Gas Exchange (including Alveoli)

Question 1

How are alveoli adapted to maximize gas exchange

Answer 1

• high surface area
• high rate of diffusion
• one cell thick walls
• short diffusion distance
• wet
• so gases can dissolve
• capillaries / blood flow
• diffusion gradient

Question 2

Define gas exchange

Answer 2

• refer to CO2 + O2
  (O2 moves from alveoli into blood, CO2 from blood to alveoli)