十二经十五络经正六合五输六原四关十二经筋
所谓经络者。直行为经。旁行为络。直行而通。统内外左右上下通行无滞。如江河之流。而为日夜五十营者。斯为
经。其回行交络。互属脏所。不当道行者为络。灵枢曰。手之三阴。从腹走手。手之三阳。从手走头。足之三阳，从头
走足。足之三阴。从足走腹。腹为阴之会。头为阳之腑。以阴接阴于腹。以阳接阳于头。三阴转而入阳。于手之指。三
阳转而入阴。于足之指。此以阴入阳。以阳入阴。无所不到。所谓通行直行为经者也。乃其间有交络者。为支分者。则
六阳经之自头。每各下入缺盆。内属以络五脏。而五脏之经。亦每各上行至喉至目系。至舌本。至巅顶。此为属正经之
旁行。不当隧道之冲。即所以为络也。然而旁行之络。实交于身。而五脏六腑又有其专精盛气之所会。其会又各有所至。
如公孙大包虚里期门等为经。别之五十络。此络之大且盛。未尝不如经。而以其旁行别出。不当隧道。故为经别。亦为
络也。经正六合者。经正以脏腑。各有本经。地方自隧道通行外。其旁地分正自有余。其他更有交流分委。或自属本经。
亦自与本经之表里阴阳相接。此自为表里之合。其合凡六。脏腑自会也。此合既不当隧道。特以本经地分壤地。相属而
合。故非经别。乃经正也。由前十二经暨十五络。与各经之六相合。共二十七气。以通行周遍于一身。而凡回环之气。
盛会之所。皆在斯矣。至于五输六原四关。从其手足正隧道扼要之处。盖十二经原皆起于手足之十指。此皆各脏腑专精
之所起所淄所入也。于是各为井荥输经原合。脏五腑六以纪之。而总不出四关。以治脏腑之有疾。则所谓扼要者名关耳。
大约经络脉络兼行二义。一以呼行三寸。吸行三寸。其流行日夜为五十营者。法以五十动而不一代者为占。此候其流行
者言也。其起发井荥输原者。以五脏六腑之地分为占。此与气口之寸关尺同占其病者。以卜无藏。此候其不流者言也。
唯脉之精。是流者与不流者俱见。足以独守经隘。以占百病。固莫精于此矣。此外人有十二经筋者。筋布散于身。而为
一身之维系。本皆属肺。以分维各经地分。故为十二经筋。属阳者于外而坚刚。其有病必以在外之风寒湿入之而成痹。
故病各以脉序。属阴者于内而柔细。然布散枢要。常与经脉协议。故病或痰滞营阻。则亦能主颠痫螈 。与外筋不同。
此筋病之大较也。张子和谓凡医必明经络根结始终。所环所会所交所过。而后知阴阳脏腑之出入虚实。不知此者。如面
墙矣。
十二经脉、十五络脉、正经、六合、五输穴、六原穴、四关、十二经筋。
所谓经络，直行的是经，旁行的是络。直行且通畅，统摄内外、左右、上下，通行无阻碍，如同江河水流，作为日夜运行五十周次的通道，这就称为“经”。那些回旋交错、互相归属脏腑的，不走在主干道路上的，就称为“络”。《灵枢》说：手部的三条阴经，从腹部走向手部；手部的三条阳经，从手部走向头部；足部的三条阳经，从头走向足部；足部的三条阴经，从足部走向腹部。腹部是阴经汇聚的地方，头部是阳经聚集的场所。以阴接阴于腹部，以阳接阳于头部。三条阴经转而进入阳经，在手部的指尖交接；三条阳经转而进入阴经，在足部的指尖交接。这就是以阴入阳，以阳入阴，无所不到。所谓通行、直行的就是“经”。
然而其中也有交错联络的，有分支分出的，那么六条阳经从头部出发，各自向下进入缺盆，向内联系并络属五脏。而五脏的经脉，也各自向上行至咽喉、目系、舌根、头顶。这是属于正经的旁行部分，不走在主隧道的冲要之处，这就是所谓的“络”。然而旁行的络脉，实际上与身体相交，而五脏六腑又有其精气旺盛汇聚之所。这些汇聚点又各有特定的到达部位，如公孙、大包、虚里、期门等，作为“经别”的五十条络脉。这些络脉宏大且旺盛，未曾不如经一般重要，但因其旁行别出，不走在主隧道中，所以称为“经别”，同时也属于“络”的范畴。
所谓“经正六合”，是指经脉的正道以脏腑为本，各有本经的地域范围，除了在主隧道中通行外，其旁侧地域自然有余。其他更有交流分派的委曲之处，有的自属于本经，也自然与本经的表里阴阳相连接。这自成为表里的合和，这种合共有六种，是脏腑自身的会合。这种合既然不走在主隧道中，只是以本经的地域壤地相互归属而合，所以不是“经别”，而是“经正”。由前述的十二经脉及十五络脉，与各经的六相合，共成二十七气，以通行周遍于一身。而凡是回环之气、盛会之处，都在这里了。
至于五输穴、六原穴、四关，是从手足正隧道扼要之处而言的。大概十二经的原穴都起于手足十指，这些都是各脏腑精气所起、所聚、所入的地方。于是各分为井、荥、输、经、原、合，脏有五（对应五输），腑有六（对应六原/六输）来记录它们，而总不出“四关”的范围。用来治疗脏腑的疾病，那么所谓扼要的地方就叫做“关”。
