Unprepared kids who want to get out of taking a test in 2017 can just tell the teacher their mesentery hurts. Irish researchers have classified a new organ in the human body while proving "the anatomic description that had been laid down over 100 years of anatomy was incorrect," according to a press release. The mesentery—which attaches the intestine to the abdomen—is the 79th organ in the human body, Inverse reports. According to Science Alert, the mesentery was described way back when by Leonardo da Vinci, but scientists have long believed it was a series of multiple structures, and therefore not an organ. But new examinations of it on a microscopic level show that it is in fact one self-contained structure, meeting the definition of an organ, the Irish Examiner reports.
Researchers now hope to figure out exactly how the mesentery works, which could lead to better treatment for digestive and abdominal diseases. "The next step is the function," lead researcher J. Calvin Coffey says. "If you understand the function you can identify abnormal function, and then you have disease." Coffey says the classification of the mesentery as an organ leads to a "whole new area of science." But while the famous medical textbook Gray's Anatomy has already been updated, Coffey tells Discovery News he doesn't know "who the final arbiter" is when it comes to officially designating organs. "The mesentery should be subjected to the same investigatory focus that is applied to other organs and systems," researchers conclude in their study, published in November in the Lancet Gastroenterology & Hepatology. (This 107-year-old organ was donated, setting a record.)