The epididymis is an elongated structure on the posterior surface of the testis. Efferent ductules of the testis transport newly developed sperms to the epididymis from the rete testis. The epididymis is formed by minute convolutions of the duct of the epididymis, so tightly compacted that they appear solid. The duct becomes progressively smaller as it passes from the head of the epididymis on the superior part of the testis to its tail. At the tail of the epididymis, the ductus deferens begins as the continuation of the epididymal duct. In the lengthy course of this duct, the sperms are stored and continue to mature.

The epididymis consists of the:
• Head of the epididymis: the superior expanded part that is composed of lobules formed by the coiled ends of 12-14 efferent ductules.
• Body of the epididymis: major part consisting of the tightly convoluted duct of the epididymis.
• Tail of the epididymis: tapering continuation with the ductus deferens, the duct that transports the sperms from the epididymis to the ejaculatory duct for expulsion via the urethra during ejaculation.