Gas Exchange

• What is FICKS LAW ?

  • determines the RATE of DIFFUSION and it states that the LARGER the SURFACE AREA, DIFFERENCE in CONCENTRATION and SHORTER the DIFFUSION DISTANCE the QUICKER the RATE
• How are the lungs adapted for rapid gas exchange ?

  • They have a LARGE SURFACE AREA due to the presence of MANY ALVEOLI which INCREASE the SURFACE AREA
  • Good supply of circulating blood to the lungs which carries carbon dioxide to the lungs and oxygen away from them ensures that the CONCENTRATION GRADIENT is STEEP - HIGH CONCENTRATION of OXYGEN and LOW CONCENTRATION of CARBON DIOXIDE is maintained by MECHANICAL VENTILATION
  • SHORT DIFFUSION DISTANCE as the ALVEOLI are just ONE CELL THICK thus REDUCING the DIFFUSION DISTANCE
• What is the equation of FICK‘S LAW ?

  Rate of Diffusion=

  (surface area) x (conc difference)÷distance