肺合大肠，大肠者传道之腑。心合小肠，小肠者受盛之腑。肝合胆，胆者清净之腑。脾
合胃，胃者五谷之腑。肾合膀胱，膀胱者津液之腑。少阴属肾，上连肺，故将两脏。三焦
者，中渎之腑，水道出焉，属膀胱，是孤之腑。此六腑之所合者也。
《素问》曰∶夫脑、髓、骨、脉、胆、女子胞，此六者，地气之所生也。皆藏于阴，象
于地，故藏而不泻，名曰奇恒之府。胃、大肠、小肠、三焦、膀胱，此五者，天气之所生也
。其气象天，故泻而不藏，此受五脏浊气，名曰传化之府。此不能久留，输泻者也。魄门亦
为五脏使，水谷不得久藏。五脏者，藏精气而不泻，故满而不能实。六腑者，传化物而不藏
，故实而不能满。水谷入口，则胃实而肠虚，食下则肠实而胃虚，故实而不满，满而不实也
。气口何以独为五脏主？胃者，水谷之海，六腑之大源也。（称六腑虽少错，于理相发为佳。
）
肝胆为合，故足厥阴与少阳为表里。脾胃为合，故足太阴与阳明为表里。肾膀胱
为合，故足少阴与太阳为表里。心与小肠为合，故手少阴与太阳为表里。肺与大肠为合，
故手太阴与阳明为表里。
五脏者，肺为之盖，巨肩陷，咽喉见于外。心为之主，缺盆之道， （音滑）骨有
余，以候内 （音曷干）。肝为之主将，使之候外，欲知坚固，视目大小。脾主为
胃（《九墟》《太素》作卫），使之迎粮，视唇舌好恶，以知吉凶。肾者主为外，使之远听，
视耳好恶，以知其性。六腑者，胃为之海，广骸（《太素》作HT ）大颈张胸，五谷乃容。
鼻隧以长，以候大肠。唇浓人中长，以候小肠。目下裹大，其胆乃横。鼻孔在外，膀胱漏泄
。鼻柱中央起，三焦乃约。此所以候六腑也。上下三等，脏安且良矣。
肺与大肠相合，大肠是传导糟粕的腑。心与小肠相合，小肠是接受和盛纳水谷的腑。肝与胆相合，胆是清净精汁的腑。脾与胃相合，胃是受纳五谷的腑。肾与膀胱相合，膀胱是贮存津液的腑。足少阴肾经属肾，向上连接肺，所以能统摄两脏。三焦是中空的管道之腑，水道由此而出，归属于膀胱，是孤独的腑。这是六腑相合的情况。
《素问》说：脑、髓、骨、脉、胆、女子胞，这六个器官，是由地气所生成的。它们都藏于阴，象征大地，所以只贮藏精气而不排泄，称为奇恒之腑（形态似腑，功能似脏的特殊器官）。胃、大肠、小肠、三焦、膀胱，这五个器官，是由天气所生成的。它们的性质像天，所以只排泄而不贮藏，这是接受五脏浊气的器官，称为传化之腑（传导和变化水谷的器官）。这些器官不能久留食物，而是负责输送和排泄的。魄门（肛门）也是五脏的役使，水谷糟粕不能在体内久藏。五脏的功能是贮藏精气而不泄泻，所以保持充满状态但不会壅实。六腑的功能是传导变化水谷而不贮藏，所以会暂时充实但不能保持持续充满。水谷入口，则胃充实而肠道空虚；食物下行，则肠道充实而胃空虚，所以说六腑是“实而不能满”，五脏是“满而不能实”。为什么寸口脉能单独作为诊断五脏病变的主宰？因为胃是水谷汇聚的大海，是六腑能量的主要来源。（虽然称六腑为五或少错，但在道理上相互阐发为佳。）
肝胆相合，所以足厥阴肝经与足少阳胆经互为表里。脾胃相合，所以足太阴脾经与足阳明胃经互为表里。肾与膀胱相合，所以足少阴肾经与足太阳膀胱经互为表里。心与小肠相合，所以手少阴心经与手太阳小肠经互为表里。肺与大肠相合，所以手太阴肺经与手阳明大肠经互为表里。
五脏中，肺位于最高处，如伞盖一般，如果肩背宽阔凹陷，咽喉就会显露在外。心是君主之官，缺盆（锁骨上窝）是道路，若颧骨有余，可以以此候察内脏情况。肝是将帅之官，主管对外适应，想要知道肝脏是否坚固，需观察眼睛的大小。脾主为胃护卫（《九墟》《太素》作“卫”），替胃迎接和运化水谷，通过观察嘴唇和舌头的色泽好坏，来预知吉凶。肾主司对外感知，使人能远听，通过观察耳朵的好坏，来了解其本性。六腑中，胃是大海，如果骨骼宽大、颈部粗壮、胸部张开，就能容纳五谷。鼻道长，可以候察大肠。嘴唇厚、人中沟长，可以候察小肠。眼下眼睑肥大，说明胆气横溢。鼻孔外露，说明膀胱漏泄失约。鼻梁中央突起，说明三焦约束有力。这就是通过面部特征来候察六腑的方法。上下三部脉象均衡，脏腑就安和良好了。
The Lung corresponds to the Large Intestine, which is the Fu-organ of transmission. The Heart corresponds to the Small Intestine, which is the Fu-organ of reception and containment. The Liver corresponds to the Gallbladder, which is the Fu-organ of purity and clarity. The Spleen corresponds to the Stomach, which is the Fu-organ receiving the five grains. The Kidney corresponds to the Bladder, which is the Fu-organ storing body fluids (Jin-Ye). The Shaoyin channel belongs to the Kidney and connects upward to the Lung; thus, it governs both Zang-organs. The Sanjiao (Triple Burner) is the Fu-organ of mid-level channels, through which water pathways emerge; it belongs to the Bladder and is the solitary Fu-organ. These constitute the correspondences of the six Fu-organs.
