Reproductive physiology

The production of sperm is a very complicated process that begins at puberty and lasts, in healthy males, until death. The production of sperm begins in the testicles and is controlled by several hormones. These hormones are regulated by the hypothalamus and the pituitary gland located in the brain.

Sperm production

The hypothalamus regulates the hormonal activity of the pituitary gland by secreting gonadotropin-releasing hormone (GnRH). This hormone controls the production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary. LH triggers the production of testosterone, a hormone needed for sperm production. FSH also triggers hormones that help with sperm production.

From beginning to end, sperm production takes about 72 days. Sperm spend the first 50 days in the testicles, and the last 22 to 24 days in the epididymis. It is in the epididymis that sperm mature and gain motility (the ability to swim). During sexual activity, motile sperm are ejaculated into the female reproductive tract and begin their journey to the fallopian tubes, the site of fertilization.