Vas deferens

VAS DEFERENS
(Bull, Ram, Buck, Stallion, Boar, Dog, Rabbit, Cock)

Bull

  • The ductus deferens or vas deferens extends from the tail of the epididymis to the pelvic part of the urethra
  • It is at first, pursues a very tortuous course upwards along the caudal border of the testicle
  • It then becomes straight and runs in the caudal border of the spermatic cord through the inguinal canal, deviates from the other structure at the vaginal ring, turns backwards into the pelvic cavity. For some distance it lies in the free edge of the genital fold by which it is kept attached to the lateral walls of the pelvis
  • The two ducts passes backward towards the dorsal face of the bladder, where they leave the genital fold, incline medially to reach the caudal part of the bladder
  • They open at the roof of the beginning of the urethra as slit - like openings - the ejaculatory orifices on either side of the colliculus seminalis, medial to the openings of the vesiculae seminalis
  • From its origin to the dorsal face of the bladder, it has a uniform diameter of about 3mm
  • Then they form an enlargement - bulbus part or ampulla, which is 10 to 12 cm long and 1.2 to 2.5 cm wide

Species difference

Ram and Buck

  • It resembles bull

Stallion

  • The caliber is about 6 mm.
  • The first part of the course has no relation to the testicle
  • The ampullated part is 15 to 20 cm long and 2 cm wide
  • The genital fold is wider and hence the two ducts are apart from each other
  • The vas deferens and the duct of seminal vesicle open in a common ejaculatory orifice on the side of the colliculus seminalis
  • The vas deferens is not tortuous and not related to any border of the testicle

Boar

  • The vas deferens in its testicular part is flexuous and is closely attached by the tunica vaginalis
  • It forms no distinct ampulla

Dog

  • The ampullae are narrow

Rabbit

  • The dilated terminal portion of the duct enters the ventral wall of the seminal vesicle dorsal to the bladder

Cock

  • The vas deferens are extremely tortuous ducts which arise from the epididymis, pass backwards and open into urodeum on the summit of a papilla lateral to the ureter
Last modified: Friday, 20 April 2012, 10:45 AM