《素问》皮部篇，黄帝问曰∶余闻皮有分部，脉有经纪，筋有结络，骨有度量，其所生病各异，
别其分部，左右上下，阴阳所在，病之始终，愿闻其道。岐伯对曰∶欲知皮部，以经脉为纪者，诸经
皆然。阳明之阳，名曰害蜚，上下同法，视其部中有浮络者，皆阳明之络也。其色多青则痛，多黑则
痹，黄赤则热，多白则寒，五色皆见，则寒热也。络盛则入客于经，阳主外，阴主内。少阳之阳，名
曰枢持，上下同法，视其部中有浮络者，皆少阳之络也。络盛则入客于经，故在阳者主内，在阴者主
出，以渗于内，诸经皆然。太阳之阳，名曰关枢，上下同法，视其部中有浮络者，皆太阳之络也。络
盛则入客于经。少阴之阴，名曰枢儒（一作 ），上下同法，视其部中有浮络者，皆少阴之络也。络
盛则入客于经，其入经也，从阳部注于经；其出者，从阴内注于骨。心主之阴，名曰害肩，上下同法，
视其部中有浮络者，皆心主
之络也。络盛则入客于经。太阴之阴，名曰关蛰，上下同法，视其部中有浮络者，皆太阴之络也。络
盛则入客于经。凡十二经络脉者，皮之部也。是故百病之始生也，必先于皮毛，邪中之则腠理开，开
则入客于络脉，留而不去，传入于经，留而不去，传入于腑，廪于肠胃。邪之始入于皮也，溯然起毫
毛，开腠理；其入于络也，则络脉盛色变；其入客于经也，则感虚乃陷下。其留于筋骨之间，寒多则
筋挛骨痛，热多则筋弛骨消，肉烁 破，毛直而败。帝曰∶夫子言皮之十二部，其生病皆何如？岐伯
曰∶皮者，脉之部也，邪客于皮则腠理开，开则邪入客于络脉，络脉满则注于经脉，经脉满则入舍于
腑脏也。故皮者有分部，不与而生大病也。帝曰∶善。皮肤属肺。经云∶肺之合皮也，其荣毛也。又
云∶肺主皮毛，在脏为肺，在体为皮毛是也。毛折爪枯，为手太阴绝。经云∶手太阴者，行气温于皮
毛者也。气不荣则皮毛焦，皮毛焦则津液去。皮绝者，津液既去则爪枯毛折，毛折者，毛先死矣。
《素问》中的皮部篇记载，黄帝问道：我听说皮肤有分属的区域，经脉有运行的纲纪，筋脉有结聚的络网，骨骼有测量的标准，它们所引发的疾病各不相同。我想了解如何辨别这些分部，以及左右上下、阴阳所在的位置和疾病的始末过程，希望能听听其中的道理。岐伯回答说：想要了解皮部，应当以经脉作为纲纪，各条经脉都是如此。阳明经的阳气，名为害蜚，上下部位遵循同样的法则，观察其所属区域中有浮露的络脉，这些都是阳明的络脉。如果颜色多青则主痛，多黑则主痹证，黄赤则主热，多白则主寒，五色都出现，则是寒热错杂。络脉充盛，邪气就会侵入并客居于经脉之中，阳主外，阴主内。少阳经的阳气，名为枢持，上下部位遵循同样的法则，观察其所属区域中有浮露的络脉，这些都是少阳的络脉。络脉充盛，邪气就会侵入并客居于经脉之中，所以在阳分的络脉主要向内传输，在阴分的络脉主要向外排出，从而渗入体内，各条经脉都是如此。太阳经的阳气，名为关枢，上下部位遵循同样的法则，观察其所属区域中有浮露的络脉，这些都是太阳的络脉。络脉充盛，邪气就会侵入并客居于经脉之中。少阴经的阴气，名为枢儒（另一种版本作“枢”），上下部位遵循同样的法则，观察其所属区域中有浮露的络脉，这些都是少阴的络脉。络脉充盛，邪气就会侵入并客居于经脉之中，邪气进入经脉后，从阳部注入经脉；邪气外出时，从阴内部注入骨骼。心包络的阴气，名为害肩，上下部位遵循同样的法则，观察其所属区域中有浮露的络脉，这些都是心包络的络脉。络脉充盛，邪气就会侵入并客居于经脉之中。太阴经的阴气，名为关蛰，上下部位遵循同样的法则，观察其所属区域中有浮露的络脉，这些都是太阴的络脉。络脉充盛，邪气就会侵入并客居于经脉之中。凡是十二经络脉，都是皮肤的分区。因此各种疾病的发生，必定先从皮毛开始，邪气侵袭人体则腠理开泄，腠理开泄则邪气进入客居络脉，停留不去，传入经脉，停留不去，传入腑脏，停滞于肠胃。邪气刚开始侵入皮肤时，毫毛竖起，腠理开泄；邪气进入络脉时，络脉充盛且颜色改变；邪气客居经脉时，正气虚弱则病邪陷入。邪气停留在筋骨之间，寒邪多则筋脉拘挛、骨骼疼痛，热邪多则筋脉弛缓、骨骼消瘦，肌肉消烁、皮肤破裂，毫毛干枯败坏。黄帝说：先生所说的皮肤十二分区，它们发生的疾病都是怎样的呢？岐伯说：皮肤是经脉的分区，邪气客居皮肤则腠理开泄，腠理开泄则邪气进入客居络脉，络脉充满则注入手足经脉，经脉充满则进入并留舍于腑脏。所以皮肤有分属区域，如果不加以区分就会产生大病。黄帝说：好。皮肤归属于肺。经书说：肺与皮相合，其荣华表现在毫毛上。又说：肺主管皮毛，在脏腑中对应肺，在形体组织中对应皮毛，就是这个意思。毫毛枯折、指甲干枯，是手太阴肺经之气绝的表现。经书说：手太阴肺经，是运行气机以滋养皮毛的。气不能滋养则皮毛焦枯，皮毛焦枯则津液流失。皮气绝者，津液既然流失则指甲干枯、毫毛枯折，毫毛枯折，意味着毫毛先死。
In the "Pi Bu Pian" (Chapter on Skin Parts) of the *Su Wen* (Basic Questions), the Yellow Emperor asked: I have heard that the skin has distinct regions, the meridians have their pathways and regulations, the sinews have connecting networks, and the bones have measurable dimensions. The diseases they generate are different. I wish to know how to distinguish these regions, their locations in the left and right, upper and lower, yin and yang, and the beginning and end of diseases. May I ask for the principles involved? Qibo replied: To understand the skin parts, one should take the meridians as the guiding principle; this applies to all meridians. The yang aspect of the Yangming Meridian is called Haifei. The methods above and below are the same. Observe the floating collaterals within the region; these are all the collaterals of Yangming. If the color is predominantly blue/green, it indicates pain; if predominantly black, it indicates Bi syndrome (obstruction); if yellow/red, it indicates heat; if predominantly white, it indicates cold; if all five colors appear, it indicates a mix of cold and heat. When the collaterals are full, pathogens enter and lodge in the main meridians. Yang governs the exterior, Yin governs the interior. The yang aspect of the Shaoyang Meridian is called Chuchi. The methods above and below are the same. Observe the floating collaterals within the region; these are all the collaterals of Shaoyang. When the collaterals are full, pathogens enter and lodge in the main meridians. Thus, what is in the yang [collaterals] governs inward transmission, and what is in the yin [collaterals] governs