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.
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 (in humans).
They are part of the
spermatic cords.
Function in ejaculation
During
ejaculation the smooth muscle in the walls of the ductus deferens or vas deferens contracts reflexively, thus propelling the sperm forward. This is also known as peristalsis. The sperm is transferred from the vas deferens into the urethra, collecting secretions from the male accessory sex glands such as the seminal vesicles, prostate gland and the bulbourethral glands, which form the bulk of semen.
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.
Investigational attempts for male contraception have focused on the vas with the use of the
intra vas device and
reversible inhibition of sperm under guidance (RISUG).
Blood supply
The Vas deferens is mainly supplied by an artery accompanying it (artery of vas deferens). This artery normally arise from either the superior vesical artery or the inferior vesical artery. Both these arteries arose from the internal iliac artery.
Additional images
See also
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Intra vas device
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Cystic fibrosis
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Excretory duct of seminal gland
External links
★ - "Inguinal Region, Scrotum and Testes: Layers of the Spermatic Cord"
★ - "The Male Pelvis: Distribution of the Peritoneum in the Male Pelvis"
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