Inadequate oxygen tension in air, e.g., at high altitude, is known as which condition?

• A. Histotoxic
• B. Anemic
• C. Anoxic
• D. Stagnant

Answer: (C)

The idea being tested is how oxygen availability affects oxygen delivery. At high altitude, the ambient oxygen partial pressure is reduced, so there’s less oxygen available to diffuse into the blood. This describes a problem with the environment having little or no oxygen, which is captured by the term anoxic.

The other conditions refer to problems after oxygen has entered the body: histotoxic means tissues can’t use oxygen even if it’s present, anemic means there isn’t enough hemoglobin to carry oxygen, and stagnant means poor circulation prevents oxygenated blood from reaching tissues. Thus, the best match for inadequate oxygen tension in the air is anoxic.