This is paired with the fu organ of the small intestine, which divides food into necessary and unnecessary parts, the latter passing to the large intestine. It is also concerned with the making of decisions. The kidneys are a zang organ and they produce basic energy, or ki, for the other five paired organs and also for reproduction, birth, development and maturity. They sustain the skeleton and brain and provide willpower and 'get up and go'. Kidneys are paired with the fu organ of the bladder, which stores waste fluids until they are passed as urine.
Bladder also gives strength or courage.
The zang organ of the 'heart governor' is concerned with the flow of blood throughout the body. It is a protector and help for the heart and has a bearing on relationships with other. This is paired with the 'triple heater' or 'burner', which passes ki around the body and allows an emotional exchange with others. The liver is a zang organ that assists with a regular flow of ki to achieve the most favorable physiological effects and emotional calmness. Positive feelings, humor, planning and creativity are also connected with it.