Disable ads (and more) with a membership for a one time $2.99 payment
What is the inspired PO2 in mmHg while breathing air at 1 ATA?
100 mmHg
160 mmHg
200 mmHg
760 mmHg
The correct answer is: 160 mmHg
To determine the inspired partial pressure of oxygen (PO2) while breathing air at 1 ATA (atmosphere absolute), it is important to understand the composition of the air we breathe. Commonly, air is composed of approximately 21% oxygen. At sea level, the atmospheric pressure is about 760 mmHg. When calculating the inspired PO2, you take the total atmospheric pressure and multiply it by the fraction of oxygen in the air: Inspired PO2 = Total Pressure × Fraction of Oxygen = 760 mmHg × 0.21 = 159.6 mmHg Rounding this figure gives approximately 160 mmHg, which aligns with the answer provided. Thus, breathing air at 1 ATA, the inspired PO2 is indeed around 160 mmHg. This understanding is critical in hyperbaric medicine, where variations in pressure can significantly affect gas exchange and patient care.