1. Composition and Pathways of Meridians in the Human Body
The meridians are the channels through which the body’s vital energy (qi) flows, encompassing both the primary meridians (jingmai) and the collateral meridians (luomai). The term “jing” refers to the primary meridians, akin to direct pathways, serving as the main trunk of the meridian system; “luo” refers to the collateral meridians, resembling a network, which are the smaller branches of the primary meridians. They connect the internal organs (zangfu) and are distributed throughout the body, linking various tissues and organs into an organic whole. The theory of meridians is one of the foundational theories of Traditional Chinese Medicine (TCM), positing that meridians can “determine life and death, address numerous diseases, and regulate deficiency and excess, making it essential for them to be unobstructed.” This theory holds significant guiding importance for clinical differentiation and treatment in various TCM disciplines, especially acupuncture.
The twelve primary meridians are the main conduits for the flow of qi and blood in the body. Qi and blood circulate continuously within these meridians, distributing throughout the body both internally and externally.
The sequence of qi and blood flow in the twelve primary meridians is illustrated in the following diagram:
Starting from the Hand Taiyin Lung Meridian (Shou Taiyin Fei Jing), it flows successively to the Foot Jueyin Liver Meridian (Zu Jueyin Gan Jing), and then returns to the Hand Taiyin Lung Meridian. This forms a complete system of the twelve primary meridians, characterized by the interconnection of yin and yang, resembling an endless loop.
2. Meridians Related to the Six-Character Formula
Below are the six meridians involved in the practice of the Six-Character Formula.
1. Foot Jueyin Liver Meridian (Zu Jueyin Gan Jing)
(1) Pathway and Branches
① Pathway:
It begins at the back of the toenail of the big toe (Dadun point), ascends along the inner side of the foot, passes the inner ankle, ascends the inner side of the lower leg, continues along the inner midline of the thigh, enters the pubic region, encircles the reproductive organs, reaches the lower abdomen, flanks the stomach, belongs to the liver, connects to the gallbladder, ascends through the diaphragm, distributes to the lateral costal region, travels behind the throat, and ascends into the nasopharynx, connecting to the eye system (the vascular connections behind the eyeball).
② Branches:
Eye system branch: This branch travels from the eye system towards the deep layers of the cheek, descending and encircling the inside of the lips.
Liver branch: This branch emerges from the liver, passes through the diaphragm, and ascends to the lungs (connecting with the Hand Taiyin Lung Meridian).
(2) Associated Organs: It belongs to the liver, connects to the gallbladder, and has relations with the lungs, stomach, kidneys, and brain.
2. Hand Shaoyin Heart Meridian (Shou Shaoyin Xin Jing)
(1) Pathway and Branches
① Pathway:
It begins at the heart, emerges belonging to the “heart system” (the network connecting the heart with other organs), descends through the diaphragm to the vicinity of the Ren Meridian’s lower abdomen point, and connects to the small intestine.
② Branches:
Ascending branch of the heart system: This branch ascends from the heart system, flanking the throat, and connects deeply through the neck and facial area to the “eye system.”
Direct branch of the heart system: This branch ascends from the heart system, travels to the lungs, then descends from the armpit, along the inner edge of the upper arm, down to the inner elbow, and along the inner forearm, exiting at the radial side of the little finger.
(2) Associated Organs: It belongs to the heart, connects to the small intestine, and has relations with the lungs, spleen, liver, and kidneys.
3. Foot Taiyin Spleen Meridian (Zu Taiyin Pi Jing)
(1) Pathway and Branches
① Pathway: The meridian begins at the inner side of the big toe (Yinbai point), ascends along the inner side of the foot, passes in front of the inner ankle, ascends the inner side of the lower leg, enters the abdominal cavity along the inner side of the thigh, belongs to the spleen and connects to the stomach, ascends through the diaphragm, flanks the esophagus, connects to the root of the tongue, and disperses under the tongue.
② Branches: This branch emerges from the stomach, ascends through the diaphragm, and enters the heart at the Ren Meridian’s zhong point, connecting with the Hand Shaoyin Heart Meridian.
(2) Associated Organs: It belongs to the spleen, connects to the stomach, and has direct relations with the heart and lungs.
