岐伯曰∶夫邪之客于形也，必先舍于皮毛，留而不去，入舍于孙脉，留而不去，入舍于
络脉，留而不去，入舍于经脉，内连五脏，散于肠胃，阴阳俱感，五脏乃伤，此邪之从皮毛
而入，极于五脏之次也。如此则治其经焉。
凡刺之数，先视其经脉，切而从之，审其虚实而
调之，不调者经刺之。
不盛不虚以经取之。
巨刺刺经脉，缪刺刺络脉，所以别也。
岐伯曰∶痛在于左而右脉病者，则巨刺之。
邪客于经，左盛则右病，右盛则左病，亦有移易者，左痛未已，而右脉先病，如此者，
必巨刺之，必中其经，非络脉也。
岐伯曰∶凡人两手足，各有三阴脉、三阳脉，以合为十二经也。手之三阴，从胸走至手
，手之三阳，从手走至头；足之三阳，从头下走至足，足之三阴，从足上走入腹。络脉传注
，周流不息，故经脉者，行血气，通阴阳，以荣于身者也。其始从中焦，注手太阴、阳明，阳明注足
阳明、太阴，太阳注手少阴、太阳，太阳注足太阳、少阴，少阴注手心主、少阳，少阳注足
少阳、厥阴，厥阴复还注手太阴。其气常以平旦为纪，以漏水下百刻，昼夜流行，与天同度
，终而复始也。
络脉者，本经之旁支而别出，以联系于十二经者也。本经之脉，由络脉而交他经，他经
之交，亦由是焉。传注周流，无有停息也。夫十二经之有络脉，犹江汉之有沱潜也；络脉之
传注于他经，犹沱潜之旁导于他水也。是以手太阴之支者，从腕后出次指端，而交于手
阳明；手阳明之支者，从缺盆上侠口鼻
，而交于足阳明；足阳明之支者，别跗上，出大指端，而交于足太阴；足太阴之支者，从胃
别上膈注心中，而交于手少阴；手少阴则直自本经少冲穴，而交于手太阳，不假支授，盖君
者，出令者也。手太阳之支者，别颊上至目内 ，而交于足太阳；足太阳之支者，从膊内左
右别下合 中，下至小指外侧端，而交于足少阴。足少阴之支者，从肺出注胸中，而交
于手厥阴；手厥阴之支者，从掌中循小指次指出其
端，而交于手少阳；手少阳之支者，从耳后出至目锐 ，而交于足少阳；足少阳之支者，从
跗上入大趾爪甲出三毛，而交于足厥阴；足厥阴之支者，从肝别贯膈上注肺，而交于手太阴
也。自寅时起，一昼夜，人之荣卫，则以五十度周于身，气行一万三千五百息，脉行八百
一十丈，营运血气，流通阴阳，昼夜流行，与天同度，终而复始也。
Qibo said: When pathogenic factors invade the human body, they first lodge in the skin and hair (mao pi). If they remain there without being expelled, they enter the fine collateral vessels (Sun Mai); if they still remain, they enter the larger collateral vessels (Luo Mai); if they continue to remain, they enter the main meridians (Jing Mai), internally connecting with the five zang organs and dispersing into the stomach and intestines. When both yin and yang are affected by pathogens, the five zang organs will be damaged. This is the sequence of pathogens entering from the skin and hair and ultimately reaching the five zang organs. In such cases, treatment should focus on the meridians.
The general principles of acupuncture require first observing the meridians, palpating and following their course, carefully assessing their excess or deficiency, and regulating them accordingly. For conditions where the meridians are not harmonized, Jing Ci (Meridian Needling) should be applied.
If the pulse shows neither excess nor deficiency, points should be selected according to the affected meridian itself.
Ju Ci (Great Puncture) targets the meridians, while Miu Ci (Counter Puncture) targets the collateral vessels; this distinguishes the two methods.
Qibo said: When pain is located on the left side but the pulse on the right side indicates pathology, Ju Ci should be employed.
When pathogens lodge in the meridians, excess on the left causes disease on the right, and excess on the right causes disease on the left. There are also cases of shifting symptoms; for instance, pain may persist on the left while the pulse on the right becomes pathological first. In such situations, Ju Ci must be used, ensuring that the needle penetrates the meridian rather than the collateral vessels.
