EVERYDAY SCIENCE

Detailed explanation-1: -In the atmospheric air, pO2 is about 159 mm Hg. In the alveolar air, it is about 104 mm Hg. The partial pressure of carbon dioxide in the atmospheric air is lesser than that of carbon dioxide in the alveolar air. In atmospheric air, pCO2 is about 0.3 mmHg.

Detailed explanation-2: -At sea level, the alveolar PAO2 is: PaO2 = (760-47) 0.21-40/0.8 = 99.7 mm Hg.

Detailed explanation-3: -In atmospheric air, pO2 is about 159 mm Hg. In alveolar air, it is about 104 mm Hg. In atmospheric air, pCO2 is about 0.3 mm Hg. In alveolar air, it is about 40 mm Hg.

Detailed explanation-4: -Generally, under normal physiologic conditions, the value of PCO2 ranges between 35 to 45 mmHg, or 4.7 to 6.0 kPa. Typically the measurement of PCO2 is performed via an arterial blood gas; however, there are other methods such as peripheral venous, central venous, or mixed venous sampling.

Detailed explanation-5: -Therefore, at sea level, where atmospheric pressure is 760 mmHg, the partial pressures of the various gases can be estimated to have partial pressures of approximately 593 mmHg for nitrogen, 160 mmHg for oxygen, and 7.6 mmHg for argon.