(医门法律)
经有十二。络亦有十二。络者兜络之义。即十二经之外城也。复有胃之大络。脾之大络
。及
奇经之大络。则又外城之通界皇华出入之总途也。故又曰络有十五焉。十二经生十二络。十
二络生一百八十系络。系络生一百八十缠络。缠络生三万四千孙络。自内而生出者。愈多则
愈小。稍大者在俞穴肌肉间。营气所主外廓。徭是出诸皮毛方为小络。方为卫气所主。故外
邪从卫而入。不遽入于营。亦以络脉缠绊之也。至络中邪盛则入于营矣。故曰络盛则入于经
。以营行经脉之中故也。然风寒六淫外邪无形易入。络脉不能禁止。而盛则入于经矣。若营
气自内所生诸病。为血为气。为痰饮。为积聚。种种有情势不能出于络外。故经盛入络。络
盛返经。留连不已。是以有取于砭射以决出其络中之邪
难经以阳跷阴跷脾之大络。共为十五络。遂为后世定名。昌谓阳跷阴跷二络之名原误。
当是
共指奇经为一大络也。盖十二经各有一络。共十二络矣。此外有胃之一大络。由胃下直贯膈
肓统络诸络脉于上复有脾之一大络。徭脾外横贯胁腹。统络诸络脉于中。复有奇经之一大络
。徭奇经环贯诸经之络于周身上下。盖十二络以络其经。三大络以络其络也。尝推奇经之义
督脉督诸阳而行于背。任脉任诸阴而行于前。不相络也。冲脉直冲于胸中。带脉横束于腰际
。不相络也。阳跷阴跷同起于足跟。一循外踝。一循内踝。并行而斗其捷。全无相络之意。
阳维阴维。一起于诸阳之会。一起于诸阴之交。名虽曰维。乃是阳自维其阳。阴自维其阴。
非交相维络也。设阳跷阴跷可言二络。则阳维阴维更可言二络矣。督任冲带俱可共言八络矣
。难经云奇经之脉。如沟渠满溢。流于深湖。故圣人不能图。是则奇经明等之络夫岂有江河
大经之水。拟诸沟渠者哉。又云人脉隆盛。入于八脉而不环周。故十二经亦不能拘之溢蓄不
能环流灌溉诸经者也。全是经盛入络。故溢蓄止在于络。不能环溉诸经也。然则奇经共为一
大络。夫复何疑。
《医门法律》
经脉有十二条，络脉也有十二条。所谓“络”，具有兜绕联络的含义，也就是十二经脉的外围屏障。此外还有胃的大络、脾的大络，以及奇经的大络，这些则是外围屏障之间沟通往来、气血出入的总通道。因此又说络脉共有十五条。十二经脉生出十二条络脉，十二条络脉生出一百八十条系络，系络生出一百八十条缠络，缠络生出三万四千条孙络。从体内向外生成的脉络，数量越多则越细小。稍大的络脉位于腧穴和肌肉之间，由营气主管其外部廓界；再往外散布到皮毛部位的才是小络，由卫气主管。所以外邪从卫分侵入，不会立刻进入营分，也是因为络脉缠绕绊阻的缘故。等到络脉中邪气亢盛时，就会进入营分了。所以说“络盛则入于经”，这是因为营气运行在经脉之中的缘故。然而风寒等六淫外邪无形易入，络脉无法禁止，邪气亢盛时就进入经脉了。如果是营气自内所生的疾病，表现为血、气、痰饮、积聚等种种有形之邪，势必要出于络脉之外。所以是“经盛入络，络盛返经”，病邪留连不止。因此需要用砭石刺络的方法来决破并排出络脉中的邪气。
《难经》将阳跷脉、阴跷脉和脾之大络合称为十五络，从而成为后世定名。我认为阳跷、阴跷二络的名称原本有误，应当是指奇经作为一大络而言。大概十二经脉各有一条络脉，共十二条络脉。除此之外，有胃的一条大络，从胃下直贯膈部与肓膜，统摄联络上方的诸络脉；又有脾的一条大络，从脾外横贯胁腹，统摄联络中间的诸络脉；还有奇经的一条大络，环绕贯通周身上下的诸经之络。大概是十二络用来联络经脉，三大络用来联络络脉。我曾推究奇经的含义：督脉总督诸阳而行于背部，任脉担任诸阴而行于前部，二者不相联络；冲脉直冲于胸中，带脉横束于腰际，二者也不相联络；阳跷脉和阴跷脉同起于足跟，一条循行于外踝，一条循行于内踝，并行而争其敏捷，完全没有相互联络的意思；阳维脉和阴维脉，一条起于诸阳之会，一条起于诸阴之交，名义上虽叫“维”，其实是阳自维其阳，阴自维其阴，并非交相维络。如果可以说阳跷、阴跷是两条络脉，那么阳维、阴维更可以算作两条络脉了，督、任、冲、带也都可共称为八条络脉了。《难经》说奇经的脉象，如同沟渠满溢，流入深湖，所以圣人不能绘制图样，这说明奇经明明白白就是络脉，难道有江河般的大经之水，能比作沟渠吗？又说人气血隆盛时，进入八脉而不环周全身，所以十二经脉也不能拘束它。溢出蓄积而不能环流灌溉诸经，完全是因为经气盛而入于络，所以溢出蓄积只停留在络脉，不能环流灌溉诸经。既然这样，那么奇经共同构成一大络，又有什么可怀疑的呢？
*Yi Men Fa Lü* (Legal Principles of Medical Practice)
There are twelve regular meridians, and there are also twelve collateral vessels. The term "collateral" implies a meaning of encircling and connecting; it serves as the outer city wall of the twelve regular meridians. Additionally, there is the great collateral of the Stomach, the great collateral of the Spleen, and the great collaterals of the extraordinary meridians. These serve as the main thoroughfares for communication and entry/exit within the outer city wall. Therefore, it is said that there are fifteen collaterals in total. The twelve regular meridians generate twelve collateral vessels; the twelve collateral vessels generate one hundred and eighty *xi luo* (connecting collaterals); the connecting collaterals generate one hundred and eighty *chan luo* (entangling collaterals); and the entangling collaterals generate thirty-four thousand *sun luo* (branchlet collaterals). Collaterals generated from the interior moving outward become progressively smaller as their number increases. Those slightly larger are located between the acupoints and muscles, governed by Ying Qi (Nutritive Qi) which controls the outer boundary. Further out, spreading into the skin and hair, they become small collaterals, governed by Wei Qi (Defensive Qi). Thus, when external pathogens enter via the Wei level, they do not immediately enter the Ying level, because the collateral vessels entangle and obstruct them. Only when the pathogens in the collaterals become excessive do they enter the Ying level. Hence it is said, "When collaterals are full/excessive, pathogens enter the meridians," because Ying Qi circulates within the meridians. However, wind-cold and other formless exogenous pathogens (Six Excesses) can easily penetrate, and the collateral vessels cannot prevent this; when the pathogenic factor becomes excessive, it enters the meridians. If diseases arise internally from Ying Qi, manifesting as blood stasis, qi stagnation, phlegm-fluid retention, or accumulations and masses—all tangible pathological factors—they inevitably seek to exit the collaterals. Therefore, it is "meridian excess entering collaterals, collateral excess returning to meridians," with pathogens lingering indefinitely. Consequently, bian stone therapy (bloodletting) is employed to pierce and drain the pathogens from the collaterals.
