O2 CO2 SKIT
Key Questions
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What is the path blood flows in the body?
What is the role of blood as it circulates?
Objective
Students will act out the flow of blood in the circulatory sytem
Materials
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poster or diagram of the circulatory system
red plastic disposable plates, 9-12" in diameter, one for each student
white foam discs (to represent oxygen)
blue foam discs (to represent carbon dioxide)
labels or name tags with the following parts of the circulatory system:
o superior vena cava
o right atrium
o right ventricle
o pulmonary artery
o the lungs (2 labels)
o pulmonary veins
o left atrium
o left ventricle
o aorta
o artery*
o capillary*
o vein*
o body cell (2 labels, minimum)*
o ascending aorta
o descending aorta
o inferior venacava
o superior venacava
* Multiple labels should be made for these parts so that each student has a role.
Procedure
1. Distribute the labels, one to each student in the class. Students wear the labels.
2. Have the students arrange themselves in a circle, according to their label, in an
order that represents the flow of blood through the circulatory system. Refer to
posters and diagrams as necessary.
3. Give the white foam discs (representing oxygen) to the students representing
the lungs. Give the blue foam discs (representing carbon dioxide) to the students
representing the body cells.
4. Talk through the journey of one plate. Have each student say the part that
he/she represents as the "blood" moves through it. Ask where the oxygen comes
from, and where it goes.
5. Start passing several plates through the system. As the plates go through the
lungs, those students attach white foam discs to the plates. As the plates go
through the capillaries, the body cells take off the white discs (oxygen) and attach
blue discs (carbon dioxide) to the plates.
6. Explain that this is not a perfect model. In the human heart, for instance, the
pulmonary artery branches off in two directions (one to each lung). Here we have
only one artery leading to one capillary leading to one vein. In the human body, the
arteries branch off ever smaller until they get to the network of capillaries.
Notes to the teacher: Oxygen Exchange
In addition to oxygen, blood also carries nutrients to the body cells. The villi, tiny
finger-like parts lining the small intestine, absorb nutrients from digested food.
Blood picks up the nutrients from the villi. Eventually, the body cells absorb the
nutrients out of the blood. To get energy, the body's cells use oxygen to "burn"
certain nutrients. This produces energy and a waste product: carbon dioxide. Along
with oxygen and nutrients, blood carries hormones and antibodies to different
parts of the body.
Blood consists of blood cells, platelets, and plasma. Red blood cells are responsible
for carrying oxygen to the rest of the body. White blood cells help to fight
infection. Platelets help your blood to clot when you get a cut. Plasma consists of
water and many dissolved substances (such as proteins and salts) required by the
body.