Theory of Meridians (Channels)
Meridians (Channels) control the Qi (Energy) and blood throughout the interior and exterior of the body. The treatment using acupuncture uses the 'points' with the needle to stimulate the balance thereby, treating the organs and problems within the body.
There are 12 meridians interconnected with the organs of the body and are in charge of transporting the Qi and blood while regulating the yin and yang (resisting pathogenics and reflecting symptoms and signs/transmitting needling sensation and regulating deficiency and excess conditions).
The other 8 extra meridian, 12 divergent meridian, 12 muscle regions and, 12 cutaneous pertained organs.