How are oxygen and carbon dioxide transported in human beings? How are lungs designed to maximize the area for exchange of gases?
Oxygen and COa Transported in human beings: The oxygen C02 enters human body via nasal passage and reaches lungs. There are numerous alveoli in lungs. They are enclosed by several blood capillaries. From alveoli, oxygen is taken up by red blood cells found in blood capillaries. Likewise carbondioxide from the different tissues is transported to alveoli of lungs. So the carbondioxide is then released through nasal passage during exhalation. The alveoli are “sites of exchange of gases”. Each lung has approx 300-350 million alveoli which increase the surface area for gaseous exchange, making respiration more efficient.