Blood that is pumped out of the left ventricle of the heart travels out at high speed and under pressure into the aorta, the main artery that supplies oxygenated blood to the body. It goes from the aorta to the main arteries and then feeds all the tissues and organs through finer arteries and finally small capillaries.
Once fresh blood arrives, the oxygen in it passes into the cells to be used to burn up sugar molecules in the metabolic process of respiration.
Deoxygenated blood picks up waste carbon dioxide and travels back to the heart through the venous system. It enters the heart at the right atrium. It then enters the right ventricle and is pumped to the lungs to pick up fresh oxygen. Freshly oxygenated blood returns to the heart, entering the left atrium. The blood then passes to the left ventricle and the cycle begins again.
Once fresh blood arrives, the oxygen in it passes into the cells to be used to burn up sugar molecules in the metabolic process of respiration.
Deoxygenated blood picks up waste carbon dioxide and travels back to the heart through the venous system. It enters the heart at the right atrium. It then enters the right ventricle and is pumped to the lungs to pick up fresh oxygen. Freshly oxygenated blood returns to the heart, entering the left atrium. The blood then passes to the left ventricle and the cycle begins again.