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。
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.