Meridians as Real Anatomy: From Bonghan Ducts to the Fascial Internet

For decades, the standard Western dismissal of acupuncture meridians went like this: “There is no anatomical structure corresponding to meridians. Therefore, they do not exist.” The logic seemed airtight. You open a cadaver, you look for glowing energy channels, you find none. Case closed.

Except the case was never really closed. It was abandoned prematurely — and three separate lines of anatomical research have reopened it with force. The primo vascular system. The fascial network. And the liquid crystalline matrix of connective tissue. Together, they suggest that meridians are not mystical highways of invisible energy. They are a real, measurable, anatomical communication system that Western science simply had not learned to see.

The Bonghan Discovery: Found, Lost, Found Again

In 1962, a North Korean scientist named Bong Han Kim published something extraordinary. Working at Pyongyang National University, Kim announced the discovery of a previously unknown anatomical system — a network of tiny tubular structures and node-like corpuscles that corresponded precisely to the acupuncture meridian map.

Between 1962 and 1965, Kim published five detailed reports. His findings described:

Bonghan corpuscles — small, oval-shaped structures approximately 1-2 millimeters in diameter, found at the locations of classical acupuncture points. These corpuscles were rich in DNA granules and contained a unique fluid.

Bonghan ducts — extremely thin tubular channels (5-30 micrometers in diameter) connecting the corpuscles, running along the paths ancient texts had described as meridians. These ducts were found inside blood vessels, on the surface of internal organs, within the lymphatic system, and in the central nervous system.

The system was anatomically distinct from blood vessels, lymphatic vessels, and nerves. It appeared to be a previously unrecognized circulatory network carrying a fluid containing high concentrations of hyaluronic acid, DNA, and hormonal substances.

Then, in 1966, Kim vanished. His research ceased. His fate remains unknown — likely a casualty of North Korean political upheaval. Because his methods were incompletely described and his work was published only in Korean and a limited-circulation journal, no outside laboratory could replicate his findings. The discovery sank into obscurity.

For thirty-six years, the Bonghan system was a footnote — occasionally referenced, widely dismissed, essentially forgotten.

Rediscovery: Seoul National University, 2002

In 2002, a biophysics team led by Dr. Kwang-Sup Soh at Seoul National University decided to look again. Using modern imaging techniques unavailable to Kim — fluorescent dye staining, confocal laser scanning microscopy, and electron microscopy — they began systematically searching for the structures Kim had described.

They found them.

Over the next decade, Soh’s team and collaborating laboratories published over a hundred papers confirming the existence of what they renamed the Primo Vascular System (PVS):

• Primo vessels (formerly Bonghan ducts) were identified on the surface of internal organs in rabbits, rats, and mice. They are translucent, thread-like structures roughly 20-50 micrometers in diameter — too thin to see with the naked eye, which explains why anatomists had missed them for centuries.

• Primo nodes (formerly Bonghan corpuscles) were found at acupuncture point locations, containing clusters of immune cells, stem cells, and chromaffin cells.

• The primo fluid flowing within these vessels was found to contain DNA granules, microcells, and hormonal substances including adrenaline and noradrenaline.

• Crucially, when fluorescent dye was injected into acupuncture points, it traveled along paths corresponding to classical meridian lines — and the channels it traveled through were primo vessels.

A 2013 review in the journal Evidence-Based Complementary and Alternative Medicine summarized the state of research: fifty years after Bong Han Kim’s initial reports, multiple independent laboratories had confirmed the existence of a threadlike structure corresponding to acupuncture meridians, distributed throughout the body in locations matching the classical texts.

The PVS remains controversial. Not all laboratories have successfully replicated the findings. The structures are extraordinarily fragile and difficult to visualize. But the research base is substantial and growing. The primo vascular system may be a novel circulatory system — the third, after blood and lymph — that carries bioactive substances along the very routes that acupuncture has mapped for over two thousand years.

Helene Langevin and the Fascial Connection

While Korean researchers pursued the primo vascular system, an entirely separate line of investigation was opening in the United States. Helene Langevin, a neurologist and researcher at the University of Vermont (later at Harvard’s Brigham and Women’s Hospital and director of the NIH’s National Center for Complementary and Integrative Health), asked a deceptively simple question: what is anatomically present at acupuncture points?

Her approach was straightforward. She took serial gross anatomical cross-sections of human arms and mapped the precise locations of classical acupuncture points against the actual tissue structures visible in each section.

The 2002 results, published in The Anatomical Record, were striking: 80% of acupuncture points corresponded to intermuscular or intramuscular connective tissue planes — the thin fascial sheets that separate and connect muscle groups.

This was not a vague correlation. Acupuncture points clustered precisely where fascial planes converge, diverge, or thicken. The remaining 20% of points corresponded to other connective tissue structures like tendons, joint capsules, or periosteum.

