Hank begins a series of videos on organ systems with a look at the nervous system and all of the things that it is responsible for in the body. Crash Course Biology is now available on DVD! http://dft.ba/-8bCC Like CrashCourse on Facebook: http://www.facebook.com/YouTubeCrashCourse Follow CrashCourse on Twitter: http://www.twitter.com/TheCrashCourse References for this episode can be found in the Google document here: http://dft.ba/-3a36 Support CrashCourse on Subbable: http://subbable.com/