It is a collective term of the liver, heart, spleen, lung, and kidney. The five zang-organs are also called five spiritual zang-organs due to their governing and participating roles in mental activities. They are primarily involved in storing essential qi to nourish the whole body rather than transporting and eliminating food residues and wastes. Essential qi has to be abundant and move without blockage so that the nutrients can be distributed evenly. Otherwise, disorders may occur due to the stagnation. That’s why the five zang-organs are characterized by storage without discharge and abundance without excess. Five zang-organs are not only closely related to each other, but also interconnected with their corresponding factors and phenomena in nature. They are the core of the theory of visceral manifestation.