Objectives (5 - 7 minutes)

1. Understanding the Respiratory System: The student should be able to identify and describe the main parts that make up the human respiratory system, including the nose, trachea, lungs, and diaphragm. This includes understanding how these parts work together to enable breathing.

2. Awareness of the Importance of Breathing: The student should be able to understand the importance of breathing for life and health. This includes learning about oxygen and carbon dioxide, and how the human body uses breathing to obtain oxygen and get rid of carbon dioxide.

3. Practical Exploration of the Respiratory System: The student should be able to explore the respiratory system in a practical way, using playful and interactive activities that allow them to better understand how the system functions.

Secondary Objectives:

• Development of Language and Scientific Vocabulary: During the lesson, students will have the opportunity to learn and use specific scientific vocabulary related to the respiratory system. This will help develop their language and communication skills.
• Stimulation of Interest in Science: Through a practical and fun approach, the lesson aims to stimulate students' interest in science and the human body.

Introduction (10 - 12 minutes)

1. Review of Previous Content: The teacher will start the lesson by reminding students about the basic concept of the human body and its parts, with emphasis on the head and chest, where the main parts of the respiratory system are located. This review will help set the stage for the new content that will be presented. (3-4 minutes)

2. Everyday Problem Situations: The teacher will present two problem situations to the students:

   • First situation: "Imagine you are running very fast and start to feel short of breath. Why does this happen?"
   • Second situation: "When you catch a cold, why does your nose get stuffy and you have difficulty breathing?" These problem situations are designed to arouse students' curiosity and encourage them to think about the respiratory system and how it functions in different circumstances. (5-6 minutes)

3. Contextualization of the Subject's Importance: The teacher will explain to the students the importance of the respiratory system for life and health. They will emphasize that breathing is one of the most important functions of the human body, as it allows us to obtain the oxygen needed to live and helps us get rid of carbon dioxide, a waste product that can be toxic in large quantities. (2-3 minutes)

4. Interesting Topic Introduction: To spark students' interest, the teacher can share some curiosities about the respiratory system. For example, they can mention that on average, a person breathes about 20,000 times a day or that the lungs are so soft that if they could be stretched, they would cover a tennis court. Another curiosity could be that the nose acts as an air filter, as it helps filter out unwanted particles in the air we breathe. (2-3 minutes)

Development (20 - 22 minutes)

1. Activity: Building an Artificial Lung

   • Materials Needed: Two small plastic bottles, two straws, string, balloons, scissors, and tape.

   • Activity Description:

     1. The teacher will divide the class into groups and distribute the necessary materials to each group.
     2. Each group will receive two plastic bottles. They should cut the bottom of one of the bottles and attach a balloon to the opening with tape, simulating the lung.
     3. Next, they should cut the top of the other bottle and insert a straw into the opening, simulating the trachea.
     4. The bottle representing the lung should be connected to the bottle representing the trachea using a straw and a piece of string, simulating the diaphragm.
     5. Now, when the group pulls the balloon out of the bottle, they will see that the diaphragm (the string) moves downward, as it does when we breathe in. When they push the balloon in, the diaphragm moves upward, as when we exhale.

   • Objective: This practical activity will allow students to understand how the diaphragm moves during breathing and how it helps fill and empty our lungs.

   • Estimated Time: 10-12 minutes

2. Activity: Breathing Game

   • Materials Needed: None.

   • Activity Description:

     1. The teacher will organize the class in a circle.
     2. Instruct students to breathe deeply and slowly. While they do this, the teacher will make a hand movement up and down, as if they were "filling" and "emptying" a balloon.
     3. The teacher will do this a few times so that students can see the movement of "filling" and "emptying" the lungs.
     4. Then, the teacher will explain that when we breathe, our lungs expand like a balloon, filling with air. When we exhale, our lungs empty.
     5. After that, the teacher will start the game. They will say "Breathe in deeply!" and make the movement of "filling" the balloon. Then, they will say "Exhale!" and make the movement of "emptying" the balloon. Students should imitate the teacher's movement.
     6. The teacher will continue the game, increasing or decreasing the speed of the commands, so that students need to focus on their breathing.

