A 49-year-old man has a pulmonary embolism that completely blocks blood flow to his left lung. As a result, which of the following will occur?

Alveolar PO2 in the left lung will equal the PO2 in inspired air-No blood flow to the left lung- No gas exchange between the alveolar air and the pulmonary capillary blood-Consequently, O2 is not added to the capillary blood. The ventilation/perfusion (V/Q) ratio in the left lung will be infinite (not zero or lower than that in the normal right lung) because Q (the denominator) is zero. Systemic aerial PO2 will, of course, be decreased because the left lung has no gas exchange. Alveolar PO2 in the right lung is unaffected.