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 ...

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 ...

This clip is an introduction to the human heart. We find out about its location within the body and its function as a pump. The heart sits within the chest cavity between the lungs and is about ...