cross section of male testis

circle organ lighting design pattern yellow art orange light petal brown ceiling eye glass flower symmetry physiology medical exam occupation medicine close-up abstract human internal penis men cross epididymis testis biology body anatomy healthcare science magnification microscope slide spermatogenesis sperm ductus deferens spermatogonia technology research biological cell laboratory equipment sex reproduction fertility stage cross-section male testes compound objective x40 sperm sperms anatomy man male boy medical view physiology anatomical gamete reproduction human man