Reader s Page Make 1 copy for Reader. Instructions will be on the front, questions on the back. As an option, the simulation may be frozen and a discussion of information on back of card undertaken. Students can fill out Part 3 of their Student Data Pages as they go. Cards should be laminated for reuse. Oxygen enters our body as we inhale through our mouth or nose and then travels to our lungs. The oxygen molecules pass through the alveoli walls by diffusion. Oxygen passes through the capillary wall by diffusion. Finally, oxygen enters the capillaries, which are so small, they must pass through in single file. Once the oxygen molecules are inside the capillaries, they attach to red blood cells and travel through the circulatory system. Once oxygen attaches to red blood cells, they are called oxygenated red blood cells. Six students wearing the Oxygen Character Cards enter the right lung. The student wearing the Alveolus Character Card steps aside to let the oxygen pass. Six students wearing the Oxygen Character Cards step into the capillary, which is so small they must go through in single file. The six students wearing the Oxygen Character Cards step single file into the capillaries. The six students wearing the Red Blood Cell Character Cards race to pick up an oxygen molecule. Each Red Blood Cell turns his or her Character Card so Oxygenated is on the front and stands near it s oxygen molecule. Card 1 18
Our cells need oxygen for energy. From the capillaries surrounding the alveoli of the lungs, Oxygenated Red Blood Cells travel into larger veins that take them back to the heart. The six oxygenated red blood cells, with their oxygen attached, rush through the capillaries one at a time until they enter the larger veins, where they can go through many at a time as they rush back to the heart. Card 2 19
As the Oxygenated Red Blood Cells enter the heart, they will move through the heart and be pumped out to the body. Six Oxygenated Red Blood Cells and their attached Oxygen move through the large vein, enter the heart. Card 3 20
The left side of the heart has very thick walls to withstand the force exerted by blood as it is pumped out of the heart to all parts of the body. The Oxygenated Red Blood Cells, with their Oxygen still attached, simulate the forceful pumping of the heart as they move into the large artery leaving the heart. Card 4 21
The oxygenated red blood cells must make their way to the cells of the body so they can deliver their oxygen and pick up waste materials. Our body cells use oxygen (O2) to break down glucose, thus releasing energy that keeps body cells alive and allows them to carry out their specific job. In order for the body cells to use oxygen to break down glucose, the oxygen molecules must leave the red blood cells on which they are traveling and diffuse through the capillary walls, through the body cell membranes, and finally into the body cells. The Oxygenated Red Blood Cells with their attached Oxygen move as a group through the large artery. When they come to an area of the artery that is narrower, they cannot all go through at the same time. When they get to the capillary, they must go through only one at a time. The Body Cell stands next to one capillary and holds the Glucose Disk so that Side 1 is showing on the front. All six oxygen molecules leave their Red Blood Cell, pass through the capillary wall and join the Body Cell. Card 5 22
It takes six oxygen molecules to break down one glucose molecule, thus releasing energy for cells to use. All six oxygen molecules race toward the Body Cell. When all six arrive in the cell, the Body Cell turns the Glucose Disk over. Card 6 23
While releasing energy from glucose, our body cells produce waste in the form of carbon dioxide (CO2) and other byproducts. These wastes need to be eliminated. Carbon Dioxide will move through the body cell membranes and through the capillary walls, where they will be picked up by red blood cells. Once the red blood cells pick up carbon dioxide molecules, they are called deoxygenated red blood cells. The Oxygen Molecules leave the scene and the Carbon Dioxide Molecules join the Body Cell. They pass through the capillary wall into the capillary. Six Red Blood Cells pick up the six Carbon Dioxide Molecules. Red Blood Cells turn the Character Cards over so the Deoxygenated side is showing. Card 7 24
The deoxygenated red blood cells will be pumped back to the lungs where they will drop off carbon dioxide and pick up fresh oxygen. The Deoxygenated Red Blood Cells, with their Carbon Dioxide Molecules, travel back to the heart through capillaries, through which they must travel in single file. Then they move into larger veins, in which more cells can go through at a time. Look at the Blood Flow Mat and follow the path back to the heart. Card 8 25
Oxygen and Carbon dioxide exchange in the lungs has just occurred. This allows oxygen to be carried to all body cells so that they can break down glucose to get energy. The Alveolus is standing next to the capillary in one of the lungs. When the Deoxygenated Red Blood Cells, with their Carbon Dioxide Molecules, reach the Alveolus, the Carbon Dioxide Molecules leave the Red Blood Cells, move through the capillary wall and into the Alveolus. The Carbon Dioxide Molecules will be forced out of the body next time the person exhales. Oxygen Molecules now join the Red Blood Cells and they turn their Character Card over to read Oxygenated. Card 9 26
Red blood cells travel through your body more than 1,000 times everyday! The heart continues pumping, so this process is repeated over and over again, not in a few body cells, but in trillions of body cells! That is a LOT of oxygen, carbon dioxide and glucose! Repeat the simulation you just did, but you must be quick if the Red Blood Cells will make the loop 1,000 times in a day! Card 10 27