Overview
Once sperm cells are produced in the testis and accumulate in the epididymis, they rely on the ductus (vas) deferens and ejaculatory duct to propel them into the urethra and out of the penis during ejaculation. The ejaculatory duct delivers sperm into the urethra, adding secretions and additives from the prostate necessary for sperm function, while providing an interface between the reproductive and urinary systems in men (see image below).
Male ductal anatomy.