Remember back in high school biology class when you had to learn all the organs in the body and their functions? Well, the mesentery wasn't one of the organs you learned about, and there's a good reason why.

The mesentery, a membrane that connects the intestine to the abdominal wall and holds it in place, has long been considered a fragmented structure made of many separate parts. But now, a University of Limerick professor has reevaluated the membrane and found that it's one continuous structure.

“During the initial research, we noticed in particular that the mesentery, which connects the gut to the body, was one continuous organ," Dr. J. Calvin Coffey, professor of surgery at the University of LImerick's Graduate Entry Medical School, said in a press release. "Up to that it was regarded as fragmented — present here, absent elsewhere and a very complex structure. The anatomic description that had been laid down over 100 years of anatomy was incorrect. This organ is far from fragmented and complex. It is simply one continuous structure."

Coffey's research has been published in the journal The Lancet Gastroenterology & Hepatology.

Although classification as an organ is new, the discovery of the mesentery is not. As the Washington Post points out, what appears to be the mesentery can be seen in a drawing by Leonardo da Vinci.

“In the paper, which has been peer-reviewed and assessed, we are now saying we have an organ in the body which hasn’t been acknowledged as such to date,” Coffey said. “When we approach it like every other organ … we can categorise abdominal disease in terms of this organ.”

And here's why you should care

Better understanding the mesentery could lead to less invasive surgeries, fewer complications, faster patient recovery and lower overall costs, according to the University of Limerick.

And mesenteric science is a specific field of medical study, just like neurology or gastroenterology, according to Coffey.

“This is relevant universally as it affects all of us," Coffey said. "Up to now there was no such field as mesenteric science. 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. Put them all together and you have the field of mesenteric science … the basis for a whole new area of science."

The study's authors note that medical students worldwide are now learning about the mesentery as a continuous organ and the new research has prompted an update in the most recent edition of the medical textbook Gray's Anatomy.

Mary Jo DiLonardo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.