Mesenteries are double-layer sheets of peritoneum that suspend most of the gut and associated structures from the posterior body wall and provide pathways for blood vessels and nerves to the viscera, which travel between the two layers. The mesenteries are named according to their associated organ. For instance, the transverse mesocolon suspends the transverse colon from the posterior abdominal wall, the sigmoid mesocolon suspends the sigmoid colon, and "THE MESENTERY" suspends the small intestine. Organs that have a mesentery are called intraperitoneal. Organs without a mesentery are called retroperitoneal.