足阳明。五脏六腑之海也。其脉大。血多。气盛。热壮。刺此者。不深弗散。不留不泻
也。
足阳明刺深六分。留十呼。足太阳深五分。留七呼。足少阳深四分。留五呼。足太阴深一分
留四呼。足少阴深二分。留三呼。足厥阴深一分留二呼。手之阴阳。其受气之道近。其气之
来疾。其刺深者。皆无过二分其留皆无过一呼。其少长大小肥瘦。以心撩之命曰法天之常。
灸之一然。灸而过此者。得恶火。则骨枯。脉涩。刺而过此者。则脱气。
手之六阳。从手至头。长五尺。五六三丈。手之六阴。从手至胸中三尺五寸。三六一丈八尺
。五六三尺。合二丈一尺。足之六阳。从足上至头八尺。六八四丈八尺。足之六阴。从足至
胸中六尺五寸。六六三丈六尺。五六三尺。合三丈九尺。跷脉从足至目七尺五寸。二七一丈
四尺。二五一尺。合一丈五尺。督任脉各四尺五寸。二四八尺。二五一尺。合九尺。凡都合
一十六丈二尺。此气之大经隧也。经脉为里。支而横者为络。络之别者为孙。盛而血者疾诛
之。盛者泻之。虚者饮药以补之。
跷脉者。少阴之别。起于然骨之后。上内踝之上。直上循阴股入阴。上循胸里。入缺盆
。上出人迎之前。入 。属目内 。合于太阳阳跷而上行。气并相还。则为濡目。气不营。则目
不合。男子数其阳。女子数其阴。当数者为经。不当数者为络也。(男子以阳跷为经。阴
跷为络。女子以阴跷为经。阳跷为络也。)
足阳明胃经，是五脏六腑气血汇聚的大海。它的脉象盛大，血气充盈，阳气旺盛，热势壮盛。针刺这条经脉时，如果不刺得深一些，邪气就不能散开；如果不留针，正气就不能得到宣泄。
足阳明经的针刺深度为六分，留针十次呼吸的时间。足太阳经针刺深度为五分，留针七次呼吸的时间。足少阳经针刺深度为四分，留针五次呼吸的时间。足太阴经针刺深度为一分，留针四次呼吸的时间。足少阴经针刺深度为二分，留针三次呼吸的时间。足厥阴经针刺深度为一分，留针两次呼吸的时间。手部的阴阳经脉，其接受经气的路径较近，经气到来的速度较快。因此，手部经脉针刺最深的也不超过二分，留针时间都不超过一次呼吸的时间。对于患者的年少与年长、体型大小、身体肥瘦，需要根据具体情况用心斟酌衡量，这叫做效法自然的常规法则。艾灸的方法也是如此。如果艾灸超过了规定的限度，就会招致“恶火”（严重的火热之邪），导致骨骼枯槁、血脉涩滞；如果针刺超过了规定的深度，就会导致气脱。
手部的六条阳经，从手指延伸至头部，每条长五尺，六条合计三丈。手部的六条阴经，从手指延伸至胸中，每条长三尺五寸，六条合计一丈八尺，加上之前的三丈，总共二丈一尺。足部的六条阳经，从足部延伸至头部，每条长八尺，六条合计四丈八尺。足部的六条阴经，从足部延伸至胸中，每条长六尺五寸，六条合计三丈六尺，加上之前的四丈八尺，总共三丈九尺。跷脉从足部延伸至眼部，每条长七尺五寸，两条合计一丈五尺。督脉和任脉各长四尺五寸，两条合计九尺。以上所有经脉长度加起来，总共是一十六丈二尺。这是人体经气运行的大通道。经脉在里层，分支横向分布的是络脉，络脉再细分的是孙脉。如果络脉中血液壅盛，应当迅速刺破放血；实证用泻法，虚证用药饮来补益。
跷脉，是足少阴肾经的别支，起始于然骨穴之后，向上经过内踝上方，沿大腿内侧上行进入阴部，再向上沿胸部内部，进入缺盆穴，向上出于人迎穴之前，进入目内眦（睛明穴），与足太阳膀胱经的阳跷脉汇合后向上行。两股经气并行且相互返还，就能滋润眼睛；如果经气不能滋养，眼睛就无法闭合。男子计算阳跷脉的长度，女子计算阴跷脉的长度。被计算的那条称为经，不被计算的那条称为络。（即：男子以阳跷脉为经，阴跷脉为络；女子以阴跷脉为经，阳跷脉为络。）
The Foot-Yangming (Stomach) channel is the sea of the five zang and six fu organs. Its pulse is large, with abundant blood and vigorous qi, characterized by strong heat. When needling this channel, if the insertion is not deep enough, the pathogenic factors will not disperse; if the needle is not retained, the healthy qi will not be properly drained.
