The chapter "Nine Needles and Twelve Originals" (Jiuzhen Shier Yuan) in the *Ling Shu* states: The Yuan-Source point of the Lung meridian is Taiyuan (LU 9); the Yuan-Source point of the Heart meridian is Daling (PC 7); the Yuan-Source point of the Liver meridian is Taichong (LR 3); the Yuan-Source point of the Spleen meridian is Taibai (SP 3); the Yuan-Source point of the Kidney meridian is Taixi (KI 3); the Yuan-Source point of the Gao (pericardial fat/mesentery) is Jiawei (CV 15); and the Yuan-Source point of the Huang (diaphragmatic cavity) is Bo Yang (CV 16). These twelve Yuan-Source points are used to treat diseases of the Zang and Fu organs.

The chapter "Ben Shu" (Roots and Transmissions) in the *Ling Shu* designates Taiyuan, Daling, Taichong, Taibai, and Taixi as the Shu-Stream points of the five Zang organs. For the six Fu organs: for the Bladder, Shugu (BL 65) is the Shu-Stream point, and Jinggu (BL 64) is the Yuan-Source point; for the Gallbladder, Linqi (GB 41) is the Shu-Stream point, and Qiuxu (GB 40) is the Yuan-Source point; for the Stomach, Xangu (ST 43) is the Shu-Stream point, and Chongyang (ST 42) is the Yuan-Source point; for the Sanjiao (Triple Burner), Zhongzhu (TE 3) is the Shu-Stream point, and Yangchi (TE 4) is the Yuan-Source point; for the Small Intestine, Houxi (SI 3) is the Shu-Stream point, and Wanggu (SI 4) is the Yuan-Source point; for the Large Intestine, Sanjian (LI 3) is the Shu-Stream point, and Hegu (LI 4) is the Yuan-Source point. It further states: The Qi of the Heart emerges from Zhongchong (PC 9), flows into Laogong (PC 8), pours into Daling (PC 7), travels through Jianshi (PC 5), and enters Quze (PC 3). This refers to the Hand-Shaoyin Heart Meridian. (Note: The points from Zhongchong downwards belong to the Hand-Jueyin Pericardium Meridian. This chapter directly refers to them as the Hand-Shaoyin Meridian, whereas other chapters do not record such points for the Hand-Shaoyin Meridian.)

The chapter "Xie Ke" (Evil Intrusion) in the *Ling Shu* records: The Yellow Emperor asked, "Why does the Hand-Shaoyin Heart Meridian alone lack [specific acupoints]?" Qibo answered, "Any pathogenic factors affecting the Heart actually affect the Pericardium (Bao Luo). The Pericardium is the meridian that protects the Heart. Therefore, the Hand-Shaoyin Heart Meridian alone lacks [these specific points]." The Yellow Emperor asked, "If the Shaoyin meridian alone lacks these points, does it mean it never becomes diseased?" Qibo replied, "If the exterior meridian is diseased but the interior organ is not, one should only select the point at the end of the sharp bone behind the palm." (This refers to Shenmen (HT 7), which belongs to the Hand-Shaoyin Heart Meridian.) The flow, exit, entry, and curvature of the remaining meridians, as well as their speed of movement, are all similar to the circulation of the Hand-Shaoyin Heart Meridian and the Hand-Jueyin Pericardium Meridian. Consequently, when Wang Bing annotated the "Qi Xue Lun" (Discussion on Acupoints) in the *Su Wen*, mentioning the fifty acupoints of the Zang organs, he only included the Five Shu points of the Pericardium meridian, without those of the Heart meridian. Only in the "Miao Ci Lun" (Discussion on Mysterious Puncture) does it mention: "One point at each end of the sharp bone of Shaoyin." Wang Bing's annotation identifies Shenmen as the Shu-Stream point of the Hand-Shaoyin Heart Meridian, likely based on the "Xie Ke" chapter.

