In many ways, the prostate gland is Grand Central Station for the male repro ductive and urinary systems: Both urine and semen must pass through this walnut-size gland, located directly beneath the bladder, before leaving the body. The prostate surrounds the urethra, the passageway for both of these bodily fluids.

Inside the prostate itself are 30 to 50 saclike glands that secrete fluids that make up about 20 percent of semen. The two ejaculatory ducts, which transport the semen and seminal vesicle liquids, converge in the prostate and join with the urethra; there, the prostate fluid is added to the mix. Containing zinc, citric acid, calcium, and more, it gives semen its milky color and helps the sperm survive in the female vagina, primarily by neutralizing the vaginal acids.

The prostate becomes fully developed during puberty, at around age 12 or 13, and remains the same size for the next 30 to 40 years. At that point, more than one in two men experience a midlife growth spurt in their prostate size. This condition, called benign prostatic hypertrophy (BPH), is a nonmalignant enlargement of the prostate. The gland can grow to the size of a plum; in very severe cases, it can become the size of a grapefruit. In most instances, BPH does not have to be treated, but the enlarged prostate may press against the urethra and cause urinary incontinence or difficulty in urination. Prescription medications or a minimally invasive procedure can help alleviate the symptoms.

ADDITIONAL FACTS

  1. Prostate cancer is the most common type of cancer in males.
  2. An Australian study found that men who masturbated more than five times a week during their twenties were one-third less likely to develop aggressive prostate cancer later in life. That’s because frequent ejaculation may prevent carcinogens from building up, say the researchers.