Testicles are the male reproductive organs responsible for producing sperm and hormones, particularly testosterone. They are typically oval-shaped and located in a pouch of skin called the scrotum, which hangs outside the body. This external position helps regulate temperature, as sperm production requires a cooler environment than the body's core temperature. Each testicle contains tiny tubes called seminiferous tubules, where sperm cells are formed. Once produced, sperm travel through a series of ducts to the epididymis, where they mature and are stored until ejaculation. The health and function of the testicles are essential for male fertility and overall hormonal balance.