十二经。正经也。又有八脉。名为奇经。兹不具论。而单论此四脉者。盖阳维阳 。两脉附于太阳经行。身之背。
以太阳统治之矣。阴维阳 两脉。行身之前。附于太阴。以太阴统治之矣。惟此四脉。主治有别不能赅于十二经中故另
详之西医画脉管。枝分派别。可谓详矣。然论络不归于经。论经不归于脏腑。譬之有千军而无一将。则亦无所统属矣。
至于奇经八脉。中国且久不讲。何怪西医不知耶。
冲脉起于少腹之内。胞中。挟脐左右上行。并足阳明之脉。至胸中而散。上挟咽。
胞中名为气海。乃呼吸之根也。人之呼气。由气海上。胸膈入肺管而出于喉其路径全循冲脉而上。故内经云冲为气
街盖指。此也凡是气逆均责于冲。故仲景有降冲逆。之法。胞中又名血海。胃中饮食之汁。奉心化血下。入胞中。即由
冲脉。导之使下。故内经云。女子二七而天癸至。太冲脉盛。月事以时下也。总之胞中为先天肾气。后天胃血交会之所。
冲脉起于胞中导先天肾气。而上行以交于胃导后天阴血下行入胞中以交于肾。导气而上。导血而下通于肾丽于阳明冲脉
之所司可知矣。
\r冲脉图\pt31A21.bmp\r
冲脉者出气之冲衢也。气生于丹田。而其出路则在脐下三寸。隔中行旁开五分。名气街穴是气之出。路故名气街近
医因灵枢。言胸气有街。腹气有街。头气有街。足气有街。遂不能指出气街穴在何处。然内经明言起于气街。挟脐上行。
则明指气街穴。在脐之下也。今人改气街作气穴大失经旨。由气街至脐旁。为肓俞肓即膜也。丹田之膜。上会于脐。故
此穴名。肓俞也。又上胸至通谷穴而散。盖有膜上胸。则散。为肺衣。而全包肺。故冲脉亦至此而散肺衣会。于咽故冲
脉又夹。咽而止总见气出于丹田。循脐旁。上胸中。走肺衣中。又上会于咽。则气从之出矣。膜中气行之道路即名冲脉。
冲主气。与任之主血者不同。可知十二正经。奇经八脉。各有所主不同皆各脏腑气。血往来之道路有散有合不得但指血
管。以为经脉也。
任脉起于少腹之内。胞室之下。出会阴之分。上毛际循脐中央。至膻中。上喉咙。绕唇终于唇下之承浆穴。与督脉
交。
督脉在背。总制诸阳。谓之曰督。任脉在腹。总统诸阴谓之曰任。阴阳。相贯。故任与督两脉必。相交下则交于前
后阴之间。上则交于唇之上下也。以先后天论之督在脊。属肾属先天任在腹。属胃属后天先天主气下交胞中。后天主。
血下。交胞中全在此二脉也。以水火论督脉属气属水任脉属血属火是任脉当又属之心。心肾相。交水火。既济。皆由。
于此。故任脉者。阴脉之海也。
\r任脉图\pt31A22.bmp\r
任脉起胞中。下至两阴之间。名会阴穴谓与督脉相会。而当两阴间。故名会阴。上至少腹聚毛之处。名中极穴。又
上至脐下三寸。为关元穴。乃元阳元阴交关之。所也。出脐中上行至于鸠尾。上二寸六分。为膻中穴。膻中是心包络生
血而出。随任脉上下。营运故任脉之穴。兼具包。络之名正见任脉。为心包行血也。从膻中上行。三寸二分陷中。为紫
宫穴。紫宫者。指心而言也。心应洛书九紫离卦。故名紫宫。任脉至此。正内合。于心故以心位。名之正见任脉。为心
行血之统脉也。又上至唇下。为承浆穴。与督脉交而任脉终。其支者循面而至于眼下。细观任督之交会起止。而知督脉
主阳主气任脉主阴主血。互相贯通。为生身之总司也。
督脉起于肾中。下至胞室。乃下行。络阴器循二阴之间。至尻贯脊历腰俞。上脑后。交颠。至囟会入鼻柱。终于人
中。与任脉交。
督脉起于肾中。下至胞室。肾中天一所生之癸水。入于胞中全在督脉导之使下也。肾气至胞。任脉应之，则心胃之
血。乃下会于胞中。此为任督。相交心肾。相济道家坎离水火交媾之乡。即在于此。督脉络阴器循二阴之间。与任脉会
于下也。贯脊上顶。交于人中。与任脉会于上也。今细察其脉。由鼻柱。上脑贯脊。抵肾由肾入胞中据此路道观之乃知
督脉主阳主生。肾气盖气生于天阳吸入鼻孔。至脑门下肺管循背脊。而下入肾又由肾入。胞中故吸入则胞。中满也。吸
入之气实由鼻由脑由脊而下。故掩鼻张口能出气而不能吸气。盖吸由脊下。非从鼻脑。不能入也。呼由膈出。故张口能
出气。也。吸由脊下督脉主之知督脉之所主乃知气之生化再详天癸。乃膀胱条。
\r督脉图\pt31A23.bmp\r
督脉起于胞中。出会阴穴。至尾闾骨端。名长强穴。上至二十一椎。名腰俞穴是腰肾筋膜所连也。再上十四椎当肾
