Watch a watermelon wrapped in rubber bands explode in slow-motion. (CBS News) Have you ever wondered if you could cause a watermelon to explode by wrapping a ton of rubber bands around it? And have you additionally wondered what that explosion would end up looking like in super slow-motion? The answer to both questions is probably not, but it's very cool to watch happen anyways.
Four valves control the flow of blood from the atria to the ventricles and from the ventricles into the two large arteries connected to the heart. 1  The tricuspid (tri-CUSS-pid) valve is in the right side of the heart, between the right atrium and the right ventricle.
There are also two semilunar valves; one between the right ventricle and the lungs (pulmonary semilunar valve) and one between the left ventricle and the aorta (aortic semilunar valve). The main purpose of the valves is to prevent backflow of blood in the heart. There are things called the chordae tendinae and papillary muscle that help control the opening and closing of the valves as blood flows through them. There are also valves in the veins.