How The Human Heart Works
The Parts of the Heart
Your heart is the pump of your body. Without it, you will die. Before we learn how the heart works, we need to know the parts of the heart. The heart is divided in half. The left side of your heart are your ventricles. Adjacent is the atria, the plural for atrium. Again, on each side they are split in half again horizontally. These are the heart's chambers. All four of them are separated by valves. The valves are just tissues that keep the blood flowing forward, not backward. There are four valves: mitral valve, tricuspid valve, pulmonary valve, and the aortic valve. Coronary arteries are arteries that run on the heart's surface. There are two main arteries that run in the heart, which are the pulmonary artery and the aorta. The pulmonary artery brings the deoxygenated blood to the lungs, where it receives oxygen to become oxygen-rich blood. The aorta is the largest artery in our body. This artery brings the oxygen-rich blood throughout your whole body to supply nutrients to your organs. There is also the inferior vena cava and the superior vena cava. The inferior vena cava brings blood from the lower part of the body to the heart that is oxygen-poor. The superior vena cava brings blood from the upper part of the body that is also oxygen-poor.
How The Heart Works
First, deoxygenated blood enters the right atrium, where then the tricuspid valve opens, letting blood flow into the right ventricle. The pulmonary valve openwhir allowing blood to flow through the pulmonary artery. This artery brings blood to the lungs, to receive oxygen. The oxygen you breathe in goes through millions of air sacs call alveoli. This is where the blood picks up oxygen. After that, the blood travels back to the heart, oxygen-rich. The blood empties out in the left atrium, where the mitral valve opens, bringing blood into left ventricle. Now the aortic valve opens, rushing in blood from the left ventricle into the aorta. Then the aorta branches off into other smaller arteries. The arteries become from arteries to arterioles, to capillaries. Capillaries are the smallest type of blood vessel there is. In the capillaries, the exchange between carbon dioxide (CO2) and nutrients. The capillary wall is so small, only one blood cell can go in at a time. That's when the CO2 the capillary wall has been holding transfers it to the cell, which releases it's nutrients to the wall. Now the blood cell is oxygen-poor again. The blood travels through the veins which lead back to the heart. The cycle starts ALL over again! Surprisingly, this happens in about one minute. Our heart is really amazing, pumping blood to our whole body.