The Five Organs refer to the heart (xin), liver (gan), spleen (pi), lungs (fei), and kidneys (shen). They have the functions of transformation and storage, characterized by the retention of essence (jing), qi, blood, body fluids (jinye), and spirit (shen) without leakage, being full but not solid. In Traditional Chinese Medicine (TCM), the concept of the Five Organs extends beyond mere anatomical definitions. The term “organ” (zang) historically means “to store.” The primary physiological functions of the Five Organs include the transformation and storage of essence, qi, blood, body fluids, and spirit, hence they are also referred to as the Five Spirit Organs. Since essence, qi, and spirit are fundamental to life activities, the Five Organs play a crucial role in human life.
1. Physiological Functions and Characteristics of the Liver1. The liver governs the smooth flow of qi: The liver’s function of smooth flow refers to its ability to regulate the movement of qi, ensuring its unobstructed flow. The movement of qi is essential for the physiological activities of all organs and tissues in the body. A normal liver function ensures the smooth flow of qi, leading to normal physiological activities throughout the body. Conversely, abnormal liver function can lead to various pathological changes. The liver’s smooth flow function is primarily reflected in the following four aspects:(1) Promoting blood circulation and body fluid metabolism: The circulation of blood and metabolism of body fluids rely on the driving force of qi and the smooth flow of qi. The physiological activities of the organs also depend on the smooth flow of liver qi.(2) Facilitating the spleen and stomach’s transformation and the secretion and excretion of bile: The liver’s smooth flow function can regulate the qi of the spleen and stomach, maintaining their ability to ascend clear and descend turbid, thus ensuring normal digestion and absorption. Additionally, the liver secretes and excretes bile, which is formed from the residual qi of the liver, aiding in digestion and absorption by the spleen and stomach.(3) Regulating emotional activities: Emotional activities are primarily governed by the heart but are closely related to the liver’s smooth flow function. Normal emotional activities depend on the smooth flow of qi, which the liver facilitates.(4) Regulating the discharge of menstrual fluid and ovulation: The normal onset and cycle of menstruation in women, as well as ejaculation in men, are closely related to the liver’s smooth flow function.2. Governing blood storage: The liver’s function of blood storage refers to its ability to store blood, regulate blood flow, and prevent bleeding. The physiological significance of blood storage includes nourishing liver qi, regulating blood volume, nourishing the liver and tendons, serving as the source of menstrual blood, and preventing bleeding.The liver governs smooth flow, which is yang in function, while its body is yin, hence the saying “the liver is yin in essence but yang in function.”3. Physiological characteristics of the liver:(1) The liver is a firm organ: This refers to the liver qi’s active and vigorous nature.(2) The liver governs the upward movement: This indicates the liver’s role in promoting the upward movement of yang qi and regulating the flow of qi.2. Physiological Functions and Characteristics of the Heart1. The heart governs consciousness: The heart has the function of receiving, processing, and reflecting information, generating consciousness, thought, and emotions; it is the supreme organ among the five organs and governs the entire body. The concept of spirit (shen) is broad, often referring to the mysterious and miraculous aspects of things. In TCM, the basic meanings of spirit include both a broad sense encompassing the functions and laws of material movement in nature and the manifestations of life activities in the human body, as well as a narrow sense referring solely to human consciousness, thought, and emotional activities. Modern medicine considers human mental, conscious, and cognitive activities as physiological functions of the brain, which reflects external objective phenomena. However, TCM attributes mental activities to the heart, based on several theoretical foundations:First, mental activities are associated with the five organs.Second, the heart is considered the site of mental activities.Third, blood serves as the material basis for mental activities. The heart governs blood, and when blood vessels are full, consciousness is clear.In summary, the ancient understanding of the heart as the “supreme organ of the five organs” is inseparable from its function of housing the spirit and governing consciousness. Therefore, Ming dynasty physician Zhang Jiebin pointed out in his work “Classified Essentials”: “The heart is the master of the organs, governing the soul and spirit, and thus when emotions stir the heart, the lungs respond; when thoughts stir the heart, the spleen responds; when anger stirs the heart, the liver responds; when fear stirs the heart, the kidneys respond; hence the five emotions are all governed by the heart.” He also stated: “Although emotional injuries belong to the five organs, they all originate from the heart.” Thus, while human consciousness and thought can be associated with the five organs, they primarily belong to the heart’s governing function. Therefore, when the heart’s governing function is normal, the spirit is uplifted, consciousness is clear, thinking is agile, and responses to external information are sensitive and normal. Conversely, if the heart’s governing function is abnormal, it can lead to disturbances in consciousness