Valves of the Heart. The heart functions by pumping blood both to the lungs and to the systems of the body. To prevent blood from flowing backwards or âregurgitatingâ back into the heart, a system of one-way valves are present in the heart.
An electric circuit is a path in which electrons from a voltage or current source flow. Electric current flows in a closed path called an electric circuit. The point where those electrons enter an electrical circuit is called the source of electrons.
Build a Circuit. A circuit is a path that electricity flows along. It starts at a power source, like a battery, and flows through a wire to a light bulb or other object and back to other side of the power source.You can build your own circuit and see how it works with this project!art 2 - Adding Power. 1  Disconnect the battery from your circuit. 2  Stand one battery so that the + end is pointing up, then set the other battery next to it so that the flat - end is pointing up. 3  Tape around the middle of the batteries to hold them together.