Scientific Qi Exploration

[Scientific Qi Exploration]

Meridian System — Part 1. The Collaterals

by Marty Eisen Ph.D.

1.  The Fifteen Collaterals (Luo) or Connecting Vessels (1,2,3)

The translation of Luo is “net.”  It is used in Chinese Medicine to refer to the Collaterals.  Just like a fishing net, the Luo Vessels catch pathogens, preventing Evil Winds from affecting the Main Meridians.  The Collaterals bifurcate from Luo Points on the twelve Primary Channels, the Ren and Du Channels, plus the extra Great Collateral of the Spleen.  Thus, there are fifteen Collaterals.

The Collaterals connect the interiorly and exteriorly related pairs of Yin and Yang Meridians.  The Fifteen Collaterals run more superficially and are thinner than the Main Meridians; however, they pass through the interior of the body.  They distribute Qi and Blood to areas of the body not fed by other Channels.  They do not have their own acupoints.

Smaller branches arise from the Collaterals and are called Minute and Superficial Collaterals and help carry Qi and Blood to all parts of the body, like capillaries.  Those that carry Qi and Blood to the surface of the body and can be seen beneath the surface as blood vessels are called Blood Luo Vessels.

Each Primary Channel actually has two Luo branching out in two directions from a Luo Point.  However, since they are not entirely unrelated, they are counted as one.  The branches are:

1.  The Transverse Luo Vessel connects the Luo Point to the (Yuan) Point on the Yin and Yang connected Meridians (4).  Other texts (1,2,3) are not specific and just state this Vessel connects with its internally-externally paired channel.

2.  The Longitudinal Luo Vessel also emerges from the Luo Point, but does not connect with the coupled Primary Meridian.  It flows proximally towards the Channel’s Organ, as described in Section 4.

2.  Yuan (Source) Points 

A Source Point is where the Yuan (Source, Original, or Ancestral) Qi is described as surfacing and lingering.  It is close to the wrists or the ankles on each of the Principal Meridians.

An early discussion of the Source Points appears in chapter one of the Spiritual Axis (Pivot).  The source points are listed and their use in diagnosis and treatment are described.  The Source Points affect the Yin Organs is implied by the statement “Select the Yuan Points when the five Yang Organs are diseased.”  They can also be used in diagnosis by associating changes in the skin over the Source Points with abnormalities in the function of the corresponding Yin Organ.  This follows from the statements: “If the 5 Yin Organs are diseased, abnormal reactions will appear at the Source Points.  If we know which Yin Organ corresponds to this Source Point, we can diagnose when the Yin Organ is diseased.”  Some examples are:  red, white, blue, or very flaccid skin, swelling, varicose veins, congested blood vessels, or a concavity around the point.

The list of Source Points given in the Spiritual Axis is different from those used today.  The Yuan Points are only listed for 5 Yin Organs, and the Source Point of the Heart is listed as Da Ling, P 7, the modern source Point of the Pericardium.  The reason may have been that at the time the Spiritual Axis was written, the Heart and Pericardium were considered a single Organ.

Only Source Points for the Yin Organs are mentioned in the Spiritual Axis.  The reason may have been that the energy of a Source Point is Original Qi, which is related to the Yin Organs, in particular, to the Kidneys. Also, the Yang Source Points are not as effective as the Yin Source Points in treating deficiencies of their corresponding Organs and so their importance may not have been discovered yet.

The Spiritual Axis also lists two other Source Points, which are not modern Source Points. It states “The Yuan Qi of of Fat (Gao) Tissues gathers at Jiuwei, Ren 15, the Yuan Qi of Membranes (Huang) gathers at Boyang (Qihai, Ren 6).”

The modern 12 Source Points in Table 1 were listed in Chapter 66 of the Classics of Difficulties.  The only difference was that it listed both P 7 and H 7 as the Source Points of the Heart.  This might have been due to the fact that the Heart and Pericardium were still considered as one Organ at that time.

The relation between the Original Qi, San Jiao (Triple Burner) and Source Points appears in the following statements in chapter 66.  “The Original Qi Is the motive force located between the two Kidneys, it is life-giving and is the root of the 12 Channels.  The Triple Burner acts as the ambassador for the Original Qi, which passes through the three Burners.  Then, it spreads to the five Yin and six Yang Organs and their Channels.  The places where the Original Qi rests are the Source Points.”

The role of the Triple Burner as the ambassador of the Original Qi explains a particular use of its Source Point, SJ 4.  This point can be used to tonify or invigorate Original Qi and to activate its circulation through the Channels.  If it is used with the Source Point of the Stomach (S 42), this combination strongly tonifies Qi as well as the Original Qi.

