Sperm is produced in the testicles under the impact of hormones FSH and LH. FSH triggers the production of sperm and LH triggers the production of testosterone, a hormone that is necessary for the development of male characteristics and the production of sperm.

A three-month period is needed for the spermatogenesis.

Male gametes (spermatozoa) are deriving from immature sperm cells called spermatids. There appear to be many intermediate stages from the initial cell to the final mature spermatozoon. Sperm is transferred to the epididymis that is used for sperm storage. From there, sperm is transferred to the urethra for ejaculation.

From the millions of spermatozoa in a sample of sperm, only one will manage to fertilize the mature oocyte for pregnancy to develop.