Picture of Prostate Gland
The prostate gland is part of the male reproductive system. It is a walnut-sized organ that lies below the bladder. It surrounds the top portion of the urethra. The prostate produces fluid that together with sperm forms semen. Semen is released through the urethra during ejaculation.
Text Reference: "What I Need to Know about Prostate Problems." National Kidney and Urologic Diseases Information Clearinghouse.