how do heart works?

Answer 1

Any of the sites below should have the answers you are looking for :-)

http://www.howstuffworks.com/heart.htm

http://www.advocatehealth.com/system/info/library/articles/heartcare/howorks.html

http://www.childrenheartinstitute.org/educate/heartwrk/hearthse.htm

http://www.americanheart.org/presenter.jhtml?identifier=1557

Answer 2

It's a muscle, and it creates it's own contraction signals with the sa node.

Answer 3

They make you fall in love then they get crushed like a grape!