The human heart is a cone shape, hollow, muscular organ located in the mediastinum between the lungs. It is a about the size of an adult fist. The heart rests on the diaphragm, tilting forward and to the left in the client’s chest. Each beat of the heart pumps about 60ml of blood, or 5L/min. During strenuous physical activity, the heart can double the amount of blood pumped to meet the increased oxygen needs of the peripheral tissues.
The heart muscle receives blood to meet its metabolic needs through the coronary arterial system. The coronary arteries originate from an area on the aorta just beyond the aortic valve. Coronary arteries are blood vessels that provide oxygen-rich blood and other nutrients to the heart muscle. The coronary arteries attach to and wrap around the heart's surface. The main coronary arteries are the left coronary artery and the right coronary artery. The left coronary artery branches off into smaller arteries. The most prominent ones are the: Left anterior descending artery, which supplies blood to the front of the heart. Left circumflex artery, which encircles the heart muscle, supplying blood to the back of the heart.The right coronary artery supplies the back of the heart. The right marginal branch usually extends from the right coronary artery and supplies blood to the lower right side of the heart.