Sperm maturing in testis. Transmission electron micrograph (TEM) of a section through a seminiferous tubule in a human testis. The tissue shows stages of sperm cell development. Spermatogonia (immature sperm cells, across bottom) rest on the basement membrane, with an irregularly-shaped nucleus of a Sertoli cell (lower centre). The Sertoli cell includes lipid fat droplets (white). Most of the epithelium consists of large primary spermatocytes (round). Near the tubule lumen (upper right) are five elongating spermatids, each showing a dense acrosomal cap (white). Magnification: x1000 when printed at 10 centimetres tall.
Model release not required. Property release not required.