ANATOMY
Circulation
The right atrium receives blood coming to your heart from your body. This blood is low in oxygen and needs to be replenished before going back out to the rest of your body. When the atria contract, the blood from the right atrium goes through the now open tricuspid valve into the right ventricle. When the ventricles contract, the low-oxygenated blood in the right ventricle travels through a semilunar valve into the pulmonary arteries and to the lungs. Here, the blood picks up a fresh supply of oxygen and circulates back to the heart through the pulmonary veins. This oxygen-rich blood enters the left atrium. When the atria contract, the blood in the left atria passes through the bicuspid valve into the left ventricle. When the ventricles contract, the blood from the left ventricle moves through another semilunar valve into the aorta. From here it is delivered throughout your body, delivering its oxygen and nutrients. Eventually the blood returns to your heart and enters the right atrium to repeat the entire process.
A healthy heart beats approximately 100,000 times each day and pumps about five quarts of blood per minute, or 75 gallons per hour. |
