Do you know how the blood in our body is transferred? The main organ heart pumps the blood with the help of arteries, veins and capillaries. In this lesson, we will study the structure of the heart, veins and arteries.
How is blood transported
On the upper right side of the heart we have vena cava which is divided into superior vena cava and inferior vena cava. Both of them bring deoxygenated blood; superior brings from the upper body and inferior brings the blood from the lower body. Both of them are veins. Below them, there is the right atrium and then right ventricle. Between them exists tricuspid valves which prevent the backflow of blood. Then there is a pulmonary artery which takes the blood to the lungs after passing through semilunar valves and pulmonary vein brings oxygenated blood back to the heart in to the left atrium. Then it passes through the bicuspid valves into the left ventricle which has the strongest elastic muscles, due to the increased pressure of blood in this chamber of the heart. Then the oxygenated blood moves to the aorta (the main artery), after passing through the semilunar valves, for further supply in the body.
Arteries
Arteries are the blood vessels which take oxygenated blood away from the heart except for the pulmonary artery which takes away deoxygenated blood. Arteries have narrow lumen. Due to the increased blood pressure, they do not have valves. They have elastic and muscular tissues.
Veins
Veins bring the deoxygenated blood back to the heart except for the pulmonary vein which brings oxygenated blood to the heart. Veins have wide lumen which decreases the pressure and have valves to prevent the backflow of the blood. Veins have less elastic muscles and tissue cells, because of reduced pressure.
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