Meridians and collaterals

The meridians and collaterals are pathways in which the qi and blood of the human body are circulated. They pertain to the zang - fu organs interiorly and extend over the body exteriorly, forming a network and linking the tissues and organs into an organic whole. The meridians, which constitute the main trunks, run longitude and interiority within the body ; while the collaterals, which represent branches of the meridians, run transversely and superficially from the meridians. They are collectively termed Jingluo ( meridians and collaterals ) in traditional Chinese medicine. This system of meridians and collaterals includes the twelve regular meridians, eight extra meridians, fifteen collaterals, twelve divergent meridians, twelve muscle regions and twelve cutaneous regions.

It is said in Chapter 33 of Miraculous Pivot " internally, the twelve regular meridians connect with the zang - fu organs, and externally with the joints, limbs and other superficial tissues of the body. " The meridians and collaterals arc distributed both interiorly and exteriorly over the body, transporting qi and blood to nourish the zang - fu organs, skin, muscles, tendons and bones. Normal functioning of various organs is thus ensured, and a relative equilibrium maintained. It is stated in Chapter 10 of Miraculous Pivot that " so important are the meridians and collaterals which determine life and death in the treatment of all diseases and the regulation of deficiency and excess conditions that one must gain a thorough understanding of them. The importance of studying the theory of meridians and collaterals can indeed never be overemphasized.

The theory of meridians and collaterals was systematized by the ancient Chinese people in their prolonged clinical practice. Its formation is generally considered to be in relation to the observation of the symptoms and signs of diseases and the transmission of needling sensation, the application of Tuina ( Chinese remedial massage ) , Daoying ( ancient deep breathing exercises ) , and ancient anatomical knowledge. Just like the other basic traditional Chinese medical theories, such as that of the zang - fu organs, of qi and blood, etc., the theory of meridians and collaterals is of great significance in guiding diagnosis and treatment in traditional Chinese medicine, and acupuncture in particular.

Responsible for the circulation of qi and blood and distributed both interiorly and exteriorly across the body, the meridians and collaterals have an extensive coverage in contents. The following is a general description of their nomenclature, functions, distribution and the order of the cyclic flow of qi and blood.

The Nomenclature of the Meridians and Collaterals and Their Composition.

The twelve regular meridians include the three yin meridians of the hand ( the Lung Meridian of Hand - Taiyin, the Pericardium Meridian of Hand - Jueyin and the Heart Meridian of Hand - Shaoyin ) , the three yang meridians of the hand ( the Large Intestine Meridian of Hand - Yangming, the Sanjiao ( Triple Energizer ) Meridian of Hand - Shaoyang and the Small Intestine Meridian of Hand - Taiyang ) , the three yang meridians of the foot ( the Stomach Meridian of Fool - Yangming, the Gallbladder Meridian of Foot - Shaoyang and the Bladder Meridian of Foot - Taiyang ) , and the three yin meridians of the foot ( the Spleen Meridian of Foot - Taiyin, the Liver Meridian of Foot - Jueyin and the Kidney Meridian of Foot - Shaoyin ) . They are called the twelve regular meridians because they are the major trunks in the system. The nomenclature of the twelve regular meridians is based on the three factors : a ) hand or foot, b ) yin or yang, and c ) a zang or fu organ. Both the upper limbs ( hands ) and lower limbs ( feet ) are divided into six regions, which are supplied respectively by the three yin ( Taiyin, Shaoyin and Jueyin ) and three yang ( Yangming, Taiyang and Shaoyang ) meridians. There exists an exterior - interior relationship between the three yin and three yang meridians :

• Taiyin - - Yangming
• Jueyin - - Shaoyang
• Shaoyin - Taiyang

In accordance with the fact that the zang organs pertain to yin, the fu organs to yang, and the medial aspect is attributed to yin, the lateral aspect, to yang, the meridians that pertain to the zang organs are yin meridians, which are mainly distributed on the medial aspect of the four limbs. Those distributed on the medial aspect of the upper limbs are three yin meridians of the hand ; while those distributed on the medial aspect of the lower limbs are three yin meridians of the foot.

The meridians that pertain to the fu organs are yang meridians, which mainly travel along the lateral aspect of the four limbs. Those traveling along the lateral aspect of the upper limbs are three yang meridians of the hand ; while those traveling along the lateral aspect of the lower limbs are the three yang meridians of the foot.

