The medical term "cardio" pertains to the heart, and "vascular" refers to the blood vessels of the body. Together they make up the cardiovascular system and deliver the oxygen that keeps organs functioning properly. According to the National Heart Lung and Blood Institute, damage to the cardiovascular system in the form of coronary heart disease, is the leading cause of death of nearly one million Americans every year.
Blood Cells
The cardiovascular system could not perform without the red blood cells and the vascular system is the network through which blood cells travel transported. Think of red blood cells as high-performance sports cars, that have room for just one passenger: either one molecule of oxygen or one molecule of carbon dioxide. The red blood cells take a ride from the right atrium through a valve that acts like a door that opens when the atrium contracts. The cells rush through, and the valve closes behind the cells as they enter the right ventricle. With the next contraction of the heart, the cells get pushed through the pulmonary artery, into the lungs. The red blood cell releases its lone passenger, carbon dioxide, and the lungs blow this molecule of carbon dioxide out of the body as you exhale. When you inhale, oxygen floods into the lungs and each one molecule of oxygen jumps into the empty passenger seat in each red blood cell.
The Return Trip
Arteries carry blood away from the heart and veins return blood to the heart.The oxygen-rich blood cells must travel through the pulmonary vein to get back into the heart, and then enter the left atrium. From the left atrium, blood cells travel to the left ventricle, through another door-like valve, the mitral valve. Next, the left ventricle contracts, forcing the blood cells through the aortic valve into the largest artery of the body, the aorta. The forceful contraction of the left ventricle is strong enough to push the cells through the aorta, away from the heart and out to the rest of the body.
Final Destination
After traveling through the body's major arterial system, the red blood cells enter the capillaries. Nearby cells immediately give up their carbon dioxide and grab on to life-supporting oxygen; the discarded carbon dioxide cells jump into the red blood cells' empty "seats." The carbon dioxide rides with the red blood cells, traveling along the veins that lead back to the heart. The process repeats for the life of the blood cell.
Cardiovascular Facts
If all the vessels of the vascular network of your body could be placed end to end, they would extend for about 60,000 miles -- this would encircle earth more than twice. The heart is a powerful and muscular organ, able to deliver the supply of oxygen and nutrients to the body over this great distance. It must beat at a rate of about 80 to 100 beats per minute in the average adult.
