Spermatogonia are diploid undifferentiated male germ cells located in the seminiferous tubules of the testes. Spermatogonia are important in the process of spermatogenesis; they turn into primary spermatocytes via growth and maturation.

Mature sperm cells that are haploid, motile, and produced during spermatogenesis are called spermatozoa. Spermatids are haploid; however, they are immature. Spermatids will turn into spermatozoa once they mature.

Spermatozoa are stored in the epididymis prior to ejaculation. Prior to entering the epididymis, spermatozoa are immotile; however, as they travel through the epididymis the cells mature and gain motility.

Spermiogenesis is the final stage of spermatogenesis. In the process of spermiogenesis, spermatids develop into spermatozoa and form axoneme—the internal structure of the spermatozoa tails. It develops by way of microtubule growth from a single centriole that constructs the internal structure of the sperm tail. Mature spermatozoa have axonemes comprised of nine outer microtubule doublets and two central microtubules. These structures aid in motility.

Spermiogenesis is the final stage of spermatogenesis. In mature spermatozoa, the acrosome is the head of the cell and, in humans, contains digestive enzymes for ovum penetration. The acrosome develops during spermiogenesis when the Golgi apparatus surrounds the nucleus. 

Mitochondria cluster around the axoneme during spermiogenesis. They supply the energy needed for sperm movement, which is achieved through movement of the flagellum.

There is a high concentration of testosterone within the seminiferous tubules. The secretion of androgen-binding protein by Sertoli cells concentrates testosterone around cells undergoing spermiogenesis, The testosterone aids in the process of sperm maturation by removing excess organelles from the developing spermatozoa. 

The seminiferous tubules and developing spermatozoa within them are temperature-sensitive; they cannot tolerate high temperatures—including the temperature of the human body. In order to manage this, the testes are located outside of the human body in a sac of skin called the scrotum. This lowers the temperature of the seminiferous tubules to optimal levels. 

Spermatogenesis—the formation of spermatozoa—occurs in the seminiferous tubules of the testes. Seminiferous tubules are composed of Sertoli cells and spermatogenic cells. There is a high concentration of testosterone present in these tubules. High testosterone concentrations support sperm development. The epididymis is the site of sperm maturation. Last, the seminal vesicles are small glands that produce the majority of the seminal fluid. 

Sertoli cells are located in the seminiferous tubules and aid in spermiogenesis. There are many ways that Sertoli cells facilitate the process of sperm maturation including the following: the contribution of testicular fluid, phagocytosis of excess cytoplasm, and the protection of sperm from the immune system. Leydig cells—interstitial cells—are responsible for secretion of testosterone.