As you read this sentence, trillions of cells are moving around in your body. From the red blood cells being pumped by your heart, to the immune cells racing across your lymphatic system, everything ...

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 ...

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 ...