Gas exchange

• Here is what happens during gas exchange, label the parts with blood in, blood out, alveoli, oxygen in, carbon dioxide out

  :

  A) Blood in

  B) carbon dioxide out

  C) oxygen in

  D) alveoli

  E) blood out

  
• Carbon dioxide is going to diffuse from the capillary to the alveoli from a high concentration to a low concentration
• Oxygen is going to diffuse from the alveoli to the capillaries from a high concentration to a low concentration
• Gaseous exchange structure:

  • The alveoli are covered in capillaries and have a large red blood cell supply
  • Capillaries are close to the alveoli so the diffusion distance is short
  • Alveoli have a large surface area to allow diffusion to take place
  • Thin walls allows quick diffusion
  • Gases move from areas of high concentration to low concentration