DUCTS
When ejaculation occurs during sexual intercourse, the sperm enter the vasa deferentia (plural of vas deferens), or sperm ducts. The sperm travel through the vasa deferentia until they reach the ejaculatory duct in the prostate gland. From the ejaculatory duct, the sperm enter the urethra, which shares the function of transporting urine from the kidneys and urinary bladder. However, a valve prevents urine from entering the urethra when the penis is erect. The urethra transports the sperm through the shaft of the penis, until the sperm exit the male body from the external opening of the penis.