The direction of the twelve meridians has a certain regularity, such as the three Yin meridians of the hand go from the chest to the hand, and intersect with the three Yang meridians of the hand at the end of the fingers, as follows:
The three yin meridians of the hand go from the chest to the hand, and intersect with the three yang meridians of the hand at the ends of the fingers; the three yang meridians of the hand go from the hand to the head, and intersect with the three yang meridians of the foot in the head and face; the three yang meridians of the foot go from the head to the foot and intersect with the three yin meridians of the foot at the end of the toes; the three yin meridians of the toes go from the foot to the abdomen, and intersect with the three yin meridians of the hand in the chest and abdomen.
To summarize, the hand meridian is mainly distributed in the upper limbs, the foot meridian is mainly distributed in the lower limbs and chest and abdomen; Yang meridian intersects in the head, yin meridian intersects in the chest and abdomen, the twelve meridians form the yin and yang, such as the ring without end. The twelve meridians form a connection between yin and yang, such as a ring without end. They have the effect of connecting the internal organs, communicating with the internal and external organs; running the qi and blood, nourishing the whole body; resisting disease and evil spirits, reflecting the symptoms of disease; and conducting and sensing and adjusting the effect of yin and yang.