Example Of Essay On The Circulation Highway

Right atrium temporarily carries deoxygenated blood from body tissues. It receives deoxygenated blood from the upper portion of the body via superior vena cava. In addition, deoxygenated blood from the lower portion of the body enters the right atrium via inferior vena cava. Upper portion of the body carries the head, neck, and other organs situated superior to the heart while lower portion carries legs and other body parts situated superior to the heart. As more blood enters the right atrium, it fills up. This makes its walls to contract causing pressure to build up. The pressure causes the tricuspid valve to open causing blood to rush into the right ventricle.
Deoxygenated blood from the right atrium continues to flow into the right ventricle until the ventricle is full. This causes its walls to contract leading to build up of pressure within it. This pressure causes the tricuspid valve to close hence preventing blood from flowing back into the right atrium. Consequently, the blood is pumped into the pulmonary artery via the pulmonary valve. This also helps pump the blood to the lungs.
The pulmonary artery continues to fill with blood until pressure in the right ventricle reduces. This causes the blood from the lungs to start flowing back into the pulmonary artery. However, the blood is prevented from flowing back into the right ventricle by the pulmonary valve which closes. When pressure in the right ventricle improves, blood is pumped to the lungs where the hemoglobin, the red pigment in the red blood cells, picks up oxygen.
Oxygenated blood from the lungs returns to the heart via pulmonary vein. The pulmonary vein empties the blood into the left atrium. As the blood continues to fill the left atrium, its walls begin to contract hence causing pressure within it to rise. This pressure causes the bicuspid valve separating the left atrium and the left ventricle to open. Consequently, blood rushes from the left atrium into the left ventricle. As this continues, pressure builds within the left ventricle causing its walls to begin to contract. This closes the bicuspid valve while it opens the aortic valve. Blood is then pumped to the rest of the body organs via aorta.
Tricuspid and bicuspid valves open and close simultaneously and so are aortic and pulmonary valves. When Tricuspid and bicuspid valves open, aortic and pulmonary valves shut while blood flow into the ventricles. On the other hand, when Tricuspid and bicuspid valves shut, aortic and pulmonary valves open while blood flow out of the ventricles. This mechanism ensures that blood flows in one direction.
Blood from the left ventricle is pumped to the rest of the body tissues via the aorta. The aorta is the main artery and has various branches that transport the oxygenated blood to different tissues and organs. It divides to form arterioles. Arterioles in turn divide into capillaries. Oxygenated blood from aorta is exchanged with carbon dioxide between blood in the capillaries and tissue fluids. Capillaries form venules which join with other veinules to form veins. Blood moves from the capillaries into venules and then into veins back to the heart. When the blood leaves the capillaries, it becomes deoxygenated. Deoxygenated blood from all tissues returns to the right atrium via vena cava. The cycle continues as long as one is alive. Some blood flows into the coronary artery which supplies the heart with oxygen and other nutrients and transports carbon dioxide and other wastes away from the heart tissues. The blood returns to the right atrium via vena cava. This movement of blood throughout the body is called blood circulation. The three main types of blood circulation are; pulmonary circulation, systemic circulation, and coronary circulation.