Teachers TryScience

Procedure 1: Cardiovascular Model Preparation (one 45 minute class period)

In this part of the lesson, students will make a large scale model of the circulatory system. The students will use their model to emulate normal cardiovascular flow and blood gas exchange.

Divide the class into 4 groups and assign each group one of the following tasks

• Group 1 - Review a diagram of the heart. Using the available materials and the classroom desks, create a large model/diagram of the heart (labeling each of the four chambers of the heart). The chambers of the heart should be large enough for balloons, balls (or potentially people) to pass through.
• Group 2 - Review a diagram of the lungs. Using the available materials, create a small-scale model/diagram or draw a pair of lungs, including the bronchi & trachea. Label the major components of the lungs. Color/decorate the lungs as desired. Some member of the group can also make symbols for capillaries (e.g., draw the symbol on numerous “Post-Its”) and place the symbols on the sites of the lung model as an intermediary between the arteries and veins.
• Group 3 - Review diagrams of the major organs of the body. Using the available materials, create models/diagrams of various body parts or organs that the group believes to be very important (besides the heart and lungs—e.g., brain, hands/feet, muscles, stomach, etc.) Label each organ/body part and group the organ models together in an area of the classroom entitled: “THE BODY”. Some member of the group can also make symbols for capillaries (e.gl, draw the symbol on numerous “Post Its”) and place the symbols on the sites of the various organ models as an intermediary between the arteries and veins.
• Group 4 –Move aside any chairs/desks, table from the middle of the room. Review a diagram of the circulatory system. Designate a space in the center of the room for the heart’s location (to be completed by Group 1). Designate a space above/below the heart for the lungs (to be completed by Group 2). Designate a space above/below the heart for the major body parts/organs (to be completed by Group 3). Using your diagram as a guide lay out materials that will serve as major arteries and veins (e.g., red & blue yarn) to be used to connect the various organs created by the other groups.

Hint: As per the resource diagrams: a) the lungs should send blood to the left atrium of the heart, b) the left ventricle should send blood out to “the body”, c) “the body” should send blood out to the right atrium of the heart, and d) the right ventricle should send blood out to the lungs.

1. Provide time for each group to explain what they have done, pointing out any labels or special notations/colors.
2. Allow a volunteer from each group to traverse the entire pathway of the circulatory system (starting and ending at the heart’s left ventricle).
3. Finally, allow the students to describe where the capillaries would be located on their diagram.
4. Allow the students to reiterate what they have learned about the organization of blood vessels and the flow of blood.

Procedure 2: Cardiovascular Model Implementation (one 45-minute class period)

1. Proceed to the class’s large-scale circulation model/diagram.
2. Provide students with an opportunity to discuss material that will circulate through the cardiac pathway (e.g., red blood cells, oxygen, carbon dioxide, glucose & other nutrients).
3. Divide the students into small groups and allow each group to choose which materials they will be creating for the model implementation.
4. Allow the students to decide how to circulate their respective materials (determining the material’s site of entry, its site of utilization & its site of removal).
5. Allow the students to execute the circulation of their respective materials, by either passing the materials from one student to another or by having the students traverse through the pathway themselves with the materials “in tow”.
6. You may play appropriate “heartbeat” music, as each group performs their respective roles .

Note: The model implementation design can be accomplished in various ways, as determined by you and/or the students. In fact, it may be more practical to circulate one set of materials at a time (for example, just oxygen and carbon dioxide). If a more scripted procedure is desired, then feel free to use the description below and/or the attached “Examples of Students Roles for Procedure 2”.

Procedure 3: Model Implementation- Cardiopulmonary Disorders (one 45-minute class period)

1. Proceed to the class’s large-scale circulation model/diagram.
2. Provide students with an opportunity to review, discuss and hypothesize how various disorders of the heart, blood vessels, and/or lungs (e.g., heart murmurs, septal defects hypertension or hypotension, atherosclerosis, anemia, patent foramen ovale, ductus arteriosus, lung disorders that decrease oxygen intake like emphysema, etc.) will affect their cardiopulmonary model.
3. Within the resource section, sample websites are provided for the viewing images/animations of various heart defects.
4. Allow the students to execute their various disorder hypotheses with the classroom model.
5. The students should analyze and discuss how well the alterations made to their cardiovascular model correlate with the respective cardiovascular disorders.