About the Prostate

The prostate is a small, squishy gland about the size of a ping-pong ball. It is important for reproduction, because it supplies the seminal fluid, which mixes with sperm from the testes. Seminal fluid helps the sperm to travel and survive.

The more you know about the prostate and the normal development and function of the prostate, where it’s located, and what it’s attached to, the better you can understand how prostate cancer develops and impacts a man’s life over time—due either to cancer growth or as a result of treatments.


Want more information? Download or order a print copy of the Prostate Cancer Patient Guide.


The prostate sits deep inside the groin, between the base of the penis and the rectum.

The seminal vesicles are rabbit-eared structures that sit on top of the prostate and store and secrete a large portion of the ejaculate.

The neurovascular bundle is a collection of nerves and vessels that run along each side of the prostate, that helps to control erectile function. In some men, they run a short distance away from the prostate, but in others, they attach to the prostate itself. Their precise location doesn’t impact prostate function or contribute to prostate cancer when it occurs.

The bladder is like a balloon that gets larger as it fills with urine. The urethra, a narrow tube that connects to the bladder, runs through the middle of the prostate and along the length of the penis, carrying both urine and semen out of the body. It is the hose that drains the bladder.

The rectum, which sits right behind the prostate, is the lower end of your intestines that connects to the anus.

Ultrasound of the prostate

Ultrasound of the prostate

Prostate Zones

The prostate is divided into several anatomic regions, or zones. Most prostate cancer starts in the peripheral zone (the back of the prostate), near the rectum. That’s why a digital rectal exam (DRE) where a doctor examines the prostate by inserting a gloved finger in the rectum, is a common and useful screening test.

In most cases, lower urinary tract symptoms are not causes by prostate cancer but are due to Benign Prostatic Hypertrophy, (BPH), which is a non-cancerous prostate condition that typically develops from the transition zone that surrounds the urethra, or urinary tube (closer to the middle of the prostate). Difficulty with urination is more typically caused by BPH than by prostate cancer.


Keep on top of the latest news about prostate health. Sign up for news alerts.


What does the prostate do?

TThe prostate is not essential for life, but it is important for reproduction. The fluids made by the prostate and seminal vesicles mix with the sperm to create semen. Healthy semen is the perfect consistency and environment for sperm transit, survival, and for fertilization. These fluids include enzymes like PSA (which is often measured as part of screening for prostate cancer),
Other substances made by the seminal vesicles and prostate—such as zinc, citrate, and fructose—which actually give sperm energy to make this the journey to the egg. Semen also contains substances like antibodies that may protect the urinary tract and sperm from bacteria and other pathogens.

The prostate typically grows during adolescence, under the control of the male hormone testosterone and its byproduct dihydrotestosterone (DHT), or dihydrotestosterone trigger the prostate to grow. Testosterone is primarily made in the testes, but a smaller amount it is also made in the adrenal glands above your kidneys.

Learn More

  • What is Prostate Cancer?

    The term “cancer” refers to a condition in which cells accumulate uncontrollably—the ability to regulate cell growth or death is lost. So instead of dying...

  • Why Genes Matter

    Janet Farrar Worthington

    Revolution.  It’s a shame that we tend to use that word so freely—to describe, say, a new style of men’s briefs, or a hand-crafted microbrew,...