Physiology 3120 Lecture Notes - Lecture 6: Altitude Training, Smoke Inhalation, Red Blood Cell

• School: Western University
• Department: Physiology
• Course: Physiology 3120
• Professor: Tom Stavraky

Document Summary

In air, the fractional concentration of o2 is 21% At sea level, the pressure is 760 mmhg. This means that the po2 of air is 160 mmhg. In the lung, air becomes saturated with water representing a pressure of 47 mmhg. The po2 of the inspired air is therefore: 0. 21 * (760 mmhg - 47 mmhg) = 150 mmhg. This po2 of inspired air allows normal gas exchange. At high altitude, the pressure is a lot lower than at sea level and the fractional concentration of oxygen is still 21% : the pressure at 5,500 m above sea level is only 380 mmhg. The po2 of inspired air at this altitude is 0. 21 * (380 mmhg - 47 mmhg) = 70 mmhg. Respiration and gas exchange in the lung is much harder with such a low po2. There is an incredible acclimatization that occurs when humans ascend to higher altitudes.