The prostate is a small gland in a man’s genital area, sitting between the bladder and the rectum. It surrounds part of a tube called the urethra that runs from the bladder to the penis. The urethra carries urine but also semen.
The prostate itself is about the size and shape of a walnut. Its main purpose is to produce semen, the fluid that carries sperm. Semen is produced in the prostate and stored there until needed. When a man is about to ejaculate, semen is released into the urethra and sperm is released into it from the testicles. The two mix and then this ejaculate is released out through the urethra for the orgasm to happen.