Gas Exchange in the Lungs

• What is the primary function of the lungs?

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

  The heart pumps blood to the lungs
• What is the name of the tube that air passes into the lungs through?

  Trachea
• What is a key feature of the trachea?

  It contains rings of cartilage
• What is the purpose of the cartilage in the trachea?

  To prevent the trachea from collapsing
• What do the bronchi split into?

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

  Alveoli
• What is the role of alveoli in the lungs?

  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 adaptations do alveoli have for gas exchange?

  They have a huge surface area
• Why do alveoli have very thin walls?

  To shorten the diffusion path
• How does a good blood supply aid gas exchange in alveoli?

  It rapidly removes oxygen from blood
• What effect does breathing have on gas exchange?

  It increases the rate of diffusion
• How does breathing affect concentration gradients in the alveoli?

  It maintains high concentration gradients
• 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 quickly remove oxygen
• Describe the process of gas exchange in the alveoli.

  1. Oxygen diffuses from air into blood
  2. Carbon dioxide diffuses from blood into air
  3. Breathing refreshes oxygen and removes carbon dioxide