In Chinese medicine the Meridians are the pathways for the movement of Qi and Blood, ensuring nourishment of the body. They also link up every part of the body and so create an organic integrity.
Disharmonies in an Organ may manifest themselves in the corresponding Meridians. A disorder in the Stomach Meridian, for example, may cause upper toothache because the Meridian passes through the upper gums; toothache in the lower jaw may be the result of a disorder of the Large Intestine Meridian. Acupuncture is the main method of rebalancing Qi and blood flow through the Meridians: reducing what is excessive, increasing what is deficient, warming what is Cold, cooling what is hot, circulating what is stagnant, moving what is congealed, stabilizing what is reckless, raising what is falling and lowering what is rising.
There are twelve regular Meridians which correspond to each of the twelve Organs. These are sometimes called the Jing Meridians (the Chinese character for Meridian is Jing meaning "river, path, track or trail" and also "blood vessel"). The Organ Meridian is the main energy channel that connect the particular Organ with other Organs and the surface of the body. In addition to the Organ Meridians are eight extra Meridians and many small, finer networks. The luo Vessels and the dai mai (which runs around the waist) act as connecting channels, keeping the Qi flowing along the Organ Meridians in balance. Together they circle the body like the longitudinal and latitudinal Meridians do the Earth. They may be viewed as a network connecting the polarities of the body: the interior with the exterior; the internal Organs with the surface; the Yin with the Yang, the material with the spirit, etc.