Physiological Functions of the Channels and Collaterals
The channel and collateral system which takes the twelve regular channels as core has the basic functions of communicating and connecting, conveying qi and blood, reaction and conduction, as well as regulating functional balance etc.
1. Communicating and Connecting All Parts of the Body
The human body is made up of the five zang – viscera, six fu – viscera, four limbs, five sense organs, nine orifices, skin, muscles, tendons and bones. Each has its own respective physiological functions, yet performs a common organic activity of the whole. This kind of organic coordination and mutual relationship is accomplished through communication and connection by the channel system. The twelve channels, eight extraordinary channels ( vessels ) and their branches criss and cross, come in and go out, and ascend and descend. They therefore communicate the links between the viscera and the limbs and joints, the viscera and the orifices, and between the viscera and the channels. This creates an organic whole not only in organizational structure but also in physiological function, completing all kinds of complex functional activities.
2. Conveying Qi and Blood to Nourish the Whole Body
Every viscus and tissue of the human body needs nourishing and moistening by qi and blood so as to perform their normal function. Qi and blood depend upon the transportation and importation by the channels and collaterals in order to distribute and nourish the body. The channels and collaterals constantly transport qi and blood to all parts of the body to irrigate viscera and tissue internally, in addition to moistening Couti, skin, and external hair. The chapter of The Viscera as the Foundation of Human Beings in Spiritual pivot states, “ The channels and collaterals transport blood and qi to adjust the yin and yang, nourish tendons and bones, and improve joint functions.”
3. Reaction and Conduction
Reaction and Conduction mean that the channel – collatera syetem functions in response to the sensation of needling and other stimulations. It is called “ channel – collateral sensation phenomenon”. This phenomenon refers to sensations produced by the stimulation of an acupoint. These sensation may include soreness, numbness, expansion, and heaviness, and can be transmitted and spread along the running course of channels and collaterals. This phenomenon is called “ getting qi “ or “ arrival of qi “.
4. Regulating Functional Balance for the body
The channels and collaterals circulate qi and blood and coordinate yin and yang in order to keep a relative balance of bodily activities. When a disease occurs in the body, the symptoms related to the disharmony of qi and blood, and excess or deficiency of yin and yang emerge. These can be treated by acupuncture and moxibustion therapy to stimulate the channel’s regulative function, and achieve the purpose of “ reducing the excess and reinforce the deficiency to making yin and yang balanced.” (Chapter of Discussion on the five sections on needling and comments on the genuine qi and pathogenic factors in spiritual pivot )