Zang-fu viscera
Zang-fu viscera (Template:Zh-stp), in visceral manifestations (Template:Zh-s), are organs contained within the human body, is the common name of five zang viscera (Template:Zh-s), six fu viscera (Template:Zh-s), and extraordinary fu-viscera (Template:Zh-s).
Zang-Fu theory is a concept within traditional Chinese medicine (TCM) that describes the functions of the organs of the body and the interactions that occur between them.  Zang  refers to the yin organs - heart, liver, spleen, lung, kidney, pericardium - whilst Fu  refers to the yang organs - small intestine, large intestine, gall bladder, urinary bladder, stomach and san jiao.  Each of the twelve zang-fu organs listed have a corresponding organ, except the pericardium and san jiao which both describe functions that are not related to an organ.  A recognised protocol in TCM texts will capitalise the first letter of the organ name when referring to the TCM concept of the organ (for example Liver, instead of liver; Spleen instead of spleen).  Each zang is paired with a fu, and each pair are assigned to one of the five elements.

# The functions of the organs
The organs dynamically regulate each other cyclically. Each organ has a corresponding organ that it is responsible for negatively regulating and an organ which it is responsible for positively regulating. The manner in which the organs interact with each other is described by five-element theory. Each organ is characterized by one of the five elements, and behaves appropriately with respect to that element (when the individual is healthy). Organ regulatory systems, with respect to the elements, to the Yin organs or the yang organs. The Yin and Yang organs relate to each other primarily in resonating energies. For example, the kidneys and the bladder are the yin and yang water organs, respectively, and resonate with each other. One does not really regulate the other, they work together.
The organs themselves are characterized not by anatomical position but by a general function within the system as a whole that may not necessarily correspond to any western anatomical account. The functions of the organs are described with respect to their roles to each other, connections to the body surface, including meridians, Qi (vital force), Spirit (psychological aspect), Jing (TCM) (essence), Xue (blood), and "fluids."
The five elements are associated energetically with the following Zang-Fu organs
- Wood: Liver, home of the Hun (, Ethereal Soul), paired with the Gall Bladder
- Fire: Heart, home of the Shen (, Aggregate Soul) paired with the Small intestine (and secondarily, the San Jiao or Triple burner and Pericardium)
- Earth: Spleen, home of the Yi (?, Intellect), paired with the Stomach
- Water: Kidney, home of the Zhi (?, Will), paired with the Bladder
- Metal: Lung, home of the Po (, Corporeal Soul), paired with the Large Intestine
TCM diagnoses rely on recognizing global patterns of disfunction in the patient, explainable in terms of five element theory and yin-yang theory. A thorough understanding of each organ's function and symptoms of disfunction will give insight into the process of disease and illness according to TCM.

# The Yin Organs

## The Lung
Metal. home of the Po (, Corporeal Soul), paired with the Large Intestine
The function of the Lung is to descend and disperse qi throughout the body.  It receives qi through the breath, and exhales the waste.  The Lung governs the skin and hair and also governs the exterior (one part of immunity).  A properly functioning Lung organ will ensure the skin and hair are of good quality and that the immune system is strong and able to fight disease.  The normal direction of the Lung is downwards, when Lung qi "rebels" it goes upwards, causing coughing and wheezing.  When the Lung is weak, there can be skin conditions such as eczema, thin or brittle hair, and a propensity to catching colds and flu.  The Lung is weakened by dryness and the emotion of grief or sadness.

## The Liver
Wood. home of the Hun (, Ethereal Soul), paired with the Gall Bladder
The function of the Liver is to ensure the smooth flow of qi throughout the body.  The liver opens to the eyes and manifests in the finger and toe nails. It also governs the sinews and tendons.  A properly functioning Liver organ will ensure that the tendons are properly nourished and not too tense or gristly.  The normal direction of Liver qi is downwards, when Liver qi "rebels" it can attack the Spleen causing nausea and poor appetite, it can rebel upwards causing tenseness in the shoulders and headaches, or it can stop flowing and become stagnant - leading to irritability and anger.  When the Liver is dysfunctional there can be conditions such as headaches, premenstrual symptoms, tense muscles, loss of appetite, insomnia, anger, irritability and frustration.