*Nan Jing* (Classic of Difficult Issues) identifies the Yang Qiao Mai (Yang Heel Vessel), Yin Qiao Mai (Yin Heel Vessel), and the Great Collateral of the Spleen as the fifteen collaterals, establishing this nomenclature for later generations. I contend that the names "Yang Qiao" and "Yin Qiao" as separate collaterals are originally erroneous; they should be understood collectively referring to the extraordinary meridians as a single great collateral. Generally, each of the twelve regular meridians has one collateral, totaling twelve collaterals. Besides these, there is the Great Collateral of the Stomach, which descends directly through the diaphragm and huang area, unifying and connecting the upper collaterals. There is also the Great Collateral of the Spleen, which traverses horizontally across the hypochondrium and abdomen, unifying and connecting the middle collaterals. Furthermore, there is the Great Collateral of the extraordinary meridians, which circles and connects the collaterals of all meridians throughout the body up and down. Thus, the twelve collaterals connect the meridians, while the three great collaterals connect the collaterals. I have deduced the meaning of the extraordinary meridians: The Du Mai (Governing Vessel) governs all yang meridians and runs along the back; the Ren Mai (Conception Vessel) assumes all yin meridians and runs along the front; neither connects with each other. The Chong Mai (Penetrating Vessel) rushes straight up into the chest; the Dai Mai (Belt Vessel) binds horizontally at the waist; neither connects with each other. The Yang Qiao Mai and Yin Qiao Mai both originate from the heel; one follows the lateral malleolus, the other the medial malleolus; they run parallel and compete in agility, showing no intention of mutual connection. The Yang Wei Mai (Yang Linking Vessel) and Yin Wei Mai (Yin Linking Vessel) originate from the meeting point of all yang meridians and the intersection of all yin meridians, respectively. Although named "Wei" (Linking), they actually link yang to its own yang and yin to its own yin, rather than linking mutually. If Yang Qiao and Yin Qiao could be considered two collaterals, then Yang Wei and Yin Wei could certainly be considered two collaterals as well, and Du, Ren, Chong, and Dai could collectively be called eight collaterals. *Nan Jing* states that the pulses of the extraordinary meridians are like ditches overflowing and flowing into deep lakes, so sages cannot map them. This clearly indicates that the extraordinary meridians are indeed collaterals. How could the water of great rivers and major meridians be compared to ditches? It further states that when human pulse energy is abundant, it enters the eight vessels without circulating cyclically, so the twelve regular meridians cannot constrain it. Overflowing and accumulating without circulating to irrigate the regular meridians is entirely due to meridian excess entering the collaterals; thus, overflow and accumulation remain only in the collaterals and cannot circulate to irrigate the regular meridians. Since this is the case, the extraordinary meridians collectively constitute one great collateral, leaving no room for doubt.