The *Suwen* states: The brain, marrow, bones, vessels, gallbladder, and uterus in women are these six organs, generated by Earth Qi. They all store Yin and resemble the Earth; therefore, they store essence without excreting, named the Marrow-like Fu-organs (Qi Heng Zhi Fu - organs that resemble Fu in structure but function like Zang). The Stomach, Large Intestine, Small Intestine, Sanjiao (Triple Burner), and Bladder are these five organs, generated by Heaven Qi. Their nature resembles Heaven; therefore, they excrete without storing. These receive turbid Qi from the five Zang-organs and are named the Transmission and Transformation Fu-orgins (Chuan Hua Zhi Fu). They cannot retain contents for long and serve to transport and excrete. The Po Gate (anus) also serves as an attendant to the five Zang-organs, preventing food and water from being stored for too long. The five Zang-organs store essence and Qi without excreting, thus remaining full but not solidly obstructed. The six Fu-organs transmit transformed substances without storing, thus becoming solid temporarily but never fully full. When food and water enter the mouth, the Stomach becomes solid while the intestines are empty; when food descends, the intestines become solid while the Stomach is empty. Thus, the Fu-organs are "solid but not full," while the Zang-organs are "full but not solid." Why does the Cun Kou pulse alone serve as the master for diagnosing the five Zang-organs? Because the Stomach is the sea of food and water and the great source of the six Fu-organs. (Although referring to five or six Fu-organs may seem erroneous, it is beneficial for theoretical clarification.)
The Liver and Gallbladder correspond; therefore, the Foot Jueyin Liver channel and the Foot Shaoyang Gallbladder channel are interior-exterior pairs. The Spleen and Stomach correspond; therefore, the Foot Taiyin Spleen channel and the Foot Yangming Stomach channel are interior-exterior pairs. The Kidney and Bladder correspond; therefore, the Foot Shaoyin Kidney channel and the Foot Yangming Bladder channel are interior-exterior pairs. The Heart and Small Intestine correspond; therefore, the Hand Shaoyin Heart channel and the Hand Taiyang Small Intestine channel are interior-exterior pairs. The Lung and Large Intestine correspond; therefore, the Hand Taiyin Lung channel and the Hand Yangming Large Intestine channel are interior-exterior pairs.
Among the five Zang-organs, the Lung acts as a canopy; if the shoulders are broad and sunken, the throat will be visible externally. The Heart is the ruler; the Quepen (supraclavicular fossa) is the pathway; if the cheekbones are prominent, one can observe internal conditions. The Liver is the general, managing external adaptation; to know its firmness, observe the size of the eyes. The Spleen protects the Stomach (written as 'Wei' in *Jiuxu* and *Taisu*), receiving grain for it; observing the condition of the lips and tongue reveals auspiciousness or inauspiciousness. The Kidney governs external perception, enabling distant hearing; observing the ears reveals its nature. Among the six Fu-organs, the Stomach is the sea; if the skeleton is broad, the neck thick, and the chest expanded, it can contain the five grains. A long nasal passage indicates the state of the Large Intestine. Thick lips and a long philtrum indicate the state of the Small Intestine. Full lower eyelids indicate the Gallbladder. Exposed nostrils indicate leakage of the Bladder. A raised central nasal column indicates the constraint of the Sanjiao (Triple Burner). This is how the six Fu-organs are observed. If the three levels (upper, middle, lower) are balanced, the Zang-organs are safe and healthy.