“Theory” is certainly not the right word from the perspective of mainstream medical culture. Most times it just refers to a body location. It’s mostly terminology.
The Upper Jiao is essentially the Thoracic Cavity, and the Orophalanx (mouth basically). Everything above the diaphragm relating to Digestion and Circulation, and almost all of of the organs of Perspiration. It belongs alongside Thoracic Cavity in a Scientific Occidental Medical Practitioner, as an Organ Group.
The Middle Jiao is the core of digestion—Stomach, Liver particularly the closest cells to the Hepatic Portal, “Spleen” (digests red blood cells more efficently than the liver), and the Duodenum. Sparing the colourful descriptions, this is areas where food is mostly converted .
Finally, the lower burner is mostly dealing with slow extraction of less and less useful food matter, and includes the Ilium, Colon, and—along similar lines to the filtering of waste matter—the Kidneys. But also the Adrenal Complex.
Then, there’s the part which is not a Theory, either—it’s a more of a conjecture, scientifically speaking. It describes digestion, and some basic interactions between organs. Some of them are direct (such as the transferring of digestate from the middle to the lower jiao), and some more conceptual.
Acupuncture has been investigated in what could be called the history section of science—for instance at Cambridge in the early 20th, Joseph Needham or Gwei–Djen Lu as he became to be known left a tome of books called Science and Civilization in China which is fascinating in its own right, but a special one called Celestial Lancets for what was called “Occidental Medicine” or even “Eastern Medical Science” at the time by Western scholars. The most detailed reference translation between Eastern and Western medical concepts I am aware of is L’Acuponcture Chinoise, though I have only rarely delved into it. There’s a nice vampire story in there, I would call it something of an Easter Egg for the observant (it’s in a section of Chinese Medicine dealing with unusual forms of death).
But the books I read were much simpler, and written by later authors trying to leave less cryptic, though more approachable for beginner–level tertiery students. Books such as Zang Fu by Jeremy Ross and the Foundations of Chinese Medicine by Giovanni Maciocia. I have read a few of these books, though I decided that there were more pressing problems I needed to apply my life to than the relatively intellectual pursuit of Scientific development of Chinese Medical concepts. I’ve left my life of scientific pontification and petty miracle working that never was to join the “one—degree war”.
I still find research in the field interesting, though.
I wrote up a Wikipedia page to go along with this image, and while despite my complaints about deletionism, much of the text I wrote seems to have been left intact since I wrote it to accompany the image in 2007 or whenever it was. I’ll leave it for now on my own blog, I realise it is not currently citable material and missing some due diligence with citations. But the above books are a pretty useful set of general citations for this. Perhaps someone will one day verify it better.
San Jiao Theory
”‘San Jiao”’ is a term found in traditional Chinese medicine, as part of modelling the workings of the human body attempted by early Chinese medical writers. References to it can be found in the oldest Chinese medical texts available, including the Yellow Emperor’s Huang Di Nei Jing.
San Jiao has been translated as ““triple heater”,” “triple warmer” (or “three warmers”),” and ““triple burner”,” the latter of which is probably favored because of the involvement of the San Jiao in metabolism. The current WHO standard term is “Triple Energizer” (TE), but many authors still prefer to use San Jiao.
The San Jiao as a body model
There are three “burning spaces”:
(the svg source is available for the above image)
This is a picture I drew of all of this as I was trying to wrap my own head around what it is. All the organ parts come from other free SVG files on WikiMedia. I uploaded it to WikiMedia, but unfortunately it didn’t get the right MetaData to stick around; a copyright notice apparently not being enough. It probably counts as original research, anyway.
The Shang Jiao (upper burner) - corresponding to the thoracic cavity. This space includes Fei (lungs) and Xin (Heart), and is associated with respiration.
The Zhong Jiao (middle burner) - corresponding to the upper part of the dorsal cavity. This space includes Wei (Stomach), Pi (usually called “Spleen”, but better called the “nutrient uptake system”, eg in Western Medical Science terms the Hepatic Portal System, various secretory pancreatic cells, perhaps the duodenum, portions of the lymphatic system carrying chyle, as well as catabolic and transaminoic functions of liver cells) and is associated with digestion.
The Xia Jiao (lower burner) - corresponding to the lower part of the dorsal cavity. This space includes Xiao Chang (small intestine), Da Chang (large intestine), Shen (Kidneys), Pang Guang (Bladder) and is associated with elimination.
Other Zang Fu organs were not included in the San Jiao model.
The Hand Channel of San Jiao Shao Yang is so called because of its generalized effects across the San Jiao. San Jiao is not an organ. In fact, many Zang Fu organ translations do not directly correspond with their defined western organ.
The Shao Yang channel is the second shallowest channel in the six divisions of channel theory, and its hand division - San Jiao - starts at the fingernail of the ring finger, travels up the outside center of the hand and arm, encompasses the elbow, continues to the back of the Acromio-clavicular joint (part of the shoulder), meeting with the other Yang channels at the junction of the seventh cervical and first thoracic vertebrae (GV-14 “da zhui”), before travelling up the neck to behind the ear, encompassing the external ear and terminating at outer tip of the eyebrow. Aside from Wai Guan (TE-5), its points’ most common clinical uses are for local problems.
San Jiao relationships
In TCM theory, the San Jiao is a yang organ paired with the Pericardium (Xin Bao) which is the yin organ associated with it. Yang (Fu) organs are typically hollow, whereas yin (Zang) organs are more solid. The triple burner, however, is said to be primarily energetic and does not have a physical component, unlike all the other organs in TCM. In dissecting a body, one would not be able to find a structure that could be called the San Jiao.
The San Jiao’s Hand-Foot partner is Dan (Gall Bladder).
San Jiao function
The San Jiao is also said to be a metabolism mechanism similar to an old-fashioned “water wheel” that is turned by incoming water and creates energy for accomplishing a task, such as grinding grain in the case of the water wheel, or for metabolising and digesting food in the case of the San Jiao. The San Jiao is closely associated with the spleen functions of transformation and transportation, particularly the metabolism of incoming food. The San Jiao is also closely associated with the kidney’s function in TCM. The San Jiao, however, is not limited to one metabolism function as the spleen or kidneys are, but is a general metaboliser which can be applied to a variety of metabolism needs.
This dual usage of San Jiao to refer to a specific metabolic function and to refer to the areas of the body is a source of confusion, and care should be taken to make it explicit which is being referred to.