Ductus deferens

The vas deferens, also called ductus deferens, is part of the male anatomy of many vertebrates; these vasa transport sperm from the epididymis to the ejaculatory ducts in anticipation of ejaculation.

There are two ducts, connecting the left and right epididymis to the ejaculatory ducts in order to move sperm. Each tube is about 30 centimeters (0.98 ft) long, 3 to 5 mm in diameter and is muscular (surrounded by smooth muscle). Its epithelium is lined by stereocilia. They are part of the spermatic cords.

The vas deferens is supplied by an accompanying artery (artery of vas deferens). This artery normally arises from the superior (sometimes inferior) vesical artery, a branch of the internal iliac artery.