||Channels (also referred to as
Meridians or Vessels), are three-dimensional pathways through which Qi
and Blood flow through the body. These Channels exist at various levels
of the body from the more superficial ones covering the skin and
cutaneous layers, to the deeply lying visceral ones. The Channels
(Meridians) are the main trunks. They run longitudinally and interiorly
within the body to connect with the Internal Organs.
The Collaterals are the branches of the main Channels and they run
transversely (sideways) and superficially from the Channels to join the
skin, muscles, tissues and joints. Together the Channels and
Collaterals form a comprehensive network linking the tissues and organs
to form an organic whole.
There are 12 Organ-Channels directly connected with the 'twelve'
Internal Organs. There are also eight Extraordinary Vessels which are
additional channels not associated with any particular organ, and
dozens of other types of channels diverging from the main channels and
connecting with each other. These are called the Collaterals,
Connecting Vessels and Divergent Channels. There are also channels that
distribute superficially over the Cutaneous and Tendino-Muscular areas.
The 12 Organ-Channels provide connections between the Internal Organs
and their respective 'openings' and sensory organs. In this way, the
Channels can be thought of as defining the organs' spheres of influence
in the body. These 12 Channels are actually 24 in number as they exist
bilaterally on each side of the midline of the body.
There are no biomedical equivalents of Channels.
Channels are not nerve pathways, although specific points along the
channels may stimulate specific nerves, specific areas of the central
and peripheral nervous systems, and Channels on the limbs often follow
the nerve pathways. Channels are not blood vessels, although specific
points may stimulate the blood and the vascular system. Channels are
not lymph vessels although specific points may stimulate the lymph and
lymphatic system. Channels are also not connective tissue routes
although acupuncture stimulation may also exert an influence over the
Because of the lack of direct translation to Western physiology,
Western science has, until recent years, questioned their legitimacy.
With the advent of MRI technology, however, scientists not only have
captured on film the acupuncture-induced neural activities of the
brain, but have also captured some of the acupuncture Channels. With
refinements in MRI technology we expect to see many more visual
evidence of their existence in the near future.
A. Twelve Primary Organ Channels
Yin channel paired with Yang channel
- The 12 Organ Channels occur symmetrically on both sides of the midline of the body to make up a total of 24 Channels.
- There are three Yin and three Yang Channels
traversing the arm. There are also three Yin and three Yang Channels
traversing the leg. These are mirrored on the opposite side of the
- Each Channel has a specified number of acupoints occurring at fixed locations along the Channel.
- These Channels have a direct connection with, and flow through, their relevant Yin or Yang organs.
- A Yin-Organ Channel flows to its paired
Yang-Organ Channel or the Yang-Organ Channel flows to its paired
Yin-Organ Channel before moving on to the next pair.
- There is a sequential and cyclical flow of Qi
through the Channels. One of the dominant interpretations of the
sequence is as follows:
(returns to Lung Channel to repeat the cycle)
| Large Intestine
An example of Channel flow between a Yin-Yang pair is provided:
- Lung Channel:
Lung Channel begins near the Stomach area, passes downward to connect
with the Large Intestine Organ, and returns upward through the
diaphragm to enter the Lung Organ. It emerges at its first point (Lung
1) at the lateral side of the chest near the fold of the armpit and
proceeds downward along the anterior aspect of the arm to end at the
radial side of the thumb. A branch splits from the main channel at the
acupoint Lung 7 (near the wrist), to travel to the tip of the index
finger where it joins the Large Intestine Channel.
- Large Intestine Channel:
Large Intestine Channel begins at the radial side of the tip of the
index finger, proceeds upward along the index finger to the lateral
aspect of arm, rises to the shoulder, crosses behind the shoulder,
enters into the supraclavicular fossa to connect with its paired Lung
Organ, and descends to the Large Intestine Organ. A Branch splits from
the main channel at the supraclavicular fossa and moves up through the
neck, crosses the cheek, enters the lower gums, curves around the lip
to the opposite side of the face and ends at the side of the nose where
it connects with the Stomach Channel, etc.
B. Eight Extraordinary Vessels
C. Twelve Divergent and Fifteen Collaterals
- The Eight Extraordinary Vessels share the
function of circulating Qi and Blood throughout the body. Unlike the 12
Primary Organ-Channels, these do not pertain to any Organ. Apart from
the Du and Ren Vessels which have their own acupoints, the other six
share points with the 12 Primary Organ Channels.
