The male reproductive system is responsible for generating, storing, and transporting the genetic material contained  in the sperm cells.  The main organs include: testicles (or testes),  the epididymides, the vas deferens, the ejaculatory duct, the urethra, and the penis.  Others are the scrotum, urogenital opening, and the prostate gland.  Testes contain two oval shaped glands about one and a half inches long and one inch wide.  The testes are suspended in a sac called the scrotum outside the body to maintain the lower temperature necessary for efficient sperm production.  The epididmyis are long oval shaped structures attached to the rear upper surface of each testicle, consisting mainly of the sperm ducts of the testes.  The ejaculatory duct is a short tubule located just above the prostate gland.  It is formed by the connection on the vas deferens and the seminal vesicles, and serves to transport spermatozoa through the prostate gland and into the urethra.