To better understand epididymitis, it helps to understand the anatomy of the testicles.

The epididymis is a long, soft, coiled tube that lies on the top of each testicle inside the scrotum. The testicles make sperm, and then the sperm pass through the epididymis as they mature. After passing through the epididymis, the sperm enter the vas deferens. The vas deferens is another tube that stores the sperm. During ejaculation, the sperm are ejected from the vas deferens, through the penis.

Anatomy images:

• Testicle
• Scrotum