Take a Breath: A Tour Through the Human Respiratory System 

Subject: The Human Respiratory System.

Grade: 5

Lesson Objective: To explain how the human respiratory system functions.

Common Core Standard: 5.L.1.2. Compare major systems of the human body.

Materials: Diagram of the human respiratory system in poster or model form. 

A pack of tissues. (For Emergencies!)

Starter

Ask a student to come to the front of the class and face the other students. Ask your student to take a deep breath.

Ask the class what the student has done.

Wait for replies, then ask why breathing is important.

Students will probably come up with obvious answers.

Now ask how breathing works.

Explain that in today’s class, students will learn how the human respiratory system functions.

Main

Tell your students that there are six parts to the respiratory system. Point to your nose and tell your students that this is where the respiratory system starts.

1. Nasal Cavity

Tell your students that the nose opens into the nasal cavity, which is above and behind the nose. Point it out on your diagram. Explain that the nasal cavity moisturizes and warms outside air as you breathe it in.

Ask your students to sniff. Wait for the inevitable giggles to die down and then ask what is in the nose. Once the class has settled, tell them that the scientific word is mucus. Ask them if they can guess what mucus does. Explain that mucus and hair help stop dust and other contaminants from entering the body.

2. Pharynx

Tell your class that this is a hollow tube about five inches long. It links the nasal cavity to the larynx. Tell students that the pharynx also has another job. Now ask the students to hold their noses and breathe through their mouths. Point out that it’s perfectly possible, if not very polite, to breathe through the mouth. Point out that the pharynx is part of the respiratory and digestive systems, which is why people can choke when they are eating.

Tell your students that the pharynx is divided into three sections.

• The nasopharynx - leads off the nasal cavity.
• The oropharynx - leads from the mouth.
• The laryngopharynx - leads into the larynx.

3. Larynx

Tell your students that the larynx is about two inches long. It allows air, and only air, to pass along to the trachea. When you cough, that is the larynx clearing your respiratory system. It’s a good idea to run through the first three components again at this point. Ask your students questions about them and repeat if some students are unsure.

4. Trachea

Tell your class that the trachea is also called the windpipe. This is a good name for this hollow tube that connects the larynx with the bronchi and lungs. The trachea lies behind the breastbone and divides into two primary bronchi. Its job is to move air into and out of the lungs. The trachea is surrounded by bands of cartilage that make it flexible.

5. Bronchi

One bronchus goes to each lung; this extension of the trachea subdivides into smaller tubes called bronchi. The bronchi bring oxygen into the lungs and take carbon dioxide away. The bronchi divide into small bronchioles, and air sacs called alveoli in the lungs.

6. Lungs

The final part of the respiratory system. The lungs lie on either side of the chest cavity. Here the alveoli exchange gases with the blood capillaries surrounding them, swapping oxygen for carbon dioxide.

 Go over the functions of the last three components as you point them out on the diagram. Now that you have finished describing the system, you might ask your students to draw a system diagram and even work with a partner to create posters or presentations on what they have learned. 

Feedback and Additional Practice

If you need to review the respiratory system parts, divide the class into six groups. Give each group the name of one part of the system. Ask them to describe what their part does in order. So, group one—the nasal cavity, group two—the pharynx, and so on.

Fun Facts

• The lungs are the only organs in the body that can float on water.
  • Answer: The alveoli are full of air.
• Ask students how many alveoli they think are in each lung.
  • Answer: Around 3 million.
• Over 200 different viruses can cause the common cold.
• Ask students to find out why we yawn.
  • Answer: To draw more oxygen into the body.
• Ask students to explain why smoking is bad for their health.

Written by Stephen Tomkinson
Education World Contributor
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