Spermatogenesis and aging in the human.
D000375:Aging / Q000502:physiology*; D000818:Animals; D006801:Humans; D007985:Leydig Cells / Q000502:physiology; D008297:Male; D012708:Sertoli Cells / Q000502:physiology; D013079:Sperm Maturation; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology / Q000648:ultrastructure