The prostate gland is a part of the male reproductive system. This small gland is approximately the size of a walnut and is located deep inside the pelvis below the urinary bladder and above the muscles of the pelvic floor. The prostate gland plays an important role in reproduction by contributing prostatic fluid into the semen, giving the semen its fluidity. The seminal fluid in turn helps in the survival and mobility of the sperm. The prostate gland is also important for the conversion of the male sex hormone testosterone to its biologically active form.