The newly oxygen-rich blood (shown in red) returns to the heart and enters the left atrium. Blood flows through the left atrium into the left ventricle. The left ventricle pumps the oxygen-rich ...

Cut through the coracoid bar and pull back to fully open the pericardial cavity. Locate the vessels entering and leaving the heart and the 2 heart chambers - atrium and ventricle. Look at diagram of ...

It opens due to a build-up of pressure in the right atrium, and prevents back flow ... blood is carried to the heart from the lungs in the pulmonary vein. It goes into the left atrium, through ...

Originally appeared on the NOVA Web site Cut to the Heart. Let's get straight to the heart of the matter—the heart's job is to move blood. Day and night, the muscles of your heart contract and ...