Testicle

• The testicles are in the abdominal cavity of roosters.
• They are surrounded by a capsule of connective tissue, the tunica albuginea, that is covered by a peritoneum.
• There is no developed septum dividing the testicles into lobules.
• The epithelial cells of the retorted seminiferous tubules are similar to that of mammals: Sertoli cells, spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoids.
• Unlike mammals, various cellular associations do not occur in segments along the seminiferous tubules. Instead, the seminiferous epithelium is arranged in narrow columns of cells that suffer independent spermatogenesis.
• There is very little connective tissue between the adjacent seminiferous tubules, and the interstitial cells are sparse. They appear alone or in small groups, primarily in larger interstitial spaces.

Seminiferous Tubules

• They are continuous to the straight tubules that are lined by Sertoli cells.
• The straight tubules lead to the anastomosing canals of the testicular network that is lined by simple cuboidal to squamous epithelium.
• The testicular network is placed outside the tunica albuginea, below the epididymis.

Epididymis

• There are three kinds of tubules inside the epididymis: the efferent ductules, the connecting ducts and the epididymal duct.
• The numerous retorted efferent ductules join the testicular network to the connecting ducts. They are lined by simple epithelium with intermittent groups of tall and low columnar cells as well as portions that seem pseudostratified.
• The epithelial cells are arranged in folds, and many of these cells have tufts of cilia.
• The connecting duct (excreting canals) has a smaller diameter than the epididymal tubules and is lined by a pseudostratified columnar epithelium.

Ductus Deferens

• At the end portion of the epididymis, the epididymal duct joins the ductus deferens (vas deferens).
• The latter is a retorted duct with a pseudostratified columnar epithelium, subjacent smooth muscle and a more peripheral layer of dense connective tissue.
• Each ductus deferens joins a small and conic ejaculating duct, whose submucosa contains erectile tissue.
• The ejaculating duct protrudes and opens in the urodeum of the cloaca, marking the end of the male ductal system.