The Meridian Wheel
There are 14 major meridians in the body, each of which has its own acupoints. Two of these vessels, Governing & Central Vessels, flow up from the region of the groin. Central Vessel carries yin energy. Governing Vessel carries yang energy. The other 12 vessels are bilateral, with one running up or down the right, & one up or down the left side of the body. Of these bilateral meridians, 6 are yin & 6 are yang.
TCM see the meridians grouped into Five Elements, each Element is a pair with one yang meridian & one yin meridian. Each element has a primary quality, with reference to elements in the natural world - Fire, Earth, Metal, Water & Wood elements.
These five elements were linked together by the energy flow of ch'i that flowed through complex pathways they called meridians. The meridians have primary pathways of flow & are distributed by the acupoints. The acupoints can control the flow of ch'i so that it is evenly distributed throughout the body. A tenet of acupuncture is that all imbalances are related to unbalanced ch'i flow. So when one system has too much energy or an excess of energy, this results in physiological disturbances that in western physiology we term inflammatory. When there is too little ch'i energy in a system it is deficient in energy; these physiological disturbances in the western system are called congestive.
In the body, once the energy block is removed & the balance restored, the physiological function that was affected by the previous energy or ch'i disturbance disappears. In TCM, pain is only a sign of over-energy, & if you drain the excess energy away the pain will also drain away.
The meridian wheel or clock flows through the 12 primary meridians. Meridian ch'i flows are continuous from one meridian to the other in a specific order, but one that does not follow the deeper flows of the Law of Five Elements. Called clock flows or wheel flows, there is an orderly progression of a 2-hour peak of energy in each meridian that then flows to the next meridian in the repeated sequence, head to foot, foot to trunk, trunk to hand & hand to head, creating a 24-hour cycle.
Ref: C Krebs & T O’Neill McGowan 2014, Energetic Kinesiology