Qibo said: Each hand and foot possesses three yin meridians and three yang meridians, combining to form the Twelve Primary Meridians. The three hand yin meridians flow from the chest to the hands; the three hand yang meridians flow from the hands to the head; the three foot yang meridians flow from the head down to the feet; and the three foot yin meridians flow from the feet up into the abdomen. Collateral vessels transmit qi continuously and without cessation. Thus, the primary meridians circulate blood and qi, connect yin and yang, and nourish the entire body.
The circulation begins at the Middle Jiao (Middle Burner), flowing into the Lung Meridian of Hand-Taiyin and the Large Intestine Meridian of Hand-Yangming. From the Large Intestine Meridian, it flows into the Stomach Meridian of Foot-Yangming and the Spleen Meridian of Foot-Taiyin. From the Foot-Taiyin, it flows into the Heart Meridian of Hand-Shaoyin and the Small Intestine Meridian of Hand-Taiyang [Note: Textual variation noted]. From the Hand-Taiyang, it flows into the Bladder Meridian of Foot-Taiyang and the Kidney Meridian of Foot-Shaoyin. From the Foot-Shaoyin, it flows into the Pericardium Meridian of Hand-Jueyin and the Sanjiao Meridian of Hand-Shaoyang. From the Hand-Shaoyang, it flows into the Gallbladder Meridian of Foot-Shaoyang and the Liver Meridian of Foot-Jueyin. Finally, the Liver Meridian returns to flow into the Lung Meridian of Hand-Taiyin.
The movement of qi is regulated by dawn (Pingdan), measured by the water clock over one hundred ke (hours), circulating day and night in accordance with the celestial movements, completing cycles endlessly.
Collateral vessels are lateral branches originating from the primary meridians, serving to connect the Twelve Primary Meridians. Qi from a primary meridian intersects with other meridians via these collaterals, and intersections among other meridians also occur through this mechanism. This transmission circulates continuously without pause. The relationship between the Twelve Primary Meridians and their collateral vessels is like that of the Yangtze and Han rivers having tributaries like Tuo and Qian waters; just as these tributaries guide water into other river systems, the collateral vessels transmit qi to other meridians.
Specifically, the branch of the Lung Meridian of Hand-Taiyin emerges from behind the wrist to the tip of the index finger, intersecting with the Large Intestine Meridian of Hand-Yangming. The branch of the Large Intestine Meridian of Hand-Yangming ascends from the Clavicle region (Quepen) alongside the mouth and nose, intersecting with the Stomach Meridian of Foot-Yangming. The branch of the Stomach Meridian of Foot-Yangming diverges on the dorsum of the foot, emerging at the tip of the great toe, intersecting with the Spleen Meridian of Foot-Taiyin. The branch of the Spleen Meridian of Foot-Taiyin diverges from the stomach, ascends through the diaphragm to the heart, and intersects with the Heart Meridian of Hand-Shaoyin. The Heart Meridian of Hand-Shaoyin directly connects from its own point Shaochong to the Small Intestine Meridian of Hand-Taiyang without relying on a branch, because the Heart acts as the sovereign ruler issuing commands. The branch of the Small Intestine Meridian of Hand-Taiyang diverges at the cheek, ascends to the inner canthus of the eye, and intersects with the Bladder Meridian of Foot-Taiyang. The branch of the Bladder Meridian of Foot-Taiyang diverges from the upper arm, descends bilaterally to converge in the popliteal fossa, continues down to the lateral end of the little toe, and intersects with the Kidney Meridian of Foot-Shaoyin. The branch of the Kidney Meridian of Foot-Shaoyin emerges from the lungs, enters the chest, and intersects with the Pericardium Meridian of Hand-Jueyin. The branch of the Pericardium Meridian of Hand-Jueyin follows from the palm along the ring finger to its tip, intersecting with the Sanjiao Meridian of Hand-Shaoyang. The branch of the Sanjiao Meridian of Hand-Shaoyang emerges from behind the ear to the outer canthus of the eye, intersecting with the Gallbladder Meridian of Foot-Shaoyang. The branch of the Gallbladder Meridian of Foot-Shaoyang enters the big toe nail bed and emerges at the hairy margin, intersecting with the Liver Meridian of Foot-Jueyin. The branch of the Liver Meridian of Foot-Jueyin diverges from the liver, pierces the diaphragm, ascends to the lungs, and intersects with the Lung Meridian of Hand-Taiyin.
Starting from the Yin hour, within a full day and night, the Ying (Nutritive) and Wei (Defensive) qi circulate fifty times around the body. Qi travels through 13,500 breaths, and the pulse travels 810 zhang. They circulate blood and qi, connect yin and yang, flow day and night, align with celestial measures, and repeat endlessly.