Spray channel

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Location of the ejaculatory duct

The spray channel (also: "spray channel", lat. Ductus ejaculatorius ) is a paired duct in male mammals, which runs from the seminal vesicles , which are also paired, through the prostate and opens into the urethra . It transports most of the ejaculate during ejaculation .

anatomy

Each ejaculatory duct is created by the union of the spermatic duct (which comes from the epididymis ) and the excretory duct ( ductus excretorius ) of the seminal vesicle on the same side. In men, the spray channel is about 2 cm long.

The injection channel does not have its own tunica muscularis , but only a mucous membrane , similar to that of the spermatic duct. A lumen of more than 2.3 mm is not normal, but suggests an expansion (dilation). The anatomy is e.g. B. by leaflet flaps at the mouth in the urethra , aligned so that a back flow of urine from the urethra into the seminal vesicles is almost impossible.

In some mammals there is no ejaculatory duct: Predators lack the seminal vesicle and consequently the duct and thus the union with the vas deferens. In pigs and sheep, the two courses are not combined.

  • Prostate - Gray1153.png

  • Lobe of the prostate with the ejaculatory duct

  • Longitudinal section through the bladder, penis and urethra (urethra)

  • Prostate with seminal vesicles and vas deferens, front and top view

Diseases

The occlusion of the ejaculatory duct is a congenital or acquired disease in which one or both injection channels are blocked or narrowed. If both injection channels are blocked, the affected man is unable to childbirth due to blocked azoospermia . If this condition is treated surgically by a transurethral resection of the ejaculatory duct (TURED) , the leaflet valves are removed and urine flowing back into the seminal vesicles can deteriorate semen quality. In addition, the urine can now also reach the epididymis via the vas deferens and possibly lead to an epididymis inflammation caused by bacteria from the urethra.

Surgical treatment of benign prostatic hyperplasia can also injure or block the injection channels.

With retrograde ejaculation , the seminal fluid that comes out of the tubules then does not flow into the urethra in the direction of the penis , but in the wrong direction: the urinary bladder .

Individual evidence

  1. ^ H. Nguyen et al .: Normal Human Ejaculatory Duct Anatomy: A Study of Cadaveric and Surgical Specimens. In: The Journal of Urology . Volume 155, No. 5, pp. 1639-1642.
  2. ↑ Uwe Gille: Urinary and sexual system, apparatus urogenitalis . In: Franz-Viktor Salomon et al. (Ed.): Anatomy for veterinary medicine . 2nd expanded edition, Enke-Verlag, Stuttgart 2008, ISBN 978-3-8304-1075-1 , pp. 389-403.
  3. ^ I. Schroeder-Printzen et al .: Surgical therapy in infertile men with ejaculatory duct obstruction: technique and outcome of a standardized surgical approach. In: Human Reproduction. ( Hum Reprod. ) June 15, 2000, No. 6, pp. 1364-1368.

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