Scientists have recognized a system of fluid-filled areas surrounded by connective tissue which fills the spaces between our organs, encompassing and possibly protecting our interiors through the body. In a study, scientists specify this network as a brand new organ — the interstitium —which they say may be the biggest organ in the human body. Learning more about this network can help us better understand how diseases such as cancer spread, and also help to explain what healing methods like acupuncture are tapping into.
It may seem like we should already have recognized all the constructions in the human body, but this assumption could be wrong. A recently published study in the journal Scientific Reports describes a fluid-filled network of tissue between the spaces under the skin, lining the intestine and lungs, and encompassing arteries, veins, and the fascia between muscles.
The idea that there is tissue and fluid in these spaces is not new — interstitial fluid is among the substantial kinds of fluid in the body — though we did not recognize it was contained in these constructions. However, the writers of the study say this tissue has a unified construction and function through the body, which makes it an organ.
Using that definition, it might be the largest organ within the body, taking up a larger volume than even our skin. This organ could help protect of the rest of our organs and tissue. Slicing it up caused the fluid to drain, draining the sacs and making them to collapse, and simply leaving the supporting proteins behind.
“This fixation artifact of collapse has made a fluid-filled tissue type throughout the body appear solid in biopsy slides for decades, and our results correct for this to expand the anatomy of most tissues,” said Neil Theise, a professor in the Department of Pathology at NYU Langone Health and co-senior author of the study, in a news release.
The consequences for all this are enormous. “This finding has potential to drive dramatic advances in medicine, including the possibility that the direct sampling of interstitial fluid may become a powerful diagnostic tool,” said Theise. A much better understanding of this interstitial system can help us understand why skin wrinkles for we age, why limbs become rigid, and how inflammatory diseases spread.