Mesentery (zoology)

[1] In vertebrates, a mesentery is a membrane consisting of a double fold of peritoneum that encloses the intestines and their associated organs and connect them with the dorsal wall of the abdominal cavity.

The mesothelium of the body wall is extended round the central gut to form a mesentery, a longitudinal partition in the sagittal plane.

[4] In the phylum Cnidaria and the class Anthozoa, the mesenteries are sheet-like partitions that extend from the body wall of the animal into its gastrovascular cavity.

They can either be "complete", joining the gastrodermis of the body wall with that of the pharynx, or "incomplete", extending only part way into the cavity (the terms "perfect" and "imperfect" are sometimes used instead).

The lower ends of the mesenterial filaments are elongated into acontia which are armed with cnidocytes (stinging cells) and can protrude through the body wall or mouth.