ABSTRACT
Spermatogenesis as well as the synthesis of testosterone in the human testis is a lifelong process that also persists in aging men. However, spermatogenic efficiency estimated by the number of spermatozoa produced per day per gram of testicular parenchyma (spermatogenic index) apparently declines with age. This decline is a result of an increase in germ cell degeneration throughout spermatogenesis as seen in all cell types of the germ cell line.
