  the ejaculatory ducts (ductus ejaculatorii) are paired structures in male anatomy. each ejaculatory duct is formed by the union of the vas deferens with the duct of the seminal vesicle. they pass through the prostate, and open into the urethra at the colliculus seminalis. during ejaculation, semen passes through the prostate gland, enters the urethra and exits the body via the tip of the penis. ==structure==  ==function== ===ejaculation===  thumb|right|325px|dissection of prostate showing ejaculatory ducts opening into the prostatic urethra. ejaculation occurs in two stages, the emission stage and the expulsion stage.rathus, s. a., nevid, j. s., fichner-rathus, l., herold, e. s. (2010). human sexuality in a world of diversity. pearsons education canada, pearson canada inc. toronto, on. the emission stage involves the workings of several structures of the ejaculatory duct; contractions of the prostate gland, the seminal vesicles, the bulbourethral gland and the vas deferens push fluids into the prostatic urethra. the semen is trapped here and it is at this point that males perceive to be the point of no return for orgasm. this may be more commonly known as a male feeling as though he is "about to come". this stage is followed by the expulsion stage. muscles at the base of the penis contract in order to propel the seminal fluid trapped in the prostatic urethra through the penile urethra and expel it through the tip of the penis. the ejaculate is expelled in spurts, due to the movement of the muscles propelling it. these muscle contractions are related to the sensations of orgasm for the male. sperm is produced in the testes and enters the ejaculatory ducts via the vas deferens. as it passes by the seminal vesicles, a fluid rich in fructose combines with sperm. this addition nourishes the sperm in order to keep it active and motile.esmail, s. (2010). hecol 211 human sexuality lecture manual 2010. department of human ecology, university of alberta, edmonton, ab. seminal fluid continues down the ejaculatory duct into the prostate gland, where an alkaline prostatic fluid is added. this addition provides the texture and odor associated with semen. the alkalinity of the prostat
Andrology Mammal_male_reproductive_system Penis