Topic: How do we breathe?

Author: Zyta Sendecka

Target group

Students of the 4th grade of an elementary school.

Core curriculum

4th grade

IV. Me and my body. The student:

1) lists the systems that build the human body: skeletal, respiratory, digestive, circulatory, reproductive and nervous systems, and gives their basic functions;

2) shows the systems that build the human body and the sensory organs on a board, a model and own body.

The general aim of education

The students describe the structure and function of the respiratory system.

Criteria of success

• You will provide the functions of the selected respiratory system;

• identify organs that build the respiratory system;

• show on the model how to inhale and exhale.

Key competences

• communication in the mother tongue; 

• communication in a foreign language;

• mathematical competence and basic competences in science and technology; 

• digital competence; 

• learning to learn; 

Methods / forms of work

Conversation, work with text, measurement and laboratory method.

Individual work and work in pairs.

Teaching aids

• resources in the e‑textbook: abstract;

• interactive or traditional board;

• tablets/computers.

Before lesson

Each student brings the following to the lesson: a drinking straw, two balloons, a rubber band, scissors, plasticine, a plastic bottle with a cap (1l) and with a cut bottom (at 2 cm), and a hole in the cap with a diameter of the straw.

Lesson plan overview (Process)

Introduction

1. The teacher gives the topic, the goal of the lesson in a language understandable for the student, and the criteria of success.

2. The teacher asks the students what does a human being breathe for. The teacher writes down the proposed answers on the board. Then, together with the students, they choose the best explanation, e.g. formulated in the following way: to deliver oxygen to the body.

Realization

1. The teacher asks the students to become familiar with the human respiratory system structure (the graphic entitled „Human respiratory system”).

2. Then, the students perform an interactive exercise 1.

3. The teacher asks students to become familiar with the functions the following elements perform during breathing: nasal cavity, larynx and lungs.

4. The students do exercise 3 themselves.

5. The teacher asks the students to do Task 4 in pairs.

6. The teacher informs the students that they will construct the following model based on the instructions presented: „How to make a lung ventilation model”.

7. The students construct a lung model and after learning the inhalation and exhalation mechanism description, they show the diaphragm on the model and determine its role during this process.

8. Then, the students perform an interactive task themselves: Sign the indicated elements of the model.

Summary

• The teacher indicates a selected organ in the illustration (the graphic entitled „Human respiratory system), and the student gives its name and function.

• The teacher asks the students to finish the sentences:

On today's lesson I have learnt that...

On today's lesson I liked...

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

How do we breathe?

In order to live we must breathe. Breathing we take up oxygen from the air. This invaluable substance is necessary to keep all the organs and all the cells in our body working. Thanks to oxygen, the body is able to obtain the energy necessary for life from food. Breathing process starts with the air from the environment getting through our nasal cavity into the lungs. Inside the lungs, the gas exchange takes place, i.e. blood absorbs oxygen and releases carbon dioxide which is subsequently removed from the body. Breathing is the task of the respiratory system.

The respiratory system consists of the respiratory tract and lungs. The first section of the respiratory tract are the nostrils, through which air is inhaled into the nasal cavity. Nasal cavity acts as a filter: it intercepts most pollutants, i.e. dust, viruses or bacteria. It also warms up the air and makes it more humid. Nasal cavity is also the organ of smell. Next is the throat – a section shared between the digestive and respiratory systems. Then the air goes into the larynx. When food is swallowed, the entrance into the larynx is closed to prevent food particles from getting in. Larynx contains vocal cords that enable us to make sounds. Next, the air goes into the trachea and then, through a pair of bronchi, into the lungs. Respiratory system along the entire length is lined with cells with cilia that retain and remove some air pollutants such as the abovementioned dust, viruses or bacteria.

Lungs resemble large, spongy and springy bags. This is where gas exchange takes place. Here, bronchi branch out into smaller and smaller tubes at the end of which there are pulmonary alveoli. In the alveoli, oxygen from the air is transferred into the blood. Blood transports oxygen throughout our body and into each cell. Cells release carbon dioxide into the blood. Carbon dioxide is then transported into the lungs where it is transferred from the blood into the alveoli. Then it is removed with exhaled air.

Gas exchange consists of supplying oxygen‑rich air into the lungs and removing from the lungs air containing a lot of carbon dioxide. It is made possible by the ventilation mechanism. It consists of inhaling and exhaling. During inhalation, oxygen‑rich air flows through the respiratory tract into the lungs. During exhalation, oxygen‑depleted air (but rich in carbon dioxide) gets out of the respiratory system.

Ventilation of the lungs (or air exchange in the lungs) is a process powered by respiratory muscles: a diaphragm and intercostal muscles. The diaphragm acts like a piston whose movement causes air to be sucked into, and pushed out of the lungs. Intercostal muscles enable the volume of the ribcage to change.

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• The human respiratory system consists of the airways (nasal cavity, throat, larynx, trachea, bronchi) and the lungs.

• The airways cleanse, moisturize and warm up the air.

• The gas exchange, that is, taking oxygen into the blood and expelling carbon dioxide from it, takes place in the pulmonary alveoli that build the lungs.

• The mechanism of lung ventilation is based on inhaling, that is sucking air into the lungs, and on exhaling, that is, pushing air out of the airways.

• In diaphragmatic ventilation, the diaphragm and intercostal muscles play an important role.