Vas deferens

A duct in the male reproductive system

Diagram of the male reproductive system.

3D medical animation of the vas deferens.

Illustration of the male reproductive tract.

Anatomy of the male pelvis.

Cross-section of the spermatic cord.

The vas deferens, also known as the ductus deferens, is a vital component of the male reproductive system. It is a muscular tube that transports sperm from the epididymis in anticipation of ejaculation.

Anatomy

The vas deferens is approximately 30 centimeters long and is a continuation of the epididymis. It ascends from the scrotum, passes through the inguinal canal, and enters the pelvic cavity. The vas deferens then travels posteriorly to the urinary bladder, where it joins with the duct of the seminal vesicle to form the ejaculatory duct.

Structure

The wall of the vas deferens is composed of three layers: an inner mucosa, a middle muscularis, and an outer adventitia. The muscularis layer is particularly thick, consisting of longitudinal and circular smooth muscle fibers, which facilitate the propulsion of sperm during ejaculation.

Blood Supply

The vas deferens receives its blood supply from the artery of the vas deferens, a branch of the superior vesical artery. Venous drainage is via the pampiniform plexus, which eventually drains into the testicular vein.

Function

The primary function of the vas deferens is to transport sperm from the epididymis to the ejaculatory duct. During ejaculation, the muscular walls of the vas deferens contract, propelling sperm forward. This process is facilitated by the presence of peristaltic waves.

Clinical Significance

The vas deferens is a key structure in vasectomy, a surgical procedure for male contraception. During a vasectomy, the vas deferens is cut and sealed to prevent sperm from entering the ejaculatory duct, thereby preventing fertilization.

Gallery

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  The male reproductive organs.

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  The vas deferens and surrounding structures.

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  The vas deferens in relation to the bladder.

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  The vas deferens and seminal vesicle.

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  Illustration of the prostate and surrounding structures.

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  Close-up of the vas deferens.

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  Testis and associated structures.

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  Histological slide of the vas deferens.

Related pages

• Epididymis
• Seminal vesicle
• Ejaculatory duct
• Vasectomy

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2013). Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
• Netter, F. H. (2014). Atlas of Human Anatomy. Elsevier.