正中。为命门穴。乃肾系贯脊之处为督脉之主盖任是心血所司。督是肾气所司故命门为督脉之主穴也。又上至第三椎为
身柱穴。肺肾相交。为一身元气之宰。故称为柱再上大椎至发际一寸宛中。为风府。发上二寸五分。为脑户。即西医脑
后叶之中缝也。至颠顶为百会穴。与肝脉交会于此。前行当囟门。为囟会穴。谓心神上照于髓。以发知觉是神与髓会之
所也又至额上发际为神庭亦是心神上出于此之义。下鼻准。至齿缝龈交穴而终。盖人身吸。天阳入鼻循脊下。肾系而入。
丹田总归督脉所主化。气化精为人身命之原总督周身脏腑。故称督也。
带脉当肾十四椎出属带脉围身一周。前垂至胞中。
带脉总束诸脉。使不妄行。如人束带故名。究带脉之所从出。则贯肾。系是带当属肾女子系胞。全赖带脉主之盖以
其根结于命门也。环腰贯脐。居于身之中停又当属之于脾。故脾病则女子带下。以其属脾。而又下垂于胞中。故随带而
下也。
\r带脉图\pt31A24.bmp\r
带脉。后在十四椎。当肾之中。前在脐。绕腰一周。带脉一穴。则在季胁当少阳部位。近图带脉三穴一。带脉穴。
在足少阳胆经。季胁之下。一寸八分。再下三寸。为五枢穴。又下为维道穴。似带脉绕行三匝。而有上中下三穴也。然
难经云。脉带起于季胁。回身一周无三匝之说也。又灵枢经曰。足少阴脉别走太阳。至十四椎。属带脉。后人遂以带。
为肾之别脉。非也。属带脉者。谓其为带脉所管束非言带脉是肾之脉也。因其穴居少阳之界。以为少阳脉者。亦非也。
肝胆能为带脉之病。然带脉终非肝。胆之脉。盖带主管结前后。前束任而经心小肠之脐中后束督而经肾系之中。人身惟
脾主中州。交合水火带脉适当腰腹之中应归为脾之脉也。其穴在胁。亦以前不。居任位后不居督位。正见其管束。前后
也。或疑带脉不与脾连。岂知腹中膜油皆脾之物。肾着阳治带脉。以脾为主。女科以妇人带下。皆归于脾。良有以也。
按此四脉。督在背。总统诸阳属先天任在腹总统诸阴属后天冲脉丽于阳明。而通于胞宫。由后天以交于先天肾者也。
带脉出于肾中。以周行脾位由先天以交于后天脾者也。四者互为功用。不可不详究焉。
十二正经，是主要的经脉。另外还有八条奇经，称为奇经八脉。这里不作全面论述，只专门讨论这四条脉：阳维脉和阳跷脉（注：原文“阳 ”疑为阳跷之误，结合上下文及中医理论修正），这两条脉依附于太阳经运行在身体背部，因为太阳经统管背部，所以它们也被太阳经所统领。阴维脉和阴跷脉（注：原文“阴 ”疑为阴跷之误）运行在身体前面，依附于太阴经，因为太阴经统管腹部前方，所以它们也被太阴经所统领。只有这四条脉，主治功能有别，不能涵盖在十二正经之中，所以单独详细论述。西医绘制脉管图，分支派别可谓详尽。然而，他们论述络脉却不归于经脉，论述经脉却不归于脏腑，这就好比有千军万马却没有将领统领，也就没有归属了。至于奇经八脉，中国医学界长久以来不再深入探讨，难怪西医不知道。
冲脉起始于小腹内部，胞宫之中，挟持肚脐左右向上行走，与足阳明胃经并行，到达胸中后散开，上行挟持咽喉。胞宫被称为气海，是呼吸的根本。人的呼气，从气海上行，经过胸膈进入肺管，再从喉咙排出，其路径完全沿着冲脉上行。所以《内经》说“冲为气街”，指的就是这个意思。凡是气逆的病证，都责之于冲脉，所以张仲景有降冲逆的方法。胞宫又名血海，胃中饮食消化后的汁液，奉心化生为血液，向下进入胞宫，即由冲脉引导使其下行。所以《内经》说：“女子到了十四岁（二七），天癸至，太冲脉旺盛，月经按时来潮。”总之，胞宫是先天肾气与后天胃血交会的地方。冲脉起于胞宫，引导先天肾气上行以与胃气相交；引导后天阴血下行进入胞宫以与肾气相交。引导气上行，引导血下行，通于肾而附丽于阳明，冲脉的职能就可以知道了。
[冲脉图]
冲脉是气运行的通道。气生于丹田，而其出路则在脐下三寸，距中线旁开五分处，名叫气街穴，这是气出来的路，所以叫气街。近世医生因为《灵枢》说胸气有街、腹气有街、头气有街、足气有街，于是无法指出气街穴具体在哪里。然而《内经》明确说“起于气街，挟脐上行”，则明确指明气街穴在脐下。现在的人把气街改为气穴，大大违背了经典原意。从气街到脐旁，是肓俞穴。“肓”即膜，丹田的膜上会合于脐，所以此穴名叫肓俞。再向上到胸部的通谷穴而散开。大概因为有膜上达胸部，就散开成为肺衣（胸膜），全包绕肺部，所以冲脉也到这里散开。肺衣会合于咽喉，所以冲脉又挟持咽喉而止。总括来看，气出于丹田，沿着脐旁，上达胸中，走在肺衣中，又上会合于咽喉，气就从这里排出了。膜中气运行的道路就叫做冲脉。冲脉主气，与任脉主血不同。可知十二正经和奇经八脉，各自有所主管的不同，都是各脏腑气血往来的道路，有散有合，不能仅仅指着血管就认为是经脉。