For the Foot-Yangming channel, the needling depth is six fen, with retention for ten breaths. For the Foot-Taiyang (Bladder) channel, the depth is five fen, retained for seven breaths. For the Foot-Shaoyang (Gallbladder) channel, the depth is four fen, retained for five breaths. For the Foot-Taiyin (Spleen) channel, the depth is one fen, retained for four breaths. For the Foot-Shaoyin (Kidney) channel, the depth is two fen, retained for three breaths. For the Foot-Jueyin (Liver) channel, the depth is one fen, retained for two breaths. In the upper limbs, the yin and yang channels have a shorter pathway for receiving qi, and the arrival of qi is rapid. Therefore, the maximum needling depth for these channels should not exceed two fen, and the retention time should not exceed one breath. Regarding the patient’s age (young or old), size, and body constitution (fat or thin), one must carefully consider and adjust accordingly; this is called following the constant laws of Heaven. The same principle applies to moxibustion. If moxibustion exceeds these limits, it may cause "evil fire" (severe pathological heat), leading to dry bones and stagnant pulses. If needling exceeds these depths, it may lead to qi depletion.
The six yang channels of the hands extend from the hands to the head, each measuring five chi, totaling three zhang (ten chi) for all six. The six yin channels of the hands extend from the hands to the chest, each measuring three chi and five cun, totaling one zhang and eight chi for all six. Combined with the yang channels, the total length is two zhang and one chi. The six yang channels of the feet extend from the feet to the head, each measuring eight chi, totaling four zhang and eight chi for all six. The six yin channels of the feet extend from the feet to the chest, each measuring six chi and five cun, totaling three zhang and nine chi for all six. The Qiao vessels (Shu Vessels) extend from the feet to the eyes, each measuring seven chi and five cun, totaling one zhang and five chi for both. The Du Mai (Governor Vessel) and Ren Mai (Conception Vessel) are each four chi and five cun long, totaling nine chi for both. All these combined amount to sixteen zhang and two chi. These are the major meridians through which qi flows. The main meridians lie internally, while branches that run horizontally are Luo vessels (Connecting Vessels); further subdivisions of Luo vessels are Sun vessels (Sun Vessels). If a vessel is full of blood, it should be pricked immediately to release it. Excess conditions are treated by draining (reducing), while deficiency conditions are treated with herbal decoctions to tonify.
The Qiao vessels are branch vessels of the Foot-Shaoyin (Kidney) channel. They originate behind the Ran Gu point, ascend above the medial malleolus, follow the medial thigh into the genital region, continue up through the interior of the chest, enter the Que Pen area, emerge anterior to the Ying Chu point, enter the inner canthus, and merge with the Yang Qiao vessel of the Foot-Taiyang (Bladder) channel to ascend. When the qi of both vessels runs together and returns, they moisten the eyes. If the qi does not nourish them, the eyes cannot close. For men, the Yang Qiao vessel is counted as the Jing (Main) vessel, and the Yin Qiao as the Luo (Connecting) vessel. For women, the Yin Qiao is counted as the Jing vessel, and the Yang Qiao as the Luo vessel.