Get to know your Interstitium (revisit this 2018 post!)
/Interstitium means A Space Between Things
Maybe you heard about this: last March (in 2018), scientists announced the discovery of a new organ, christening it the interstitium. This news even made the mainstream press.
What these scientists were talking about, of course, is fascia. It’s just that they came upon it unexpectedly and by a different route than did scientists affiliated with the Fascia Research Society.
I attended a webinar with representatives from both groups, and the best my non-scientifically inclined mind could make of it was this: the new group views the new organ as ubiquitous, fluid-filled space that is supported by a lattice of protein fibers, whereas the Fascia Research group regards this tissue as fibrous proteins that are associated with a fluid matrix. Apples and apples, it seems to me, although there may be subtleties I’m missing. In both views, the body is understood as an ecosystem rather than a mechanism, with this ubiquitous fabric as a primary constituent. So whatever name we give to our new organ, we are making progress in understanding the true nature of our bodies.
Wellcome Library, London
Fascia means “bandage”
With their mechanical interpretation of the body, ancient anatomists dubbed the bands and sheets of tissue they found in cadavers fascia, meaning “band” or “bandage.” They understood what they were looking at as merely a container of other tissues. This belief was maintained until the late twentieth century.
But fascia is so much more than a container that needs to be “blasted” into jelly (see FasciaBlaster—I won’t dignify this with a link!) Fascia, we now know, is sentient. It is replete with sensory nerve endings, more by far than muscles have. And those nerve endings are the source of our interior bodily sensations, as well as the sensations of our body in space, our proprioception. Researchers now (in 2025) believe that fascia, with at least 250 million sensory receptors, is our largest sensory organ,
Our fascia lets us know that we have a body! That’s so much more than a bandage can do—I think it’s time to give it a splendid new name.
The word interstitium means “a space that intervenes between things.” It’s a lovely, ancient word, but also a modern term that is broad enough to include the intricate properties of this tissue about which we still have so much to learn.
© 2018 Mary Bond, revised 2025