The circulatory system is the body 's transport system; it gets rid of waste and gets oxygen and nutrigens to the cells in the body. The circulatory system is made up of blood, blood vessles, the heart, and the lymphatic system. The heart pumps blood throughout the body through tubes called blood vessles. The circulatory system 's ammune system is the lymphatic system. Every one of these things work to maintain homeostasis throughout the body. There are three major blood vessles, they are the arteries, cappilaries, and veins. Arteries carry oxygenated blood away from the heart. Arteries can also withstand high amounts of pressure from the heart pumping blood, becuase they are thick-walled, elastic vessles. Arteries …show more content…
Deoxygenated blood enters the heart through the right atrium through the superior vena cava and the inferior vena cava. Then the deoxygenated blood drains into the right ventricle through the right atrioventricular (AV) valve, it has three flaps in its structure. When these ventricles contract, the AV valve closes the opening between the ventricle and atrium so blood doesn 't flow back up into the atrium. When the right ventricle contracts, it forces the deoxygenated blood through the pulmonary semilunar valve and into the pulmonary artery.The pulmonary artery then carries blood this is low in oxygen to the lungs, where they become oxygenated. The freshly oxygenated blood returns to the heart by the pulmonary veins. These veins are the only ones that contain oxygenated blood, while the other veins only contain deoxygenated blood. The pulmonary veins enter the left atrium, and when it relaxes, the oxygenated blood goes into the left ventricle through the AV valve, it has two flaps in its structure. As the left ventricle contracts, the oxygenated blood pumps into the aorta, which is the main artery of the body. In order to get to the aorta, blood passes through the aortic semilunar valve, which also keeps blood flowing from the aorta into the left