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 ...

only allows blood to pass through one cell at a time Other features Thick muscular walls to withstand blood flowing at high pressure as it leaves the heart; the largest artery is the aorta Contain ...

open as wide as it should, restricting blood flow through the heart - this means less blood reaches the body, pressure builds up and the lungs can swell with fluid close properly and allow blood ...

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 ...