任脉起始于小腹内部，胞室之下，出会阴部位，向上经过阴毛际，沿着肚脐中央，到达膻中，上行至喉咙，环绕嘴唇，终于唇下的承浆穴，与督脉相交。
督脉在背部，总制诸阳，所以叫作“督”。任脉在腹部，总统诸阴，所以叫作“任”。阴阳相互贯通，所以任脉与督脉两脉必须相交。下部交于前后阴之间，上部交于嘴唇的上下。用先后天理论来说，督脉在脊柱，属肾，属先天；任脉在腹部，属胃，属后天。先天主气，下交于胞中；后天主血，下交于胞中，全在这两条脉的作用。用水火理论来说，督脉属气、属水；任脉属血、属火。因此任脉又属于心，心肾相交，水火既济，都由于此。所以任脉是阴脉之海。
[任脉图]
任脉起于胞中，下至两阴之间，名为会阴穴，谓其与督脉相会，且正当两阴之间，所以名叫会阴。向上至少腹聚毛之处，名为中极穴。再向上至脐下三寸，为关元穴，是元阳元阴交汇关锁的地方。出脐中上行至鸠尾穴上二寸六分，为膻中穴。膻中是心包络生血而出，随着任脉上下营运，所以任脉的穴位兼具心包络之名，正见任脉是为心包行血的脉络。从膻中上行三寸二分凹陷处，为紫宫穴。紫宫，指代心脏。心对应洛书九紫离卦，所以名叫紫宫。任脉到这里，正内合于心，所以用心位命名，正见任脉是为心行血的统脉。再向上至唇下，为承浆穴，与督脉相交，任脉至此终结。其支脉循行面部直到眼下。仔细观察任督的交会起止，就知道督脉主阳、主气，任脉主阴、主血，互相贯通，是生成身体的总司。
督脉起于肾中，下至胞室，乃下行，络阴器，循行二阴之间，至尾骨，贯穿脊柱，经过腰俞穴，上行至脑后，交于头顶，至囟会穴，入鼻柱，终于人中穴，与任脉相交。
督脉起于肾中，下至胞室。肾中天一所生的癸水，进入胞中，全靠督脉引导使其下行。肾气到达胞中，任脉应之，则心胃之血，便下会于胞中。这是任督相交、心肾相济。道家所说的坎离水火交媾之乡，就在这里。督脉络阴器，循行二阴之间，与任脉在下部交会。贯穿脊柱上顶，交于人中的位置，与任脉在上部交会。现在仔细考察其脉路，由鼻柱上脑，贯穿脊柱，抵肾，由肾入胞中。据此路线观察，才知道督脉主阳、主生。肾气，盖因气生于天阳，吸入鼻孔，至脑门下肺管，循背脊而下入肾，又由肾入胞中。所以吸气时胞中充满。吸入之气确实是由鼻、由脑、由脊而下，所以掩住鼻子张开嘴能出气而不能吸气。因为吸气的路径由脊下入，不从鼻脑直接入。呼气由膈肌出来，所以张口能出气。吸气由脊下入，由督脉主管。知道督脉的主管范围，就知道了气的生化过程。再详述天癸，乃是膀胱的枝条。
[督脉图]
督脉起于胞中，出会阴穴，至尾闾骨端，名长强穴。向上至第二十一椎，名腰俞穴，这是腰肾筋膜相连的地方。再向上至第十四椎，当肾脏正中，为命门穴，是肾系贯穿脊柱的地方，为督脉的主穴。盖任脉由心血所主管，督脉由肾气所主管，所以命门是督脉的主穴。再向上至第三椎，为身柱穴，肺肾相交，为一身元气的主宰，所以称为柱。再向上至大椎，至发际一寸宛中，为风府穴。发上二寸五分，为脑户穴，即西医脑后叶的中缝。至头顶为百会穴，与肝脉交会于此。前行当囟门，为囟会穴，谓心神上照于髓，以产生知觉，是神与髓会合的地方。又至额上发际为神庭穴，也是心神上出于此的含义。下至鼻尖，至齿缝龈交穴而终。盖人身吸入天阳之气，入鼻循脊下入肾系而入丹田，总归督脉所主管，化气化为精，为人身生命的本源，总督周身脏腑，所以称其为督。
带脉正当第十四椎处，出于肾，属于带脉，围身体一周，前垂至胞中。
带脉总束诸脉，使不妄行，像人束腰带一样，所以得名。究其带脉之所从出，则贯穿肾，系连带脉，当属肾。女子系胞，全靠带脉主管，因为其根结于命门。环腰贯脐，居于身之中停，又当属之于脾。所以脾病则女子带下，因为其属脾，而又下垂于胞中，所以随带脉而下。
[带脉图]
