PBS
Pbs Nova Online: Amazing Heart Facts
This concise PBS NOVA site contains interesting facts about the heart and how it works.
Science Museum of Minnesota
Lesson Plan: Lub Dub (Valves)
In this concise site, students investigate the source of the sounds of the heart. Contains related connecting links.
Science Museum of Minnesota
Lesson Plan Site: Sounds of the Heart
In this site, students investigate the sounds of the heart, construct a stethoscope, and investigate the workings of valves.