## The Spleen
Earth. Home of the Yi (?, Intellect), paired with the Stomach
The function of the Spleen is to transform food and drink into qi and blood and transport these substances around the body.  The Spleen governs the extremities, the muscles and the blood vessels.  When the Spleen is functioning well, digestion will be good, the muscles will be strong and circulation will be efficient.  When the Spleen is weak there can be nausea, this often occurs when the Liver "attacks" the Spleen.  Cold hands and feet, lack of muscle tone, easy bruising and poor concentration/overthinking can be signs that the Spleen is weak.  The Spleen is weakened by dampness.

## The Kidney
Water. Home of the Zhi (?, Will), paired with the Bladder
The Kidneys store Essence, govern birth, growth, reproduction and development. They also produce the Marrow which fills the brain and control the bones. The Kidneys are often referred to as the 'Root of Life' or the 'Root of the Pre-Heaven Qi'. Kidneys house the Will Power (Zhi).

## The Heart
Fire. Home of the Shen (, Aggregate Soul) paired with the Small intestine
The Heart is considered to be the most important Internal Organ, sometimes described as the 'ruler', 'emperor' or monarch. The main function of the Heart is to govern the blood, which it does in two ways: transforming Food-Qi into Blood, and circulating the Blood just the same as in Western Medicine.

## The Pericardium
Fire. Paired with the San Jiao or Triple burner
The Pericardium is closely related to the Heart. Known as 'Master of the Heart' (Xin Zhu) and 'Envelope of the Heart' (Xin Bao). The traditional view of the Pericardium is that it functions as an external covering of the Heart, protecting it from attacks by exterior pathogenic factors. Like the Heart, the Pericardium governs Blood and houses the Mind. The Pericardium as a channel is also linked to the Triple Burner: 'The Triple Burner protects the Internal Organs on the outside and the Pericardium protects the Heart on the outside'.

# The Yang Organs

## The Large intestine
Metal
The function of the Large Intestine is to control the passage and conduction of stools. In the process, it transforms the stools and reabsorsbs fluids from them. It receives food and drink from the Small Intestine, conducts the food and drink down, and after absorbing some of the fluids, it excretes the stools. The Large Intestine is closely related to the Lungs, in the way that Lung Qi aids in its downward movement, therefore influencing defecation. As the Lungs control the skin, the Large Intestine also has influence on it.

## The Gall bladder
Wood

## The Urinary bladder
Water

## The Stomach
Earth

## The Small intestine
Fire

## The Triple Burner (San jiao)
Fire

# Association between the zangfu and particular souls
The association between the zangfu and particular souls or spirits is a later accretion and has been largely absent from the discourse of traditional Chinese medicine for at least the past 200 years.
This theory treats each of the Zang organs as organs that nourish the body.  The Zang systems include organs, senses, emotions, and the
musculoskeletal system--essentially, the entire person divided into five
categorical systems.  Zang organs are also known as yin organs, and each has a Fu partner, a yang organ (see Yin Yang).  Fu organs can be viewed as hollow organs that aid in digestion.  In addition to bodily functions, each Zang organ is the home of an aspect of the spirit.
With a thorough understanding of the Zang Fu organs, practitioners can achieve therapeutic results accordingly. The theory is always in service of practical, therapeutic application, with the goal of an "elegant" treatment. An elegant treatment uses the least amount of force for the greatest therapeutic benefit, and requires true mastery of the art of traditional Chinese Medicine.

# Criticism
Some scholars have characterized the conceptual framework of TCM as pseudoscientific.
Proponents reply that TCM is a prescientific system that continues to have practical relevance.
See Acupuncture: Criticism of TCM theory.