the series of arterial arches formed in the mesentery by anastomoses between adjacent jejunal and ileal arteries and from which vasa recta arise. The arterial arcades of the ileum are shorter and more complex than those of the jejunum.arterial arches of ileum, under arch, arterial arches of jejunum, under arch, marginal artery of colon. SYN: intermesenteric arterial anastomoses, Riolan arc (1), Riolan arcades.
