Atrophied seminiferous tubules. Light micrograph of atrophied (shrunk) seminiferous tubules (oval, seen in cross-section) from the testis of a 94-year-old man. The seminiferous tubules are the site of sperm production (spermatogenesis). In the central region of each tubule are spermatozoa, formed from gametes undergoing initial meiosis and later spermiogenesis (development into sperm cells). Here, the seminiferous tubules are atrophied (shrunk), fibrous tissue has formed between the tubules, and almost no sperm cells are being produced.