This lesson describes the structures and functions of the components of the mammalian gaseous exchange system. The PowerPoint and accompanying resources have been designed to cover point 3.1.1 [c] of the OCR A-level Biology A specification and contains links to future topics such as transport in animals as well as prior knowledge checks of their recall of the content of previously covered modules.
The lesson is filled with a range of activities such as guided discussion periods, exam-style questions (with markschemes) and quiz competitions and these run alongside the slides containing the detailed A-level Biology content to cover the following features:
- The incomplete rings of cartilage, ciliated pseudostratified columnar epithelium and goblet cells in the trachea
- The narrowing airways of the primary, secondary and tertiary bronchi
- The elastic fibres and smooth muscle in the terminal and respiratory bronchioles and the change from simple columnar epithelium to simple cuboidal epithelium
- The large surface area to volume ratio and the simple squamous epithelium of the alveoli
- The pleural cavity and fluid of the lungs
When describing the production of mucus by the goblet cells in the trachea, time is taken to consider cystic fibrosis and the inheritance of this autosomal recessive disorder. Students will be supported in working out genotypes from a pedigree tree to prepare them for module 6.1.2 (Patterns of inheritance)