Cardiovascular System: Lesson Plan by Meryl Divya Joseph
Identify the location, function and structure of the heart. Demonstrate the overall distribution of blood in the circulatory system followed by a brief overview of arteries and veins. Actively participate in the class discussions and observe the teacher modeling. Accuracy and precision will be expected and observed.
Grade Level: 6-8
Time: approximately one hour. If time overrides, save the artery and vein introduction for next class.
A mat or large poster with an anatomically correct heart drawn or printed on it (see below).
Red (oxygenated blood cell) and blue (deoxygenated blood cell) balloons
Ask everyone to point to where their heart is on their body. Identify the location of the sternum and ribcage and ask why there might be bones like this around the heart (protection). Make sure everyone is pointing to the middle of the breastbones, or slightly to the left.
Have each student put a fist in the air. This is about the size of each of their hearts. Have them compare the size of their fists with those of their friends.
Now tell the students to squeeze their fist as hard as they can without hurting themselves. This is how your heart pumps.
Question to ask Students:
Why does your heart pump? (to circulate blood)
Discuss how muscles help you move things around and what your heart moves around in your body. For one minute, have the group squeeze their hands as hard and as fast as they can. Although it seems easy at first, the group will get a clear idea of how hard the heart works through this simple activity.
Trace the pathway of blood through the heart on the diagram. The heart is the “pump” for ALL of the blood in the body. The right and left sides of the heart are different pathways for the blood. The “septum” in the middle of the heart keeps the blood on each side from mixing with the other.
Talk about what the role of blood is in the body (delivering oxygen, nutrients and other things to cells in the body). The heart is the pump that pushes the blood throughout the body.
Questions to ask Students:
Where does blood get the oxygen it delivers? (The lungs)
What waste product is exhaled from the lungs? (Carbon dioxide)
Second Anticipatory Set:
Have the students breathe in and breathe out. Explain that carbon dioxide is also carried in the blood. Tell them that blood entering the right side of the heart is coming from the muscles and is low in oxygen and high in carbon dioxide. Once blood enters the right side of the heart it gets pushed back to the lungs for more oxygen. The blood then comes back to the heart for another push to the rest of the body and muscles. There are two sides of the heart so low oxygen blood and high oxygen blood do not get mixed up and go to the wrong place. Your blood delivers (what ?) to the appropriate cells. The blood also takes away the waste products (what?) the body doesn’t need. The heart is the engine that pushes it around. Together, this system is called the circulatory system.
Ask students which side of the heart they think has to push harder, the right side that sends blood past the lungs, or the left side that sends blood all over the body. Tell them that the left side has to pump harder and point out on the diagram, that the right side of the heart muscle is smaller than the left. The left side has to push harder so it needs to be a bigger muscle.
Second Teacher Modeling:
Point out on the slide that the heart is divided into four rooms (or chambers) and that it has four one-way doors (called valves).
The two top rooms are called the Left and Right Atrium and the two bottom rooms are called the Left and Right Ventricles.
Point out on the slide that each room in the heart has one a one-way door at its exit.
Have the students brainstorm about what these doors are for. These doors let blood flow out of each of the rooms, but not back in.
The four doorways have names too; they are the Pulmonary, Aortic, Tricuspid, and Mitral (also known as Bicuspid) valves.
The Bicuspid Valve is the Mitral Valve located between the Left Atrium and Ventricle; all the other Valves in the Heart are Tricuspid Valves that have 3 sections that come together (as opposed to the two sections of a Bicuspid).
Questions to ask the students:
How does your blood move around your body?
Do you hear the “lub dub” of your heart?
Why do you need blood?
What is carried in blood and why?
Each pair will trace the pathway of blood through the heart using the mat or poster.
Starting at the top of the mat/poster (the aorta) I will demonstrate how blood flows through the heart, pointing out each chamber and valve. I will begin in the right atrium, move to the right ventricle, then out to the lungs. Once in the lungs, I will pick up a red water balloon (this is oxygen-rich, bright, red blood). Then I will move back through the heart with the balloon passing through the left atrium and left ventricle, and on to a muscle in the body. I will give the muscle the oxygen rich blood (red balloon) and exchange it for oxygen-depleted blood (a blue balloon), and continue back through the heart to the lungs where the body gets rid of the waste product (which is carbon dioxide).
This is a mapping exercise. Each pair will be timed, however it is very important that the focus is placed on moving through each chamber and valve. The rest of the groups can act as referees and monitor each team’s progress. If a team skips a “heart part” the team will have 5 seconds added to their final time. With 3 red balloons and 3 blue balloons, it takes the average pair about 20 seconds to move through the heart. Point out that this is approximately how long it takes for a blood cell to travel through an adult’s entire body.
Questions to ask Students:
Does all of the blood in your body pass through your heart? (yes)
Why are there two sides in the heart? (to keep the oxygenated blood and deoxygenated blood from mixing)
How does blood circulate to different parts of your body? (veins and arteries constricting and dilating)
What can we do make our hearts stronger? (healthy lifestyle)
What isn’t healthy for the heart? (smoking, cholesterol, inactivity)
Review with the students that the heart is a muscle and that it never stops as long as you are alive. While the heart is the “pump,” for your body’s blood, the “pipes” are the blood vessels. These vessels are called arteries, veins and capillaries.
Question to ask Students:
What is the difference between arteries and veins?
Tell the students that an easy way to remember the difference between arteries and veins is to think of the “A” in arteries and the “IN” in veins. Arteries carry blood Away from the heart,and VeINs carry blood IN to the heart. Point out that the heart has its own arteries and veins too. Have the students discuss why it might be important to keep these blood vessels clean and clear. A few ways to do so are: to be as healthy as possible, exercise, eat well, talk to your doctor about what is best for you, learn about your heart and body and how to best take care of your body because everybody is different. It is also important to never smoke cigarettes. Smoking can make arteries clog up, and no matter whom you are; smoking is bad for the body and bad for the heart.
Assessment (2 Parts):
The student will receive one grade for the mapping exercise.
A: 25 seconds or below with accuracy in the heart
B. Accuracy but over 30 seconds
C. Some accuracy and over 30 seconds
D. No accuracy or over 1 minute
For homework the students will reflect on what they have learned from the activity. They will then write a journal entry pretending they are a drop of blood traveling through the circulatory system. The students can be creative or accurate whichever fits their personality, and they will be graded as such:
Minimum 1, Maximum 5
1. No concept of circulatory system
2 Some understanding but not able to link ideas together
3. Able to identify key functions and structures, but unaware of the basic idea and concept.
4. Explains the concept well but not a well developed essay.
5. Able to identify key functions and structure, can explain the idea and concept behind the circulatory system as well as outline an introduction, body and conclusion.