Langevin went further. Using ultrasound imaging on living subjects, she demonstrated that acupuncture needle insertion at traditional points engaged the connective tissue differently than needle insertion at non-points. When an acupuncture needle is rotated — the technique that produces the characteristic “de qi” sensation of heaviness or aching — the connective tissue physically winds around the needle like spaghetti around a fork. This mechanical coupling between needle and tissue triggers a cascade of cellular events.

Her team measured the biomechanics: needle rotation generated a measurable pull on the surrounding fascial matrix. This mechanical signal was transduced into cellular responses — fibroblasts (the primary cells of connective tissue) changed their shape, spread out, and began producing signaling molecules including ATP and adenosine.

In a subsequent study, Langevin and colleagues measured electrical impedance along connective tissue planes associated with acupuncture meridians. They found that meridian-associated fascial planes showed greater electrical conductance than non-meridian control segments — meaning these tissue pathways actually conduct bioelectric signals more efficiently.

The implications rearrange everything. Meridians may not be separate, mystical channels overlaid on the body. They may be the body’s own connective tissue communication network — identified by Chinese physicians through centuries of clinical observation, mapped through palpation and empirical testing, and described in the only language available to them.

The Fascial Internet: A Body-Wide Communication System

To understand why fascia matters so profoundly, you need to reconsider what connective tissue actually is.

Fascia is not packing material. It is not the white stuff you cut away to get to the “real” anatomy. Fascia is the body’s largest sensory organ — a continuous, three-dimensional web of connective tissue that extends from the crown of the head to the soles of the feet, from the surface of the skin to the membranes surrounding every organ, every muscle fiber, every nerve, and every blood vessel.

You cannot cut fascia out of the body and hold up a separate piece. It is one structure. If you could dissolve everything else — bones, muscles, organs, blood — the fascial web would retain the complete three-dimensional shape of the body.

In 2011, Yu Bai and colleagues published research using digital imaging to create three-dimensional reconstructions of fascial tissue in human cadavers. Their conclusion: the fascial connective tissue network of the human body “conspicuously approximates” the theoretical meridian system of Traditional Chinese Medicine. Thick connective tissue tracts visible in imaging corresponded to the courses of major meridians.

Here is what fascia does that makes it a plausible meridian substrate:

Mechanotransduction. Fascia converts mechanical force into cellular signals. When you press, stretch, needle, or manipulate connective tissue, fibroblasts detect the mechanical input and respond by releasing signaling molecules, changing gene expression, and remodeling the tissue matrix. This is the molecular mechanism behind bodywork, acupuncture, and manual therapy.

Piezoelectricity. Collagen, the primary structural protein of fascia, generates electrical charges when mechanically deformed. Press on connective tissue and it literally produces electricity. Bone healing, for example, is guided by piezoelectric signals generated by mechanical stress on collagen. The body’s connective tissue matrix is, in effect, a pressure-to-electricity transducer spanning the entire organism.

Semiconductor properties. Mae-Wan Ho, a biophysicist at the Open University in the UK, proposed that the body’s connective tissue network functions as a liquid crystalline matrix — a semiconductor that can conduct protons (hydrogen ions) and electrons throughout the organism at speeds far exceeding chemical diffusion. Collagen fibers, aligned in regular arrays with layers of structured water molecules bound to their surfaces, create conditions for rapid, body-wide signal transmission.

This liquid crystalline model offers something remarkable: a physical mechanism for the near-instantaneous body-wide effects that acupuncture practitioners observe clinically but that nerve conduction alone cannot explain.

The Integration: Three Discoveries, One System

Step back and see the convergence:

The primo vascular system provides a network of microscopic vessels and nodes, carrying bioactive substances along meridian pathways — a circulatory component.

The fascial network provides a continuous connective tissue matrix that conducts mechanical, electrical, and chemical signals along pathways corresponding to meridians — a structural and signaling component.

The liquid crystalline matrix of collagen and bound water provides a mechanism for rapid, body-wide information transfer through the connective tissue — a communication component.

These are not competing theories. They may be three aspects of a single, integrated system that Western anatomy simply had not recognized because it fell between the cracks of existing categories — not quite circulatory, not quite nervous, not quite musculoskeletal.

Chinese physicians, lacking microscopes and fluorescent dyes and ultrasound machines, identified this system through the only tools they had: their hands, their eyes, their patients’ reports, and centuries of accumulated clinical observation. They called the pathways meridians. They called the functional activity flowing through them qi. They mapped the system with acupuncture points.

The map was imperfect — like any map drawn before precision instruments. But the territory it described? The territory is real. And modern science is only beginning to explore its full dimensions.

What would medicine look like if we recognized that the body has not two but three circulatory systems — blood, lymph, and a connective tissue network that carries information, immune signals, and bioactive substances along pathways that acupuncture has mapped for two and a half thousand years?