2.46: Explain How Alveoli are Adapted for Gas Exchange by Diffusion Between Air in the Lungs and Blood in Capillaries

ALVEOLI: Tiny Air Sacs where Gas Exchange Takes place

Diagram:

                                         

ADAPTATIONS:

FEATURE	ADAPTATION
FOLDED	Increases the Surface Area to Volume Ratio for the Diffusion of Gases (Efficient Rate of Gas Exchange)
THIN CELL WALLS	One Cell thick so the Distance of Diffusion is short, Increasing the Rate of Diffusion of Gases
STRONG CONCENTRATION GRADIENT	Each Alveolus is Surrounded by Blood Capillaries which Maintains a Strong Concentration Gradient and Blood Supply, Allowing Oxygen to Diffuse Out and Carbon Dioxide to Diffuse In
EACH ALVEOLUS IS VENTILATED	Access to the Lungs Helps Remove Waste Carbon Dioxide and Replenishing Oxygen Levels in the Alveolar Air, Also Allows the Maximum Concentration Gradient between the Blood and the Air in the Alveoli