Science Form Three: Chapter 1 - Respiration System

Adaptations of alveoli:

• The alveoli are one cell thick so that there is a short diffusion pathway for the gases and therefore faster diffusion rate.
• There are a large amount of alveoli to provide a larger surface area for gas exchange so more eefficient.
• The alveoli are surrounded by a vast network of capillaries, this increases the surface area of alveoli which are in contact with a capillary and allows for more efficient gas exchange.
• The alveoli walls are moistened, so gaseous exchange is more efficient through diffusion