Explain the schematic representation of gaseous exchange in tissues.
When we breathe in, we take in O2 , which reaches the lung alveoli. O2 then diffuses into blood of the surrounding capillaries from the alveoli, which has a high concentration of O2 by diffusion.
This oxygenated blood is then distributed to all the body cells by the heart.
After supplying O2 to the body cells, the blood collects CO2 , which is produced after cellular respiration in the cells. The tissues or cells have high concentration of CO2 than the blood, so CO2 diffuses from high concentration (in cells) to low concentration (in blood). The blood carries CO 2 to lung alveoli.
The lungs have a high concentration of O2. Therefore, it diffuses into the blood. Blood, on the other hand, has more concentration of CO2, which moves into the area of its lower concentration in the lung alveoli. Thus, the exchange of gases occurs in the alveoli and tissues. The oxygen inhaled is transported to all parts of the body while the CO2 produced in the cells is collected from the cells and exhaled out.