大约经络脉络兼有两层含义。一是关于气血运行的，一呼行三寸，一行行三寸，其流行一天一夜为五十营，占候的依据是脉搏跳动五十次而没有一次歇止的，这是占候其流动的气血。二是关于穴位起始的，井、荥、输、原等，以五脏六腑的地域分布来占候。这与气口的寸、关、尺三部同占疾病，因为卜问没有藏匿的病邪，这是占候其不流动的部分（即病邪所在）。唯有脉的精微之处，是流动与不流动都能见到的，足以独自守住经气的隘口，以占断百病，确实没有比这更精妙的了。
此外，人有十二经筋。筋布散于全身，作为一身维系的关键。它们原本都属于肺，以分别维系各经的地域，所以称为十二经筋。属于阳经的筋在外侧而坚刚，如果有病，必定是因为外部的风寒湿邪侵入而成痹证，所以病症各按脉的顺序表现。属于阴经的筋在内侧而柔细，但布散在枢要之处，常与经脉协调配合。所以如果发生痰滞营阻，也能导致癫痫、抽搐等症状，这与外部的筋病不同。这是筋病的大致情况。张子和说，凡是医生必须明白经络的根结、始终、所环、会所、交所、所过，然后才能知道阴阳脏腑的出入虚实。不知道这些的人，就像面对着墙壁一样（一无所知）。
Twelve Regular Meridians, Fifteen Collaterals, Regular Meridians, Six Pairs of Interior-Exterior Connections, Five Shu Points, Six Yuan Source Points, Four Passes, Twelve Muscle Regions (Jin).
The so-called meridians and collaterals: those that run straight are the **Regular Meridians** (Jing, 经), and those that branch off are the **Collaterals** (Luo, 络). The straight-running ones are unobstructed, connecting the interior and exterior, left and right, upper and lower, circulating without stagnation, like the flow of rivers. They serve as the pathways for the fifty circuits completed in a day and night. This is what is called the "Meridian" (Jing). Those that loop back, intersect, and belong to the Zang organs, which do not travel along the main thoroughfares, are called "Collaterals" (Luo). The *Ling Shu* states: The three Yin meridians of the hand travel from the abdomen to the hand; the three Yang meridians of the hand travel from the hand to the head; the three Yang meridians of the foot travel from the head to the foot; the three Yin meridians of the foot travel from the foot to the abdomen. The abdomen is the convergence of Yin, and the head is the gathering place of Yang. Yin connects with Yin at the abdomen, and Yang connects with Yang at the head. The three Yin meridians turn to enter the Yang meridians at the fingertips of the hands, and the three Yang meridians turn to enter the Yin meridians at the fingertips of the feet. This is entering Yang through Yin and entering Yin through Yang, reaching everywhere. What circulates and runs straight is the "Meridian" (Jing).
