The fundamental building block of male fertility is the sperm cell. Often thought of as a “lean, mean racing machine,” sperm cells are essentially concentrated packets of genetic material (DNA) with a propeller designed to get them to the egg. The mature sperm cell, however, is an endpoint. It takes almost 2.5 months of timed development to produce a single sperm cell.
Sperm are initially formed in small microscopic tubes within the testicle called seminiferous tubules. As an organ, the testicle is designed to produce two things: sperm and testosterone or “T” (the male sex hormone). Hence, the cell population inside the testicle is composed of three basic types of cells:
- Germ cells – “sperm producing” cells
- Sertoli cells – “nursing cells” that foster the growth and development of immature/early stage sperm
- Leydig cells – “testosterone producing” cells
The primary impulse for the testicle to produce both testosterone and sperm actually originates from the brain, and specifically the pituitary gland. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are released from the pituitary into the blood and trigger sperm and testosterone development, respectively. Testosterone is immediately released into the blood and is readily available for use.
Once sperm cells are made, they begin the long process of maturation, which takes, on average, 72 days to complete. This concept plays a central role in defining therapy for men with fertility issues. The fact that men produce millions of new sperm every day makes it highly beneficial to men who want to alter their lifestyle habits. Knowing that sperm take about 72 days to mature, men who do make lifestyle changes only need to wait about 3 months before seeing improvements in sperm quality and increasing your chance for reproductive success.
The maturation process for sperm continues as they wind their way through the seminiferous tubules and into a slender, worm-like appendage outside the testicle called the epididymis. This gland, in turn, becomes the vas deferens, and sperm is carried out to the scrotum, up through the groin, into the pelvis, and ultimately into the prostate gland.
The prostate gland and seminal vesicles produce the fluid released during orgasm and ejaculation called semen.