Male reproductive system. Remaining dormant until puberty, the male reproductive system is intended to produce and deliver the male gamete, sperm, to the female to enable fertilization. The male gonads, the testes, serve two functions: to manufacture motile sperm and to produce male sex hormones. The accessory ducts, including the epididymis, ductus deferens and urethra, serve to aid in the delivery of sperm from its production site to the exterior of the body. The accessory glands, the prostate, seminal vesicles, and bulbourethral glands serve to produce semen, which is composed of proteins which facilitate the motility of sperm.