   • Objective: This practical activity will help students better understand the concept of breathing and the importance of the "filling" and "emptying" movement of the lungs.

   • Estimated Time: 8-10 minutes

3. Activity: Obstructed Trachea Game

   • Materials Needed: One straw per student.

   • Activity Description:

     1. The teacher will ask students to breathe deeply and slowly through a straw. They should notice that it is easy to pull air through the straw.
     2. Then, the teacher will fold a straw in half and ask students to breathe through it again. This time, they should notice that it is harder to pull air.
     3. The teacher will explain that when we have a stuffy nose, it is as if our "trachea" (straw) is folded, making it difficult for air to pass through.

   • Objective: This practical activity will help students understand how a stuffy nose can make breathing difficult.

   • Estimated Time: 8-10 minutes

It is important to note that the teacher can choose to perform only one of the activities described above, or even combine elements from different activities for greater diversification and dynamism during the lesson.

Return (8 - 10 minutes)

1. Group Discussion on Activities: The teacher will gather all students in a large circle for a group discussion. Each group will have the opportunity to share their findings and experiences with the practical activities carried out. The teacher will encourage students to describe what they observed during the activities, asking questions like: "What happened when you pulled the balloon out of the bottle?", "How was it to breathe through the folded straw?", "Did you notice any difference between breathing with and without the straw?" This discussion will allow students to consolidate their understanding of how the respiratory system works. (3-4 minutes)

2. Connection with Theory: After the discussion, the teacher will make the connection between the practical activities and the theory presented at the beginning of the lesson. They will reinforce the main points of the lesson, explaining how the diaphragm, lungs, trachea, and nose work together to enable breathing. The teacher will also reinforce the importance of breathing for life and health. (2-3 minutes)

3. Individual Reflection: To conclude the lesson, the teacher will propose that students reflect individually on what they have learned. They will ask two simple questions to stimulate students' reflection:

   • "What was the most interesting part of today's lesson and why?"
   • "What did you learn today about the respiratory system that you didn't know before?" Students will have a minute to think about these questions. Then, the teacher may ask some volunteers to share their answers with the class. This will allow the teacher to assess students' understanding and also identify which aspects of the content need to be reinforced in the future. (3-4 minutes)

4. Lesson Closure: To conclude the lesson, the teacher will thank the students for their active participation and reinforce the importance of what was learned. They may say: "You all did a great job today, exploring and learning about the respiratory system. Remember, breathing is essential for our life and health. Keep curious and exploring the world around you!" (1 minute)

Conclusion (5 - 7 minutes)

1. Lesson Summary: The teacher will summarize the main points covered during the lesson. They will remind students about the main parts of the respiratory system (nose, trachea, lungs, and diaphragm) and how they work together to enable breathing. The teacher will also reinforce the importance of breathing for life and health. (2-3 minutes)

2. Connection between Theory, Activities, and Practice: The teacher will explain how the lesson connected theory, practical activities, and practice. They will emphasize that the practical activities served to illustrate and reinforce the theoretical concepts learned. Additionally, the playful activities allowed students to explore the respiratory system in a practical and fun way, which helped make the content more meaningful and memorable. (1-2 minutes)

3. Extra Materials: The teacher will suggest some extra materials for students who wish to deepen their knowledge of the respiratory system. These could include children's books about the human body, educational videos online, or interactive games that explore the respiratory system. The teacher may suggest that students look for these materials at home, or they may provide some of these materials for the classroom. (1 minute)

4. Importance of the Respiratory System: Finally, the teacher will reinforce the importance of the respiratory system for students' daily lives. They may mention that thanks to the respiratory system, we can run, jump, play, and do all the activities we love. Additionally, breathing helps us stay healthy, as it allows us to obtain the oxygen our body needs and helps us get rid of carbon dioxide, a toxic waste product. (1 minute)