However, among them, there are intersecting and linking branches. The six Yang meridians originate from the head and each descend into the **Quepen** (ST12, Clavicular Fossa), internally connecting and networking with the five Zang organs. The meridians of the five Zang organs also ascend to the throat, the eye system, the root of the tongue, and the vertex. These are the side-branching parts of the regular meridians, not traveling through the main tunnels, thus constituting the "Collaterals" (Luo). Yet, these side-branching collaterals actually intersect with the body. The five Zang and six Fu organs have specific locations where their refined Qi gathers. These gatherings reach specific points, such as **Gongsun** (SP4), **Dabao** (SP21), **Xuli** (RN15), and **Qimen** (LR14), forming the fifty **Extraordinary Collaterals** (Jingbie, 经别) of the meridians. These collaterals are grand and vigorous, comparable to the meridians themselves, but because they branch off sideways and do not follow the main tunnels, they are called "Extraordinary Collaterals" (Jingbie) and also belong to the category of "Collaterals" (Luo).
The term "Regular Meridians' Six Pairs" (Jingzheng Liuhe, 经正六合) refers to the fact that the regular meridians are rooted in the Zang and Fu organs, each having its own territorial domain. Besides circulating through the main tunnels, the adjacent territories naturally have surplus connections. There are further exchanges and distributions, some belonging to the same meridian, naturally connecting with the interior-exterior and Yin-Yang pairs of that meridian. This forms the interior-exterior connections, totaling six pairs, representing the mutual association of Zang and Fu organs. Since these connections do not lie within the main tunnels but rather associate through the territorial domains of the respective meridians, they are not "Extraordinary Collaterals" (Jingbie) but "Regular Meridian Alignments" (Jingzheng). From the aforementioned twelve regular meridians and fifteen collaterals, combined with the six alignments of each meridian, there are twenty-seven Qi flows that circulate throughout the body. All looping Qi and major gatherings occur here.
Regarding the **Five Shu Points** (Wushu, 五输), **Six Yuan Source Points** (Liuyuan, 六原), and **Four Passes** (Siguan, 四关): these refer to the critical junctures in the main tunnels of the hands and feet. Generally, the Yuan Source points of the twelve meridians all originate at the ten fingers of the hands and feet. These are the sites where the refined Qi of each Zang and Fu organ originates, gathers, and enters. Thus, they are classified into Jing (Well), Ying (Spring), Shu (Stream), Jing (River), Yuan (Source), and He (Sea) points. The five Zang correspond to the five Shu points, and the six Fu correspond to the six Yuan points, recorded accordingly. All fall within the scope of the "Four Passes." To treat diseases of the Zang and Fu organs, these critical junctures are named "Passes" (Guan).
Generally, the concepts of meridians and collaterals encompass two meanings. One relates to the circulation of Qi and Blood: inhaling moves it three cun, exhaling moves it three cun, completing fifty circuits in a day and night. The diagnostic criterion is observing whether the pulse beats fifty times without interruption. This assesses the flowing Qi. The other relates to the origin of points: Jing, Ying, Shu, and Yuan points are assessed based on the territorial distribution of the five Zang and six Fu organs. This is similar to diagnosing via the Cun, Guan, and Chi positions of the radial artery, as hidden pathologies cannot be concealed. This assesses the non-flowing aspects (pathological stagnation). Only the essence of the pulse reveals both flowing and non-flowing states, allowing one to guard the narrow passages of the meridians and diagnose hundreds of diseases. Nothing is more precise than this.
Furthermore, humans have the **Twelve Muscle Regions** (Shier Jingjin, 十二经筋). The Jin (sinews/tendons) are distributed throughout the body, serving as the structural support. They originally belong to the Lung, dividing and maintaining the territories of each meridian, hence the name "Twelve Muscle Regions." The Yang muscle regions are external and firm/hard. When diseased, it is usually due to external Wind, Cold, or Dampness invading, resulting in Bi syndrome (painful obstruction). Thus, the symptoms follow the order of the meridians. The Yin muscle regions are internal and soft/fine. However, they are distributed at pivotal points and often coordinate with the meridians. Therefore, if Phlegm stagnates or Nutritive Qi is obstructed, they can also lead to epilepsy or convulsions, differing from external muscle region diseases. This is the general overview of Jin diseases. Zhang Zihe stated that any physician must understand the roots, endings, beginnings, and ends, the loops, gatherings, intersections, and passages of the meridians. Only then can one comprehend the entry and exit, deficiency and excess of Yin-Yang and Zang-Fu organs. Those who do not know this are like facing a wall (ignorant).