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, ...

Your heart pumps blood from your head to your toes, provides cells with fresh oxygen, and removes waste products. Located in ...