Heart - The Zang Organs

The channel of the heart, located in the thorax, leads to the small intestine, and heart is thus externally and internally related to the small intestine. (Each zang organ is linked with a fu organ by a channel, a situation known as external-internal relation.) The heart also opens into the tongue. (Each zang organ opens into a sense organe which indicates a close structural or physiological and pathological relationship between the internal organs and the sense organs.) The main physiological functions of the heart are controlling blood and vessels and housing the mind.

1. Controlling blood and vessels. Vessels are the site of blood containment and circulation, the impulse of the heart sending blood incessantly through the vessels to nourish the whole body. When blood supply is sufficient and blood circulation normal, the complexion will be rosy and lustrous, and vitality full. The tissues and organs are well nourished and function properly.
2. Housing the mind. The heart is considered the main organ governing mental activities and generalizing the physiological function of the brain. Spirit, consciousness, memory, thinking and sleep are well dominated by this function of the heart. The two function of the heart have a mutual effect and correlation. According to Neijing: “The heart dominates the vessels and the vessels supply the mind.”
3. Opening into the tongue. The two functions of the heart, i.e., controlling blood and vessels and housing the mind, are closely related to the color, form, motility, and sense of taste of the tongue. This is also expressed as “the tongue is the mirror of the heart”.

ZANG-FU (Internal Organs)

The term zang-fu in traditional Chinese medicine refers to the gross anatomical entities of the internal organs. At the same time, it is also a generalization of the physiological functions of the human body. The heart, liver, spleen, lung, kidney and pericardium grouped together are known as the six zang organs. Their main physiological functions are manufacturing and storing essential substances including vital essence, qi (vital energy), blood and body fluid. The small intestine, gall bladder, stomach, large intestine, urinary bladder and sanjiao are known collectively as the six fu organs. Their main functions are to receive and digest food, absorb nutrient substances, and transmit and excrete wastes. There are in addition extraordinary fu organs including the brain and the uterus.

The zang organs are different in function from the fu, but the difference is only relative. In physiological activities, astructural and functional connection as well as co-ordination exists not only among the zang and the fu organs as separate entities, but also among the zang and the fu organs collectively, and even among the zang-fu organs on the one hand and the five sense organs and five tissues on the other. The theory of zang-fu taking the five zang organs (six including the pericardium) as core explains the peculiarity of traditional Chinese medicine, i.e. the concept of regarding the body as an integral whole physiologically and pathologically.