• The Lung Meridian of Hand - Taiyin
• The Large Intestine Meridian of Hand - Yangming
• The Stomach Meridian of Foot - Yangming
• The Spleen Meridian of Foot - Taiyin
• The Heart Meridian of Hand - Shaoyin
• The Small Intestine Meridian of Hand - Taiyang
• The Bladder Meridian of Foot - Taiyang
• The Kidney Meridian of foot - Shaoyin
• The Pericardium Meridian of Hand - Jueyin
• The Sanjiao Meridian of Hand - Shaoyang
• The Gallbladder Meridian of Foot - Shaoyang
• The Liver Meridian of Foot - Jueyin

The eight extra meridians, different from the twelve regular meridians, are called the extra meridians in short. Their nomenclature is explained as follows. Du means governing. Running along the midline of the back, the Du ( Governor Vessel ) Meridian governs all the yang meridians. Ren means fostering and responsibility. Going along the midline of the abdomen, the Ren ( Conception Vessel ) Meridian is responsible for all the yin meridians. Chong means a vital pass. As it regulates the flow of qi and blood in the twelve regular meridians, the Chong Meridian is called " the sea of the twelve primary meridians. " Dai means a girdle. The Dai Meridian goes around the waist, binding up all the meridians. Qiao means the heel. The one starting from below the external malleolus is the Yangqiao Meridian, while the one starting from below the internal malleolus is the Yinqiao Meridian. Wei denotes connection and network. The Yangwei Meridian connects and networks the exterior yang of the whole body while the Yinwei Meridian connects and networks the interior yin of the whole body.

• Du Meridian
• Ren Meridian
• Chong Meridian
• Dai Meridian
• Yangqiao Meridian
• Yangwei Meridian
• Yinqiao Meridian
• Yinwei Meridian

Besides, the twelve divergent meridians are those going out from the regular meridians and the fifteen collaterals are branches arising from the regular meridians.

Connected with their own relating regular meridians, the twelve muscle regions and cutaneous regions of the twelve regular meridians are named after hand or foot, three yin or three yang respectively as well.

Functions of the Meridians and Collaterals.The network of the meridians and collaterals is closely connected with the tissues and organs of the body, and plays an important role in human physiology pathology, prevention and treatment of ailments.

• Transporting qi and blood and regulating yin and yang. Under normal conditions, the system of the meridians and collaterals functions to transport qi and blood and regulate the balance between yin and yang of the whole body. Chapter 47 in Miraculous Pivot says : " The meridians and collaterals transport blood and qi to adjust yin and yang, nourish tendons and bones, and improve joint function. " The meridians and collaterals are passages for the circulation of qi and blood. Transversely and longitudinally, they cross with each other in both the interior and exterior of the body. " Nutrient qi flows inside the meridians and defensive qi runs outside the meridians, " thus the interior and the exterior, the upper and lower portions and the left and right sides of the body are kept in a close association, and a relative equilibrium of normal life activities is maintained.
• Resisting pathogens and reflecting symptoms and signs. Under pathological conditions, the system of the meridians and collaterals exerts its functions of combating pathogens and reflecting systemic or local symptoms and signs. Chapter 71 in Miraculous Pivot points out, " When the lung and heart are involved in a pathogenic invasion, the pathogenic qi lingers in both elbows ; when the liver is involved, it lingers in both axillae ; when the spleen is involved, it stays in both groins ; when the kidney is involved, it stays in both popliteal fosse. " This classical exposition shows that various symptoms and signs of diseases of the internal organs may find their way to the particular location where the corresponding meridians traverse. Occasionally, disorders of internal organs may give rise to reactionary signs on the face or in the five sense organs. For instance, flare - up of the heart lire may cause ulceration on the tongue ; perverse ascension of the liver fire may lead to congestion and swelling of the eye ; deficiency of kidney qi may result in decrease of hearing, etc. Besides, when the antipathogenic qi is deficient and pathogenic qi predominant, the meridians and collaterals may serve as passages for pathogen transmission. Disorders of meridians and collaterals developing from the exterior may traverse inward to impair the internal organs in the interior. Conversely, diseases of internal organs may affect the meridians and collaterals, as is described in Chapter 22 of Plain Questions, " In a case of liver disease, the pain in both hypochondria may extend to the lower abdomen, " and " a patient with a heart disease may have pain in the chest, fullness of the costal region, pain in the hypochondrium, back, shoulder, and even in the medial aspect of both arms. "
• Transmitting needling sensation and regulating deficiency and excess conditions. In the treatment and prevention of disease, the system of the meridians and collaterals assumes the responsibility of transmitting needling sensation and regulating deficiency or excess conditions. When acumoxibustion therapy is applied, stimulation of the acupoints is transmitted to the relevant zang - fu organs. Consequently, normal free flow of qi and blood is restored, the functions of zang - fu organs regulated, and diseases cured. It is said in Precious Supplementary Prescriptions " located on the courses of the meridians and collaterals, acupoints usher qi to the distant sites to achieve curative aims. " Chapter 5 in Miraculous Pivot states, " The key point in acupuncture treatment is to know how to regulate yin and yang, " meaning that the therapeutic action of acupuncture and moxibustion is realized mainly through the function of meridians and collaterals in regulating yin and yang. " The arrival of qi, " a phenomenon in acupuncture is the functional manifestation of the meridians and collaterals in transmitting needling sensation. Therapeutic results are closely related to " the arrival of qi. " Therefore, the first chapter in Miraculous Pivot points out, " In acupuncture, the arrival of qi is essential to obtaining therapeutic effects. " And Chapter 9 in Miraculous Pivot says, " Acupuncture treatment must aim at regulating the flow of qi. " To induce " the arrival of qi " and to employ the reinforcing and reducing methods in acupuncture are simply for the purpose of regulating the flow of qi, and neither of them can be successful without the transmissive function of the meridians and collaterals.