带脉，后方在第十四椎，当肾之中，前方在脐，绕腰一周。带脉的一个穴位，则在季胁，当少阳部位。近世的图显示带脉有三穴：一带脉穴，在足少阳胆经，季胁之下，一寸八分。再下三寸，为五枢穴。又下为维道穴。似乎带脉绕行三匝，而有上中下三穴。然而《难经》说：“脉带起于季胁，回身一周”，没有三匝的说法。又《灵枢经》说：“足少阴脉别走太阳，至十四椎，属带脉。”后人遂以带脉为肾之别脉，这是不对的。“属带脉者”，谓其为带脉所管束，并非言带脉是肾的脉。因其穴位居在少阳之界，以为它是少阳脉，也不对。肝胆能为带脉的病，然带脉终究不是肝胆之脉。盖带脉主管结前后，前束任脉而经过心小肠的脐中，后束督脉而经过肾系的中部。人身只有脾主中州，交合水火，带脉适当腰腹之中，应归为脾之脉。其穴位在胁，也因为前不居任脉之位，后不居督脉之位，正见其管束前后的作用。有人怀疑带脉不与脾相连，岂知腹中的膜油都是脾之物。肾着阳治带脉，以脾为主；女科认为妇人带下，都归于脾，是有道理的。
综上所述，这四条脉：督脉在背，总统诸阳，属先天；任脉在腹，总统诸阴，属后天；冲脉附丽于阳明，而通于胞宫，由后天以交于先天的肾；带脉出于肾中，以周行脾位，由先天以交于后天的脾。四者互为功用，不可不详加研究。
The twelve regular meridians are the primary meridians. There are additionally eight extraordinary vessels, known as the Eight Extraordinary Vessels (Qi Jing Ba Mai). A comprehensive discussion is not provided here; instead, only these four vessels are discussed in detail: The Yang Wei Mai (Yang Linking Vessel) and Yang Qiao Mai (Yang Heel Vessel), which run along the Taiyang Meridian on the back of the body. Since the Taiyang Meridian governs the back, these two are also governed by it. The Yin Wei Mai (Yin Linking Vessel) and Yin Qiao Mai (Yin Heel Vessel) run along the anterior aspect of the body, attaching to the Taiyin Meridian. Since the Taiyin Meridian governs the anterior abdomen, these two are also governed by it. These four vessels have distinct therapeutic indications and cannot be fully encompassed within the twelve regular meridians; therefore, they are detailed separately. Western medicine's diagrams of blood vessels show intricate branching, which can be considered detailed. However, their discussion of collateral vessels does not return to the main meridians, and their discussion of meridians does not return to the Zang-Fu organs. This is like having an army of thousands without a general, resulting in a lack of command and control. As for the Eight Extraordinary Vessels, Chinese medicine has long neglected deep study of them, so it is no wonder that Western medicine is unaware of them.
