At the altitude of 6500 meters, the atmospheric pressure is 347 mmHg. What is the inspired PO2.: (A) 73 mm Hg, (B) 63 mm Hg, (C) 53 mm Hg, (D) 83 mm Hg
Answer is B. According to law of paial pressures : Pressure exeed by a gas in a mixture is directly propoional to its concentration in the mixture. In inspired gases; 20 % = O2 78% = N2 PH2O = 47 mmHg (air humidified with inspiration) =347 - 47 = 300 mmHg = gaseous component