Zo Fu translates as “internal organs” in Japanese There are five Zo organs and six Fu organs (including the Triple heater meridian). In Traditional Oriental medicine, the focus is on the internal organs as much as the muscle, sinew, and skeleton system. Adding Heart constrictor and Triple Heater meridians create the basis twelve organs of traditional Oriental medicine. Zo and Fu work together as a full energetic system.
Yin organs are Zo organs and are considered the dense organs.
Lung energy - responsible for respiration and the intake of air (空気) which is sent to the heart. It also eliminates waste (co2). Lungs eliminate the excessive heat of the internal organs and are responsible for the circulation of Ki energy and defensive Ki energy. Oriental medicine considers the skin as a part of the lungs, as air intake and heat reduction depend on the healthy skin.
Spleen energy - responsible for transforming food into the blood (血 ) and food Ki energy, which is sent to the Heart meridian. This is related to the Western understanding of the function of the pancreas. The Spleen energy also distributes Ki energy to each organ and purifies the body, and is responsible for the female reproductive system and its related functions.
Heart energy - the master organ of all organs, is the main combustion chamber of the primary Ki energy which combines, Air from the lungs and food energy from the Spleen, Stomach, and Small Intestine, to create primary Ki energy. The Heart meridian is also responsible for distribution of blood.
Kidney energy - responsible for controlling water in the body, the overall balance of Yin and Yang energy and the distribution of essence (神). The Oriental medicine definition of the kidney meridian is closely related to the Western understanding of the adrenal glands. Kidney energy is responsible for purifying the blood and supporting the reproductive system.
Liver energy - stores and circulates the blood and circulated the Ki energy throughout the body, The liver is also responsible for the purification of the blood.