The Chong Mai (Penetrating Vessel) originates inside the lower abdomen, within the Bao Zhong (Uterus/Metropolis). It ascends bilaterally alongside the umbilicus, runs parallel to the Foot-Yangming Stomach Meridian, disperses upon reaching the chest, and ascends to flank the pharynx. The Bao Zhong is called Qi Hai (Sea of Qi), which is the root of respiration. Human exhalation rises from the Qi Hai, passes through the thoracic diaphragm into the lung tubes, and exits via the larynx. Its path entirely follows the ascent of the Chong Mai. Thus, the *Nei Jing* states that "Chong is the Qi Street," referring to this. Any condition involving rebellious Qi is attributed to the Chong Mai; therefore, Zhang Zhongjing had methods to descend rebellious Qi. The Bao Zhong is also named Xue Hai (Sea of Blood). The fluids from dietary intake processed in the stomach are transformed into blood by the Heart, descend into the Bao Zhong, and are guided downward by the Chong Mai. Thus, the *Nei Jing* states: "When a girl reaches fourteen years old (two sevens), Tian Gui arrives, the Tai Chong Mai becomes abundant, and menstruation occurs at the proper time." In summary, the Bao Zhong is the intersection of innate Kidney Qi and acquired Stomach blood. The Chong Mai originates in the Bao Zhong, guiding innate Kidney Qi upward to intersect with Stomach Qi, and guiding acquired Yin blood downward into the Bao Zhong to intersect with Kidney Qi. By guiding Qi upward and Blood downward, connecting to the Kidneys and attaching to the Yangming, the functions of the Chong Mai become clear.
