Researchers identify new organ in the abdomen

Researchers have identified a new organ in the human body, the mesentery, in the abdomen. They say it performs important functions that affect systems throughout the body, from cardiovascular to immunological.

The mesentery was depicted by Leonardo da Vinci as one contiguous organ but in 1885, Sir Fredrick Treves presented the mesentery as fragmented amongst the small intestine, transverse colon and sigmoid colon.

J Calvin Coffey, foundation chair of surgery at the University of Limerick, has now reclassified this part of the digestive system as a contiguous organ and in a new study, established the anatomy and structure of the mesentery, using images and compiling research to show that the organ's continuity could be seen only when it was exposed in a certain way.

The current findings echo those of Carl Toldt, who accurately described the presence of the mesentery in 1878. However, his research was largely overlooked. At the time Treves' findings supported the statements of Henry Gray, who mentioned multiple mesenteries in the 1858 first edition of his book "Gray's Anatomy," the go-to medical textbook for students around the world. However, Treves's research contained an error that persisted for over a century, according to the researchers who wrote in the Lancet Gastroenterology & Hepatology journal, published in November. According to them, Treves failed to give the mesentery, a double sheet of connective tissue that curls through the abdomen, the importance it deserved, as an organ.

Treves declared that the mesentery existed only sporadically, in disjointed ribbons, dispersed among the intestines and therefore did not meet the definition of an organ; an organ, broadly speaking, must be a self-contained structure that performs a specific bodily function.

According to the researchers, it was not correct to say that the mesentery was divided. They point out that the anatomic description that had been laid down over 100 years of anatomy was incorrect. This organ is far from fragmented and complex,'' writes Coffey. ''It is simply one continuous structure.''