Vas deferens

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Vas deferens

Male Anatomy

Vertical section of the testis, to show the arrangement of the ducts.
Gray's	subject #259 1245
Artery	Inferior vesical artery, Artery of the ductus deferens
Lymph	external iliac lymph nodes, internal iliac lymph nodes
Precursor	Wolffian duct
MeSH	Vas+Deferens

The vas deferens (plural: vasa deferentia), also called ductus deferens, (Latin: "carrying-away vessel") is part of the male anatomy of some species, including humans.

1 Structure
2 Function in ejaculation
3 Significance in contraception
4 Additional images
5 See also
6 External links

[edit] Structure

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.

They are part of the spermatic cords.

[edit] Function in ejaculation

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 on route. Hence the hoary joke: "Between men and women, there is a vas deferens."

[edit] Significance in contraception

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.

[edit] Additional images

Male reproductive system.	Coronal section of pelvis, showing arrangement of fasciæ. Viewed from behind.	The relations of the femoral and abdominal inguinal rings, seen from within the abdomen. Right side.	The spermatic cord in the inguinal canal.
Fundus of the bladder with the vesiculæ seminales.	Vertical section of bladder, penis, and urethra.	Prostate with seminal vesicles and seminal ducts, viewed from in front and above.	Prostate