Dictionary: Spermatogenesis

Our bodies are constantly replacing old cells with new cells through the process of mitosis. But how does the human body develop our sex cells? This process is done through meiosis. In males, the production of sperm is known as spermatogenesis and the production of eggs is known as oogenesis. In spermatogenesis, the gametes produced by the male are known as spermatozoa or sperm. In oogenesis, females produce ova, or eggs.
Spermatogenesis begins at puberty and occurs within the testes. Within the testes are seminiferous tubules. The walls of the seminiferous tubules are filled with cells called Sertoli cells. Sertoli cells provide nutrients and protection for the developing sperm. In between the seminiferous tubules are Leydig cells. Leydig cells are responsible for the hormone productino of testosterone. There are five steps that are needed for the developing sperm to turn into mature sperm. The first stage is known as the spermatogonium which happens within the outer region of the seminiferous tubules. The spermatogonium is where the cells replicate DNA in the S phase of meiosis. Next the primary spermatocyte is produced through Meiosis I. The secondary spermatocyte is produced through Meiosis II. As the developing sperm get closer to the lumen, the spermatid is formed. Lastly, the spermatozoan is formed and heads out the lumen (inner region of the seminiferous tubules) and through the epididymis.