Students’ Learning Outcomes
· Describe the mechanism of respiration in humans.
Information for Teachers
· Many animals possess special breathing mechanisms which increase the rate of exchange of gases between the animals and the external environment.
· The movement of air into and out of the lungs, called “ventilation” renews the oxygen supply in the lungs and removes the surplus carbon dioxide.
· Breathing is a part of respiration in which air is inhaled and exhaled from the lungs.
Concept Map
Material / Resources
Charts showing breathing mechanism a large plastic bottle, vinyl tube of about 6 mm straw used for two balloons, plastic bags, thread, rubber band, plasticizes, a pair of scissors, plastic bottle.
Worm up activity
· Call one student in front of the class.
· Ask the student to take a deep breath and ask the other students to follow the same instruction.
· Now ask them what they did?
(Expected response: They take in and give out the air)
· Ask the students to put their hand on their chest and feel the change in the thoracic cavity.
· After the students response introduce the today’s topic that how the thoracic cavity helps in inhaling and exhaling.
Development
Activity 1
· Show the model / chart of human respiratory system.
· Ask the students to point out / identify parts of the respiratory system.
· Talk about the path or way of air in respiratory system.
· Draw the path way of air on the board by students instruction and ask them to
Activity 2
· Show a chart or draw on the board a diagram of the thoracic cavity.
· Ask the students to inhale air and ask:
o When you inhale, do your ribs move outwards or inwards?
o Will the diaphragm move upwards or downwards on inhaling are?
· Now ask the students to exhale air and ask:
o When you exhale, do your ribs move outwards or inwards?
o On exhalation, will the diaphragm move upwards or downwards?
· Inform the students that the capacity volume of the thoracic cavity will increase during inhalation and decrease during exhalation.
Activity 2
· Prepare a model as shown in figure.
· Ask the students to pull the rubber sheet/balloon attached at the base of the model representing the lungs carefully while diaphragm is being pulled downwards.
· Ask the following questions to involve the students:
o What happens to the balloon representing the lungs?
o On inhalation, will the diaphragm move upwards or downwards?
o What happens when the diaphragm (rubber sheet) is pull down?
o What happens when the diaphragm (rubber sheet) is relaxed?
o What is the relationship between movement of diaphragm (rubber sheet) and lungs (balloons)?
Sum up / Conclusion
· Sum up the lesson by telling the students that breathing is a part of respiration in which air is inhaled and exhaled from the lungs.
· When air enters the lungs it is called inspiration and when air is removed from the lungs it is called expiration.
Assessment
· Draw the given table on the board and ask the students to copy on their notebooks.
· Ask the students to fill the table that how do parts of thoracic cavity help in inhaling and exhaling?
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Parts of thoracic cavity
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Inhalation
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Exhalation
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Ribs
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Diaphragm
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· Ask the following questions to enhance their learning.
o Which contains more oxygen inhaled air or exhaled air?
o What is gaseous exchange?
o What happens in your lungs?
o Why does exhaled air have more carbon dioxide than inhaled air?
Follow up
· Ask the students to prepare a model at home by joining 4 cards strips with thumb pins as shown in the figure.
· Ask the students to bring their model next day and share the working and mechanism of breathing with their class fellows.
