【Question】What is the relationship between the twelve meridians and collaterals?
【Insight】The human body’s meridian system consists of meridians and collaterals, where collaterals are branches of the meridians that interconnect and form a network throughout the body.
Collaterals include three categories: bie luo (branch collaterals), fu luo (floating collaterals), and sun luo (small collaterals). The bie luo are larger branches, totaling 15, which are derived from the twelve meridians at the wrist and ankle joints, along with the collaterals of the ren mai (Conception Vessel), du mai (Governing Vessel), and the large collateral of the pi (Spleen), hence also referred to as the fifteen branch collaterals or fifteen collaterals. The fu luo are branches that run superficially, while the sun luo are the smallest branches.
The collaterals branching from the twelve meridians, as well as those from the ren mai, du mai, and the large collateral of the pi, are all named after their respective luo xue (collateral points), specifically:
The shou tai yin luo mai (Hand Taiyin Collateral) is called lie que, the zu tai yin luo mai (Foot Taiyin Collateral) is called gong sun; the shou shao yin luo mai (Hand Shaoyin Collateral) is called tong li, the zu shao yin luo mai (Foot Shaoyin Collateral) is called da zhong; the shou jue yin luo mai (Hand Jueyin Collateral) is called nei guan, the zu jue yin luo mai (Foot Jueyin Collateral) is called li gou; the shou tai yang luo mai (Hand Taiyang Collateral) is called zhi zheng, the zu tai yang luo mai (Foot Taiyang Collateral) is called fei yang; the shou yang ming luo mai (Hand Yangming Collateral) is called pian li, and the zu yang ming luo mai (Foot Yangming Collateral) is called feng long; the shou shao yang luo mai (Hand Shaoyang Collateral) is called wai guan, and the zu shao yang luo mai (Foot Shaoyang Collateral) is called guang ming.
The collateral of the ren mai is called jiu wei, the collateral of the du mai is called chang qiang, and the large collateral of the pi is called da bao.
The distribution of the fifteen collaterals follows a specific pattern. After branching from the collaterals of the twelve meridians, they all connect to the corresponding meridians, meaning that the Yin collaterals connect to the Yang meridians and vice versa.
The branch collaterals of the ren mai are distributed in the abdominal area and descend; the branch collaterals of the du mai are distributed in the lumbar and back area and ascend; the large collateral of the pi branches out and spreads to the lateral rib area.