4. Hand Taiyin Lung Meridian (Shou Taiyin Fei Jing)
(1) Pathway and Branches
① Pathway: The Hand Taiyin Lung Meridian begins at the Zhongwan area, descends to the vicinity of the navel, connects to the large intestine, then ascends along the upper opening of the stomach, passes through the diaphragm, directly connects to the lungs, ascends to the trachea and throat, traverses horizontally across the clavicle to the armpit, and continues along the inner side of the upper limb, reaching the radial tip of the thumb.
② Branches: A branch emerges from the back of the wrist, proceeding to the radial tip of the index finger, connecting with the Hand Yangming Large Intestine Meridian.
(2) Associated Organs: It belongs to the lungs, connects to the large intestine, passes through the diaphragm, and has relations with the stomach and kidneys.
5. Foot Shaoyin Kidney Meridian (Zu Shaoyin Shen Jing)
(1) Pathway and Branches
① Pathway: The Foot Shaoyin Kidney Meridian begins at the tip of the little toe, diagonally moves to the sole of the foot (Yongquan point), passes behind the inner ankle to enter the heel, ascends along the inner edge of the lower leg, exits at the inner side of the popliteal fossa, and continues up the inner edge of the thigh, entering the spine and passing through the vertebrae, belonging to the kidneys and connecting to the bladder.
② Branches:
Direct branch from the waist: This branch ascends from the kidneys, passes through the liver, ascends through the diaphragm, enters the lungs, travels along the throat, and ascends to both sides of the root of the tongue.
Lung branch: This branch emerges from the lungs, connects to the heart, flows into the chest (at the zhong point), and connects with the Hand Jueyin Pericardium Meridian.
(2) Associated Organs: It belongs to the kidneys, connects to the bladder, and has direct relations with the liver, lungs, and heart.
6. Hand Shaoyang Sanjiao Meridian (Shou Shaoyang Sanjiao Jing)
(1) Pathway and Branches
① Pathway: The Hand Shaoyang Sanjiao Meridian begins at the ulnar side of the ring finger, travels along the back of the hand, ascends through the forearm, passes through the elbow, ascends along the outer side of the upper arm, reaches the shoulder, intersects behind the Foot Shaoyang Gallbladder Meridian, enters the chest, and disperses at the zhong point of the Ren Meridian, descending through the diaphragm to broadly distribute to the Sanjiao.
② Branches:
Chest branch: This branch emerges from the zhong point, ascends out of the chest, reaches the back of the neck, intersects with the Du Meridian at the Dazhui point, ascends to the neck, travels behind the ear, and curves down towards the cheek, reaching below the eye socket.
Ear branch: This branch emerges from behind the ear, enters the ear, exits in front of the ear, passes in front of the Shangguan point, and intersects with the previous branch at the cheek, ascending to the outer corner of the eye.
(2) Associated Organs: It belongs to the Sanjiao and connects to the Pericardium.
(3) Concept of Sanjiao
The Sanjiao is not an independent organ but a special concept used to delineate parts of the body and internal organs. It divides the body into three physiological and pathological regions: the upper jiao (chest, including the heart and lungs), the middle jiao (upper abdomen, including the spleen, stomach, liver, and gallbladder), and the lower jiao (lower abdomen, including the kidneys, bladder, small intestine, and large intestine).
7. Acupoints
Acupoints, commonly referred to as points, are known as “shu” which means “to transport” and “to conduct.” Acupoints are primarily distributed along the meridians, belonging to the meridians, connecting the internal organs with the body surface, and facilitating the flow of qi and blood between the internal organs and the body surface. The essence of life movement, known as “true qi,” circulates in these acupoints, both outward and inward, following the meridians to reach the five zang organs, six fu organs, and all limbs. Therefore, acupoints possess functions such as disease resistance, pain response, disease transmission, stimulus reception, and information transmission.
Due to the communication role of acupoints, pathological changes in the internal organs’ qi and blood can be reflected on the body surface at corresponding acupoints, which may exhibit tenderness, soreness, numbness, nodules, swelling, discoloration, papules, and depressions. Thus, utilizing these pathological responses of acupoints can assist in diagnosing diseases. More importantly, acupoints play a crucial role in treating diseases; through acupuncture, tui na (Chinese therapeutic massage), and other stimuli at the corresponding acupoints, the meridians can be unblocked, and the qi and blood of the internal organs can be regulated to achieve therapeutic goals.
