China's earliest medical text, The Yellow Emperor's Canon of Internal Medicine, says at its outset that the meridian system is the most fundamental system of the body. The jingmai are the vertical meridians (channels) through the body. There are 12 regular meridians in addition to a horizontal network which runs from the jingmai throughout the body.
在中國最早的醫書《黃帝內經》中，開宗明義指出，人體的最基本系統是經絡，經脈是人體內的縱行的管道，包括十二正經、十二經別等四組，加上橫行的十五絡脈及聯絡經絡的奇經八脈共有六組。