What are the functions of the Heart, Pericardium and Small Intestine?

In Chinese Medicine, the Heart governs Blood and the vessels and houses Shen; the Pericardium protects the Heart and participates in the functional organization of the chest; and the Small Intestine receives, transforms and separates the clear from the turbid. Although related, these systems have different functions within the Zang-Fu model.

In this article, you will understand how the Heart, Pericardium and Small Intestine are defined, the Heart's relationship with circulation and consciousness, the manifestations observed in the face, tongue and sweat, and the role of the Small Intestine in transformation and separation.

Continue reading to learn about the roles of each system and understand why the Heart and Small Intestine form a pair, while the Pericardium acts as the Heart's enclosure and protector.

How are these three systems understood in Chinese Medicine?

In Traditional Chinese Medicine, the Heart, Pericardium and Small Intestine do not represent anatomical structures alone. Their names identify functional systems built from the relationships observed among circulation, mental activity, digestion and external manifestations. Their roles are therefore broader than those recognized by modern anatomy and physiology.

The Heart system comprises the Heart itself, the Small Intestine, the vessels, face, tongue and related channel. This organization shows that its traditional functions are recognized through different regions and activities, not only by observing the organ located in the chest.

The Pericardium occupies a particular position because it surrounds and protects the Heart. The Small Intestine, in turn, belongs to the Fu bowels and participates in receiving, transforming and separating contents from the Stomach. Each system has its own roles, although they remain related within traditional theory.

What does it mean for the Heart to govern Blood and the vessels?

Chinese Medicine states that the Heart governs Blood and the vessels. This expression describes its participation in propelling Blood and maintaining its circulation. The system's proper function allows Blood to travel through the vessels and reach the different parts of the body.

The vessels are considered the tissues associated with the Heart because they form the pathways through which Blood circulates. The strength attributed to Heart Qi promotes this movement, while Blood provides the material basis required. In this way, cardiac activity, circulation and the condition of the vessels are studied together.

This traditional function has some similarity to the circulatory role of the anatomical heart, but the two concepts are not identical. The Heart of Chinese Medicine also includes mental, sensory and emotional relationships that do not belong to the modern cardiological definition. A diagnosis from one system should therefore not be automatically translated into the other.

What is the relationship between the Heart and Shen?

The Heart is described as the organ that stores Shen and governs mental and conscious activities. This relationship includes the capacity to maintain presence, organized thought, perception and an appropriate response to the environment. The Heart therefore occupies a central place in the traditional integration of bodily life and consciousness.

The expression “governing Shen” does not mean that all mental capacities are produced exclusively by the Heart. Other systems also participate in memory, reflection, planning and will. The Heart represents the center where these different activities manifest consciously and in a coordinated way.

When the state of Shen is assessed, characteristics such as clarity of the gaze, coherence of speech, attention, orientation and quality of contact are observed. These manifestations help us understand how conscious activity is being expressed. They belong to traditional assessment and do not replace neurological, psychiatric or psychological examinations.

How does the Heart manifest in the face, tongue, sweat and joy?

Chinese Medicine states that the Heart's radiance manifests in the face. The color, luminosity and vitality of a person's appearance are traditionally observed as reflections of its activity and of Blood circulation. However, isolated facial changes do not identify a pattern, because they must be interpreted alongside other signs.

The Heart also opens into the tongue. This association especially involves the tongue's appearance and the ability to speak and communicate thoughts. The theory holds that Heart Qi and Blood participate in nourishing it, allowing changes in this system to be investigated through features of the tongue and speech.

Sweat is described as the fluid related to the Heart, while joy is its corresponding emotion. These relationships do not mean that every instance of perspiration or expression of joy indicates a cardiac problem. They function as correspondences used to organize physical and emotional signs within a broader pattern.

What is the main function of the Pericardium?

The Pericardium is defined as the structure that surrounds and protects the Heart. In traditional language, it acts as a protective layer that prevents harmful influences from directly reaching the most central system. This function explains why it is often described as the Heart's protector, enclosure or external representative.

Its protective position does not mean that it is considered merely a passive membrane. The Pericardium has its own channel and participates in the functional organization of the chest. In channel theory, it belongs to the three Yin channels of the hand and maintains an interior-exterior relationship with the Sanjiao.

The Heart and Pericardium remain closely related, but they are not treated as identical concepts. The Heart holds the central position in relation to Blood and Shen, while the Pericardium primarily performs a function of surrounding and protecting it, receiving in some situations influences that might otherwise reach the Heart.

How does the Pericardium participate in the functions of the Heart?

By protecting the Heart, the Pericardium indirectly participates in preserving the functions attributed to it. Traditional literature relates changes in the Pericardium to manifestations in the chest, the circulation of Qi and Blood and consciousness, especially when certain factors reach deeper regions of the body.

This relationship appears clearly in the theory of febrile diseases, in which heat can penetrate the Pericardium and alter consciousness. In this context, the expression does not necessarily describe inflammation of the anatomical pericardium, but a traditional pattern characterized by mental impairment associated with the intense presence of heat.

The roles of the Pericardium therefore accompany some of the Heart's functions without replacing it. It is observed mainly in relation to protection, the chest and preservation of conscious activity. Traditional diagnoses involving the Pericardium do not automatically correspond to the diseases called pericarditis or pericardial effusion in modern medicine.

What does it mean for the Small Intestine to receive and transform?

The Small Intestine receives the contents initially decomposed by the Stomach. After receiving them, it continues their transformation, participates in the absorption of usable parts and conducts waste toward the following stages. It is therefore called the bowel responsible for reception, temporary holding and transformation.

Receiving does not merely mean allowing food to enter. The contents must remain long enough for further transformations to occur. The holding function is temporary because the Small Intestine should not permanently store what it receives, but process and move it onward according to its characteristics.

Transformation corresponds to continuing the process begun in the Stomach. The nourishing part is used, while waste proceeds toward the Large Intestine. Chinese Medicine describes this activity as an important stage in the passage from initial digestion to absorption and elimination.

What does it mean to separate the clear from the turbid?

Separating the clear from the turbid is one of the Small Intestine's central functions. The clear corresponds to nourishing substances and fluids that can be used by the body. The turbid represents waste that will not be used and must continue its path until it is eliminated.

This separation occurs during the transformation of the contents received. Usable components are absorbed, while solid waste is conducted toward the Large Intestine. Some fluids are also separated and directed according to the internal processes of distribution and elimination described by Chinese Medicine.

The word “clear” does not mean that every usable substance is visually transparent, just as “turbid” does not merely describe appearance. The terms indicate the functional quality of the contents: what can nourish and be integrated into the body is distinguished from what must be discarded.

How do the Heart and Small Intestine operate as a pair?

The Heart and Small Intestine form an interior-exterior pair within the Zang-Fu system. The Heart is a Yin Zang organ, while the Small Intestine is a Yang Fu bowel. The connection between them also appears in the organization of their respective channels.

The pair brings together systems with different functions. The Heart governs Blood, the vessels and conscious manifestation, while the Small Intestine receives, transforms and separates contents. Their association does not mean that they perform the same activity, but that they are understood as related parts of a broader functional organization.

The Pericardium does not form a second pair with the Small Intestine. It protects the Heart and, in channel theory, is related to the Sanjiao. Thus, the three appear near one another in the study of Chinese Medicine but occupy different positions: the Heart and Small Intestine form a pair, while the Pericardium surrounds and protects the Heart.

About the author

Prof. Tibério Z has more than 30 years of experience teaching spirituality, metaphysics, holistic therapies and consciousness development.