Where Is Your Prostate and What Does It Do?
Last Revised August 24, 1995
Only males have prostates, so only men can get cancer of the prostate. That's the good news for
women! The prostate is an important part of a man's "urogenital" system, and proper functioning of
the prostate is important to proper bladder control and normal sexual function.
Where is your prostate?
A man's prostate gland is a solid organ found immediately below his bladder (see Figure 1), and it
surrounds the "urethra" -- which is the tube connecting the bladder and the penis through which a man
urinates. The other important parts of the male urogenital system are the seminal vesicles and the
Figure 1. The male urogenital system, showing the prostate
immediately below the bladder and surrounding the urethra.
The normal prostate in a young adult man is about the size of a walnut. However, its size can change
over time, and in many men the prostate gets larger as we get older, particularly once a man gets over
the age of 40 or 50 years. This can affect the ability to urinate.
You can obviously see or feel your penis and your testicles. However, it is impossible to see your
prostate and extremely difficult to feel it. Your doctor can feel some parts of your prostate by
inserting his gloved finger into your rectum. This procedure is called a digital rectal examination or
DRE and can be important in trying to diagnose prostate
cancer and other prostatic diseases.
What does your prostate do?
Your prostate has two important functions: one is to help control urination and the other is to help
The prostate has a so-called passive role in the process of urination. It helps to control the rate at
which urine flows out of the bladder and into the urethra. It does this by the effect of muscle fibers in
the prostate that surround the urethra.
The prostate also has an active role in sexual activity. The prostate gland makes a whitish glandular
secretion which collects within the prostate and is fed into the urethra during ejaculation. This
glandular secretion helps the motility of the sperm in the urethra and makes up about a third of the
seminal fluid, thus giving seminal fluid its whitish appearance.
Control of the prostate
The growth of the prostate and control over how it works are fundamentally based on the levels of the
male sex hormone testosterone, which is produced by the testes. The production of testosterone is
itself controlled by another complex set of hormonal interactions.