[Diagram of Chong Mai]
The Chong Mai is the thoroughfare for the exit of Qi. Qi is generated in the Dan Tian (Elixir Field), and its exit point is three cun below the umbilicus, five fen lateral to the midline, known as the Qi Jie acupoint. This is the pathway where Qi exits, hence the name Qi Jie. Modern physicians, due to the *Ling Shu* stating that there are Qi Streets in the chest, abdomen, head, and feet, fail to identify the specific location of the Qi Jie acupoint. However, the *Nei Jing* clearly states "originates at Qi Jie, ascending alongside the umbilicus," explicitly indicating that the Qi Jie acupoint is below the umbilicus. Changing "Qi Jie" to "Qi Xue" today greatly deviates from the classic intent. From Qi Jie to the side of the umbilicus lies the Huang Shu acupoint. "Huang" refers to membrane; the membranes of the Dan Tian converge at the umbilicus, hence the name Huang Shu. Ascending further to the chest, it disperses at the Tong Gu acupoint. Presumably, because membranes reach the chest, they disperse to form the pleura (lung coat), completely enveloping the lungs; thus, the Chong Mai also disperses here. The pleura converges at the pharynx, so the Chong Mai flanks the pharynx and terminates. Generally, Qi emerges from the Dan Tian, travels alongside the umbilicus, reaches the chest, moves through the pleura, and converges at the pharynx, from where Qi is expelled. The pathway of Qi movement within the membranes is named the Chong Mai. The Chong Mai governs Qi, differing from the Ren Mai which governs Blood. Thus, it is evident that the twelve regular meridians and the Eight Extraordinary Vessels each have distinct governance; they are all pathways for the circulation of Qi and Blood among the Zang-Fu organs, with dispersion and convergence, and cannot be merely identified as blood vessels.
The Ren Mai (Conception Vessel) originates inside the lower abdomen, below the Bao Shi (Uterus), emerges at the Hui Yin region, ascends past the pubic hair line, follows the center of the umbilicus, reaches the Tan Zhong, ascends to the throat, circles the lips, and finally terminates at the Cheng Jiang acupoint below the lower lip, intersecting with the Du Mai.
The Du Mai (Governing Vessel) is located on the back, commanding all Yang meridians, hence named "Du" (Governor). The Ren Mai is located on the abdomen, commanding all Yin meridians, hence named "Ren" (Conception). Yin and Yang interpenetrate; thus, the Ren and Du vessels must intersect. Inferiorly, they intersect between the anterior and posterior orifices; superiorly, they intersect above and below the lips. Using the theory of Pre-Heaven and Post-Heaven: The Du Mai is in the spine, belongs to the Kidneys, and relates to Pre-Heaven; the Ren Mai is in the abdomen, belongs to the Stomach, and relates to Post-Heaven. Pre-Heaven governs Qi and descends to intersect in the Bao Zhong; Post-Heaven governs Blood and descends to intersect in the Bao Zhong. This all depends on these two vessels. Using the theory of Water and Fire: The Du Mai relates to Qi and Water; the Ren Mai relates to Blood and Fire. Therefore, the Ren Mai also pertains to the Heart. The Heart and Kidneys intersect, achieving the balance of Water and Fire, all occurring here. Thus, the Ren Mai is the Sea of Yin Vessels.