- The Eight Extraordinary Vessels are:
- Governing (Du) Vessel: Du
Vessel governs all the Yang Channels of the body. All the Yang Channels
converge with this channel. There are four pathways but mainly, they
traverse the midline of the back of the body through the spinal column,
up to the top of the head, and down the midline of the front of the
face to end inside the mouth. The Du Vessel supplies the brain and
spinal cord and has its own set of points.
- Conception (Ren) Vessel: Ren
Vessel governs all the Yin Channels of the body. All the Yin Channels
converge with this channel. There are two pathways. One pathway arises
from the lower abdomen and traverses the front midline of the body to
the chin. The other pathway enters the spine and rises along the back
with the Du Vessel. Its function is to receive and bear the Qi of the
- Chong Vessel: Chong
Vessel arises from the pelvic cavity and runs parallel with the Kidney
Channel from the lower abdomen to the eye area. This is called the Sea
of Blood as it functions as a reservoir of Qi and Blood of the 12
Organ-Channels. The Chong Vessel is particularly implicated in
gynecology and disorders of the reproductive organs.
- Girdle Vessel: Girdle
Vessel encircles the waist and its function is to 'bind up all the
meridians'. This Vessel can be involved in disorders of the lower half
of the body.
- Yang Heel Vessel: Yang
Heel Vessel starts at the outer ankles and rises upward on the outer
(lateral) aspect of the body to meet the Yin Heel Vessel at the eyes.
- Yin Heel Vessel: Yin Heel Vessel starts at the inner ankles and rises upward along the inner thigh to meet the Yang Heel Vessel at the eyes.
Jointly, the Yang and Yin Heel Vessels regulate movement of the legs.
- Yang Link Vessel: Yang
Link Vessel starts at the outer (lateral) side of the foot to rise up
along the lateral side of the body, lateral neck and head. It connects
with all the Yang Channels and dominates the Exterior of the body.
- Yin Link Vessel:
Yin Link Vessel starts above the inner ankles and rises up along the
inner thighs, abdomen, chest and ends near the throat. It connects with
all the Yin meridians and dominates the interior of the body.
Jointly, the Yang Link and Yin Link Vessels regulate the flow of Qi in
the Yin and Yang Channels, and help maintain equilibrium and
coordination between the Yin and Yang Channels.
D. Twelve Muscle Regions and Twelve Cutaneous Regions
- The 12 Divergent and 15 Collaterals branch out from the 12 Primary Organ Channels.
- The Divergents run deeper in the body and
govern the inside while the Collaterals distribute over the body
surface and control the surface.
- They help connect and strengthen the relationship between the Exteriorly-Internally related Yin and Yang Channels.
- These are regions where the Qi and Blood of the Channels nourish the muscles, tendons and skin.
- Muscle Regions are distributed under the skin while the Cutaneous Regions are located in the outermost layers of the skin.
Qi Circulation in the Channels
The behavior, distribution, and flow of Qi in the body vary with the type of Qi as follows:
A. Nutritive Qi (Ying Qi)
B. Defensive Qi (Wei Qi)
- Nutritive Qi is derived from the food nutrients in the Stomach and Spleen.
- Nutritive Qi is related to Blood in that the
transformation of Nutritive Qi contributes to the formation of Blood.
Nutritive Qi and Blood are inseparable as the two flow together in the
blood vessels and Channels to nourish and warm the internal organs and
the entire body. Its importance is related to its function of
regulating the 5 Yin organs (Liver, Heart, Spleen, Lungs and Kidneys)
while moistening the 6 Yang organs (Gallbladder, Small Intestines,
Stomach, Large Intestine, San Jiao and Urinary Bladder)
- There are more than one interpretation of the
sequential and cyclical flow of Nutritive Qi in the Channels. One of
the more popular views was provided above under 12 Primary Organ
C. Original Qi (Yuan Qi)
- Defensive Qi is also formed from the nutrients
in food but it is characteristically more 'lubricating' and 'slippery'
than Nutritive Qi. Its characteristics enable it to slip in and out of
the Channels and tissues.
- During the day, Defensive Qi flows on the
Exterior (outside the channels) between the skin and muscles. It is
able to move both inside and outside the Channels to spread to and
penetrate the surrounding tissues. Whereas, Nutritive Qi is retained
within the walls of the Channels.
- Its function is to protect the body from
exterior pathogenic factors such bacterial and viral infections; to
warm the muscles; and to open and close the pores of the skin.
