urination.
2. The internal and external relationship between the lung and the large intestine
The lung governs depuration and descent while the large intestine controls transmission. Normal function of the lung will transmit fluid downward to moisten the large intestine and promote the transmission of the large intestine. Normal function of the large intestine will ensure smoothness of the large intestinal qi and promote depuration and descent of lung-qi. So physiologically the lung and the large intestine depend on each other. Pathologically, failure of the lung to depurate and descend and failure of the large intestine to transmit will affect each other, bringing on various symptoms due to disorder of both the lung and the large intestine, such as chest oppression, cough, retention of dry feces or constipation.
3. The internal and external relationship between the spleen and the stomach
The spleen and the stomach are all located in the abdomen and pertain to the middle energizer, together governing the digestion and absorption of food and serving as the source of qi, blood and body fluid. That is why the spleen and the stomach are regarded as the "acquired base of life" in all the classics of TCM, the theory about which is known as "the theory of the spleen and the stomach".
The physiological relationship between the spleen and the stomach covers the following three aspects.
①Coordination in reception and transportation
The spleen governs transportation and transformation while the stomach controls reception and digestion. This is what the coordination of the spleen and stomach in reception and transportation means. After being taken into the stomach, food is primarily digested in the stomach, making it possible for the transportation and transformation of the spleen; after being further digested in the spleen, food nutrients are absorbed by the spleen to meet the need of the stomach for further reception. Only when reception and transportation are well coordinated can normal digestion and absorption of food be ensured.
②Mutual influence of ascent and descent
Spleen-qi governs the elevation of the lucid while stomach-qi controls the descent of the turbid, both of which restrict and assist each other. Through elevating the lucid the spleen transports food nutrients up to the heart and the lung; through descending the turbid the stomach moves the waste of food downwards. Without the descent of stomach-qi the waste of food will stagnate in the middle energizer, food nutrients cannot be transported to the other parts of the body and spleen-qi cannot rise; without the ascent of spleen-qi food nutrients cannot be transported upwards, leading to mixture of the lucid and the turbid in the abdomen and failure of stomach qi to descend. Only when the ascent of spleen-qi and descent of stomach qi coordinate with each other can digestion be normally carried on. That is why TCM holds that "ascent ensures normal function of the spleen and descent harmonizes the function of the stomach".
③Mutual promotion between dryness and dampness
The spleen prefers dryness and dislikes dampness while the stomach prefers moisture and dislikes dryness. Mutual promotion between dryness and dampness indiates that the spleen and stomach physiologically promote each other. The preference and aversion of the spleen are just opposite to those of the stomach. The spleen is a zang-organ and pertains to yin in nature. It transports, transforms and elevates the lucid with the assistance of dryness of yang-qi. Dampness pertains to pathogenic factor of yin in nature, tending to encumbering the spleen and affecting the functions of the spleen to transport and transform food and elevate the lucid. That is why the spleen prefers dryness and dislikes dampness. The stomach is a fu-organ and pertains to yang in nature. With the moisture of yin-fluid the stomach digests and descends food. Dryness is a pathogenic factor of yang in nature, tending to damage stomach-fluid and affecting the functions of the spleen to digest and descend food. That is why the stomach prefers moisture and dislikes dryness. Physiologically yin-fluid in the spleen is beneficial to the digestion and downward transmission of food. Besides, dryness of yang-qi in the stomach is helpful to the spleen to transport and transform food and elevate the lucid. So the spleen and the stomach promote each other with dryness and dampness, playing a very important role in the digestion of food and absorption of food nutrients.
Since the spleen and the stomach are closely related to each other in physiology, clinically spleen disorder and stomach disorder tend to affect each other, frequently leading to spleen disorder involving the stomach and stomach disorder involving the spleen, consequently bringing on the symptoms of anorexia, stomach distension, abdominal distension, vomiting, belching and diarrhea, etc.
4. The internal and external relationship between the liver and the gallbladder
The internal and external relationship between the liver and the gallbladder lies in the fact that both the liver and the gallbladder govern dredging and dispersing. The liver secretes and excretes bile while the gallbladder, attached to the liver, stores and excretes bile. The bile, coming from the liver and stored in the gallbladder, is excreted into the small intestine to assist digestion. Such a movement of the bile is accomplished by the free and smooth activity of qi to be ensured by the dredging and dispersing functions of the liver. However, the dredging and dispersing functions of the liver can be affected by the state of the gallbladder. The mutual action of the liver and the gallbladder on the flow of qi is due to the fact that both the liver and the gallbladder govern the activities of dredging and dispersing. For example, failure of the liver to dredge and disperse may lead to inhibited flow of gallbladder-qi and unsmooth excretion of the bile; stagnation of the bile may affect the functions of the liver to dredge and disperse, leading to stagnation of liver-qi. Furthermore, failure of both the liver and the gallbladder to dredge and disperse will inhibit the excretion of the bile, bringing on hypochondriac pain, jaundice and anorexia.
5. The internal and external relationship between the kidney and the bladder
The internal and external relationship between the kidney and the bladder lies in their dependence and mutual coordination in the excretion of urine. The turbid part of water in the body is transformed into urine by qi-transforming function of the kidney and transported down into the bladder to be discharged out of the body. The storage and excretion of urine by the bladder are accomplished by qi-transforming function of the kidney. Sufficiency of kidney-qi and normal qi-transformation will enable the bladder to open and close properly to excrete urine. Disorder of qi-transformation in the kidney will affect the function of the bladder, leading to dysuria or polyuria and enuresis, etc. If there is damp-heat in the bladder, it will inhibit the activity of qi, give rise to invasion of pathogenic factors into the kidney and affect qi-transforming function of the kidney, consequently impairing the kidney and clinically bringing on the symptoms of frequent urination, urgent urination and painful urination due to inhibited qi-transformation in the bladder and unsmooth urination as well as aching waist and lumbago due to impairment of the kidney.
Besides, Huangdi Neijing holds that the kidney is externally and internally related not only to the bladder, but also to the triple energizer. Since the kidney governs water and the triple energizer is water passage, they coordinate with each other in the metabolism of water. The triple energizer is connected with the upper and lower parts of the body. It can transport water in the whole body to the kidney. If kidney-qi is in disorder, it will lead to abnormal flow of water and accumulation of water in the triple energizer, eventually causing edema. Furthermore, the triple energizer can transport the primordial qi from the kidney to the whole body.