major arterial circle of the iris major arterial circle of the iris major arterial circle of the iris" (also: "major circulus arteriosus of iris", or "circulus arteriosus iridis major") is a circular artery of the eye formed by anastomoses of the anterior ciliary arteries and long posterior ciliary arteries at the ciliary body. it supplies arterial blood to the iris, ciliary processes of the ciliary body, and anterior choroid. major circulus arteriosus of irisdetailsidentifierslatincirculus arteriosus iridis majorta98a15.2.03.034ta24482fma58529anatomical terminology the major arterial circle of the iris is situated within the ciliary stroma in the anterior part of the ciliary body near the root of the iris.