Heart Valves
The heart acts as the central pump for the circulatory system. To ensure that the blood flows properly, the heart has four valves: the tricuspid valve, pulmonary valve, mitral valve and aortic valve.
How do the valves work, and what do they do? The heart can be thought of as having two halves. The right half includes the right atrium and right ventricle that are separated by the tricuspid valve. The left half includes the left atrium and left ventricle that are separated by the mitral valve.
From the right atrium, the blood flows through the tricuspid valve to the right ventricle. The tricuspid valve prevents the blood from flowing backward between heart beats. The right ventricle pumps the blood out the pulmonary valve into the pulmonary artery that goes to the lungs.
In the lungs, the blood picks up oxygen and releases carbon dioxide. This oxygenated blood flows back through the pulmonary vein to the left atrium. The blood then travels through the mitral valve to the left ventricle, and is then pumped through the aortic valve to the aorta. The aorta branches into the many arteries, and then capillaries, delivering oxygenated blood to the body's organs, tissues and cells. Once the capillaries deliver the oxygen to the cells, the now deoxygenated blood travels through venules into veins, and then to the superior and inferior vena cava to start all over again. |