[Diagram of Ren Mai]
The Ren Mai originates in the Bao Zhong, descends to the space between the two yins, named Hui Yin Acupoint, signifying its meeting with the Du Mai at the space between the two yins. Ascending to the area of pubic hair in the lower abdomen, it is named Zhong Ji Acupoint. Further up to three cun below the umbilicus is Guan Yuan Acupoint, the place where Primordial Yang and Primordial Yin intersect and lock. Ascending from the umbilicus to two cun six fen above Jiu Wei is Tan Zhong Acupoint. Tan Zhong is where the Pericardium generates blood and circulates up and down with the Ren Mai; thus, the acupoints of the Ren Mai bear the name of the Pericardium, confirming that the Ren Mai conducts blood for the Pericardium. Ascending three cun two fen from Tan Zhong to the depression is Zi Gong Acupoint. Zi Gong refers to the Heart. The Heart corresponds to the Nine Purple Li Trigram of the Luo Shu, hence named Zi Gong. The Ren Mai here internally connects with the Heart, hence named after the Heart's position, confirming that the Ren Mai is the master vessel conducting blood for the Heart. Ascending further to below the lip is Cheng Jiang Acupoint, where it intersects with the Du Mai, marking the end of the Ren Mai. Its branch runs along the face to below the eyes. Carefully observing the intersection and termination of the Ren and Du Mai reveals that the Du Mai governs Yang and Qi, while the Ren Mai governs Yin and Blood. They interconnect and are the chief directors of bodily formation.
The Du Mai originates in the Kidneys, descends to the Bao Shi, then runs downward, links to the genitalia, follows the space between the two yins, reaches the sacrum, penetrates the spine, passes through Yao Shu, ascends to the back of the head, intersects at the vertex, enters at Xi Hui, goes up the nasal column, and finally terminates at Ren Zhong, intersecting with the Ren Mai.
The Du Mai originates in the Kidneys and descends to the Bao Shi. The Gui Water (Yin Water) generated by Heavenly One in the Kidneys enters the Bao Zhong, entirely guided downward by the Du Mai. When Kidney Qi reaches the Bao Zhong, the Ren Mai responds, causing the blood of the Heart and Stomach to converge in the Bao Zhong. This is the intersection of Ren and Du, and the mutual assistance of Heart and Kidney. This is the realm of Kan-Li water-fire coition described by Daoists. The Du Mai links the genitalia, follows the space between the two yins, and meets the Ren Mai inferiorly. It penetrates the spine to the crown and meets the Ren Mai superiorly at Ren Zhong. Careful examination of its pathway shows it goes from the nasal column to the brain, penetrates the spine, reaches the Kidneys, and enters the Bao Zhong. Observing this route, we know the Du Mai governs Yang and generation. Kidney Qi: Qi is born from Heavenly Yang, inhaled through the nose, reaches the base of the brain and lung tubes, follows the dorsal spine downward into the Kidneys, and from the Kidneys into the Bao Zhong. Thus, inhalation fills the Bao Zhong. Inhaled air indeed travels from the nose, through the brain, and down the spine. Therefore, holding the nose while opening the mouth allows exhalation but not inhalation. Because inhalation enters via the spine, it cannot enter directly from the nose/brain. Exhalation comes out via the diaphragm, so opening the mouth allows exhalation. Inhalation enters via the spine, governed by the Du Mai. Knowing what the Du Mai governs reveals the generation and transformation of Qi. Further detailing Tian Gui, it is a branch of the Bladder.
[Diagram of Du Mai]
The Du Mai originates in the Bao Zhong, emerges at Hui Yin Acupoint, reaches the end of the coccyx, named Chang Qiang Acupoint. Ascending to the 21st vertebra is Yao Shu Acupoint, where the lumbar and kidney fascia connect. Ascending further to the 14th vertebra, centered over the Kidneys, is Ming Men Acupoint, where the Kidney system penetrates the spine. It is the master acupoint of the Du Mai. Since the Ren Mai is governed by Heart Blood and the Du Mai by Kidney Qi, Ming Men is the master acupoint of the Du Mai. Ascending further to the 3rd vertebra is Shen Zhu Acupoint. Lung and Kidney intersect, serving as the master of primordial Qi for the whole body, hence named Zhu (Pillar). Ascending further to Da Zhui, one cun into the hairline depression, is Feng Fu Acupoint. Two cun five fen above the hairline is Nao Hu Acupoint, which corresponds to the midline suture of the occipital lobe in Western medicine. At the vertex is Bai Hui Acupoint, where it intersects with the Liver Meridian. Forward at the fontanelle is Xi Hui Acupoint, signifying that Spirit shines upward onto the Marrow to generate perception, a place where Spirit and Marrow meet. Further up to the forehead hairline is Shen Ting Acupoint, also implying Spirit emerging upward. Descending to the tip of the nose, ending at the gum intersection Yin Jiao Acupoint. Human inhalation of Heavenly Yang enters the nose, follows the spine down to the Kidney system, and enters the Dan Tian, all governed by the Du Mai. It transforms Qi into Essence, the origin of life, commanding all Zang-Fu organs, hence named Du.
