All of the following Mesenteries are present in an Adult, except:

The mesenteries of the ascending colon, descending colon, and rectum are lost in adults and become retroperitoneal. Mesentery of the Midgut and Hindgut and its derivatives (dorsal common mesentery) The abdominal pa of the midgut and hindgut only possesses a dorsal mesentery, In the area of the jejunum and ileum it forms the mesentery proper. The dorsal mesentery of the jejunum and ileum is the mesentery proper In the area of the colon it is called the dorsal mesocolon and forms the following mesenteries Mesentery of transverse colon- Transverse Mesocolon Mesentery of Appendix: Mesoappendix Mesentery of Sigmoid colon: Sigmoid Mesocolon The mesenteries of the ascending colon, descending colon, and rectum are lost by Zygosis as a result they become retroperitonealized. Note: The mesentery in the area of the duodenum is called the dorsal mesoduodenum. This however also disappears. Ref: Vishram Singh 2nd edition Pgno: 80