The heart is such a wonderful organ that keeps the entire body alive. It has four chambers: two atria receiving blood and two ventricles pumping it to the lungs and the rest of the body.
The atria and ventricles are formed by cardiac muscles. The muscles contract at about the same time in order to maximize the power of each pump. They are like the switch and wiring network of a lighting system.
Read the full story here.– EJinsight