MESENTERY

n. Me2z'ean-tV-ia. Gr., uttrtvrtpiov, nevevrtpov (from filtrot, middle, and ivrepov. any one of the entrails). Lat., mesenterium. Fr., mesentere. Ger., Gekrose, Gekrosmantel. It.,Sp., me sente rio. 1. A fold of the peritonaeum by which a portion of the intestinal canal, especially the jejunum and ileum, is attached loosely to the posterior wall of the abdomen; as sometimes used, a similar fold by which any organ is attached. [A, 5.] 2. In the Actiniae, vertical sapta which divide the body cavity into a number of chambers each of which communicates with cavities in the tentacles and with the others by a general cavity into which the oesophagus opens. They are arranged in pairs, consisting of an imperfect and perfect m. (each having longitudinal muscles on the opposed surfaces), with the exception of the directive mesenteries (q. v.). [L, 355.] Cupcal m. See MESOC^ECUM. Cardiac m. See MESOCARDIUM. Colic m. See ME SO COLON. Directive mesenteries. Mesenteries in the Actiniae which are situated at each end of the sagittal axis of the animal. One pair is perfect and one imperfect, termed respectively macro-directive and micro-directive. [L,.355.] Gastric m. See MESOGASTRIUM. Imperfect mesenteries. Syn.: microscepta. The smaller of the two varieties of mesenteries in the Actiniae. They are attached only to the body walls, having a free margin, and are unprovided with unproductive organs and filaments. [L, 335.] Perfect mesenteries. Syn.: macronaepta. The larger of the two varieties of m's in the Actiniae which are attached to the body wall and the oesophagus and are furnished with reproductive organs and filaments. [L, 355.] Rectal m. See ME SO RECTUM. Uterine m. See MESOMETRIUM. MKSF.riTHKL, (Ger.), n. Mas-eap-e-teal'. See Mesodermic EPITHELIUM. [s. 756]