三十六难曰∶脏各有一耳，肾独有两者，何也？然∶肾两者，非皆肾也，其左者为肾，右者
为命门。命门者，诸神精之所舍，原气之所系也，男子以藏精，女子以系胞。故知肾有一也。
三十七难曰∶五脏之气，于何发起，通于何许，可晓以不？然∶五脏者，当上关于九窍也。
故肺气通于鼻，鼻和则知香臭矣；肝气通于目，目和则知黑白矣；脾气通于口，口和则知谷
味矣；心气通于舌，舌和则知五味矣；肾气通于耳，耳和则知五音矣。
五脏不和，则九窍不通；六腑不和，则留结为痈。
邪在六腑，则阳脉不和；阳脉不和，则气留之；气留之则阳脉盛矣。邪在五脏，则阴脉
不和；阴脉不和，则血留之；血留之则阴脉盛矣。阴气太盛，则阳气不得相营也，故曰格。阳
气太盛，则阴气不得相营也，故曰关。阴阳俱盛不得相营也，故曰关格，关格者，不得尽其命
而死矣。
经言，气独行于五脏，不营于六腑者，何也？然∶夫气之所行也，如水之流，不得息也。
故阴脉营于五脏，阳脉营于六腑，如环无端，莫知其纪，终而复始，其不覆溢，人气内温于脏腑，
外濡于腠理。
三十八难曰∶脏唯有五，腑独有六者，何也？然∶所以腑有六者，谓三焦也。有原气之别焉，
主持诸气，有名而无形，其经属手少阳。此外府也，故言腑有六焉。
第三十六难问道：五脏各有一个，唯独肾脏有两个，这是为什么呢？回答说：两个肾并不都是通常所说的“肾”，其中左边那个称为肾，右边那个称为命门。命门，是各种精神精气藏舍的地方，也是原气系连的关键所在。男子依靠它来储藏精液，女子依靠它来维系子宫（胞宫）。因此可以说肾脏在功能上其实只有一个。
第三十七难问道：五脏的气血，是从哪里发起的，通达于哪些部位，可以讲清楚吗？回答说：五脏之气，向上联系着九窍。所以肺气通于鼻，鼻气调和就能辨别香臭；肝气通于目，目气调和就能分辨黑白；脾气通于口，口气调和就能知晓五谷的味道；心气通于舌，舌气调和就能辨别五味；肾气通于耳，耳气调和就能听辨五音。
如果五脏不和，那么九窍就会不通畅；六腑不和，气血就会滞留凝结而成痈肿。
邪气侵犯六腑，就会导致阳脉不和；阳脉不和，气就会停留；气停留则阳脉就会亢盛。邪气侵犯五脏，就会导致阴脉不和；阴脉不和，血就会停留；血停留则阴脉就会亢盛。阴气太盛，阳气就不能与之相互协调，这就叫做“格”（格拒）。阳气太盛，阴气就不能与之相互协调，这就叫做“关”（关闭）。阴阳都亢盛而不能相互协调，这就叫做“关格”，患关格病的人，生命就无法延续而死亡。
经书说，气只在五脏运行，不滋养六腑，这是什么原因呢？回答说：气的运行，就像水流一样，不会停止。所以阴脉滋养五脏，阳脉滋养六腑，像圆环一样没有尽头，不知其起止，循环往复，不停止也不溢出。人的正气内能温煦脏腑，外能滋润腠理。
第三十八难问道：脏只有五个，腑却独有六个，这是为什么呢？回答说：之所以说腑有六个，是因为包括了“三焦”。三焦是原气的别道，主持全身诸气，有名而无实质形态，其经脉归属于手少阳经。这是外腑，所以说腑有六个。
Difficulty 36 asks: Each of the Zang organs has one, yet the Kidneys uniquely have two. Why is this? The answer is: The two kidneys are not both "Kidneys" in the strict sense; the left one is called the Kidney (Shen), and the right one is called the Gate of Vitality (Mingmen). The Gate of Vitality is the residence where all spiritual essences are stored and the root where the Original Qi (Yuanqi) is attached. In men, it stores Essence (Jing); in women, it connects to the Uterus (Baoguo). Therefore, it can be understood that functionally, there is only one Kidney.
Difficulty 37 asks: From where do the Qi of the five Zang organs originate, through which pathways do they connect, and can this be explained? The answer is: The Qi of the five Zang organs connects superiorly to the nine orifices. Thus, Lung Qi connects to the nose; when nasal Qi is harmonious, one can distinguish fragrances from foul odors. Liver Qi connects to the eyes; when eye Qi is harmonious, one can distinguish black from white. Spleen Qi connects to the mouth; when oral Qi is harmonious, one can perceive the flavors of grains. Heart Qi connects to the tongue; when lingual Qi is harmonious, one can discern the five flavors. Kidney Qi connects to the ears; when auricular Qi is harmonious, one can perceive the five tones.
If the five Zang organs are disharmonious, the nine orifices will be obstructed; if the six Fu organs are disharmonious, stagnation and knotting will occur, leading to carbuncles.
When pathogenic factors reside in the six Fu organs, the Yang pulses become discordant; when Yang pulses are discordant, Qi stagnates; when Qi stagnates, the Yang pulses become excessive. When pathogenic factors reside in the five Zang organs, the Yin pulses become discordant; when Yin pulses are discordant, Blood stagnates; when Blood stagnates, the Yin pulses become excessive. If Yin Qi becomes excessively strong, Yang Qi cannot circulate with it, which is termed "Ge" (Rejection/Obstruction). If Yang Qi becomes excessively strong, Yin Qi cannot circulate with it, which is termed "Guan" (Closure). If both Yin and Yang Qi are excessive and cannot circulate with each other, it is termed "Guan Ge" (Closure and Rejection). Those suffering from Guan Ge will not survive their natural lifespan.
The Classics state that Qi circulates exclusively within the five Zang organs and does not nourish the six Fu organs. Why is this? The answer is: The movement of Qi is like flowing water, never ceasing. Thus, Yin pulses nourish the five Zang organs, and Yang pulses nourish the six Fu organs. Like a circle without beginning or end, its cycles are countless, ending and restarting continuously, without overflowing or depleting. Human Qi internally warms the Zang and Fu organs and externally moistens the Couli (interstitial spaces/skin layers).
Difficulty 38 asks: There are only five Zang organs, yet there are uniquely six Fu organs. Why is this? The answer is: The reason there are six Fu organs is due to the inclusion of the Sanjiao (Triple Burner). The Sanjiao is a distinct pathway of the Original Qi (Yuanqi), governing all Qi throughout the body. It has a name but no substantial form, and its meridian belongs to the Hand-Shaoyang (Sanjiao) channel. As an external Fu organ, it is said that there are six Fu organs.