The human body is an amazing and expansive place, full of strange twists and turns. It’s likely we’ll never discover all its secrets, but we do have a pretty solid grasp on the major parts. So even though new research has convincingly made the case for reclassifying the mesentery—a folded membrane that connects your intestines to the wall of your abdominal cavity and keeps everything snugly in place—as a single, continuous organ, scientists have not, as some headlines proclaim, discovered a “brand-new organ.” In fact, we've known about the existence of the mesentery (pronounced MEH-zun-terry) for centuries; Leonardo da Vinci even included it in his anatomical notes.
The mesentery has historically been seen as a series of unimportant attachments to the abdominal lining. But researcher J. Calvin Coffey of the University Hospital Limerick in Ireland suspected that there might be more to it. He and his colleagues examined the membrane and surrounding tissue under a microscope in 2012. They found that, rather than a group of disconnected but similar pieces, the mesentery was actually all one piece. The researchers published their findings in The Lancet Gastroenterology & Hepatology.
Inspired by this realization, Coffey initiated a campaign to reclassify the mesentery as a separate organ. He believes that full organ status is the key to understanding what’s going on in our guts.
“Up to now there was no such field as mesenteric science,” he said in a statement. “Now we have established anatomy and the structure. The next step is the function. If you understand the function you can identify abnormal function, and then you have disease.”
His lobbying paid off; the latest edition of Gray's Anatomy categorizes the mesentery as an organ.
Coffey’s new paper, written with his colleague D. Peter O’Leary, makes a strong case for initiating the mesentery into the organ club. “The mesentery should be subjected to the same investigatory focus that is applied to other organs and systems,” they write.
“This is relevant universally,” Coffey added in the statement. “It affects all of us.”