- They are Du, Ren, Chong, Dai, Yin Qiao, Yang Qiao, Yin Wei, and Yang Wei. Only Du and Ren have their points .
- They are not exteriorly–interiorly related and do NOT pertain to or communicate with the Zang-Fu organs.
- Functions: (1) strengthening the association among the meridians; (2) as a reservoir, regulating the volume of Qi and blood.
