Lesson Plan

• Describe the main structures of the human gas exchange system (lungs, trachea, bronchi, bronchioles, alveoli, capillary network).
• Explain how structural features of each component facilitate efficient gas exchange.
• Apply Fick’s law to predict factors influencing diffusion rate in the alveolar‑capillary membrane.
• Compare the roles of cartilage, smooth muscle, and surfactant in maintaining airway patency.
• Analyse a diagram to trace the pathway of air from entry to gas exchange.

• Projector and screen
• Printed handouts of a respiratory‑tract diagram
• Whiteboard and markers
• Interactive quiz platform (e.g., Kahoot)
• Lung model or 3‑D printed airway pieces (optional)
• Labeling worksheets

Begin with a quick question: “What part of your body do you think is most important for breathing and why?” Use students’ responses to activate prior knowledge of the airway. Explain that today they will explore how each structure is specially adapted to move air and exchange gases, and they will be able to label and explain the whole pathway by the end of the lesson.

1. Do‑Now (5') – Students complete a blank diagram labeling the major airway structures from memory; teacher collects for a quick check.
2. Mini‑lecture (10') – Using a slide, present the hierarchical pathway (trachea → bronchi → bronchioles → alveoli → capillaries) and highlight key structural features.
3. Guided inquiry (12') – In small groups, students examine the detailed table of features, discuss how each aids gas exchange, and create a short poster summarising their findings.
4. Concept application (8') – Work through a Fick’s‑law problem: predict how increasing alveolar wall thickness would affect O₂ diffusion.
5. Interactive quiz (5') – Kahoot quiz to reinforce terminology and functional relationships.
6. Summary & exit ticket (5') – Each student writes one concise sentence linking a specific structure to its function and submits it as an exit ticket.

Review the pathway, emphasizing how structural adaptations ensure rapid diffusion. Collect exit tickets to gauge understanding and address any lingering misconceptions. For homework, assign a short worksheet where students must label a new diagram and answer a brief question on how a disease (e.g., asthma) would disrupt one part of the system.