In the 1960’s, a Chinese researcher by the name of Bong Han Kim discovered and elaborated upon a pseudo-vascular system within the human body, comparable to but distinct from both the blood and lymphatic systems . Using high-quality stains, Kim was able to figure out the logistics of a sweeping network of nodes and vessels that seemed to, in his opinion, relate heavily to tissue regeneration.
What’s most interesting about this concept is that it actually has its roots in 1622, when a professor of anatomy and surgery in Italy named Gasparo Aselli found what appeared to be a system of veins that, when ruptured, bled white. Dubbing them the “lacteis venis” (milky veins), they would later be rediscovered almost half-a-dozen times right up to the end of the first world war. Regrettably, still, it never lead to experimentation on them. That is, until Bong Han.
Utilizing a form of phosphorous, Bong Han observed the movement of the particles with radioactive visualization techniques. What was most stunning about it, is that the movement of the particles corresponded to the meridian lines that are oft spoken of within Traditional Chinese Medicine.
In modernity, it’s not uncommon to characterize it as the pathways from which acupuncture meridians are derived. However:
Due to the considerable difference between ancient and modern anatomical nomenclature, it is difficult to comprehend the full extent of the morphological properties of acupuncture points described by ancient scholars. It seems that detailed descriptions of anatomical structures given in the ancient Chinese sources would require microscopic histological examination. It is not known if ancient Chinese medical doctors used any magnifying tools in their anatomical work. 
Prior to his disappearance (which we will be examining in depth later this week), his work ground to a halt and, from there, never really garnered the attention some feel it should have. It remains, perhaps, the only thorough science into the primo-vascular system that we have.