What causes the heart sounds?
Heart sounds can be contributed to the opening and closing of valves in order for blood to flow throughout the heart to become oxygen rich.
From the body oxygen poor blood flows into the heart. From the heart the oxygen poor blood is pumped into the lungs to acquire oxygen. From the lungs the heart receives newly oxygenation blood. The heart than pumps the oxygen rich blood into the body. This process uses pumps and valves causing swishing and pumping noises known as the heart beat.