To make a working model of a heart, its necessary to know the basic anatomy of the organ. A simple model can be created using a plastic wide-mouthed jar, balloons, a skewer and two flexible straws used to represent a heart's atrium and ventricle. Using the model aids students in understanding how blood is transported by the heart valves.
Fill the jar with water and cut the neck off the balloon before placing it over the mouth of the jar. With the skewer, poke two holes in the balloon approximately 2 centimeters apart. Insert a flexible straw in each hole. Use the neck of the balloon to make a heart valve. Tape the piece onto the end of one of the straws. Then place the "heart" jar into a basin to catch any water run-off. Push and release the balloon stretched over the jar; the neck or valve causes the liquid to flow one way.
Four valves in the heart regulate the flow of blood in and out of the muscle. Circulation is regulated by the tricuspid valve between the heart's right atrium and its right ventricle.
The pulmonary valve regulates the circulation between the right ventricle and pulmonary arteries. The pulmonary arteries carry blood to the lungs where it retains oxygen.
The mitral valve in the heart muscle permits the flow of oxygen-rich blood to travel from the heart's left atrium through the organ's left ventricle.
The heart's aortic valve passes oxygen-rich blood between the left ventricle and the aorta, which is the body's biggest artery.