and thought, resulting in insomnia, vivid dreams, restlessness, or even delirium; or it may lead to sluggish responses, forgetfulness, mental fatigue, or even coma and unresponsiveness.2. The heart governs blood vessels: It has the function of circulating and generating blood. The term “governs” implies management and control. Blood refers to the vital substance in the body, while vessels refer to the channels through which qi and blood flow, also known as “blood houses” in TCM. The heart’s governance of blood vessels refers to its physiological function of propelling blood through the vessels. The heart is located in the chest, connected to the vessels, forming a closed circulatory system.The heart beats continuously throughout a person’s life, delivering blood to all organs and tissues to maintain normal life activities. The rhythmic beating of the heart corresponds with the rhythmic pulsation of the vessels, known as the “pulse,” which can be palpated at certain body locations, such as the neck (ying pulse), wrist (cun kou pulse), and dorsum of the foot (fu yang pulse). TCM uses the palpation of these pulse points to assess the overall state of qi and blood, serving as a basis for clinical diagnosis, known as “pulse diagnosis.”The heartbeat can also be felt beneath the left breast, an area referred to as “xu li” in TCM. Palpating the xu li can aid in diagnosing heart conditions.The face has a rich supply of qi and blood, and the state of the heart’s qi and blood is often reflected in the complexion and luster of the face, hence the saying “the heart’s manifestation is on the face.” Observing color is also an important method in TCM for diagnosing diseases.TCM believes that the heart’s ability to beat normally and propel qi and blood relies on the strength of heart qi. Under physiological conditions, when heart qi is robust, the function of propelling blood is normal, leading to smooth circulation of qi and blood throughout the body, reflected in a rosy and radiant complexion, and a regular, strong pulse. If the heart’s governance of blood vessels is dysfunctional, it can lead to corresponding pathological changes, primarily manifested in the following aspects:1. Insufficient heart qi: This refers to a deficiency of the heart’s essence, leading to reduced blood circulation. Symptoms may include palpitations, a pale complexion, and a weak pulse.2. Blood stasis in the heart: If heart qi is insufficient, blood circulation may be impaired, leading to blood stasis in the heart. Symptoms may include palpitations, chest tightness or pain, a gray complexion, cyanosis of the lips, and irregular pulse.3. Heart blood deficiency: The normal function of the heart governing blood vessels relies on strong heart qi, sufficient blood volume, and unobstructed vessels. If heart blood is deficient, the vessels may not be adequately filled, leading to symptoms such as palpitations, a pale complexion, and a weak, thin pulse.3. Physiological Functions and Characteristics of the Spleen1. Governing transformation and transportation: The spleen’s function of transformation refers to its ability to digest food and absorb its essence (guo jing) and body fluids (shui jing), transporting them to the heart and lungs for distribution throughout the body. Since the components absorbed by the spleen include both essence and body fluids, the spleen’s function of transformation is often divided into two aspects: one is the transformation of essence, and the other is the transformation of body fluids. The transformation of essence refers to the absorption of nutrients from digested food and their transportation to the heart and lungs for distribution. Since these nutrients are the primary raw materials for generating qi and blood, the spleen is also referred to as the source of qi and blood transformation, “the spleen governs the stomach’s transportation of body fluids.” The transformation of body fluids refers to the absorption of certain body fluids from digested food, converting them into body fluids and transporting them to the heart and lungs. However, the functions of transforming essence and body fluids are closely related and cannot be distinctly separated.2. Governing blood production and containment: The spleen governs blood production, with the essence of food and fluids transported to the heart and lungs transforming into blood. The spleen also governs blood containment, with spleen qi having a consolidating effect, preventing blood from leaking out of the vessels.3. The spleen governs the upward movement of clear substances: It transports the essence of food and fluids upward to the heart and lungs, generating qi and blood to nourish the entire body; it also maintains the relative stability of the internal organs’ positions to prevent them from descending.4. Physiological characteristics of the spleen:(1) Spleen qi governs upward movement: This refers to the spleen qi’s movement, primarily characterized by its upward movement, specifically in terms of ascending clear substances and lifting the internal organs. The term “ascending clear” refers to the spleen’s absorption of nutrients and their upward transportation to the heart, lungs, and head, where they are transformed into qi and blood to nourish the entire body. Thus, it is said that “the spleen is healthy when it ascends.” The upward lifting of internal organs refers to the spleen qi’s ability to maintain the relative stability of the internal organs’ positions, preventing them from descending.