Your Beating Heart reveals how oxygen from your lungs is carried round your body by the blood, pumped by the heart, and taken to the cells – every single one of them. This nonstop activity involves trillions of red blood cells and a vast network of arteries, veins and capillaries. You’ll find out what the blood is made of, what happens when you exercise, and see how a heart transplant works. Oh, and if your brain is deprived of oxygen for even a few minutes, it will be damaged – so it’s as well no one has to remember to breathe!