1.7 D Internal Anatomy Teenage Boys :

The system is designed to produce, store, and transport sperm cells. The testicles / testes contain chambers / tubules, where sperm is produced. The testicles also produce the hormone TESTOSTERONE that causes most of the changes in males during puberty.

The EPIDIDYMIS, a storage compartment composed of tiny tubes, lies behind and is attached to each testicle. These tubes store the sperm cells while they mature. Each testicle connects to a tube called the VAS DEFERENS or sperm duct. The mature sperm move toward the main part of the body through the vas deferens. The tube widens; at which point it is called the AMPULLA. Sperm cells are stored in the ampulla until ejaculation. At the end of the ampulla are two small sacs called SEMINAL VESICLES. These vesicles contribute to the production of semen, a white sticky fluid that carries and nourishes the sperm.

From here, the fluid and sperm cells flow into the ejaculatory ducts that connect the seminal vesicles with the opening of the urethra in the PROSTATE GLAND. The prostate gland adds more fluid to the production of semen. The semen carries the sperm through the urethra. The urethra is a tube in the center of the penis, sheltered by soft tissue. The semen and sperm are then released from the urinary opening during ejaculation. During ejaculation, a small valve between the bladder and the urethra closes, preventing urination.