The Heart blood flow

http://www.youtube.com/watch?v=q0s-1MC1hcE&feature=related

http://www.youtube.com/watch?v=VfQGSw5bL7w&feature=related

http://www.youtube.com/watch?v=hCp4hVC2fnM&feature=related

http://www.youtube.com/watch?v=D3ZDJgFDdk0&feature=related

http://www.youtube.com/watch?v=_5bC8eeVaYI&feature=related
http://www.youtube.com/watch?v=j8Nrjre2FPM&feature=related
http://www.youtube.com/watch?v=2q7t1dpLXa0&feature=related