The Airplane You Are Riding Suddenly Depressurizes at 10,000 Feet

Multiple Choice

The airplane you are riding suddenly depressurizes at 10,000 feet in the air. This causes the PO₂ of the airplane's air to drastically decrease. You pass out before you can put on your oxygen mask. After a few seconds, the PO₂ in your alveoli rapidly drops to 60 mmHg instead of the normal 104 mmHg. How will this affect blood gas concentrations?

A) PO₂ in the alveoli will be so low that oxygen will diffuse from hemoglobin into the alveoli, where it is exhaled. This causes blood oxygen concentrations to drop throughout the body.
B) Blood PCO₂ will increase because the air contains less oxygen.
C) Blood PO₂ will become low and much less oxygen will be delivered to tissues until cabin pressure returns.
D) PO₂ in the alveoli will be too low for gas exchange to even occur, so tissues will receive no oxygen during the depressurization event.