Yinyang Theory and Terminology of Twelve Meridians in Huangdi's Canon of Medicine

Terminology of meridians was closely related with yinyang theory of TCM.The concepts of Meridian and channel and the munber twelve were all inspired by relative concepts of yinyang.Because of the equivalence of yinqi and yangqi,meridians were named three yin meridians and three yang meridians.The terminology of meridians according to the equivalent interior and exterior,upper and down,before and behind embodied the regulation and balance of yin and yang of human body.