Ren meridian has the function of governing all yin meridians in the whole body. "The abdomen is yin and the back is yang", and its pulse gas intersects with the yin meridians of the hands and feet, so it is also called "the sea of yin veins", which is connected with the Du meridian in the opposite direction. Therefore, it has the functions of regulating the imbalance between yin and yang and regulating the yin meridian, and is in charge of the viscera: lung, spleen, heart, kidney and liver.
Du meridian runs on the back of human body, taking the meaning of du behind it and managing the yang of the whole body. Du meridian intersects with three Yang meridians of hands and feet and Yangwei meridians for many times, and is related to all Yang meridians, so it plays a regulatory role in qi and blood of the whole body Yang meridians, reflecting the functions of brain and kidney. Du meridian is connected with ren meridian in throat and perineum, and is in charge of internal organs: large intestine, stomach, small intestine, bladder and gallbladder.
Hands and feet are internal yin and external yang, and they correspond to three yin meridians and three yang meridians respectively. Sanyin Meridian is Taiyin, Shaoyin and Jueyin, Sanyang Meridian is Taiyang, Shaoyang and Yangming, so the twelve meridians is as follows:
Hand Taiyin Lung Meridian, Hand Shaoyin Heart Meridian, Hand Jueyin Pericardium Meridian,
Hand Taiyang Small Intestine Meridian, Hand Shaoyang Sanjiao Meridian and Hand Yangming Large Intestine Meridian;
Foot Taiyin Spleen Meridian, Foot Shaoyin Kidney Meridian, Foot Jueyin Liver Meridian,
Foot Taiyang bladder meridian, foot Shaoyang gallbladder meridian and foot Yangming stomach meridian.