In my analysis, the statements in these three chapters differ. The "Jiuzhen Shier Yuan" chapter mentions only the two Yuan-Source points on the left and right for the five Zang organs, plus the Yuan-Source points of Gao and Huang, totaling twelve Yuan-Source points. The "Ben Shu" chapter treats the five Yuan-Source points of the previous chapter as the Shu-Stream points of the five Zang organs, adds the Yuan-Source points of the six Fu organs, omits the Yuan-Source points of Gao and Huang, and notes that the Hand-Shaoyin Heart Meridian lacks Shu-Stream points, substituting them with those of the Hand-Jueyin Pericardium Meridian. The "Xie Ke" chapter explicitly locates the Shu-Stream point of the Hand-Shaoyin Heart Meridian at the end of the sharp bone behind the palm, yet still omits the Jing, Ying, Jing, He, and Yuan-Source points of Shaoyin, Gao, and Huang. The *Nan Jing* (Classic of Difficult Issues) agrees with this view. However, upon consulting the *Zhen Jiu Jia Yi Jing* (A-B Classic of Acupuncture and Moxibustion), it states: Shaochong (HT 9) is Wood, the Jing-Well point where the Shaoyin meridian emerges; Shaofu (HT 8) is Fire, the Ying-Spring point where the Shaoyin meridian flows; Shenmen (HT 7) is Earth, the Shu-Stream point where the Shaoyin meridian pours; Lingdao (HT 4) is Metal, the Jing-River point where the Shaoyin meridian travels; and Shaohai (HT 3) is Water, the He-Sea point where the Shaoyin meridian enters. Thus, the Five Shu points of the twelve meridians become complete.

However, a detailed inquiry into the meaning of "Yuan" and "Shu" reveals that, as stated in the "Jiuzhen Shier Yuan" and "Ben Shu" chapters, the Yuan-Source point of Yin meridians is identical to the Shu-Stream point. Although Yang meridians distinguish between Shu-Stream and Yuan-Source points, the Shu-Stream point passes through the Yuan-Source point, sharing the same Qi. Therefore, treating the Yuan-Source point of a Yang meridian is equivalent to treating its Shu-Stream point; treating the Shu-Stream point of a Yin meridian is equivalent to treating its Yuan-Source point. The *Nan Jing* (Chapter 66) asks: "Why are the Shu-Stream points considered the Yuan-Source points for all twelve meridians?" The answer is: The Shu-Stream points of the five Zang organs are pathways for Sanjiao Qi and sites where Yuan Qi resides. It further states: "Yuan" is an honorific title for the Sanjiao; thus, wherever Qi stops, it is called a Yuan-Source point. When the Zang and Fu organs are diseased, their Yuan-Source points should be selected. Furthermore, the chapter "Shun Qi Yi Ri Fen Wei Si Shi" (Regulating Qi Divided into Four Times of the Day) in the *Ling Shu* states that the Yuan-Source point alone does not correspond to the four seasons, but corresponds numerically through its connection with the meridians. In this sense, Shu-Stream points can be merged with Yuan-Source points, and Jing-River points can also be merged with Yuan-Source points. Since Shu-Stream points precede Yuan-Source points and Jing-River points follow them, and because the acupoints are adjacent and the meridians are close, their Qi and numerical correspondences are consistent. This principle is discussed in detail in the "Needling Techniques" category, Chapter 17.

[Image: Diagram of Root, Mark, and Middle Qi of Upper, Middle, and Lower Jiao]
The Qi of the Six Meridians takes Wind, Cold, Heat, Dampness, Fire, and Dryness as its Root (Ben), and the Three Yin and Three Yang as its Mark (Biao). The Middle Qi (Zhong Qi) is seen between the Root and the Mark. The Middle Qi arises from the interior-exterior relationship: Shaoyang and Jueyin are interior-exterior pairs; Yangming and Taiyin are interior-exterior pairs; Taiyang and Shaoyin are interior-exterior pairs. Because interior and exterior meridians connect, they serve as each other's Middle Qi. This concept originates from the "Liu Wei Zhi Da Lun" (Great Discussion on the Six Subtle Principles) in the *Su Wen*; see the "Yun Qi" category, Part 6, for details.

[Image: Diagram of Organ-Meridian Correspondence to Heaven's Root, Mark, and Middle Qi]
Regarding the Root and Mark of Zang-Fu organs and meridians: the Zang-Fu organs are the Root, residing internally; the twelve meridians are the Mark, residing externally. The interior-exterior connected meridians serve as the Middle Qi, positioned centrally. "Connected" means the interior and exterior meridians mutually link and support each other. For example, the Foot-Taiyang Bladder Meridian connects to the Kidney, and the Foot-Shaoyin Kidney Meridian connects to the Bladder. The rest follow this pattern.