Go with the Flow
Key Question
* What is the role of each heart chamber?
Objective
Students will name and locate the major areas and structure of the heart and trace
the pathway of the blood through the heart, lungs, and body.
Materials
For each student
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copy of heart diagram (in Appendix)
red and blue pencils, markers, or crayons
For the class
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heart model
transparency of the heart
Procedure
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 cava the major veins). The
Superior vena cava gets its blood from the parts of the body higher than the
heart the 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 valve the 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.
Heart Diagram