Image: testis of a mouse stained with hematoxylin and eosin.
Seminiferous tubule: they are ducts with walls made up of germ cells and Sertoli cells, and limited by a very thin outer layer of myoepithelial cells. Sperm cells are produced in the seminiferous tubules.
Spermatogonia: they are a pool of undifferentiated and poorly differentiated germ cells that proliferate, and finally undergo meiosis. The process is known as spermatogenesis.
Primary spermatocyte: it is the cell type that begins meiosis I.
Secondary spermatocyte: it is the cell type undegoing meiosis II.
Spaermatid: it is the haploid cell inmediatly after miosis.
Sperm cell: or male gamete. It is the mature sperm cell that results of the spermatid maturation (spermiogenesis).
Sertoli cell: it is a type of somatic cell found among the germ cells, in the walls of the seminiferous tubules. Sertoli cells provide support to germ cells and coordinate the waves of gametogenesis. They also release hormones.
Leydig cell: or interstitial cells. They are found outside the seminiferous tubules and release hormones.
Tunica albuginea: it is a coat of connective tissue that covers the outer surface of the testis.