The evolution of the human heart! - We created this video showing the development of the human heart, starting from day 20, when the first primitive tube begins to beat. Over the following weeks, the heart loops, partitions, and rapidly grows more complex. By around day 70 (week 10), it has reached its fully developed four-chambered form, complete with visible blood vessels. This visualization highlights each stage leading to the final structure—showing the aorta, pulmonary arteries, ventricles,

The documentary "First in Human" premieres Aug 10 at 9 pm ET on Discovery. It will be available on Discovery Go at 9 am the next morning. To learn about the making of the film and clinical trials, please join our Twitter chat today (8/9) at 1 pm ET. We're using the hashtag #FirstinHuman. | National Cancer Institute