Gallery of Color Pages of Hearts:
The heart is located at the center of the chest. The muscle mass is greater on the left side and the apex of the heart is pointed slightly to the left.
The heart is a muscular organ in humans and other animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, and also assists in the removal of metabolic wastes. The heart is located in the middle compartment of the mediastinum in the chest.
The heart pumps blood through both circulatory systems. Blood low in oxygen from the systemic circulation enters the right atrium from the superior and inferior vena cavae and passes to the right ventricle. From here it is pumped into the pulmonary circulation, through the lungs where it receives oxygen and gives off carbon dioxide. Oxygenated blood then returns to the left atrium, passes through the left ventricle and is pumped out through the aorta to the systemic circulation−where the oxygen is used and metabolized to carbon dioxide. In addition the blood carries nutrients from the liver and gastrointestinal tract to various organs of the body, while transporting waste to the liver and kidneys. Normally with each heartbeat the right ventricle pumps the same amount of blood into the lungs as the left ventricle pumps to the body. Veins transport blood to the heart and carry deoxygenated blood - except for the pulmonary and portal veins. Arteries transport blood away from the heart, and apart from the pulmonary artery hold oxygenated blood. Their increased distance from the heart cause veins to have lower pressures than arteries. The heart contracts at a resting rate close to 72 beats per minute. Exercise temporarily increases the rate, but lowers resting heart rate in the long term, and is good for heart health.
