This lesson is only available to users who have subscribed to the Biology course. Please log in, or click here if you would like to gain access to the full course.
Introduction to the lesson
In the last lesson we looked at the trachea, the bronchi and the bronchioles. These are airways leading to the true gas exchange surface: the alveoli. In this lesson, we will learn about the alveoli and the mechanism by which gases are exchanged between the alveoli and the blood capillaries.
Alveoli
Read the section “Alveoli" on p.189-190 of your text book.
Learning Activity 1
Answer the following questions in your exercise book.
- Describe the role of elastic fibres in the alveoli.
- Describe the structure of the alveoli. Illustrate your descriptions with diagrams.
- Answer Questions 9.2 and 9.3 on p.190 of your text book.
- How do oxygen and carbon dioxide molecules move between the air and the blood?
- What is this process called?
- What about the structure of the alveoli facilitates this movement?
- How is the concentration gradient maintained?
Definitions and review
Mindmap
Add this section to your chapter nine mindmap.