This 3D animation shows sperm production and ejaculation in the male reproductive system. The animation begins with a view of the male genitalia, then zooms in to the testicles to highlight the seminiferous tubules inside. A microscopic view inside a seminiferous tubule reveals the sperm cells developing as they move from the outer edge of the tubule into its central passageway. The view changes to show the male reproductive system again, highlighting the path of the sperm from the testes through the epididymis and vas deferens, where the seminal vesicles and prostate gland add fluid to the sperm. Finally, the sperm, now in a fluid called semen, pass out of the body through the urethra.