Vas deferens
The
vas deferens, also called
ductus deferens, (
Latin: "carrying-away vessel") is part of the
male anatomy of some species, including humans. There are two such ducts; they are muscular tubes (surrounded by
smooth muscle) connecting the left and right
epididymis to the
ejaculatory ducts in order to move
sperm. Each tube is about 30 centimeters long.
During
ejaculation the smooth muscle in the wall of the vas deferens contracts reflexively, thus propelling the sperm forward. The sperm are transferred from the ductus deferens into the urethra, collecting fluids from the male accessory sex glands en route. Hence the hoary joke: "Between men and women, there is a vas deferens."
The procedure of
deferentectomy, popularly known as a
vasectomy, is a method of
contraception in which the vasa deferentia (Latin plural) are permanently cut, though in some cases it can be reversed. A modern variation, which is also popularly known as a vasectomy even though it does not include cutting the vas, involves injecting an obstructive material into the ductus to block the flow of sperm.
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Intra vas device*
Cystic fibrosis