The Dai Mai (Girdle Vessel) originates at the 14th vertebra near the Kidneys, belongs to the Dai Mai, encircles the body once, and hangs forward to the Bao Zhong.
The Dai Mai binds all meridians, preventing erratic flow, much like a person tying a belt, hence the name. Investigating its origin, it penetrates the Kidneys and ties to the Dai Mai, belonging to the Kidneys. For women, binding the uterus relies entirely on the Dai Mai, because its root connects to Ming Men. Encircling the waist and penetrating the umbilicus, situated in the middle of the body, it also belongs to the Spleen. Therefore, Spleen disease causes leukorrhea in women; because it belongs to the Spleen and hangs down to the Bao Zhong, it flows down with the Dai Mai.
[Diagram of Dai Mai]
The Dai Mai is posterior at the 14th vertebra, centered over the Kidneys, and anterior at the umbilicus, encircling the waist once. One acupoint of the Dai Mai is at the costal margin, in the Shaoyang region. Recent diagrams show three acupoints for the Dai Mai: Dai Mai Acupoint is on the Foot-Shaoyang Gallbladder Meridian, one cun eight fen below the costal margin. Three cun lower is Wu Shu Acupoint. Lower still is Wei Dao Acupoint. It seems the Dai Mai winds around three times, having upper, middle, and lower acupoints. However, the *Nan Jing* states: "The Dai Mai originates at the costal margin and encircles the body once," with no mention of three windings. Also, the *Ling Shu* states: "The Foot-Shaoyin Meridian branches to the Taiyang, reaches the 14th vertebra, and belongs to the Dai Mai." Later scholars mistakenly considered the Dai Mai a branch of the Kidney meridian, which is incorrect. "Belonging to the Dai Mai" means being bound by the Dai Mai, not that the Dai Mai is the Kidney's meridian. Considering its acupoints are in the Shaoyang boundary, some think it is a Shaoyang meridian, which is also incorrect. The Liver and Gallbladder can cause Dai Mai diseases, but the Dai Mai is ultimately not the Liver/Gallbladder meridian. The Dai Mai manages the front and back binding: anteriorly binding the Ren Mai and passing through the umbilicus (Heart/Small Intestine connection); posteriorly binding the Du Mai and passing through the Kidney system. Only the Spleen governs the Middle Jiao, harmonizing Water and Fire. The Dai Mai is exactly in the middle of the waist and abdomen, so it should belong to the Spleen meridian. Its acupoints are in the hypochondrium because it is neither in the Ren position nor the Du position, confirming its role in binding front and back. Some doubt the Dai Mai connects to the Spleen, not knowing that membranes and oil in the abdomen are products of the Spleen. Treating Dai Mai diseases with Kidney Yang focuses on the Spleen; Gynecology attributes female leukorrhea to the Spleen, which is well-founded.
In summary, regarding these four vessels: The Du Mai is on the back, commands all Yang, and belongs to Pre-Heaven. The Ren Mai is on the abdomen, commands all Yin, and belongs to Post-Heaven. The Chong Mai attaches to Yangming and connects to the Bao Gong (Uterus), interacting with Pre-Heaven Kidney via Post-Heaven. The Dai Mai originates from the Kidneys and circulates through the Spleen position, interacting with Post-Heaven Spleen via Pre-Heaven. The four interact mutually and require detailed investigation.