(2) Preferring dryness and disliking dampness: The condition for the spleen qi’s upward movement is that the spleen is dry and not obstructed by phlegm or dampness. Hence, it is said that “the spleen ascends when it is dry.”4. Physiological Functions and Characteristics of the Lungs1. The lungs govern qi: The lungs are responsible for inhalation and exhalation, participating in the formation of zong qi (ancestral qi), thus governing the qi of the entire body.2. The lungs connect to all vessels, assisting the heart in governing blood vessels.3. The lungs govern the dispersal and descending of qi.4. The lungs govern the movement of water, regulating water metabolism, serving as the upper source of water, transporting body fluids throughout the body; distributing essence, fluids, and nutrients; dispersing defensive qi to the surface; and descending body fluids to the bladder, clearing the respiratory tract, and inhaling clear qi into the body.5. Physiological characteristics of the lungs:(1) The lungs are the canopy and delicate organ: The lungs are referred to as the canopy because they are located in the chest, at the highest position. They are considered delicate because they are a clear and subtle organ, sensitive to external pathogens.(2) Governing dispersal and descending: The lungs govern dispersal, meaning that lung qi has the function of ascending and dispersing outward: firstly, through the lung’s qi transformation, expelling turbid qi from the body; secondly, distributing the body fluids and nutrients transformed by the spleen to the entire body, reaching the skin and hair; thirdly, dispersing defensive qi and regulating the opening and closing of the pores, transforming the metabolized body fluids into sweat for excretion; the lungs govern descending, meaning that lung qi has the function of clearing and descending inward: firstly, inhaling clear qi from the environment and distributing zong qi downward to nourish the original qi; secondly, distributing the clear qi inhaled by the lungs and the body fluids and nutrients transported from the spleen downward; thirdly, transporting the turbid fluids produced by the organs downward to the kidneys and bladder, serving as the source of urine production.5. Physiological Functions and Characteristics of the Kidneys1. Storing essence and governing growth, development, reproduction, and organ qi transformation: (1) Essence refers narrowly to the reproductive essence inherited from parents and stored in the kidneys, known as congenital essence. Postnatal essence comes from the refined substances of food and fluids, hence the saying “the kidneys govern water and store the essence of the five organs and six bowels.” Therefore, the composition of kidney essence is based on congenital essence and relies on postnatal essence for nourishment. Congenital and postnatal essences support each other and work together. When the body reaches a certain developmental stage, and reproductive functions mature, kidney essence can transform into reproductive essence for discharge.(2) Governing reproduction: This refers to the physiological functions of kidney essence and its transformed qi. Essence is the fundamental substance for forming and maintaining life activities, promoting growth and reproduction. The state of human growth and development can be observed through hair, teeth, bones, and reproductive functions. The development of reproductive organs, the maturity and maintenance of sexual functions, and reproductive capacity are closely related to the essence and qi in the kidneys. When a person reaches youth, the essence and qi in the kidneys gradually become abundant, leading to the maturation of reproductive organs and the production of a substance known as “tian gui” (heavenly water), which promotes the development and maintenance of sexual functions. Sexual intercourse leads to conception.(3) Promoting and regulating organ qi transformation: Organ qi transformation refers to the rise and fall of qi in the organs, which drives and regulates the functions of the organs, thereby promoting and regulating the metabolism of essence, qi, blood, and body fluids, as well as their energy transformations. Kidney qi is transformed from kidney essence, and the interactions of kidney essence, kidney qi, and their differentiated kidney yin and kidney yang play a crucial role in promoting and regulating organ qi transformation. Kidney yin has cooling, calming, inhibiting, and consolidating effects, while kidney yang has warming, promoting, exciting, and dispersing effects. Kidney yang is the source of all yang qi in the body, while kidney yin is the source of all yin qi, hence the saying “the yang qi of the five organs cannot arise without this, and the yin qi of the five organs cannot be nourished without this.” When kidney yang is abundant and kidney yin is sufficient, the physiological functions of the organs are normal, and organ qi transformation can function properly.2. Governing water: The kidneys govern water, meaning that kidney qi has the function of managing and regulating the metabolism of body fluids throughout the body. This is primarily reflected in two aspects:(1) The promoting effect of kidney qi on the organs involved in body fluid metabolism.(2) The kidney’s role in urine production and excretion.3. Governing the intake of qi: The kidneys govern the intake of qi, meaning that kidney qi has the function of receiving the clear qi inhaled by the lungs, maintaining the depth of inhalation, and preventing shallow breathing.4. Physiological characteristics of the kidneys: The kidneys are characterized by their ability to conceal and protect, which summarizes their function of storing essence. Their functions of receiving qi, governing reproduction, and regulating excretion all reflect this ability to conceal, corresponding with the winter season.