The video shows a 3D model of a human heart. The heart is shown in a cross-section view, with the left side of the heart being highlighted. The heart is colored in shades of red and blue, with the arteries and veins being highlighted in blue and red respectively. The animation shows the heart beating, with the chambers and valves moving in a realistic manner. The animation is smooth and detailed, providing a clear view of the heart's structure and function.