The prostate is a walnut-shaped gland in the male reproductive system that is located beneath the bladder and in front of the rectum. It surrounds the upper part of the urethra, which is the tube that carries urine from the bladder.
The size of the prostate varies with age. As a man ages, the prostate can grow larger.
The prostate has several important functions:
- Helps control urine flow, semen, and seminal fluid
- Essential for erections
- Produces seminal fluid to carry and nourish sperm
- Contains nerves needed to achieve an erection
- Provides the push sperm need to swim their way out of the penis
- Produces prostate specific antigen
The prostate is divided into lobes and zones. There are four lobes: anterior, median, lateral, and posterior. There are three zones: peripheral, central, and transitional. These terms refer to specific areas of the prostate to help the physician know where the cancer is located in the prostate.
Prostate Specific Antigen (PSA) is a substance produced by the prostate gland. It keeps semen in liquid form so sperm can swim. It is present in the bloodstream, and the level is a valuable piece of information in understanding a man’s prostate cancer risk, along with the digital rectal exam and other tests.
The level of PSA in a man’s blood can be a marker of many different prostate conditions, not only prostate cancer. The most frequent benign (non-cancerous) conditions that cause an elevation in PSA are the following:
- Prostatitis – inflammation of the prostate
- Benign Prostatic Hyperplasia (BHP) – enlargement of the prostate