Look at Figure 7.14. The size of your clenched fist, your heart is located i the chest cavity between your lungs. It lies directly behind the sternum (commonly known as the breastbone) to which the ribs are connected. The pointed end or apex of the heart which points downward, forward and to the left, rests on the diaphragm the base of the chest cavity.The broader top of the heart is turned upward, backward and to right. A vertical section through the heart would reveal its four chambers (as shown in Figure 7.15 (b)