Heart 101, National Geographic

The human heart beats up to 3 billion times over an average lifespan. Learn about the anatomy of the heart and how this muscular organ provides lifegiving oxygen throughout the body. Subscribe: , NationalGeographic, Hearts, Educational About National Geographic: National Geographic is the world s premium destination for science, exploration, and adventure. Through their worldclass scientists, photographers, journalists, and filmmakers, Nat Geo gets you closer to the storie