Someone just reminded m of this site, that is a kind of simple way to understand how the heart works by comparing it to a house. I know it is probably too simple for some, but thought it might help others in understanding the heart or explaining to friends and family.
http://www.childrenheartinstitute.org/educate/heartwrk/hearthse.htm
http://www.childrenheartinstitute.org/educate/heartwrk/hearthse.htm
