The mesentery is a fold of membranous tissue that arises from the posterior wall of the peritoneal cavity and attaches to the intestinal tract. Within it are the arteries and veins that supply the intestine. The term can be used narrowly to denote just the material that supplies the jejunum and ileum of the small intestine, or broadly to include the right, left and transverse mesocolon, mesoappendix, mesosigmoid and mesorectum.The human mesentery, also called the mesenteric organ, mainly comprises the small intestinal mesentery, the right, left and transverse mesocolon, mesosigmoid and mesorectum. Conventional teaching has described the mesocolon as a fragmented structure; the small intestinal mesentery, transverse and sigmoid mesocolon all terminate at their insertion into the posterior abdominal wall. Recent advances in gastrointestinal anatomy have demonstrated that the mesenteric organ is actually a single, continuous structure that reaches from the duodenojejunal flexure to the level of the distal mesorectum. This simpler concept has been shown to have significant implications.