The simple anatomy of the ductal system consists of a testis where the sperm is produced and then transported to the epididymis.

The epididymis is adherent to the testis, and consists of a single tubule approximately 30 cm in length coiled within a tough outer covering. The epididymis is responsible for the maturation and transport of the sperm. The epididymis at its tail connects to the vas deferens.

The vas deferens then connects to the seminal vesicle, where together they form the common ejaculatory duct that empties into the prostatic urethra.

An obstruction can occur at any point along this path.