Question

How can a decrease in the percent of oxygen in the air affect the movement of oxygen in the body?

Short answer

If the amount of oxygen drops in the inspired air, there would be reduced partial pressure.

Step-by-step solution

Step 1. Introduction

• The lungs can hold a large volume of air, but they are not usually filled to maximal capacity.
• Lung volume measurements include tidal volume, expiratory reserve volume, inspiratory reserve volume, and residual volume. The sum of these equals the total lung capacity.

Step 2. Explanation

• Oxygen moves from the lung to the bloodstream to the tissues according to the pressure gradient. This is measured as the partial pressure of oxygen.
• If the amount of oxygen drops in the inspired air, there would be reduced partial pressure. This would decrease the driving force that moves the oxygen into the blood and into the tissues. PO2 is also reduced at high elevations:PO2 at high elevations is lower than at sea level because the total atmospheric pressure is less than atmospheric pressure at sea level.