Irish scientists have recently identified a new human organ the "mesentery" that has existed in the digestive system for hundreds of years.

Although its function is still unclear, the discovery opens up "a whole new area of science," according to J Calvin Coffey, a researcher at the University Hospital Limerick who first discovered it in 2012.

Mesentery is a fold of the peritoneum which attaches the stomach, small intestine, pancreas, spleen, and other organs to the posterior wall of the abdomen.

"Up till then 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.

"When we approach it like every other organ...we can categorise abdominal disease in terms of this organ," Coffey said.Although there are generally considered to be five vital organs in the human body, there are in fact now 79, including the mesentery.