outward discharge, allowing seepage into the interior. This applies to all meridians. The yang aspect of the Taiyang Meridian is called Guanshu. The methods above and below are the same. Observe the floating collaterals within the region; these are all the collaterals of Taiyang. When the collaterals are full, pathogens enter and lodge in the main meridians. The yin aspect of the Shaoyin Meridian is called Shuru (alternatively written as 'Shu'). The methods above and below are the same. Observe the floating collaterals within the region; these are all the collaterals of Shaoyin. When the collaterals are full, pathogens enter and lodge in the main meridians. Upon entering the meridians, they flow from the yang regions into the meridians; upon exiting, they flow from the yin interior into the bones. The yin aspect of the Pericardium (Heart Master) is called Haijian. The methods above and below are the same. Observe the floating collaterals within the region; these are all the collaterals of the Pericardium. When the collaterals are full, pathogens enter and lodge in the main meridians. The yin aspect of the Taiyin Meridian is called Guanzhe. The methods above and below are the same. Observe the floating collaterals within the region; these are all the collaterals of Taiyin. When the collaterals are full, pathogens enter and lodge in the main meridians. All twelve meridian collateral systems are the divisions of the skin. Therefore, the onset of all diseases must first occur in the hair and skin. When pathogens attack, the interstices (Cou Li) open; when open, pathogens enter and lodge in the collaterals. If they remain without departing, they transmit to the meridians; if they remain without departing, they transmit to the fu organs, stagnating in the intestines and stomach. When pathogens initially enter the skin, the body hair stands erect, and the interstices open. When they enter the collaterals, the collaterals become full and the color changes. When they lodge in the meridians, deficiency allows them to sink inward. If they remain between the sinews and bones, excessive cold causes sinew spasms and bone pain; excessive heat causes sinew flaccidity and bone wasting, muscle emaciation, skin cracking, and the stiffening and deterioration of body hair. The Emperor said: You spoke of the twelve divisions of the skin; what kind of diseases do they produce? Qibo said: The skin is the division of the meridians. When pathogens lodge in the skin, the interstices open; when open, pathogens enter and lodge in the collaterals. When collaterals are full, they transmit to the main meridians; when main meridians are full, they enter and reside in the zang-fu organs. Thus, the skin has specific divisions; failing to observe them leads to serious diseases. The Emperor said: Excellent. The skin belongs to the Lung. The classics state: The Lung combines with the skin, and its flourishing aspect manifests in the body hair. It also states: The Lung governs the skin and hair. In the zang organs, it corresponds to the Lung; in the形体 (body structures), it corresponds to the skin and hair. Withered body hair and dry nails indicate the exhaustion of the Hand-Taiyin [Lung Meridian]. The classics state: The Hand-Taiyin [Meridian] circulates qi to nourish the skin and hair. If qi does not nourish, the skin and hair become scorched/dry; if skin and hair become scorched/dry, body fluids are lost. In cases of skin exhaustion, once body fluids are lost, the nails become dry and the body hair withers. Withered body hair indicates that the hair dies first.