Question : How does gaseous exchange take place in the alveoli?

1.	Question : How does gaseous exchange take place in the alveoli?
Answer» Solution :The PRIMARY site for the exchange of gases is the alveoli. The UPTAKE of `O_(2)` and the release of `CO_(2)` occur between the blood and tissues by simple diffusion driven by partial pressure gradient of `O_(2)` and `CO_(2)` . Partial pressure is the pressure contributed by an individual gas in a mixture of gases . It is represented as `pO_(2)` for oxygen and `pCO_(2)` for carbon - dioxide . Due to pressure gradients , `O_(2)` from the alveoli enters into the blood and REACHES the tissues . `CO_(2)` enters into the blood from the tissues and reaches alveoli for ELIMINATION . As the solubility of `CO_(2)` is 20-25 times higher than that of `O_(2)` , the partial pressure of `CO_(2)` is much higher than that of `O_(2)` .

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