Common iliac arteries are two large terminal branches of abdominal aorta. They arise from the bifurcation of aorta at the level of 4th lumbar vertebra.
Dimensions:
Both right and left common iliac arteries, in adults, are about 4cm long and more than 1cm in diameter.
Origin:
Right and left common iliac arteries arise from the terminal part of abdominal aorta at the level of 4th lumbar vertebra.
Course:
After their origin, the arteries (on their respective side) run downward and laterally along the medial border of psoas muscle.
End:
Each artery ends in front of the sacroiliac joint of respective side. Each artery bifurcates into external and internal iliac arteries.
Important relation:
At the bifurcation into external and internal iliac arteries, the common iliac artery is crossed in front by the ureter. This relation is fairly constant.