Structure of testes and accessory ducts
Male reproductive system · Biology
Study notes
A vasectomy cuts the vas deferens — sperm can't reach the semen, but testosterone and ejaculation continue normally, which is why it's such reliable contraception. Undescended testes (cryptorchidism) in a newborn boy need correction — inside the warm abdomen, sperm production fails; the cooler scrotum (2–3°C lower) is essential for fertility.