A hyperbaric chamber supplies oxygen at

• A. Decreased pressure
• B. Normal atmospheric pressure
• C. Variable pressure
• D. Increased pressure

Answer: (D)

Hyperbaric oxygen therapy works by delivering oxygen at a pressure greater than Earth's atmosphere. The increased ambient pressure drives more oxygen into the blood plasma, raising tissue oxygen levels even when hemoglobin is already saturated. This relies on Henry’s law: higher pressure means more gas dissolves in the liquid portions of the body, enhancing oxygen delivery to tissues. Because of this, a hyperbaric chamber operates at increased pressure (typically around 2 to 3 atmospheres absolute), not at decreased or normal pressure.