It forms the renal system with the bladder, bone marrow, brain, hair and ears. The Kidneys are the source of essence, Qi and bones, and are the source of yin and yang in the internal organs and the source of
The kidney and the bladder, bone marrow, brain, hair, ears, etc. constitute the kidney system. The kidney is the source of yin and yang and the source of life for the human body’s organs and internal organs, so it is called the innate source. It belongs to water in the five elements and is the yin of yang. It corresponds to winter in the four seasons.