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Circulatory System Essay

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Circulatory System
A simple definition for the circulatory system would be that it is the main transportation and cooling system for the body. Red Blood Cells have an important job in this system in that they carry all sorts of packages that are needed by all the cells in the body. Red blood cells carry oxygen and nutrients to the cells, which is needed in order for cells to survive. Besides red blood cells there are also White Blood Cells moving in the circulatory system. White Blood Cells can be considered as the paramedics, police and street cleaners of the circulatory system. Anytime we have a cold, a cut, or an infection the white blood cells go to work. From research I also came to find out that white blood cells also help cuts or …show more content…

Blood enters the right side of the heart through a chamber called the Right Atrium. Atrium is another word for an 'entry room.' Since the right atrium is located above the Right Ventricle, a combination of gravity and an easy squeeze pushes the blood though the Tricuspid Valve into the right ventricle. The tricuspid valve is a valve made up of three 'leaflets' that allows blood to go from top to bottom in the heart but closes to prevent the blood from backing up into the right atrium when the right ventricle squeezes. After the blood is in the right ventricle, the right ventricle begins its contraction to push the blood out toward the lungs. The blood then leaves the right ventricle and enters the pulmonary artery. This artery and its two branches are the only arteries in the body to carry deoxygenated blood.
When the blood leaves the pulmonary arteries it enters capillaries in the lungs. Capillaries are very, very small blood vessels that act as the connectors between veins and arteries. The capillaries in the lungs are very special because they are located against the alveoli or air sacks. When blood in the capillaries goes past the air sacks, red blood cells pick up oxygen. Capillaries are so small, in some places, that only one red blood cell at a time can get through. When the blood has picked up its oxygen, it enters some blood vessels known as the cardiac veins. This is fully oxygenated blood and it is now in veins. The cardiac veins

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