The eight extraordinary Qi vessels and the twelve primary Qi channels (meridians) comprise the main part of the channel system. Most of the eight vessels branch out from the twelve primary channels and share the function of circulating Qi throughout the body. These vessels form a web of complex interconnections with the channels. At the same time, each has its own functional characteristics and clinic utility independent of the channels.
Traditional Chinese medicine emphasizes the twelve primary organ-related channels and only two of the eight vessels (the Governing and the Conception Vessels). The other six vessels are not used very often simply because they are not understood as well as the other channels, and there is still a lot of research being conducted on them. Although they were discovered two thousand years ago, little has been written about them. There is a lot of research on the extraordinary vessels being conducted today, especially in Japan, but the results of one researcher often contradict the results that another has achieved.
I would like to compile and summarize the important points from the limited number of available documents. Since references from original Chinese sources are very scarce, and references from Western textbooks are tentative, esoteric, or in disagreement with one another, I have used my own judgment in selecting ideas and details.
What are the Eight Vessels?
The eight vessels are called “Qi Jing Ba Mai.” “Qi” means “odd, strange, or mysterious.” “Jing” means “meridian or channels.” “Ba” means “eight” and “Mai” means “vessels.” Qi Jing Ba Mai is then translated as “Odd Meridians and Eight Vessels” or “extraordinary meridian (EM).”
Odd has a meaning of strange in Chinese. It is used simply because these eight vessels are not well understood yet. Many Chinese doctors explain that they are called “Odd” simply because there are four vessels that are not paired. Since these eight vessels also serve the function of homeostasis, sometimes they are called “Homeostatic Meridians.” French acupuncturists call them “Miraculous Meridians” because they were able to create therapeutic effects when all other techniques had failed. In addition, because each of these channels exerts a strong effect upon psychic functioning and individuality, the command points are among the most important psychological points in the body.
For this reason, they are occasionally called “The Eight Psychic Channels.”
These vessels are:
- Governing Vessel (Du Mai)
- Conception Vessel (Ren Mai)
- Thrusting Vessel (Chong Mai)
- Girdle (or Belt) Vessel (Dai Mai)
- Yang Heel Vessel (Yangchiao Mai)
- Yin Heel Vessel (Yinchiao Mai)
- Yang Linking Vessel (Yangwei Mai)
- Yin Linking Vessel (Yinwei Mai).
The first brief mention of some of these eight vessels is found in the second part of the Nei Jing chapter of the book Huang Di Nei Jing Su Wen (The Yellow Emperor’s Classic,) (Han dynasty, circa 100-300 B.C.) by Ling Shu. Also, some of the vessels were mentioned in Bian Que’s classic Nan Jing (Classic on Disorders,) (Qin and Han dynasty, 221 B.C. to 220 A.D.). It was not until the 16th century that all eight vessels were deeply studied by Li, Shi-Zhen (1518-1593 A.D.) and revealed in his book Qi Jing Ba Mai Kao (Deep Study of the Extraordinary Eight Vessels). From then until only recently, very few documents have been published on this subject. Although there is more research being published, as yet, there is still no single document, which is able to define this subject systematically and in depth.
General Functions of the Eight Vessels
Serve as Qi Reservoirs. Because the eight vessels are so different from each other, it is difficult to generalize their characteristics and functions. However, Bian Que in his Nan Jing specified one of the most common characteristics of the eight vessels. He reported that the twelve organ-related Qi channels constitute rivers, and the eight extraordinary vessels constitute reservoirs. The reservoirs, especially the Conception and Governing Vessels, absorb excess Qi from the main channels, and then return it when they are deficient.
You should understand however, that because of the limited number of traditional documents, as well as the lack of modern, scientific methods of Qi research, it is difficult to determine the precise behavior and characteristics of these eight vessels. The main difficulty probably lies in the fact that they can be taken at different levels, because they perform different functions and contain every kind of Qi such as Ying Qi, Wei Qi, Jing Qi, and even blood.
When the twelve primary channels are deficient in Qi, the eight vessels will supply it. This store of Qi can easily be tapped with acupuncture needles through those cavities, which connect the eight vessels with the twelve channels. The connection cavities behave like the gate of a reservoir, which can be used to adjust the strength of the Qi flow in the rivers and the level of Qi in the reservoir. Sometimes, when it is necessary, the reservoir will release Qi by itself. For example, when a person has had a shock, either physically or mentally, the Qi in some of the main channels will be deficient. This will cause particular organs to be stressed, and Qi will accumulate rapidly around these organs. When this happens, the reservoir must release Qi to increase the deficient circulation and prevent further damage.
Guarding Specific Areas Against ‘Evil Qi’. The Qi, which protects the body from outside intruders, is called “Wei Qi” (Guardian Qi). Among the eight vessels, the Thrusting Vessel, the Governing Vessel, and the Conception Vessel play major roles in guarding the abdomen, thorax, and the back.
Regulating the Changes of Life Cycles. According to chapter 1 of “Su Wen,” the Thrusting Vessel and the Conception Vessel also regulate the changes of the life cycles, which occur at 7-year intervals for women and 8-year intervals for men.
Circulating Jing Qi to the Entire Body, Particularly the Five ‘Ancestral Organs’. One of the most important functions of the eight vessels is to deliver Jing Qi (Essence Qi, which has been converted from Original Essence and sexual Essence) to the entire body, including the skin and hair. They must also deliver Jing Qi to the five ancestral organs: the brain and spinal cord, the liver and gall bladder system, the bone marrow, the uterus, and the blood system.