Scientists had officially declared another part of the human body. The new organ is known as the mesentery.

Mesentery had been discovered by scientists hundreds of years back, but it was thought to be just fragments of the digestive system. Science Alert said one of the earliest definitions of mesentery was made by Leonardo da Vinci, however it was ignored, thinking that it is just some kind of an attachment in the abdomen.

Through the years, mesentery has been defined as "a double fold of peritoneum - the lining of the abdominal cavity - that attaches our intestine to the wall of our abdomen, and keeps everything locked in place," the report said.

It is only until now that the mesentery has been understood. Calvin Coffey, a Professor of Surgery at UL's Graduate Entry Medical School found out through microscopic tests that mesentery is not just a fragment, rather a continuous structure.

"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," Professor Coffey said in a statement published in University of Limerick's website.

"During the initial research, we noticed in particular that the mesentery, which connects the gut to the body, was one continuous organ. 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 explained.

The new discovery does not change human anatomy, but it can open a whole new field of medical science that could improve human health. Since mesentery had already been formally classified as the organ, the next step is to learn its function and soon investigate the role of mesentery in different abdominal diseases.

A paper published in The Lancet Gastroenterology & Hepatology, outlines the bases for categorizing the mesentery as an organ.