Gas exchange in 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 is the tube called that air passes into the lungs through?

  Trachea
• What prevents the trachea from collapsing during inhalation?

  Rings of cartilage
• What do the bronchioles subdivide into?

  Bronchioles
• What are the tiny air sacs in the lungs called?

  Alveoli
• What is the primary function of alveoli?

  Sites of gas exchange
• What happens to oxygen in the alveoli?

  It diffuses into the bloodstream
• What happens to carbon dioxide in the alveoli?

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

  • Millions of alveoli provide a large surface area
  • Very thin walls for 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 be able to do by the end of the video?

  Describe lung adaptations for gas exchange