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The six Yang meridians of the hand run from the hand to the head, each measuring five chi, totaling three zhang (ten chi) for all six.
The six Yin meridians of the hand run from the chest to the hand, each measuring three chi and five cun, totaling one zhang and eight chi for all six; adding the extra three chi from the calculation with the Yang meridians, the total is two zhang and one chi.
The six Yang meridians of the foot run from the head to the foot, each measuring eight chi, totaling four zhang and eight chi for all six.
The six Yin meridians of the foot run from the foot into the chest, each measuring six chi and five cun, totaling three zhang and nine chi for all six.
The Du Mai (Governing Vessel) and Ren Mai (Conception Vessel) each measure four chi and five cun, totaling nine chi.
The two Qiao Mai (Yang and Yin Heel Vessels) run from the foot to the eye, each measuring seven chi and five cun, totaling one zhang and five chi.
These fourteen meridians together measure sixteen zhang and two chi; these are the great channels through which Qi flows.

The term "Jing" (Meridian) refers to the major pathways where Qi and Blood flow continuously and rhythmically. The term "Mai" (Vessel) refers to the blood vessels based on their distribution and course within the body. The term "Luo" (Collateral) refers to the side branches of the main meridians that diverge to connect with the twelve regular meridians. For example, the branch of the Hand-Taiyin Lung Meridian emerges from behind the wrist, reaches the tip of the index finger, and connects with the Yangming Meridian.

When measuring acupoints on the limbs, this "Middle Finger Same-Body Cun" method must be used, as limb lengths are consistent among individuals. When measuring acupoints on the trunk, one's own body proportions should be used. The method is: for men, use the left hand; for women, use the right hand. The distance between the two transverse creases at the middle joint of the middle finger constitutes one cun. One may use the pith of a rice stalk or a thin bamboo splint for measurement, ensuring it breaks easily without stretching or shrinking. If rope is used, its tendency to stretch makes it inaccurate.

The *Neijing* states: The West corresponds to white, internally connecting to the Lung, opening into the nose, storing essence in the Lung, so diseases often manifest in the back. Its flavor is pungent, its element is Metal, its animal is the horse, its grain is rice, its musical note is Shang, its number is nine, its odor is fishy, and its fluid is mucus. The Lung governs the nose; in nature, it corresponds to Dryness; in earth, to Metal; in the body, to skin and hair; in the zang-fu, to the Lung; in color, to white; in sound, to Shang; in vocalization, to crying; in pathological change, to coughing; in orifice, to the nose; in flavor, to pungent; and in emotion, to sorrow. Sorrow damages the Lung, while Joy overcomes Sorrow. Heat damages skin and hair, while Cold overcomes Heat. Pungency damages skin and hair, while Bitterness overcomes Pungency. It corresponds to the four seasons, specifically Autumn, and in the heavens, to the planet Venus (Tai Bai). Thus, one can know that disease resides in the skin and hair.

The Lung is the root of Qi and the residence of Po (Corporeal Soul); its brilliance manifests in the hair, and it nourishes the skin. It is considered Taiyang within Yang, communicating with the Qi of Autumn.
The Lung is like the Prime Minister, responsible for regulation and coordination. The Lung harmonizes with the skin, its brilliance is in the hair, and it is controlled by the Heart. The color of the Lung should be white, resembling goose feathers (lustrous), not salt (dull). If Lung Qi is exhausted, the skin and hair become dry; if dry, fluids are lost; if fluids are lost, the skin joints are damaged; if damaged, the skin becomes withered and hair breaks. If hair breaks, death occurs and cannot be cured.

The pulse of the Hand-Taiyin Lung Meridian originates in the Middle Jiao, descends to connect with the Large Intestine, returns along the stomach opening, ascends through the diaphragm, and enters the Lung. From the Lung system (the throat), it emerges horizontally under the axilla, runs down the medial aspect of the arm, anterior to the Shaoyin Heart and Jueyin Pericardium meridians, descends to the elbow, follows the medial aspect of the forearm along the lower border of the radius, enters the Cun Kou (radial artery pulse point), ascends to the Thenar eminence (Yu Ji), follows the border of the thenar eminence, and emerges at the tip of the thumb. Its branch emerges straight from behind the wrist to the medial side of the index finger, reaching its tip. There are eleven acupoints on this meridian, totaling twenty-two points on both sides.