The arterial blood supply of the jejunum and ileum is provided by the superior mesenteric artery (SMA) and its branches. The superior mesenteric artery enters the mesentery of the small intestine and gives off numerous jejunal and ileal arteries. These arteries then anastomose and form many arterial loops called arterial arcades. Also, the terminal ileum receives arterial supply from another branch of the superior mesenteric artery - the ileocolic artery.