Gas Exchange in the Lungs

• 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 is a key feature of the trachea?

  It contains rings of cartilage
• What do the rings of cartilage in the trachea prevent?

  Collapse of the trachea when inhaling
• What do the trachea split into?

  Bronchi
• What are bronchioles?

  Smaller tubes that branch from bronchi
• What are the tiny air sacs in the lungs called?

  Alveoli
• How do gases diffuse in and out of the bloodstream?

  Through the alveoli
• 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?

  Millions of alveoli create a large 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 the blood
• What effect does breathing have on gas exchange?

  It increases the rate of diffusion
• What does breathing do to carbon dioxide in the alveoli?

  It takes away carbon dioxide
• What is the result of high concentration gradients in the alveoli?

  Increased rate of diffusion
• What are the adaptations of the lungs for gas exchange?

  • Millions of alveoli for large surface area
  • Very thin walls for short diffusion path
  • Good blood supply to rapidly remove oxygen
  • Breathing increases concentration gradients