- Although Defensive Qi flows on the exterior
(between skin and muscles) and is responsible for protecting the
exterior while the Nutritive Qi nourishes the interior, Defensive Qi
also affects the interior as well. This is because in the evening,
Defensive Qi flows inward to warm the Yin organs.
- In a 24-hour period Defensive Qi circulates
throughout the body 50 times: 25 times on the Exterior during the day,
and 25 times in the Interior during the night.
- Yuan Qi is Essence transformed and manifested
as Qi. Original Qi is the foundation of all the Yin and Yang energies
of the body. It is the basal energy and the basis for all the
functional activities of the Channels.
- The Nutritive and Defensive Qi's circulate through the body motivated by the Original Qi.
- As such, Original Qi may circulate with the
Nutritive Qi in the channels and also spread to and penetrate the
tissues along with Defensive Qi. Additionally, Original Qi utilizes a
special envoy, the San Jiao, as its main vehicle of transport within
the trunk of the body.
For additional information on Qi, please see Vital Substances
under Asian Medical Theory.
Functions of Channels and Collaterals
Because the network of Channels and Collaterals
connect with all the organic components of the body including skin,
muscles, tissues, bones and organs, they assume a vital role in human
physiology, pathology, treatment and prevention. The main functions of
Channels and Collaterals are:
A. Transport Qi and Blood, moisten and nourish the body, and regulate Yin and Yang
B. Resisting Pathogens and responding to the dysfunctions of the body
- Channels and Collaterals transport Qi and Blood to adjust Yin and Yang, and nourish all the organic components of the body.
- Qi reflects the Yang aspect of substances and Blood reflects the Yin aspect.
- It is by means of the Channels that Qi and
Blood spread throughout the body to provide the functional force (Qi)
and nourishment (Blood, Yin and Body Fluids).
C. Transmitting disease
- When the normal functioning of the body is interrupted, imbalance and illness occurs.
- Channels respond to the presence of imbalance (disease) by reflecting symptoms and signs.
- Symptoms and signs may be manifested on
certain acupoints or Pain Points (Ashi) by way of spontaneous
tenderness or tenderness on palpation.
D. Transmitting acupuncture stimulation
- External diseases invading the body can travel interiorly to the Internal Organs via the Channels and Collaterals.
- Conversely, internal diseases originating from
the Organs can travel exteriorly to the Skin and Muscles via the same
Channels and Collaterals.
- Acupuncture utilizes the Channels and Collaterals to send its Qi and Blood regulating effects to local and distant targets.
- The 'arrival of Qi' or 'De Qi' is a sensation
of heaviness, fullness, warmth, soreness, etc., that is felt at the
puncture site upon successful needling of an acupoint. This is
considered the functional manifestation of the Channels and Collaterals
after successful transmission of the needling stimulation.
Channel vs. Organ Pathologies
In one respect, the Organs and their relevant
Channels form an inseparable energetic unit. Yet there is also
individualism between them. Their unity is reflected in the fact that
disorders of the Internal Organs can affect their relevant Channels,
and disorders that start in the Channels can move inward to affect
their relevant Internal Organs. On the other hand, their individual
identities are reflected by the fact that Channels pertain to the
superficial Exterior energetic layers of the body, while the Organs
pertain to the Interior of the body.
The superficial layers of the body include the skin, muscles and
Channels. The internal layers include the Organs and bones. A disease
that starts in a Channel can move to its relevant Organ, and vice
versa, revealing their energetic unity. Conversely, a disease may occur
in one layer without affecting the other layer, confirming their
For example, a sciatic-like leg pain that travels along the Bladder
Channel at the back of the legs without any other Bladder-Organ
symptoms, such as urinary problems, reflects a disorder of the Bladder
Channel that has not affected the Bladder Organ. Conversely, urinary
disorders without any Channel related muscular symptoms may reflect a
disorder of the Bladder Organ that has not affected the Bladder
Channel. However, if a person who has endured chronic urinary problems,
long-term, later starts to manifest muscular and other Channel related
symptoms, then the Internal Bladder Organ disorder is said to have
moved to the External layer to affect its Channel.
Each of the 12 Primary Organ Channels and their Connecting and Muscle
Channels, as well as the Eight Extraordinary Vessels have a set of
pathology specific to those Channels which are distinct and separate
from the pathologies of their relevant Organs. In the treatment of any
disorder, the practitioner must first deduce whether the disorder involves a problem related to the Channel or Organ or both.
The Treatment Principles will vary according to the findings and diagnoses.