The Lungs and Respiratory System

Author(s): Kimberly Besst, Deborah Rauchwerger, Karen Hauser, Robbie Ruelas,

Lesson Overview

Grade level(s):

Elementary School (K-5), Grade 2, Grade 3, Grade 4, Grade 5


Biology/Life Science


Respiratory System

Big ideas(s):

  1. Our bodies need oxygen to survive and work.  Oxygen is used to make energy.
  2. Our respiratory system, which helps us breathe in oxygen and breathe out carbon dioxide, includes the mouth, nose, windpipe, and lungs.  The diaphragm is the muscle that helps us breathe.
  3. Tobacco contains many toxic chemicals and gunk including nicotine and tar.  Tobacco use can cause short-term and long-term damages to our bodies, especially our lungs.
  4. Tobacco use is addictive.

What you need:

Materials used from the SEP Resource Center:

  • Lung specimens (healthy and diseased)
  • Lung slices
  • Gloves
  • Balloon-bottle model lungs
  • Anatomical Lung model
  • Respiratory system poster
  • Asthma kit (different sized straws and balled up paper/foil)


Whole group for the intro, then split class into two groups that will rotate through the stations.



Time needed:

1 hour

Author Name(s): 
Kimberly Besst, Deborah Rauchwerger, Karen Hauser, Robbie Ruelas,

Students review what they already know about breathing and the respiratory system. After a brief introduction to the respiratory system, students break into two groups and rotate through two stations. At one station the students observe and touch human lung specimens and discuss the effects of smoking. At the other station, students simulate the effect of astma on breathing.

Getting ready: 

Get the two stations ready:

For Station 1: Dissection table + smoking
Put on gloves and remove the lung specimens from the containers, trying to let as much fluid as possible leak out before putting them on the trays.
Have the respiratory system model and the lung balloon model ready.

For station 2: Asthma Straw activity
Have the Asthma kit ready.

Lesson Implementation / Outline


(1) What do we know? & Intro (15 mins)

Have everyone take a deep breath in, and then out.
Ask students:
What is breathing? Why do you need to breathe?
What parts of your body are used for breathing?
Take another breath. Where did  the air come in? What part of your body got bigger?
How do you think different activities, like running or swimming, affect your breathing?

It is important to first understand how the body breathes in air. We can live without food for a few weeks, without water for a few days, but without air for only a few minutes.

Big Idea #1: Breathing is essential for life. We breathe in oxygen from the air. All parts of our body need oxygen to survive and function because oxygen is used to make energy.

Breathing is essential for life. 
Ask students:
Why do we need to breathe?  What is it in the air that is so important to us?

[Use attached powerpoint to explain the following concepts]

It is the oxygen from the air that we need.
All cells/part of our body need energy to survive and function. 
They make energy using the oxygen that we breathe in and the foods we eat.

Glucose (food) + Oxygen --> Energy + Carbon Dioxide (waste)

Big Idea #2: Our respiratory system, which helps us breathe in oxygen and breathe out carbon dioxide, includes the mouth, nose, windpipe, and lungs. The diaphragm is the muscle that helps us breathe.

The body system that helps us breathe is called the respiratory system.
Mouth and Nose: We breathe in air through our mouth and nose.
Windpipe:  From the mouth and nose, air passes through our windpipe and into the lungs.
Lungs:  Lungs are made up of millions of small air sacs where oxygen is transported into the blood. These air sacs are called alveoli,

Once oxygen enters our blood, it is carried by the red blood cells to all cells throughout the body. In this way, the respiratory system and our heart work together to help the body function. 

When we breathe in, the muscle under our lungs - called the diaphragm - pulls the lungs down.  This sucks air into our lungs (use the demo model).  Our lungs are stretchy like a balloon, so when the muscle relaxes, the lungs collapse and air is pushed back out.

Now split the class into 2 different activity stations.


STATION 1: Dissection Table  + Smoking (15 mins)

Prep: Give each student ONE glove. 

