At a deeper level: the superior part of the wall is supplied by the superior epigastric artery, a terminal branch of the internal thoracic artery; the lateral part of the wall is supplied by branches of the tenth and eleventh intercostal arteries and the subcostal artery; and the inferior part of the wall is supplied by the medially placed inferior epigastric artery and the laterally placed deep circumflex iliac artery, both branches of the external iliac artery.