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Journal of Undergraduate Research

Keywords

respiratory response, altitude, blood oxygen concentrations, oxygen molecules

College

Life Sciences

Department

Health Science

Abstract

Oxygen is the essential element in the air we breathe. The concentration of oxygen is constant in the atmosphere at approximately 21%. However barometric pressure is not constant throughout the atmosphere. The barometric pressure measures the amount of pressure the particles in the atmosphere exert and varies depending on altitude and weather. At sea level the barometric pressure is 760mmHg. The oxygen molecules accessible for respiration exert 21% of that pressure. The pressure of these oxygen molecules is 160mmHg and is referred to as the partial pressure of oxygen. As the altitude increases the total barometric pressure decreases from 760mmHg to 448mmHg at 14,000ft. The partial pressure of oxygen lowers to 94mmHg at this altitude. This difference in the partial pressure decreases the oxygen available to the body by 42% from sea level to 14,000 ft. The body must adjust to this decreased amount of oxygen. It does so by increasing the amount of breathing. This increase in respiration is referred to as the Respiratory Response and is measured by minute ventilation (Liters/minute). It is the body’s key adaptation for adjusting to lower oxygen levels at higher altitudes.

Included in

Physiology Commons

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