Spermatogenesis

This is magnified image of the germinal epithelium. The epithelium rests on a basement membrane and surrounds a lumen where sprematozoa are released. Identify the spermatogonia, located in the basal compartments of both membranes. These cells appear round and pale, with prominent nucleoli. Sertoli cells, with their characteristic oval-shaped nuclei, are also visible. These provide support to the developing primary spermatocytes, which have large, granulated nuclei that are preparing for the first meiotic division. Secondary spermatocytes, which contain 23 pairs of chromatids, are rarely visible. The products of meiosis are the haploid spermatids, which contain dark, round nuclei and a decreasing amount of cytoplasm. These differentiate further into spermatozoa. Remember that cytokinesis is incomplete during these steps, and cytoplasmic bridges connect the cells and allow for their synchronous development.