Gas exchange in the lungs

• What is the main function of the lungs?

  Gas exchange
• How does blood collect oxygen in the lungs?

  The heart pumps blood to the lungs
• What are the two main tubes that air passes into the lungs through?

  The trachea and bronchi
• What is the function of the cartilage in the trachea?

  It prevents the trachea from collapsing
• What do bronchioles subdivide into?

  Smaller tubes called bronchioles
• What are alveoli?

  Tiny air sacs for gas exchange
• What is the primary role of alveoli in the lungs?

  Sites of gas exchange
• How does oxygen move in the alveoli?

  It diffuses into the bloodstream
• How does carbon dioxide move in the alveoli?

  It diffuses out of the bloodstream
• What adaptations do alveoli have for gas exchange?

  • Millions of alveoli provide a huge surface area
  • Very thin walls for a short diffusion path
  • Good blood supply to maintain concentration gradient
• Why is a good blood supply important for alveoli?

  It ensures a steep concentration gradient
• How does breathing affect gas exchange?

  It increases the rate of diffusion
• What does breathing bring into the alveoli?

  Fresh oxygen
• What does breathing remove from the alveoli?

  Carbon dioxide
• Why is it important to learn the adaptations of the lungs?

  They are frequently tested in exams
• What should you do to prepare for questions on lung adaptations?

  Review the revision workbook