Objectives (5 minutes)

1. Understand the importance of the respiratory system for human life: Students should be able to understand that the respiratory system is essential for our survival, allowing the entry of oxygen and the exit of carbon dioxide, which are necessary for the functioning of our body.

2. Identify the main parts of the respiratory system: Students should be able to identify and name the main parts of the respiratory system, such as the nose, throat, trachea, lungs, and diaphragm. They should also be able to describe the function of each of these parts.

3. Understand the breathing process: Students should be able to describe, in simple terms, how the breathing process occurs. This includes inhalation, where oxygen-rich air enters the body, and exhalation, where carbon dioxide-rich air is released from the body.

Introduction (10 - 15 minutes)

1. Content review: The teacher should start the lesson by reminding students of what they have already learned about the human body and the importance of keeping our bodies healthy. Students can be asked which parts of the body they know, how they function, and why they are important. (5 minutes)

2. Problem Situations: Next, the teacher should present two problem situations that will stimulate students' curiosity about the respiratory system.

   • The first problem situation could be: 'Imagine you are running and suddenly need to stop and rest. Why are you breathing so fast and hard? What is happening inside your body?'

   • The second problem situation could be: 'What if you are running and someone covers your nose and mouth, what do you think will happen? Why is this dangerous?' (5 minutes)

3. Contextualization: The teacher should explain that our body needs oxygen to function properly and that breathing is how we obtain this oxygen. Similarly, we need to get rid of carbon dioxide, which is a waste product of our body. The teacher can use everyday examples, such as running, to illustrate the importance of the respiratory system. (5 minutes)

4. Introduction to the topic: The teacher should then introduce the topic of the lesson, explaining that they will learn more about the system that allows us to breathe, called the respiratory system. It can be said that the respiratory system is like an air machine inside our body, which helps us breathe and live. Additionally, the teacher can mention that this is one of the most important systems in the human body, without which we could not live. (5 minutes)

Development (25 - 30 minutes)

1. Explanation about the respiratory system (10 - 15 minutes)

   • The teacher should start by explaining that the respiratory system is composed of various parts, such as the nose, mouth, throat, larynx, trachea, bronchi, lungs, and diaphragm.

   • Each part should be identified on the child's body, if possible, or on an anatomical model if available.

   • The function of each part should be explained clearly and simply. For example, the nose and mouth are the entry points for air into our body, the throat and larynx help guide the air to the trachea, which is like a tube that carries air to the lungs. The lungs are like balloons that fill with air when we breathe in and empty when we breathe out. The diaphragm is a muscle that contracts and relaxes to help fill and empty the lungs.

2. Demonstration of the breathing process (10 - 15 minutes)

   • The teacher should then demonstrate the breathing process to the students. To do this, they can ask students to place one hand on their chest and another on their abdomen.

   • The teacher should then show how, when we inhale, air enters through the nose or mouth, passes through the throat, larynx, trachea, bronchi, and finally reaches the lungs. During inhalation, the diaphragm contracts and descends, expanding the thoracic cavity (chest cavity) to allow air to enter the lungs. During exhalation, the diaphragm relaxes and rises, reducing the space in the chest cavity and forcing air out of the lungs.

   • The teacher should repeat this process of inhalation and exhalation several times so that students can see and feel what is happening during breathing.

   • While demonstrating, the teacher should explain that when we inhale, we are bringing oxygen into our body, which is used to burn the food we eat and gives us energy. And when we exhale, we are releasing carbon dioxide, which is a waste product of our body.

3. Interactive Activity: 'The Runner' (5 - 10 minutes)

   • To reinforce students' understanding of the respiratory system, the teacher can propose an activity called 'The Runner'.

   • In this activity, students will simulate the breathing process, acting as if they are running. They will inhale and exhale deeply, moving their arms and trunk up and down, as if they are running.

   • During the activity, the teacher can ask questions like: 'What do you feel when you inhale deeply? And when you exhale?' or 'Why do you think the air enters and exits our lungs when we breathe?'

4. Interactive Activity: 'The Air Stop' (5 - 10 minutes)

   • To complement the interactive activities, the teacher can propose the activity 'The Air Stop'.

   • In this activity, students will recall the importance of breathing, as they will simulate the sensation of not being able to breathe. They will hold their breath for a few seconds to understand the discomfort of not being able to breathe.

