Human bodies are designed to move in order to circulate blood and nutrients to every cell. Staying active and on the move is crucial to our health for a lot of reasons. But it's especially important ...

The circulatory system consists of one heart, five liters of blood, and approximately 96,000 kilometers of blood vessels, responsible for transporting nutrients and waste throughout the body. Water ...

Red blood cells carry oxygen from the lungs to every other organ, and blood-forming stem cells must make about 200 billion new red blood cells each day to keep the oxygen flowing. For many years, ...