What is the prostate? The prostate is a small gland that only men have. It is normally about the size of a walnut. The prostate is located underneath the bladder and in front of the rectum. Because the prostate is close to the rectum, it can be felt by a doctor during a digital rectal exam (the part of a routine physical exam where the doctor inserts a gloved, lubricated finger into a man's anus). The prostate makes and stores fluid that is part of semen, and this fluid is released from a man's penis during ejaculation. The prostate is signaled to do its job by the male hormone testosterone, which can influence the behavior of the prostate gland and prostate cancer. Nerves to the penis, which are important in producing and maintaining an erection, run very close to the prostate. The prostate completely encircles the tube that carriers urine from the bladder to the penis, called the ... read more on Prostate Cancer: The Basics