At this station we are going to see what real human lungs look like.  The lungs come from people who donated their body to science after they died.  Because of this they are very special, and we all have to be very careful with them.  You can touch and feel them with your gloved hand, but be gentle do not pick them up or pull on them. To help preserve the lungs, we keep them in a special alcohol solution, which might smell a little funny.   It is ok if you don’t feel like touching the lungs, you can just look at them or look at the models. 

  1. Have students put on their one glove.
  2. Give a quick overview of lungs on the anatomical model, then show it again on the actual specimens.
  3. Allow the students to feel the lung specimens.  Encourage them to compare and contrast the normal vs. diseased lung.
  4. For students who are not at the specimens, they can use the bottle-lung models to see how the diaphragm helps inflate the lungs or look at the images of smoker vs. non-smoker lungs.

A lot of people think the lungs are like big air filled bags. But as you can see and feel they are actually pretty solid and heavy.  Our airways are like a tree.  It starts with a big trunk (our windpipe) that then divides into smaller and smaller branches.  At the very tip of each branch you have the leaves, which are like the air-filled sacs (alveoli).  All of the alveoli are surrounded with blood vessels.  This is why the lungs are so solid.

Healthy Lung vs. Smoker's Lung


This is a normal lung, and this is the lung of a smoker.  Do you guys notice any differences?
What do you know about smoking?

Big Idea #3:Tobacco contains many toxic chemicals and junk including nicotine and tar.

Nicotine and tar are harmful chemicals found in tobacco products, such as cigarettes, cigars, chewing tobacco and snuff. People who use these products breathe in air contaminated with the toxic chemicals and junk. 

Since the smoke the smokers breathe in travels the same route through the respiratory system as air, all this junk clogs up their lungs (see images of normal vs. smoker lungs) and makes it hard to breathe.  Emphysema which is a disease you get from smoking, destroys the alveoli sacs.  This is like popping all the little alveoli balloons in the lungs.  It leaves big empty spaces and reduces how much oxygen you can get (emphysema vs normal alveoli image).

Normal vs. Emphysema alveoli

 What is second-hand smoke?

Everyone physically around the smokers are affected by breathing in the smoke. This second hand smoke has many of the same chemicals as the inhaled smoke.


STATION 2: Asthma Straw activity (15 mins)

What happens when someone gets less air?

Explain that they get less oxygen, and remind them that oxygen works together with food to produce energy. With less oxygen, the cells make less energy to carry out the body’s functions.

What kinds of things would prevent us from getting the normal amount of air when we breathe?
Does anyone have or know some who has asthma?

Asthma is a common breathing condition that causes your airways to get smaller.  It only happens sometimes, and doesn’t last for very long (these are called asthma attacks).  It can feel like you are breathing through a straw, and you might also have wheezes. An asthma attack can be caused by different things for different people: for some it might be triggered by pollen, dust, smoke, exercise, stress, or getting sick.

  1. Give every student a small straw and a bubble tea straw.
  2. Ask each student to first breathe five deep, normal breaths without a straw.
  3. Ask each student to breathe five deep breaths out of the bubble tea straw, and ask whether breathing is harder this way.
  4. Ask each student to breathe five breaths out of the narrow straw and compare it to the previous two situations.
  5. Now have the student “race” by blowing paper or tin foil balls across the table to a finish line.  Some students should have big straws, little, straws and no straws (normal breath)
  6. Ask the students which was easier.

Whenever the student breathes through the straw, this is similar to breathing through smaller airways (like in asthma) but also like having less lung space (like in smoking). Unlike asthma though, which only happens sometimes, smokers have a hard time breathing ALL the time.  This relates to the effect of tobacco on the respiratory system because less oxygen is able to fill the lungs with so much tar present. The less amount of oxygen in the body, the less oxygen to the muscles. Once again, oxygen works together with food to produce energy, such as the energy needed to exercise.

Do you think it would be harder to run around and play if you could only breathe through a straw?


Wrap-up / Closure: 

 Questions/Review (5-10 mins)

What are some cool or new things/words that you learned today?

Breathing is necessary for us to live.
We breathe in (oxygen), and breathe out (carbon dioxide).
Trace the flow of air through our respiratory system using the diagram. 

thelungs.ppt8.41 MB
NGSS Topics
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