The indications for using the Yang Source Points are different than for the Yin Source Points.  They have a very little tonifying effect and ability to regulate their related Organs (Fu), even though the Classics of Difficulties states “When the six Fu are diseased, select from their Source Points”.  Their main use is to dispel various Pathogenic Factors and to treat disorders along their corresponding Channels.  For example, LI4 dispels Exterior Wind and regulates the whole Large Intestine Channel, but has a negligible effect on the Large Intestine Organ.  SI 4 mainly treats stiffness, contraction or pain in the hand, arm, shoulder, neck and back along the entire course of the Small Intestine Channel.


Source Point



L 9 (Tai Yuan) Great Abyss At the radial end of the transverse crease of the wrist, in the depression on the lateral side of the radial artery.

Large Intestine

LI 4 (He Gu) Union Valley On the dorsum of the hand, between the first and second metacarpal bones, approximately in the middle of the second metacarpal bone on the radial side.


S 42 (Chong Yang) Surging Yang On the highest part of the instep of the foot, between the tendons of long extensor muscle of the great toe and long extensor muscle of toes, where the pulsation of the dorsal artery of foot is palpable


Sp 3 (Tai Bai) Supreme White On the medial side of the foot in the depression proximal and inferior to the head of the first metatarsal bone.


H 7 (Shen Men) Spirit Gate At the ulnar end of the transverse crease of the wrist, in the depression on the radial side of the tendon of m. flexor carpi ulnaris.

Small Intestine

SI 4 (Wan Gu) Wrist Bone On the ulnar side of the palm, in the depression between the base of the 5th metacarpal bone and hamate bone.


B 64 (Jing Gu) Capital Bone Below the tuberosity of the fifth metatarsal bone, at the junction of the red and white skin.


K 3 (Tai Xi) Great Ravine In the depression between the tip of the medial malleolus and Achilles’ tendon.


P 7 (Da Ling) Great Mound In the middle of the transverse crease of the wrist, between the tendons of m. palmaris longus and m. flexor carpi radialis.

San Jiao

SJ 4 (Yang Chi) Yang Pool On the transverse crease of the dorsum of wrist, in the depression lateral to the tendon of m. extensor digitorum communis.


G 40 (Qiu Xu) Hill Ruins Anterior and inferior to the external malleolus, in the depression on the lateral side of the tendon of m. extensor digitorum longus.


Liv 3 (Tai Chong) Great Surge On the dorsum of the foot, in the hollow distal to the junction of the first and second metatarsal bones.


Table 1          The Twelve Yuan (Source) Points

3.  Luo (Connecting) Points

The Luo Connecting points appear in Table 2.


Luo Point



L 7 (Lie Que) Broken Sequence Superior to the styloid process of the radius, 1.5 cun above the transverse crease of the wrist between brachioradial muscle and the tendon of long abductor muscle of the thumb.

Large Intestine

LI 6 (Pian Li) Veering Passageway With the elbow flexed and the radial side of arm upward, the point is on the line joining Yangxi (LI 5) and Quchi (LI 11), 3 cun above the crease of the wrist.


S 40 (Feng Long) Bountiful Bulge On the lower leg, midway between the tibiofemoral joint line (level with the popliteal crease) and the lateral malleolus, two finger-breadths lateral to the anterior crest of the tibia.


Sp 4 (Gong Sun) Yellow Emporer On the medial side of the foot, in the depression distal and inferior to the base of the first metatarsal bone, at the junction of the red and white skin.

Spleen (Great Luo)

Sp 21 (Da Bao) Great Embracement On the mid-axillary line, in the seventh intercostal space.


H 5 (Tong Li) Connecting Li With the palm facing upward, the point is on the radial side of the tendon of m. flexor carpi ulnaris, 1 cun above the transverse crease of the wrist.

Small Intestine

SI 7 (Zhi Zheng) Branch to the Correct On a line connecting Yanggu SI-5 and Xiaohai SI-8, 5 cun proximal to Yanggu SI-5, in the groove between the anterior border of the ulna and the muscle belly of flexor carpi ulnaris.


B 58 (Fei Yang) Taking Flight 7 cun directly above Kunlun (BL-60), on the posterior border of fibula, about 1 cun lateral and inferior to Chengshang (BL-57).


K 4 (Da Zhong) Large Goblet Posterior and inferior to the medial malleolus, in the depression anterior to the medial side of the attachment of Achilles’ tendon.


P 6 (Neiguan) Inner Pass 2 cun above the transverse crease of the wrist, between the tendons of m. palmaris longus and m. flexor radialis.

San Jiao

SJ 5 (Wai Guan) Outer Pass 2 cun proximal to Yangchi SJ 4, in the depression between the radius and the ulna, on the radial side of the extensor digitorum communis tendons.


G 37 (Guang Ming) Bright Light 5 cun directly above the tip of the external malleolus, on the anterior border of the fibula.


Liv 5 (Li Gou) Woodworm Canal 5 cun above the tip of the medial malleolus, on the midline of the medial surface of the tibia, near the medial border of the tibia.


