Spermatogenic tubules are composed of germ cells and Sertoli cells (Fig. 11.3). Tight junctions between the Sertoli cells form a diffusion barrier that divides the testis into two functional compartments. The basal compartment consists of Leydig cells and the outer portion of the tubules that contain the spermatogonia. The adluminal compartment contains the inner two-thirds of the tubules and includes primary and secondary spermatocytes and spermatids. The Sertoli cell lines the spermatogenic tubule, and the inner portion of the Sertoli cell consists of an arborised cytoplasm so that spermatogenesis takes place within a network of Sertoli cell cytoplasm.
