Heart

The heart is situated in the chest, above the Diaphragm, and is enveloped by pericardium externally. TCM believes that the heart governs all the other zang-fu organs and, therefore, is a "monarch organ". The heart, pertaining to fire in the five elements, consists of heart-yin, the material structures containing the heart-blood, and heart-yang, the functional activities.As for physiological functions, the heart is thought to, first, dominate blood and vessels since it is the motive force for blood circulation. The blood vessels are the physical structures containing the blood. The blood vessels are linked with the heart to form a closed system, and blood circulation is performed by the cooperation of the heart and the blood vessels. Under the impulse of heart-qi, blood is transported to all parts of the body for nutritive prupose. Thereby the condition of heart-qi and the blood volume may be shown in both the pulse condition and the complexion. That's why Basis Questions (Su Wen ) says, "The heart has its outward manifestation in the face or complexion". As a result, whether heart-qi and heart-blood are sufficient or not can affect the strength, rate and rhythm of the heart.

The heart houses the mind, also known as the heart dominating the mental activities. The mind, in its broad meaning, refers to the outward manifestations of the life activities of the whole body, and, in its narrow sense, to mental activities controlled by the heart, including consciousness, spirit, thinking, etc. The zang-fu theory holds that mental activities and thinking are to take the heart's functions as their basis. Spirit, consciousness, thinking, memory and sleep are all related to the function of the heart in housing the mind. Therefore, Miraculous Pivot (Ling Shu ) says, "The heart is the residence of the mind" and also, "The heart takes on the performance of activities." The heart opens into the tongue. "Resuscitation", in TCM, means the close relationship between a particular zang-organ and one of the sense organs in the structure, physiology and pathology. So the heart, though being in the body, is connected with the tongue by the heart-meridians. Through such a connection, whether the heart functions normally or not can be clearly learnt from the tongue condition. In other words, the tongue condition may show the physiological and pathological changes of the heart. So TCM holds: "The tongue serves as the mirror( or body opening ) of the heart". In addition, the heart has its outward manifestations in the face. The heart corresponds to joy in the emotions. And its meridians connect with associate with, be related to the small intestine with which they are internally-externally related.

The pericardium, serving as the peripheral tissue surrounding the heart, plays a part in protecting the heart When exogenous pathogenic factors attack the heart, the pericardium is always the first to be attacked. The heart, if invaded by the pathogens, will be impaired and diseases will ensue. For example, high fever, coma and red tongue are described as "heat-pathogen attacking the pericardium," and, in fact, the clinical manifestations of the pericardium invaded by exogenous pathogens are the same as those of the heart. For this reason, the pericardium is usually regarded as an attachment to the heart.

Lungs

The lungs, including the two lobes, one on the left and right separately, are situate in the thorax. They are compared to the "canopy" becausea of its uppermost position among all the zang-fu organs. They are also termed "delicate zang organs".

The lungs dominate qi and respiration. They are the place of exchange between the gases inside and outside the body. Basic Question ( Su Wen ) says, "atmosphere communicating to the lungs". The lungs also govern dispersing and descending, and regulates water passage, and communicate with numerous vessels to coordinate functional activities of the whole body, assisting the heart to adjust normal circulation of qi and blood. The lungs corresponds to melancholy in the emotions and are related to the skin and hair externally. They open into the nose and their conditions are reflected on vellum hairs. In the meridian-collnteral relation,the lungs and the large intestine are exteriorly-interiorly related because of interconnecting-interpertaining of the Lung Meridianof Hand-Taiyin and the Large Intestine Meridian of Hand-Yangming.

Spleen

People are apt to associate the livcr with its functions of storing blood and governing normal flow of qi. The former is concerned with the liver's capability in storing blood and regulating the blood volume. A certain amount of blood stored in the liver can restrict liver-yang hyperactivity so as to maintain the normal flow of qi. If the liver fails to function normally in storing blood. Such pathological changes as liver-blood deficiency or bleeding will occur. The liver also play a principal role in regulating the blood volume，especially the volume in the peripheral portion of the body. The latter, governing the normal flow of qi, is an important link in regulating qi movement, promoting the circulation of blood and body, as well as harmonizing emotional activities. The liver's another function is incarnated in its regulating emotional activities, promoting digestion and absorption and keeping qi and blood flowing normally. Besides the above, the liver are also closely related to the tendons, nails and the eyes. It has its specific body opening in  the eyes and its outward manifestation on the nails.

Liver

The liver is at the right hypochondriac region below the diaphragm in the upper abdomen. The liver and gallbladder make a pair of zang-fu. The liver meridian connects with the gallbladder to form an exteriorinterior relationship.

People are apt to associate the livcr with its functions of storing blood and governing normal flow of qi. The former is concerned with the liver's capability in storing blood and regulating the blood volume. A certain amount of blood stored in the liver can restrict liver-yang hyperactivity so as to maintain the normal flow of qi. If the liver fails to function normally in storing blood. Such pathological changes as liver-blood deficiency or bleeding will occur. The liver also play a principal role in regulating the blood volume，especially the volume in the peripheral portion of the body. The latter, governing the normal flow of qi, is an important link in regulating qi movement, promoting the circulation of blood and body, as well as harmonizing emotional activities. The liver's another function is incarnated in its regulating emotional activities, promoting digestion and absorption and keeping qi and blood flowing normally. Besides the above, the liver are also closely related to the tendons, nails and the eyes. It has its specific body opening in  the eyes and its outward manifestation on the nails.

kidney

The kidneys, situated in the lumbar zone, one on either side of the spinal column, store the congenital essence and are, therefore, considered as the "foundation of prenatal life". Their main physiological functions are: storing essence; dominating growth, development and reproduction; regulating water metabolism and receiving qi. The kidneys also take charge of the bone and manufacturc marrow. Meanwhile, the kidneys have their conditioias revealed on  hairs and open into the ears and, the two"private parts"-urethra and anus. The kidneys' meridians connect with the urinary bladder, with which they are internally-externally related.