Structure of The Testes

Each testis is enclosed by a tough, white fibrous capsule along the back border of which the connective tissues thicken and extend into the organ, forming a mass, called the "mediastinum testis." From this structure, thin dividers of connective tissue, called "septa," pass into the testis and divide it into about 250 "lobules." A lobule contains one to four highly coiled "seminiferous tubules," each of which is up to 70 cm long when uncoiled. These tubules course around the back and become united into a complex network of channels called the "rete testis." The rete testis is located within the mediastinum testis and gives rise to several ducts that join a tube called the epididymis. The epididymis is coiled around the outer surface of the testis. The seminiferous tubules are lined with a specialized stratified tissue, called "germinal epithelium, which functions to produce the male sex cells.