Hypoxemia is caused by reduced oxygen in the blood or restricted blood flow. Which of the following describes what happens to the partial pressure of oxygen in the blood?

• A. The partial pressure of oxygen in the blood is higher than normal.
• B. The partial pressure of oxygen in the blood is lower than normal.
• C. The partial pressure of oxygen in the blood continuously drops until zero.
• D. The partial pressure of oxygen in the blood continuously rises to maximum capacity.

Answer: (B)