L3.2.2.2: Ductus (Vas) Deferens

• Ductus (vas) Deferens

  ○ Etymology: carrying-away vessel.

  ○ Runs from the epididymis through the inguinal canal and arches over the bladder.

  ■ Ampulla: end of the ductus deferens, empties into the ejaculatory duct.

  ■ Ejaculatory duct: passes through the prostate to merge with the urethra.

  ○ Main Function: To propel live sperm from their storage sites.
• Ductus (vas) Deferens

  ● Runs upward from the epididymis via the spermatic cord into the inguinal canal, to pelvic cavity and then arches over the superior aspect of the urinary bladder.

  ● It loops medially over the ureter and descends along the posterior bladder wall.

  ➔ The sperm travel to the ampulla (expanded terminal portion of the

  ductus deferens) and are emptied to the;

  ➔ Ejaculatory duct that passes through the prostate to merge with the urethra
• Ductus (vas) Deferens

  REMEMBER: During ejaculation, thick layers of smooth muscles in its walls create peristaltic waves that squeeze the sperm forward (creates a trajectory)
• The Ductus (vas) deferens: A reference point for birth control

  ● Some men voluntarily take responsibility for birth control by having a vasectomy, where:

  ➔ A small incision is made to the scrotum, then the ductus deferens is cut and tied.

  EFFECT: Sperm no longer leave the body and later die and are phagocytized (male becomes sterile)

  HOWEVER, Testosterone is still produced so the man retains his sex drive and secondary sex characteristics