The arteries which supply the ureter vary along its course. The upper third of the ureter, closest to the kidney, is supplied by the renal arteries. The middle part of the ureter is supplied by the common iliac arteries, direct branches from the abdominal aorta, and gonadal arteries; the gonadal arteries being the testicular artery in men and the ovarian artery in women. The lower third of the ureter, closest to the bladder, is supplied by branches from the internal iliac arteries, mainly the superior and inferior vesical arteries. The arterial supply can be variable, with arteries that contribute include the middle rectal artery, branches directly from the aorta, and, in women, the uterine and vaginal arteries.