What is the prominent vascular structure in the outer third of the myometrium, a branch of the uterine artery?

• A. Arcuate vessels
• B. Ovarian artery
• C. Internal iliac arteries
• D. Uterine arteries

Answer: (A)

Arcuate arteries are the prominent vessels in the outer third of the myometrium. They branch from the uterine artery and travel in a circular pattern within the outer myometrium, forming a network that gives off radial arteries toward the endometrium to supply the uterine muscle. This distinct layered arrangement helps differentiate them from other pelvic vessels: the ovarian artery primarily supplies the ovaries, the internal iliac arteries are large pelvic trunks that give rise to the uterine arteries, and the uterine arteries themselves are the main source but the specific vessels described in the outer myometrium are the arcuate arteries.