Scientists recently discovered what they call a new human organ that exists in the digestive system.

Named the mesentery, previously it was thought that the organ consisted of fragmented and disparate structures. The researchers found, however, that it is a continuous organ and sketched evidence to classify it as such in a review published in The Lancet Gastroenterology & Hepatology.

"In the document, which has been peer-reviewed and evaluated, we are now saying that we have an organ in the body that has not been recognized as such to date," said J. Calvin Coffey, a researcher at the University Hospital Limerick in Ireland. , who made the discovery for the first time, said in a statement.

The mesentery is a double fold of the peritoneum, which is the lining of the abdominal cavity. It connects the intestine with the abdomen.

While the specific function of the mesentery is still unknown, studying it as an organ could lead to new discoveries about its impact on abdominal diseases.

"When we approach it like any other organ ... we can categorize abdominal disease in terms of this organ," Coffey said.

The Mesentery

The mesentery

Is a continuous set of tissues formed by the double fold of the peritoneum that connects the intestines to the wall of the abdomen. The term mesentery is used for the small intestine and the mesenteric organ is sometimes used to refer to the rest of the mesentery that incorporates mesocolon, mesoappendix, mesosigmoid and mesorectum. [Citation needed] Reclassification has been proposed as an organ due to research at the University of Limerick in 2010

Conventional teaching had described the mesocolon as a fragmented structure with all the named parts: the ascending, transverse, descending and sigmoid mesocolons, the mesoappendix and the mesorectum as separately ending its insertion in the posterior abdominal wall.

In 2012, after detailed microscopic examinations and electron microscopy, it was demonstrated that the mesocolon was a unique and continuous structure that started from the duodenojejunal flexure and extended to the level of the distal mesorectum. This simpler concept has allowed substantial advances in different aspects of surgery in the colon and rectum. It has also had implications for the sciences related to surgery, anatomy and development.

Horizontal disposition of the peritoneum, in the lower part of the abdomen: The peritoneum and mesentery are marked with red.

Structure

The mesentery of the small intestine arises from the root of the mesentery (or mesenteric root) and is connected to the structures in front of the spinal column. The root is narrow, about 15 cm long, 20 cm wide, and runs obliquely from the duodenojejunal flexure on the left side of the second lumbar vertebra to the right sacroiliac joint. The root of the mesentery extends from the duodenojejunal flexure to the ileocecal junction. This section of the small intestine is located centrally in the abdominal cavity and is located behind the transverse colon and the greater omentum.

The mesentery will attach to the colon in the gastrointestinal margin and continue as a mesentery of the mesocolon, sometimes collectively called the mesenteric organ. The parts of the mesocolon take their names from the part of the colon to which they are attached. These are the transverse mesocolon that attaches to the transverse colon, the sigmoid mesocolon attached to the sigmoid colon, the mesoappendix that attaches to the appendix, and the mesorectum that attaches to the upper third of the rectum.

Traditionally, the mesocolic regions were taught to be separate sections with separate insertions in the posterior abdominal wall. In 2012, the first detailed observational and histological studies of the mesocolon were performed and several new findings were discovered. The study included 109 patients undergoing open, elective and total abdominal colectomy. The anatomical observations were recorded during the surgery and in the postoperative samples.

Vertical disposition of the peritoneum: Main cavity, red; omental bursa, blue

These studies showed that the mesocolon is continuous from the ileocaecal to the rectosigmoid level. It was also shown that a mesenteric con fl uence occurs at the ileocaecal and rectosigmoid junctions, as well as at the hepatic and splenic fl exures and that each confluence involves peritoneal and omental attachments. The proximal rectum was shown to originate at the con fl uence of the mesorectum and mesosigmoid. A plane occupied by perinephric fascia was shown to separate the entire apposed small intestinal mesentery and the mesocolon from the retroperitoneum. Deep in the pelvis, this fascia coalesces to give rise to presacral fascia.

References

1 . Coffey, J Calvin; O'Leary, D Peter (2016). "The mesentery: structure, function, and role in disease". The Lancet Gastroenterology & Hepatology. 1 (3): 238–247. doi:10.1016/S2468-1253(16)30026-7.
2 . Guarino, Ben (4 January 2017). "Meet the mesentery: Irish scientists say this gut membrane should be upgraded to an organ". Washington Post. Retrieved 4 January 2017.
3 . "Irish surgeon identifies emerging area of medical science".
Jump up ^ The human body may have a new organ—the mesentery (arstechnica.com, 4 January 2017)
4 . Coffey JC (August 2013). "Surgical anatomy and anatomic surgery – Clinical and scientific mutualism". The Surgeon.
5 . Coffey JC, Sehgal R, Culligan K, et al. (June 2014). "Terminology and nomenclature in colonic surgery: universal application of a rule-based approach derived from updates on mesenteric anatomy". Techniques in Coloproctology. .
6 . Zheng, MH; Zhang, S; Feng, B (15 March 2016). "Complete mesocolic excision: Lessons from anatomy translating to better oncologic outcome"