The prostate gland does not produce sperm. Instead, it plays a supportive role in male reproduction by contributing fluids that nourish and protect sperm. This article explains the prostate’s function, where sperm are made, and how these components combine to form semen.
What the Prostate Gland Does
The prostate is a walnut-sized gland located below the bladder and in front of the rectum, surrounding the urethra. It produces prostatic fluid, a substance that makes up about 25% to 30% of the total semen volume. This fluid contains enzymes, citric acid, and zinc, important for sperm survival and function.
One enzyme in prostatic fluid is prostate-specific antigen (PSA). After ejaculation, PSA helps thin the semen, allowing sperm to move more easily and increasing their chances of reaching and fertilizing an egg. Prostatic fluid also neutralizes the acidic environment of the vagina, which can be harmful to sperm. During ejaculation, the prostate contracts to forcefully push prostatic fluid into the urethra, contributing to semen expulsion.
Where Sperm are Made
Sperm are produced in the testes, located in the scrotum. This continuous process, called spermatogenesis, begins around puberty and continues throughout a man’s life. Within each testis are tiny, coiled tubes called seminiferous tubules, where germ cells develop into immature sperm cells.
After their initial formation in the seminiferous tubules, these developing sperm move to the epididymis. The epididymis is a long, coiled tube located on the back of each testicle. Here, sperm undergo further maturation and are stored until ejaculation. The entire process, from germ cell to mature sperm, takes approximately 64 to 70 days.
How Semen is Formed
Semen is a fluid composed of sperm and secretions from several glands in the male reproductive system. While sperm originate in the testes and mature in the epididymis, they combine with fluids from other accessory glands to form the final ejaculatory fluid.
Upon ejaculation, mature sperm travel from the epididymis through the vas deferens. They then mix with fluid from the seminal vesicles, two sac-like glands located behind the bladder. Seminal vesicle fluid makes up the largest portion of semen, 65% to 75%, and is rich in fructose, providing energy for sperm motility. Prostatic fluid is added as the mixture passes through the prostate gland. Finally, secretions from the bulbourethral glands also contribute a small amount to the semen, all of which mix together in the urethra before expulsion.