Sperm are stored and then mature in the epididymis until ejaculation where they are delivered to the urethra via the vas deferens. Ejaculation ejects both sperm and semen. Semen is a complex mixture of fluids and molecules that supports sperm and facilitates fertilization and is produced by the seminal vesicles, prostate gland, and bulbourethral gland. What are the parts of a sperm? The sperm has a head with a nucleus and a cap (the acrosome). The acrosome contains enzymes that enable the sperm to digest a path into the egg. The sperm also has one flagellum (that is powered by numerous nearby mitochondria) for motility. What hormones are involved in human male reproduction?