The heart circulates blood through two pathways: the pulmonary circuit and the systemic circuit. The pulmonary circuit is made up of the heart, lungs, pulmonary veins and pulmonary arteries. This circuit pumps deoxygenated blood from the heart to the lungs where it becomes oxygenated and returns to the heart. The systemic circuit is made up of the heart and all the remaining arteries, arterioles, capillaries, venules, and veins in the body. This circuit pumps oxygenated blood from the heart to all the tissues, muscles and organs in the body, to provide them with the nutrients and gases they need in order to function. The heart contains electrical pacemaker cells, which cause it to contract. THe contraction of the heart produces a heartbeat. …show more content…
Valves contribute to preventing backflow, ensuring that the blood continues to flow in one direction through the heart. The heart is a single organ, but it acts as a double pump. The first pump carries oxygen-poor blood to your lungs, where it offloads carbon dioxide and picks up oxygen. It then delivers oxygen-rich blood back to your heart. The second pump delivers oxygen-rich blood to every part of your body. Blood that needs more oxygen is then sent back to the heart to begin the cycle again. The right ventricle pumps blood to your lungs and the left ventricle pumps blood all around your body. The muscular walls of the left ventricle are thicker than the walls of the right ventricle, making it a much more powerful pump. Because of this, it is easier to feel your heart beating on the left side of your chest. Simply, the left and right ventricles enable the heart to produce its double