LABORATORY 1 Effective Physics Teaching Includes Laboratory Activities as an Integral Part of Classroom Instruction By Leona Marie C. Camano Activity on Model of the Human Chest Cavity Objectives Materials 1. Explain how the lungs work, 2. Describe how the movement of the diaphragm helps the air go in and out of the lungs, and 3. Relate the model to human lungs 1 two-liter empty plastic bottle with cap, 3 balloons (1 big, 2 small), 2 sturdy straws, 1 pair of scissors, and 3 rubber bands or tape When you breathe in, a muscle under your chest called the diaphragm contracts, and your ribs expand. This expansion of the space reduces air pressure in your lungs. Outside air will rush in. When you exhale, your diaphragm moves upward, and your ribs return causing the air to move out of the lungs. Concepts Figure 1 The model works in a similar way: When you pull on the larger balloon, the space within the bottle expands, and the air expands. Because the pressure within the container is now lower, the higher pressure outside pulls air in. (This is similar to breathing in.) When you push in the larger balloon, the air within the bottle becomes compressed, which increases the pressure. This higher pressure sends the air out of the balloon. (This is equivalent to exhaling). Make a Model of Your Lungs 1. Using a pair of scissors, cut the bottom out of a 2-liter empty plastic bottle. 2. Create one hole in the cap of the plastic bottle. Make sure that the hole is just big enough for a straw to fit through. 3. Attach one straw to each other, to form like a branch. 4. Place one balloon in the end of each straw, and secure them with rubber bands or tape, as shown in Figure 2. Procedure 5. Stick the straw through the hole of the bottle cap, then locked it tightly on the lid. Refer to figure 3. 6. Stretch out the larger balloon and place it over the open bottom of the bottle. Secure it with the rubber band or tape as tightly as possible. Refer to Figure 4 of the finished lung model. 7. Pull the larger balloon down; that is, away from the bottle, to blow up the two small balloons. 8. Push the larger balloon towards the bottle to let the air out of the two small balloons. 1. What does each part of the constructed lung model represent? Guide questions 2. 3. 4. 5. 6. 7. 8. 9. What happens as you pull down the balloon at the bottom of the model? What happens as you push up the balloon? How does the movement of the diaphragm cause the air to go in and out of the lungs? What might happen if you prick the large balloon? Why did the small balloons inflate when you pull down the large balloon? Why did the small balloons deflate when you push up the large balloon? How pressure affects the movement of air in and out of the lungs? Relate the inflation and deflation of the small balloons to your lungs. Criteria Discussion Questions Organization Rubric Cooperation and Teamwork Presentation 5 All discussion questions thoroughly and clearly explain on the relationship of the model to the human lungs Materials are complete and organized to present the ideas well. Members are on tasks and have defined responsibilities at all times. Presenters are confident in the delivery, and they did an excellent job of engaging the class. 4 3 2 Only two discussion questions are answered. Only one discussion question is answered. Materials are complete and well organized. Some materials are complete and organized. Materials are incomplete and not organized. Members have defined responsibilities most of the time. Most members know their responsibilities but have no defined responsibilities. Presenters are not consistent with the level of confidence/ preparedness they showed but have some strong moments. Members do not know their task and have no defined responsibilities. All discussion questions explain on the relationship of the model to the human lungs Presenters are occasionally confident with their presentation however the presentation was not engaging. Presenters are unconfident and demonstrated little evidence of planning prior to the presentation. Proof of Implementation References Respiratory and Circulatory Systems (2020). Sci-Box (A Self-Learning Package) for JHS for Grade 9. Module 1. Department of Education, Iloilo. Lungs Expanding and Contracting. https://www.google.com/url?sa=tsource=web&rct=j&url=https:///www.sfi.ie/site-files/primaryscience/media/pdfs/col/lungs_activity.pdf&ved=2ahUKEwj_cDivbb6AhWLtlYBHYW9CPkQ6sMDegQILRAB&usg=AOvVaw0TPNicdDaHsU0O2wxzVON