The Geography

8. The meridians: the network

經絡 (jīng luò). Two words:

• 經 (jīng) = the warp of a loom — the vertical, principal routes
• 絡 (luò) = net — the horizontal, secondary connections

That is: a fabric. Vertical main lines, horizontal connections.

The system has:

• 12 regular meridians (正經) — each connected to one organ
• 8 extraordinary vessels (奇經八脈) — reservoirs, not channels
• A plexus of secondaries (luo branches, tendinomuscular channels)

What are they, really? There is no anatomical structure that corresponds to them. The most serious modern hypotheses speak of connective-tissue planes (fasciae), neurovascular bundles, or simply an empirical map of referred sensations. The honest answer: we do not know, and the system works as a map of experience independently of the answer.

9. The flow of the Twelve

Remember the posture with arms held high. Here is the rule, and it is simple:

YIN channels flow upward (from earth to heaven). YANG channels flow downward (from heaven to earth).

In detail:

…and back to the start. An endless loop. The qi makes one complete circuit in 24 hours (see ch. 19).

The six levels (六經)

Each meridian also has a “depth name”:

• Yin (from surface to deep): 太陰 Taiyin → 少陰 Shaoyin → 厥陰 Jueyin
• Yang (from surface to deep): 太陽 Taiyang → 陽明 Yangming → 少陽 Shaoyang

So the full title is e.g. “Taiyin meridian of the hand — Lung”. This system is the skeleton of classical diagnosis: illness “enters” from Taiyang and “deepens” toward Jueyin.

10. The Eight Extraordinary Vessels

奇經八脈 (qí jīng bā mài) — “eight strange channels”.

They are called “extraordinary” because:

• They do not connect directly to an organ
• They are not part of the circulating loop
• They act as reservoirs: they absorb the surplus of the twelve and lend it back to deficiency

The classical image: the twelve are rivers, the eight are lakes and dams.

They are tied to the pre-natal level — which is why they are the main field of Qigong and internal work, whereas the twelve are the main field of acupuncture.

The four most important:

1. 任脈 Ren Mai — Conception Vessel (anterior midline)
2. 督脈 Du Mai — Governing Vessel (posterior midline)
3. 衝脈 Chong Mai — Penetrating Vessel (deep central axis)
4. 帶脈 Dai Mai — Belt Vessel (the only horizontal one — a belt around the waist, “tying” all the vertical ones)

The other four (Yin/Yang Qiao, Yin/Yang Wei) handle left-right balance and the connection of levels.

11. Ren Mai and Du Mai: the two seas

These two are the axis of all the practice.

任脈 — Ren Mai, Conception Vessel

• Route: from the perineum (point 會陰 Huiyin) it rises along the anterior midline — pubic region, belly, sternum, throat — up to below the lower lip
• Title: 陰脈之海 — “the Sea of all Yin channels”
• Function: nourishes, holds, feeds. Governs the Yin of the body. Closely linked to fertility and pregnancy (hence “conception”)
• The character 任 means “to take on, bear responsibility, carry in the womb”

督脈 — Du Mai, Governing Vessel

• Route: from the perineum/coccyx it rises up the spine, over the crown, down the forehead and nose, ending at the gums of the upper lip
• Title: 陽脈之海 — “the Sea of all Yang channels”
• Function: governs, warms, activates. Controls the Yang. Directly related to brain and spinal cord
• The character 督 means “to oversee, to command”

The circuit

The two nearly touch at both ends: at the perineum below and at the mouth above. At the mouth there is a gap — and here comes one of the most practical instructions in the whole tradition:

搭鵲橋 — “set up the magpie bridge”: rest the tip of the tongue on the roof of the mouth, behind the upper teeth.

This “closes” the circuit. It is the first instruction in any serious qigong practice and it is not symbolic — try to hold your tongue there for ten minutes while sitting and you will understand why they say so.

12. The Four Seas

Beyond the two “seas of channels”, the classical Ling Shu (靈樞) defines 四海 — four seas, that is, four centres of storage and distribution:

Note the logic: two seas you take from outside (food, air) and two you inherit or produce inside (blood, marrow). The system demands all four.

13. The three Dantian

丹田 (dān tián) = “cinnabar field” — an alchemical term, the place where the transformation is “cooked”.

Practical warning from the tradition itself: the beginner works in the lower dantian. Premature concentration on the upper dantian is traditionally connected with what is called 走火入魔 (zǒu huǒ rù mó, “fire runs wild, demons enter”) — over-stimulation, insomnia, headaches, mental instability. This is not superstition; it is a serious warning, and the modern literature on meditation-related adverse effects says similar things. See the Tibetan srog rlung essay for the parallel diagnostic category.

The key phrase: 氣沉丹田 (qì chén dān tián) — “the qi sinks into the dantian”. Practically: the centre of gravity and the attention drop low. Top light, bottom heavy. This is the root.

14. The Three Gates

三關 (sān guān) — the three points along the Du Mai (back) where the flow typically sticks. They are, not accidentally, the three points where the spine changes curvature.

1. 尾閭關 Weilü Guan — the Gate of the Coccyx

• Location: sacrum / coccyx
• The problem: pronounced lumbar lordosis, a “stuck-out” buttock, tight pelvis
• The instruction: 尾閭中正 — “the coccyx aligned”. The pelvis in neutral, the sacrum “hangs” downward. Not tightening — release

2. 夾脊關 Jiaji Guan — the Gate between the Shoulder-Blades

• Location: mid-thoracic, between the shoulder blades (~T4–T7)
• The problem: a thrust-out chest, closed back, shoulders pulled back
• The instruction: 拔背 — the back “opens”, the shoulder blades spread lightly outward
• This is the gate you feel opening and closing in practice. The sense that “the body moves between the shoulder blades” is exactly this

3. 玉枕關 Yuzhen Guan — the Gate of the Jade Pillow

• Location: occipital bone, base of the skull
• The problem: the chin juts out, the neck compresses (the classic “screen posture”)
• The instruction: 虛靈頂勁 — the crown of the head hangs lightly upward, the chin tucks a little, the neck lengthens

How to think of them all together: these are the three points where the spine “folds” under gravity. To “open” them does not mean to force them apart with muscle — it means to remove the compression, so the column can lengthen itself from the two ends.

15. The Small and the Great Celestial Orbit

小周天 — Small Celestial Orbit (Microcosmic Orbit)

The fundamental circulation practice.

The route:

┌──── crown of head ────┐ │ │ [Yuzhen] forehead ↑ ↓ [Jiaji] mouth ↑ (tongue = bridge) [Weilü] ↓ ↑ chest │ ↓ └──── perineum ←──── lower belly (Huiyin)

Rises up the BACK (Du Mai), descends down the FRONT (Ren Mai).

The mnemonic: yang rises up the back, yin descends down the front — and the two close at the perineum below and at the tongue above.

It is called “celestial orbit” because it is held to be a miniature of the daily rotation of the heavens. The micro–macrocosmic correspondence is not decorative in this system; it is its foundational assumption.

大周天 — Great Celestial Orbit (Macrocosmic Orbit)

An extension: the circuit now includes the four limbs, that is, the twelve regular meridians. The qi reaches the soles (point 湧泉 Yongquan, “Bubbling Well”) and the palms (勞宮 Laogong).

Why it matters for Tai Chi: the principle 上下相隨 (“above and below follow each other”) is exactly the bodily expression of the great orbit. And the phrase 其根在腳，發於腿，主宰於腰，形於手指 — “the root is in the soles, it issues from the legs, is governed by the waist, is expressed in the fingers” — describes the same route in mechanical rather than energetic terms.