This video explains how the heart, blood, and blood vessels work together to circulate oxygen, nutrients, and other vital ...

Human bodies make 2 million red blood cells per second. They each live for 120 days and spend that time zooming completely around the body every 20 seconds, carrying oxygen from the lungs to other ...

Red blood cells transport oxygen throughout your body, including to vital organs and tissues. They also help your body get rid of carbon dioxide. Too little or too many red blood cells may be ...

Explore the shape, structure, and movement of red blood cells under the microscope in this fascinating science clip.

Red blood cells carry oxygen from the lungs around the body. They then carry carbon dioxide from around the body back to the lungs. These cells are an important component of blood. However, a range of ...