Interstitium

The largest organ in the body? 

The human body is incredibly complicated, and it’s no surprise that we haven’t cracked every code that makes our fleshy forms run smoothly. Researchers are constantly finding new mechanisms by which our immune systems work, our cells function, and our muscles move. But far less often – if ever – do we hear that scientists have identified a new organ. However, according to a report published in the journal Scientific Reports, US doctors have identified a new organ that is one of the biggest in the body, and one that was there the entire time. The new organ has been named Interstitium.

In between the spaces in our bodies — beneath the skin, lining the gut and lungs, surrounding blood vessels and fascia between muscles, and more — there’s a fluid-filled network of tissue. This tissue has a unified structure and function throughout the body that makes it an organ. Using that definition, Interstitium could be the largest organ in the body, taking up a bigger volume than even our skin.

What is the organ made of?

The organ is a network of interconnected, fluid-filled spaces all over the body and is made up of both strong (collagen) and flexible (elastin) connective tissue proteins, with interstitial fluid moving throughout.

Functions

1. The interstitium might have a unified function or functions.
2. This organ might help protect the rest of our organs and tissue.
3. It could also explain the spread of certain cancers, as well as how a number of diseases progress in the body.
4. The fluid-filled sacs throughout this tissue could help interstitial fluid travel throughout the body. That’s important because fluid in this network is the largest source of lymph, which is a critical part of the immune system.

Benefits

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. A better understanding of this interstitial network could help us understand why skin wrinkles as we age, why limbs get stiff, and how inflammatory diseases spread. It may also explain why cancers that spread into the space between organs are more likely to show up in other parts of the body.

As something that surrounds our blood vessels and organs, the interstitium might help protect them from tearing and may help absorb shocks that could otherwise damage parts of our body. It’s even possible that studying these spaces could help reveal what acupuncture is or isn’t doing within the body.