   • After the activity, the teacher can ask questions like: 'How did you feel when you couldn't breathe? Why do you think this is dangerous?'.

5. Discussion and conclusion (5 - 10 minutes)

   • At the end of the activities, the teacher should promote a classroom discussion, asking students what they learned from the activities and how they felt while doing the simulations.

   • The teacher should then summarize the main points of the lesson, reinforcing the importance of the respiratory system for human life and how it functions.

   • Finally, the teacher should reiterate the importance of taking care of the respiratory system and overall health, reminding students about the importance of breathing fresh air, exercising, and maintaining a healthy diet.

   • The teacher can also suggest that students research at home about the respiratory system and how to maintain lung health. (5 - 10 minutes)

Return (5 - 10 minutes)

1. Group discussion (3 - 4 minutes)

   • The teacher should gather all students in a circle for a group discussion. Each group should share what they learned during the 'The Runner' and 'The Air Stop' activities.

   • The teacher can ask targeted questions to each group, such as: 'What did you feel during 'The Runner' activity?' or 'Why do you think it is dangerous not to be able to breathe, as in 'The Air Stop' activity?'.

2. Connection to theory (2 - 3 minutes)

   • After the group presentations, the teacher should make the connection between the practical activities and the theory presented at the beginning of the lesson.

   • For example, the teacher can say: 'During 'The Runner' activity, we simulated the breathing process. When we run, our body needs more oxygen to provide the energy we need. That's why we breathe faster and harder. In 'The Air Stop' activity, we could feel the discomfort of not being able to breathe. This happens because our body needs oxygen to live. That's why it is very important to take care of our respiratory system and always breathe fresh air'.

3. Reflection (1 - 3 minutes)

   • To conclude the lesson, the teacher should propose that students reflect on what they have learned. The teacher can ask two simple questions for this reflection:

     1. 'What did you find most interesting about the respiratory system? Why?'
     2. 'Why is it important to take care of our respiratory system?'

   • The teacher should give a minute for students to think about the answers before sharing them with the class.

4. Learning verification (1 - 2 minutes)

   • The teacher should listen to the students' answers and praise their contributions. They can then reinforce the importance of the respiratory system and overall health, and how what they learned in the lesson can be applied in their daily lives.

   • Finally, the teacher can encourage students to continue learning about the human body and the importance of staying healthy, suggesting that they talk to their parents or do additional research at home. (5 - 10 minutes)

Conclusion (5 - 10 minutes)

1. Recapitulation of contents (2 - 3 minutes)

   • The teacher should start the conclusion by recapping the main points covered in the lesson about the respiratory system. They should review the parts of the respiratory system, their functions, and the breathing process.

   • The teacher can use images or drawings on the board to help reinforce the students' visual memory.

   • The teacher should ask students if they remember the parts of the respiratory system and their functions, encouraging them to respond and helping those who have difficulty remembering.

2. Connection between theory and practice (1 - 2 minutes)

   • The teacher should then explain again how the practical activities 'The Runner' and 'The Air Stop' connect with the theory presented in the lesson.

   • They can reinforce that during 'The Runner' activity, they simulated the breathing process and could see and feel how the air enters and exits the lungs. And during 'The Air Stop' activity, they could understand the importance of breathing and how uncomfortable it is not to be able to breathe.

   • The teacher can ask students if they can see the connection between the practical activities and the theory, encouraging them to think critically.

3. Suggestion of extra materials (1 - 2 minutes)

   • The teacher can then suggest some extra materials for students who want to deepen their knowledge about the respiratory system.

   • They can recommend books, websites, educational videos, or interactive apps that have additional information about the respiratory system and the importance of taking care of lung health.

   • The teacher should remind students that learning is a continuous process and that they are responsible for their own learning.

4. Importance of the subject for everyday life (1 - 2 minutes)

   • Finally, the teacher should emphasize the importance of the respiratory system for everyday life. They should remind students that breathing is a vital function of the human body and that without oxygen, we would not be able to live.

   • They can explain that the respiratory system is like the 'air machine' of our body, which allows us to breathe and live.

   • Additionally, the teacher can highlight that taking care of the respiratory system is essential to maintain good health. They should remind students about the importance of breathing fresh air, exercising, and maintaining a healthy diet.

   • The teacher can conclude the lesson by reinforcing the idea that by learning about the respiratory system, students are acquiring knowledge that can be applied in their daily lives to stay healthy and active. (5 - 10 minutes)