In a study published Tuesday in Scientific Reports, researchers explain that the interstitium is space beneath the skin that contains fluid-filled structures, which may act as a "shock absorber" to keep other organs safe. And it's everywhere ... beneath the skin across the body, surrounding internal organs, even wrapped around veins and arteries.
But how could something so massive go unnoticed for so long? As The Daily Beast explained, the interstitium isn't actually new to doctors — it's just that they previously thought it was simply dense connective tissue. That's because the tiny fluid structures were drained and compacted when the tissues were made into slides, so scientists never saw them — until now.
The interstitium would be the body's 80th organ.