Lesson Plan

7. Explain how exercise, asthma and smoking affect the respiratory system

KS3-05-07

Intent

Learning Intention

  • Understand the impact of exercise, asthma and smoking on the human gas exchange system

National Curriculum

  • Gas Exchange Systems - the impact of exercise, asthma and smoking on the human gas exchange system

Working Scientifically

  • Present observations and data using appropriate methods, including tables and graphs

Learning Outcomes

  • Describe factors that affect the respiratory system

Resources

Resources: A stopwatch and the handout. 

Core Handout: A series of exercises on exercise, breathing, smoking and airways. 

Rocket words

  • asthma
  • emphysema
  • cilia
  • mucus
  • tar

Implementation

Prior Learning 

Use the previous lesson to recap on the structure and function of the respiratory system. Recap on the dangers of smoking and the benefits of exercise for overall health from KS2 learning. The students should have an awareness of the harmful chemicals in tobacco smoke and the benefits of regular physical activity for the cardiovascular and respiratory systems.

Starter

Ask the students to list 5 things that are bad for respiratory health.  

Main Teaching

The students will learn about exercise, asthma and smoking and their impact on the respiratory system. After this, they will conduct an investigation into a type of exersise and its impact on breathing rate and heart rate.

Career Film: Palm Kevin Cautivar works as a Clinical Health Assistant for the National Health Service.

Expert Film: Kevin Mantle, a personal trainer at Norfolk Health & Fitness, covers how smoking and asthma can affect exercise.

Mission Assignment

The students are going to investigate how exercise affects breathing and heart rate. Give them the following instructions: 

  1. In your group, choose somebody to be the exerciser, someone to measure heart rate and someone to measure breathing rate. The exerciser could measure one of these.
  2. Measure the exerciser’s pulse at rest (sitting down) for 15 seconds. Multiply the number of beats by 4 to get the heart rate (beats per minute). Record this in the table.
  3. Measure the exerciser’s breathing rate at rest for 15 seconds. Multiply the number of breaths by 4 to get the breathing rate (breaths per minute). Record this in the table.
  4. The person exercising should now begin to exercise for 4 minutes.
  5. After exercise, immediately measure and record the heart rate and breathing rate as before.
  6. Take the heart rate and breathing rate again at 2 minutes after exercise and 4 minutes after exercise. If you have a pulse meter, you may be able to record pulse rate during exercise too, e.g. after 2 minutes, adding this to your table.

Differentiated tasks (Support/Challenge)

Support: For students who require more support, use the results from the most able group and then analyse them collectively as a class. 

Challenge: Compare two or more different exercises. This can be done by either repeating the whole experiment with different exercises or looking at someone else’s results. If the students are looking at someone else’s results to compare, ask them what other variables could have caused this effect and how it could be controlled for.

Impact & Assessment Opportunities

Plenary

Divide the class into four groups and assign each group one of the following categories: "Asthma", "Smoking", "Exercise" and "Healthy Respiratory System".

  1. In each corner of the classroom, put up a poster with the name of the category and some key facts or information about it.
  2. Ask each group to move to the corner that corresponds with their assigned category.
  3. Once everyone is in their corner, give each group a few minutes to come up with a list of 3-5 key points about their category.
  4. Bring the class back together and ask each group to share their key points with the class. As they do so, encourage the other groups to add any additional information they may have learned during the lesson.

Teacher Mastery

Exercise is very important. It helps to boost your mood, reduce the risk of major illnesses and improve the rate of gaseous exchange.  

The more exercise you do, the higher the concentration of carbon dioxide in your respiring tissues and in your blood. This makes your blood a lot more acidic. Different measures take place to prevent the blood from becoming too acidic. For example, there are substances in the blood plasma that react with the increased levels of carbon dioxide to remove it. Your breathing speeds up too. This ensures that more carbon dioxide is removed from the bloodstream.  

Smoking has a negative effect on the gas exchange system in humans. Long-term, it can cause heart disease, lung disease and even cancer. Smoking damages the cilia in the airways. Cilia are the tiny hairs that usually waft the mucus and known pathogens out of the lungs. Once they become damaged, they can no longer waft the mucus out. This means that the mucus builds up and becomes trapped within the lungs. This is why many smokers develop what is known as the ‘smoker’s cough’. This irritates the bronchi which may eventually lead to bronchitis. Bronchitis is when the mucus membrane in the bronchi becomes inflamed.  

Smoking can also damage the walls of the alveoli. The one-cell thick walls of the alveoli begin to break down and join together. This creates spaces that are larger than usual. This means that gases have a larger distance to travel to undergo successful and efficient gas exchange. This reduces diffusion ability and tends to lead to emphysema. It occurs in the bronchi and reduces the airflow both in and out of the lungs. The lining of the cell wall becomes so damaged that it is past the point of repair.

Smoking also increases the levels of carbon monoxide in the lungs. Carbon monoxide joins with the haemoglobin in red blood cells and so decreases their ability to carry oxygen around the body. This will eventually lead to coronary heart disease. Cigarettes also contain tar. Tar is a carcinogen. This increases the chances of lung cancer in an individual. 

Asthma is a respiratory condition. An individual with asthma will have spasm attacks in the bronchi, hyperreactivity and inflammation. This reduces their ability to breathe. Asthma will reduce the airways which makes it increasingly difficult to inhale and exhale. Mucus clogs up the airways which increases the chances of choking and tissues will continue to get damaged due to further narrowing of the airways.