Hi Ben,
I think that the structure that you are referring to is the epididymis which carries sperm away from the testicles. You can find more information about a self exam at the following website [url="http://tcrc.acor.org/tcexam.html."]http://tcrc.acor.org/tcexam.html.[/url] In addition, don't be afraid to schedule a routine physical with your family doctor. It's Worth the peace of mind.
Dave