The prostate is a muscular, walnut-sized gland that surrounds part of the urethra, the tube that transports urine and sperm out of the body. A gland is a group of cells that secretes chemicals that act on or control the activity of other cells or organs.
The prostate is part of the male reproductive system. Its main job is to make seminal fluid, the milky substance that transports sperm.
Sperm is produced in the testicles, which also make the male hormone testosterone. Testosterone stimulates the growth and function of the prostate during puberty.
During sexual climax (orgasm), the muscles of the prostate contract to push semen through the urethra and out the penis. The urethra also carries urine, a waste product made by the kidneys and stored in the bladder. When the penis is erect during sexual intercourse, the flow of urine is blocked from the urethra, allowing only semen to be ejaculated at orgasm.
Where Is the Prostate Located?
The prostate is located directly beneath the bladder and in front of the rectum. Because the first portion of the urethra passes through the prostate, the passage of urine or semen through the urethra can be obstructed if the gland becomes enlarged.
What Is Prostate Cancer?
Prostate cancer is the most common cancer, excluding skin cancers, in American men. It is a malignant tumor of the prostate. In most men, the cancer grows very slowly. In fact, many men with the disease will never know they have the condition. Early prostate cancer is confined to the prostate gland itself. The majority of patients with this type of cancer can live for years with no problems.
Prostate cancer is characterized by both "grade" and "stage." The grade is given to indicate how the cancer cells look under the microscope when a biopsy is analyzed. The grade often predicts how quickly a cancer is growing and will spread -- the higher the grade, the more likely it is that the cancer will grow and spread rapidly. The size and extent of the tumor when first detected determine its stage.