Go with the Flow
* What is the role of each heart chamber?
For each student
For the class
1. With the transparency of the heart projected on the wall and a handout in front of the students, talk about the flow of blood through the body. Students will trace the pathway of blood through the heart and lung by adding arrows to the diagram. Use red pencils for the oxygen-rich blood and blue pencils for the less oxygen-rich blood.
2. Start on the left side of the heart. Number the chambers for discussion purposes. Chamber number one is the right atrium. What do we see leading to this chamber? (Answer: the Superior and Inferior vena cavathe major veins). The Superior vena cava gets its blood from the parts of the body higher than the heartthe head and arms. The Inferior vena cava gets its blood from areas of the body below the heart, the torso and legs. The blood returning to the heart and entering the right atrium is loaded with carbon dioxide. Color the veins and the right atrium blue.
Between the right atrium and right ventricle is a valvethe tricuspid valve. This valve helps move the blood through the body.
3. Chamber number two is the right ventricle which ejects used blood into the pulmonary artery, enroute to the lungs. The blood here is loaded with carbon dioxide and should be colored blue. Follow the pulmonary arteries to the lungs and color them blue.
4. Chamber number three is the left atrium which receives oxygen-rich blood from the lungs via the pulmonary veins. Color the left atrium red and the pulmonary veins red.
Between the left atrium and the left ventricle is the bicuspid valve, also called the mitral valve, because it is shaped like a bishop's miter (a tall, pointed hat). Operating like the tricuspid valve, the bicuspid valve controls the flow of blood into the left ventricle. The tricuspid and bicuspid valves open and close simultaneously. The closing of these two valves is the "Lub Dub" sound heard through the stethoscope. The tricuspid and bicuspid valves are also known as atrioventricular (AV) valves.
5. Chamber number four, the left ventricle, is the largest heart chamber and the strongest pump. It discharges blood into the aorta through the aortic valve.The pulmonary and aortic valves operate at the same time. The "Dub" sound heard is the closing of these valves. From the aorta, all body tissues receive oxygen-rich blood. Color the left ventricle and aorta red.
Notes to the teacher: The Heart as a Pump
The heart's labor is finely tuned. Both atria simultaneously fill with blood. Then the bicuspid and the tricuspid valves open, also simultaneously, to allow blood to flow into the ventricles. As the blood collects in the ventricles, they contract, ejecting blood into the lungs and the body. Meanwhile, the atria relax and again fill with blood.
Note: The plural of atrium is atria.
A Change of Heart: Interactive Heart
The Heart: An Online Exploration
The Heart: An Inquiry About the Heart
| lesson 1: Pulse of Life| lesson 2: Keeps on Pumpin' | lesson 3: Under Pressure | lesson 4: Sounds of the Heart | lesson 4a: Valves and Pumps | lesson 5: Lub Dub (valves) | lesson 5a: The Heart as a Pump | lesson 6: Go With the Flow | lesson 7: Lung Model | lesson 8: Ins and Outs of Respiration | lesson 9: Catch Your Breath | lesson 10: O2 CO2 Skit | lesson 11: X-Rays |
Visiting the Science Museum of Minnesota?