Under general conditions, the blood volume of the viscera, tissues, and organs of the body is relatively constant. However, it must be able to adapt to such changes as the functional state of the body and the influence of the climatic changes. For example, when a person is at rest or asleep, the amount of blood needs to be relatively decreased, and the partial blood flows back to the liver to be stored. When the body is performing physical labor, the amount of blood needs to be increased, and the liver will expel the blood it has stored, to increase the volume of blood in circulation, thus satisfying the demand by the body's activities. Thus, Wang Bing said in explanation in the Plain Questions, "When the body moves about, the blood is distributed into the meridians, and when the body is at rest, and the blood flows back to the liver where it is stored. " Since the liver has the physiological function of retaining and regulating blood, there is a saying, "The liver is the sea of blood. " This is why the physiological activities of the various parts of the body are in close relation with the liver.

If the liver is diseased, its function of blood-storing will be abnormal, which not only leads to the disorder of the blood, but also affects the physiological functions of other vis-cera, tissues, and organs. Malfunctioning of the liver in storing blood is manifested in two pathological changes. First, the storage of blood may be insufficient, and the amount of blood distributed to various parts of the body decreased, thus making the liver unable to satisfy the body's physiological demand, causing numbness of limbs, scanty menstrua-tion, and even amenorrhea. Secondly, the liver may fail to store the blood, causing hem-orrhage syndromes, such symptoms as hematemesis, hemoptysis, epistaxis, metrorrhagia and metrostaxis, etc.

In addition, it is said in the visceral manifestation theory that "The liver stores the etherial soul. " The etherial soul is born of the vitality. However, both take the blood as their material basis. The heart dominates the blood vessels which house the mind, while the liver stores the blood which houses the etherial soul. If the blood-storing function of the liver is normal, the etherial soul can be housed . If liver-blood is insufficient, and heart-blood is impaired, the etherial soul cannot be housed, and there will be fright, dream-disturbed sleep, somnambulism, somniloquy, and hallucination.

As the mentioned above, the liver stores blood, and dominates the conducting and dispersing functions. Yet there is an interdependant and inter-restraining relationship be-tween these two functions. In physiology, domination of the liver in the conducting and dispersing functions regulates the functional activity of the qi, and the flow of qi leads to the circulation of blood, which flows back to the liver to be stored. If liver-blood is am-ple, yin-blood of liver can control liver-yang to avoid an overactive state. In pathology, these two functions often affect each other. For example, failure of the liver in storing blood may lead to insufficiency of liver-blood, and the liver will lack the nourishment of blood. This leads to a disturbance of the liver's conducting and dispersing functions, characterized by irascibility, restlessness of mind, mental depression, dream-disturbed sleep, dull pain in the chest and lateral costal region, irregular menstruation, etc.