Gas exchange takes place in the lungs where oxygen is absorbed into the blood and carbon dioxide is removed from the blood
There are different adaptations to maximise gas exchange:
Many alveoli - large surface area
Short diffusion distance - alveoli and capillaries are one cell thick
Large concentration gradient - blood flow maintains low concentration of O2, high concentration of CO2 in the blood, ventilation maintains high concentration of O2 and low concentration of CO2 in the alveoli