Ren 15 (Jiu Wei) Turtledove Tail 7 cun above the umbilicus, locate the point in supine position with the arms uplifted.


Du 1 (Chang Qiang) Long Strong Midway between the tip of the coccyx and the anus; locate the point in prone position.


Table 2          The Fifteen Luo (Connecting) Points

To understand the uses of the Connecting Points requires knowledge of their pathways, which will be described in the next section.

4.  The Connecting Channel Pathways

The diagrams of the pathways will only be shown for one side of the body, since the pathway on the other side has a similar description.

(a)  The Lung Collateral Meridian

Bifurcating from L 7, it runs to the Large Intestine Meridian.  Another branch follows the Lung Meridian into the hand and spreads through the thenar eminence, as shown in Fig. 1


 Figure 1     The Lung Collateral Meridian

(b)  The Large Intestine Collateral Meridian

It starts from LI 6 and joins the Lung Meridian at the wrist, ascends the arm through Jian Yu (Shoulder Bone, LI-15: anterior and inferior to the acromion, on the upper portion of m. deltoideus. When the arm is in full abduction, the point is in the depression appearing at the anterior border of the acromioclavicular joint.).  Then it ascends to the jaw and cheek and divides.  One branch connects with the teeth and the other enters the ear to join the Chong Meridian (See Fig 2).


Figure 2             The Large Intestine Collateral Meridian

(c)   The Stomach Collateral Meridian

It starts at S 40 and connects with the Spleen Meridian.  A branch ascends along the lateral aspect of the tibia to the top of the head, where it converges with the other Yang Meridians on the head and neck.  Then, it descends to connect with the throat, as shown in Fig. 3.

Chapter 10 in the Spiritual Axis lists all of the Connecting Channels along with an extra Connecting Channel of the Stomach called the Great Collateral of the Stomach or Xu Li.  Xu Li is also mentioned in chapter 18 of the Ling Shu: “It penetrates the diaphragm, connects with the Lungs and exits below the left breast. One can feel its pulsation by hand: it is the place where the Gathering Qi (Zong Qi) of the vessels [or channels] is situated.”

The Ling Shu does not mention S 40 in connection with the Xu Li .  Maciocia in (5) states that S 40 affects the Xu Li.  Since Xu Li flows to Lungs and Heart and influences the Zong Qi, he uses S 40 to treat the heart when the pulse is irregular.  He considers ST-40 to be an important point to affect the rate and rhythm of the heart.  A diagram of the Stomach Great (Luo) Connecting Channel appears in (3).

According to (6), the Great Luo of the Stomach involves a circuit from the Upper to the Middle Heater.  It starts at Ru Gen (Breast Root) (S 18: Directly below the nipple, in the fifth intercostal space.), flows down to the Stomach, penetrates the Lung and back to  S 18, where cycle begins all over again.

This vessel pathway serves as a vent to drain excess Stomach Heat up out of the Stomach. However, in flowing upwards the Upper Heater, which is adverse to Heat, attempts to dump the Heat back into the Stomach. Inevitably it gets shunted back up due to the nature of heat to rise.  From a western biomedical perspective, this is gastric reflux.  Chinese medicine uses this circuit to treat this condition.

This Connecting Channel is not mentioned in some modern, western texts, which list only 15 Connecting Channels.  Also some authors interpret Xu Li as the Luo point of the Great Stomach Luo Channel and state that it is near S 18.



Figure 3                         The Stomach Collateral Meridian   

(d)  The Spleen Collateral Meridian

It originates at Sp 4 and connects with the Stomach Meridian.  A branch runs upward, enters the abdomen and connects with the Large Intestine and Stomach (See Fig. 4).



 Figure 4                           The Spleen Collateral Meridian


(e)    The Spleen (Great Luo) Collateral Meridian

It begins at Sp 21, emerges 3 cun below Yuan Ye (Armpit Abyss) (G 22: On the mid-axillary line when the arm is raised, 3 cun below the axilla, in the 4th intercostal space).  Spreading through the chest and lateral costal region, it gathers the Blood from all the Connecting Channels (See Fig. 5).


Figure 5                The Spleen (Great Luo) Collateral Meridian



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About Martin Eisen

By profession, Dr. Eisen was a university Professor specializing in constructing mathematical models such as those in cancer chemotherapy and epilepsy. He has studied and taught Yoga, Judo, and Aikido. Dr. Eisen was the founder and chief-instructor of the Shotokan Karate Clubs at Carnegie-Mellon and Dusquene Universities and the University of Pittsburgh. He helped teach Yoga in Graterford prison. His curiousity about the relation of Qi to healing and martial arts led him to study TCM, Tai Chi and Praying Mantis Kung Fu. He was initiated as a Disciple of Master Gin Foon Mark. Dr. Eisen now teaches (at his Kwoon and by webcam), writes and researches Praying Mantis, Qigong and Yang Tai Chi - see
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