where sperm are made
Semen is made up of sperm (male cells for sexual reproduction) floating in a fluid called seminal plasma. Sperm, also called spermatozoa, are made by a man's testicles and mature (grow up) in the epididymis. The fluids in seminal plasma come from different glands in the man's body: the seminal vesicles, prostate and bulbourethral glands (also called the Cowper's glands).