Meiosis takes place in the testes, which are located in the scrotum. Sperm move from the testis to the epididymis, where they mature. Upon ejaculation, the sperm move through the ductus deferens and then to the urethra. The seminal vesicles, prostate gland, and bulbourethral gland add fluids to the sperm to form semen. The testes also produce testosterone, the male sex hormone. The testes, found in the scrotum, are located outside the body cavity. If the testes are retained within the body cavity (a condition known as cryptorchidism), sperm production, but not testosterone production, will either cease or be greatly decreased, it is too warm in the pelvic cavity for sperm to be produced.