We promised you blood today and we're delivering blood.

To begin with, as hearts slow with age, they deliver less blood and oxygen to the body.

It then delivers oxygen-rich blood back to your heart.

The second pump delivers oxygen-rich blood to every part of your body.

When the heart and blood vessels are not able to deliver enough blood to the vital organs, the body goes into shock.

Because the arteries are clogged, they can't deliver enough blood to the legs to support exertion.

Researchers are also working on the development of a small total artificial heart that would deliver blood by continuous flow rather than pulsation.

These blood vessels deliver oxygen-rich blood to every corner of our bodies.

Later, the condition was identified as orthostatic intolerance, the body's inability to deliver enough blood to the brain.

Somehow Mary's eyes remained open, for the brain has enough oxygen for up to a minute's activity even after the heart stops delivering blood.