The heart is situated inside the thorax in vertebrates and in the human body is slightly to the left. The human heart consists of 4 main chambers, 2 atria and 2 ventricles. The right side of the heart receives blood from the body and pumps it to the lungs where it is oxygenated and returns to the left side of the heart. The left side of the heart pumps the oxygen-carrying blood to the rest of the body. A heartbeat is a single pumping cycle of the heart which comprises three major stages: atrial systole, ventricular systole and complete cardiac diastole.
It is the universal symbol of love and the heart is also called a Valentine.
- http://www.bible.org/page.php?page_id=858.# The seat of Sin, the heart