Can we call Interstitium an organ (yet)?


Human Body has always been a mystery. Scientists have always been curious about human anatomy. But None would ever expect the doctors to discover a new body part. Recently researchers have done that and named it Interstitium.

But what is organ then?

Organs are composed of main tissue, parenchyma, and “sporadic” tissues, stroma. The main tissue is that which is unique for the specific organ, such as the myocardium, the main tissue of the heart, while sporadic tissues include the nervesblood vessels, and connective tissues. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Functionally related organs often cooperate to form whole organ systems.

Interstitium is a fluid filled space existing between skin and organs. Now this is a network of fluid filled spaces and is found all over the body. So it had been there forever, only been discovered now.

The fluid filled spaces were discovered in connective tissues all over the body. It is found below the skin’s surface, linings and muscles according to the new research published on March 27, 2018 in the journal scientific reports.

Block view of Interstitium

Researchers thought it to be dense “wall” of collagen [a fiber protein]. Though recent study states that interstitium is more of a open fluid network. Dr. Neil Theise, a professor of pathology at New York University Langone School of Medicine states “Instead of a dense wall, this tissue is more like open, fluid filled highway

Researchers admit that the fluid filled spaces have been there since inception but was hidden. The major reason being, these can not be seen in standard microscopic slides. During microscopic experiments, tissue samples are prepared. Tissue samples are first extracted, treated chemically, cut into thin slices and dye is applied. After these processes, the slice is placed on the slide and viewed under microscope.

Related: How to view cheek cell under microscope?

But this process of fixing the tissue drains out the fluid and make the fluid filled spaces collapse. The interstitium was hidden for decades because of the process; the features were not highlighted. Thanks to the new imaging technology that helped the researchers find out about the new so-called-organ.

Discovery of Interstitium

The research is based on the use of a relatively new tool. This tool is called probe based Confocal Laser endomicroscopy or pCLE. The tool is a combination of laser and sensors with an endoscope as published by National institutes of health journal. The laser and the sensors analyze the fluorescent patterns and provide the view of living tissues.

Dr. David Carr-Locke and Dr. Petros Benias are the discoverers of these networks of fluid filled spaces. They used the new technology at Mount Sinai-Beth Israel Medical center at New York while examining the bile duct of a cancer patient when something unusual caught their attention. They were researching on cancer spread. A series of interconnected cavities in the tissue layers were spotted previously unknown in anatomy.

Interstitium founder
Dr. David Carr-Locke
Interstitium founder
Dr. Petros Benias






The fluid cavities collapse when the slices are put on to the slides. Theise said, “the findings appear to explain why cancer tumors that invade this layer of tissue can spread to the lymph nodes. According to the researchers, this occurs because these fluid-filled spaces are a source of a fluid called lymph and drain into the lymphatic system. (Lymph is a fluid that contains infection-fighting white blood cells.)”

Researchers have found out that the fluid filled spaces are present in every individual. The report suggests that the whole process underwent a certain protocol show interstitium.

What is more fascinating?

Probably, It comes as a fascination that the spaces and cavities were present in every individual at the juncture of major organs. Interstitium is found in the lining of digestive tract, lungs, urinary systems and muscles. Researchers believe that interstitium acts as a shock absorber. It protects the major organs from disruptive shocks.


Organ system
The organ system

Scientists have been studying to understand the spread of cancer in the body. They discovery helped to attain much gainful information. Interstitium consists of interstitial fluid (lymph) and drains it into the lymphatic system.

But can we call it an organ (yet)?

The distinction is unofficial as of now. However, a consensus is required to appraise interstitium as an organ. It would thus require a series of conferences and studies to develop the idea. The idea of creating a boundary under which organs can be specified. Hence, enumerating interstitium as organ is still a dilemma for the scientists.

So, it will not be right to declare it as an organ right away but to know more of its functions. We need to know if it really provides the realm to the organ system.

Can we call Interstitium an organ (yet)?
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Can we call Interstitium an organ (yet)?
The curiosity of scientists and advancement in imaging technology has led to the discovery of new organ called the Interstitium. But, can we call it an organ yet?
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