Aveloi is adapted for gas exchange by diffusuon

• 1)lungs contain lots of tiny sacs like alveoli
• 2)alveoli is surrounded by capillaries(has low concetration of oxygen)
• 3)so oxygen diffuses from alveoli into blood
• 4)more carbon dioxide in blood then alveoli so diffuses from blood into alveoli and is then breathed out
• Alveoli adaptations for faster diffusion

  • Big surface area
  • One cell thick
  • Goof blood supply