Final answer:
Spermatogenesis is the process of sperm production that starts at puberty and continues for life, involving continuous division of stem cells called spermatogonia in the seminiferous tubules of the testes.
Step-by-step explanation:
Spermatogenesis Process
Spermatogenesis is the process through which sperm is produced within the seminiferous tubules in the testes. This process is initiated at puberty and continues throughout a man's life, with a production cycle of approximately 64 days to make mature sperm. A decrease in sperm production can occur in later adulthood, but it typically still continues uninterrupted.
Origin of Sperm-Producing Cells
The cells responsible for sperm production are known as spermatogonia, which are diploid stem cells. These stem cells do not run out because they undergo mitosis to make identical copies of themselves before further dividing by meiosis to produce haploid spermatids. Spermatids then mature into sperm capable of fertilization after being transported to and maturing in the epididymis.
How Sperm Production Is Sustained
Sperm production in the seminiferous tubules is maintained by the continuous division of spermatogonia, which are the stem cells of the testis. The stem cells have the ability to perpetually replenish the sperm production line. Testosterone, secreted by Leydig cells, also plays a critical role by maintaining high concentrations necessary for sperm production.