Library

The *Jing Lun* (Classic Discussions) records: The Du Mai (Governor Vessel) presents a floating pulse at the Cun, Guan, and Chi positions, with a straight up-and-down trajectory. The Du Mai originates at the Huiyin point (lower extreme), runs parallel along the interior of the spine, ascends to the Fengfu point (GV16), enters the brain, reaches the vertex, follows the forehead down to the nasal bridge, and terminates at the Yinjiao point (GV28) in the upper gum line. Zhang Jiegu stated: "Du" means "capital," serving as the chief guideline for all Yang vessels.

The Ren Mai (Conception Vessel) at the Cun Kou position presents as tight, thin, solid, and long, reaching the Guan position; it is also described as having a bead-like pulsation at the edge of the Cun Kou. "Ren" means "to bear or conceive," serving as the sea of all Yin vessels. The Ren Mai originates below the Zhongji point (CV3), travels along the interior of the abdomen, passes through the Guanyuan point (CV4), reaches the throat, arrives at the Chengjiang point (CV24), descends to the Yinjiao point (GV28), and when looking upward, the Chengqi point (ST1) under the eye can be seen; it serves as the chief guideline for all Yin vessels.

The Chong Mai (Penetrating Vessel) presents a firm pulse at the Cun, Guan, and Chi positions, with a straight up-and-down trajectory. The Chong Mai originates at the Qichong point (ST30), flanks the umbilicus on both sides, ascends to the chest where it disperses. As the root of the twelve regular meridians, it is called the "Sea of Meridians" and also the "Sea of Blood."

The Yang Qiao Mai (Yang Heel Vessel) pulses at the Cun position on both sides, originating from the middle of the heel, ascending past the lateral malleolus, following the hypochondrium to the shoulder, flanking the corner of the mouth to the eye, and terminating at the Fengchi point (GB20) behind the ear.

The Yin Qiao Mai (Yin Heel Vessel) pulses at the Chi position on both sides, originating above the medial malleolus, ascending along the Yin aspect to the chest and throat, and terminating at the Jingming point (BL1) in the inner canthus of the eye.

The Dai Mai (Girdle Vessel) pulses at the Guan position on both sides, originating at the costal margin, encircling the body once like a belt.

The Yin Wei Mai (Yin Linking Vessel) slants upward from the Chi position's exterior to the Cun position, originating at the intersection of all Yin vessels, emerging five cun above the medial malleolus, following the thigh into the lower abdomen, ascending along the hypochondrium to the chest, and ending at the anterior vertex.

The Yang Wei Mai (Yang Linking Vessel) slants upward from the Chi position's interior to the Cun position, originating at the convergence of all Yang vessels, emerging one cun and five fen below the lateral malleolus, ascending past the knee to the hip joint, reaching the lower abdomen, following the head into the ear, and stopping at the Benshen point (GB13).

*Huibian* states: The Eight Extraordinary Vessels lie outside the Twelve Regular Meridians and have no Zang-Fu organs paired with them, hence they are called "Extraordinary." The pulses of the Zang-Fu organs have fixed positions at Cun, Guan, and Chi; fixed qualities at Floating, Middle, and Deep levels; and fixed forms corresponding to String, Hook, Feather, and Stone. These extraordinary vessels constitute a separate category; their shapes are inherently different, their pathways distinct, and their symptoms vary, necessitating different medical approaches.

Li Shizhen stated: The Eight Extraordinary Vessels are not constrained by the Twelve Regular Meridians. When the qi of the regular meridians is abundant, it overflows into the extraordinary vessels. Thus, Qin Yueren compared this to rain falling from the sky: when ditches and channels overflow, the water flows wildly into rivers and marshes. The Yang Wei Mai governs the exterior of the whole body, and the Yin Wei Mai governs the interior, analogous to Heaven and Earth. The Yang Qiao Mai governs the Yang of the left and right sides, and the Yin Qiao Mai governs the Yin of the left and right sides, analogous to East and West. The Du Mai governs the Yang of the posterior, and the Ren and Chong Mails govern the Yin of the anterior, analogous to South and North. The Dai Mai horizontally binds all vessels, analogous to the Six Directions.