Once sperm cells can be produced in the testis and accumulate in the epididymis, they rely on the ductus deferens and ejaculatory duct to propel them into the urethra and out of the penis during ejaculation. The ejaculatory duct will deliver the sperm into the urethra by adding the additives and secretions from the prostate required for the sperm function while providing an interface between the urinary and reproductive systems in men.