TCM believes that the human body is an organic whole and that all the tissues and organs in the body depend on each other in function. Such an interdependence between these tissues and organs can also be explained according to the theory of yin and yang. That is why it is said in Huangdi Neijing that "man has a physical shape which is inseparable from yin and yang". 

Generally speaking, the upper part of the body pertains to yang while the lower part to yin; the exterior pertains to yang while the interior to yin the back pertains to yang while the chest and the abdomen to yin the chest pertains to yang because it is located in the upper part of the body while the abdomen to yin because it is located in the lower part of the body; the lateral sides of the four limbs pertain to yang while the medial sides to yin. 

As to the zang-organs and the fu-organs, the five zang-organs pertain to yin because they store essence, but never discharge it; the six fu-organs pertain to yang because they transport and transform food, but never store it. Among the five zang-organs, the heart and the lung are located in the chest, so they pertain to yang; but the liver, the spleen and the kidney are located in the abdomen, so they pertain to yin. Each organ itself can be further divided into yin and yang aspects, such as heart-yin and heart-yang, kidney-yin and kidney-yang, etc.