Distribution of the Fourteen Meridians. The twelve regular meridians together with the Du and Ren Meridians are called " the fourteen meridians. " The twelve regular meridians are distributed symmetrically at the left and right sides of the body. Both the Du and Ren Meridians emerge from the perineum, and ascend respectively along the midlines of the front and back of the body.

• Distribution in the Limbs : The medial aspect of the limbs attributes to yin, the lateral to yang. Each limb is supplied by the three yin and three yang meridians. On the upper limbs, the anterior border of the medial aspect and the radial end of the thumb are supplied by the meridian of Hand - Taiwan ; the middle of the medial aspect and the radial end of the middle finger by the meridian of Hand - Jueyin ; the posterior border of the medial aspect and the radial end of the small finger by the meridian of Hand - Shaoyin, while the meridian of Hand - Yangming goes from the radial end of the index finger to the anterior border of the lateral aspect : the meridian of Hand - Shaoyang from the ulnar end of the index finger to the middle of the lateral aspect, the meridian of Hand - Taiyang from the ulnar end of the small finger to the posterior border of the lateral aspect. On the lower limbs, the anterior border of the lateral aspect and the lateral end of the second toe are supplied by the meridian of Foot - Yangming ; the middle of the lateral side and the lateral end of the fourth toe by the meridian of Foot - Shaoyang : the posterior border of the lateral aspect and the lateral end of the little toe by the meridian of Foot - Taiyang, while the meridian of Foot - Taiyin runs from the medial end of the great toe to the middle of the medial aspect of the lower limb and Further goes round to its anterior border, the meridian of Foot - Jueyin goes from the lateral end of the great toe to the anterior border of the medial aspect of the lower limb and further shifts to the middle ; and the meridian of Foot - Shaoyin starts under the little toe, crosses the sole and further goes along the posterior border of the medial aspect of the lower limb.
• Distribution in the Body Trunk : In the thoracic and abdominal regions, the Ren Meridian is situated on the midline. The first line lateral to it is the Kidney Meridian of Foot - Shaoyin, the second lateral line is the Stomach Meridian of Foot - Yangming, and the Lung Meridian of Hand - Taiyin and the Spleen Meridian of Foot - Taiyin correspond to the third line. The Gallbladder Meridian of Foot - Shaoyang is located at the lateral side of the hypochondrium and the lumbar region, while the Liver Meridian of Foot - Jueyin is in the region of the anterior external genitalia and hypochondrium. On the back, the Du Meridian stays in the middle, while both the first and second lines lateral to the Du Meridian are the Bladder Meridian of Foot - Taiyang.
• Distribution in the Head, Face and Neck : The Yangming Meridians of Hand and Foot run in the facial region ; and the Shaoyang Meridian of Hand and Foot travel in the lateral aspect of the head. The Du Meridian goes along the midline of the neck and head, while the Bladder Meridian of Foot - Taiyang runs on both sides of the Du Meridian. Among the twelve regular meridians, the yin meridians pertaining to the zang organs communicate with the fu organs, while the yang meridians pertaining to the fu organs communicate with the zang organs, thus forming an exterior - interior relation between yin and yang, the zang and fu organs. The zang organs ( the lung, heart and pericardium ) that are situated in the chest are connected with the yin meridians of the hand, while those ( the spleen, liver and kidney ) in the abdomen are linked with the yin meridians of the foot. The six - fu organs, however, are related to yang meridians in accordance with their respective exterior - interior relations. All the three yang meridians of the - band and foot traverse the head and facial regions. In this way, between the twelve regular meridians and the head, face, chest and abdomen a specific relationship is established. Chapter 38 of Miraculous Pivot states, " The three yin meridians of the hand go from the chest to the hand ; the three yang meridians of the hand run from the hand to the head ; the three yang meridians of the foot travel from the head to the foot ; and the three yin meridians of the foot go from the foot to the abdomen. " The meridians of the hand and foot are connected with each other, forming an interminable circulation of yin and yang.

Not only do the twelve regular meridians have their fixed courses, but also they cross at given places as follows : the yin meridians ( the interior meridians ) meet the yang meridians ( the exterior meridians ) in the four limbs ; the yin meridians meet the yin meridians bearing the same name on the head and face ; and the three yin meridians of the hand and the three yin meridians of the foot meet in the chest.

Cyclical Flow of Qi in the Twelve Regular Meridians. The twelve regular meridians link one another in a fixed order. A cyclical flow of qi is maintained by the connection of the meridians of the hand and foot, yin and yang, exterior and interior.

Meridian Maximal activity ( HOURS )

• L 3 - 5

• Li 5 - 7 Sunrise

• S 7 - 9
• Sp 9 - 11

• H 11 - 13 Midday

• Si 13 - 15
• B 15 - 17

• K 17 - 19 Sunset

• P 19 - 21
• Sj 21 - 23

• G 23 - 1 Midnight

• Liv 1 - 3