Adaptions

Question 1

Surface Area

Answer 1

• Alveoli each has
  multiple folds and multiple
  capillaries around them
• This increases surface area
• This means more
  particles can diffuse and be
  exchanged at a time causing faster rate

Question 2

1 cell thick

Answer 2

• Each alveoli is lined with single layer of flattened epithelial cells
• 1 cell thick
• Short diffusion distance
• Creating faster rate of diffusion and gas exchange

Question 3

Capillary Network

Answer 3

• Large blood capillary network
• Steep concentration gradient maintained
• Faster rate of diffusion

Question 4

Ventilation

Answer 4

• Ventilation always brings in air containing a high(er) oxygen
  concentration
• Large concentration of
  oxygen in the alveoli but a low level in the blood
• Steep concentration gradient
• Faster rate of diffusion and gas exchange.