HMB472H1 Chapter Notes -Hypoxemia, Cardiac Output, Stroke Volume
Document Summary
Low partial pressure of oxygen at altitude is what limits exercise performance. The reduced barometric pressure at altitude is referred to as hypobaric environment or simply hypobaria (low atmospheric pressure). Low atmospheric pressure also means a lower partial pressure of oxygen which limits pulmonary diffusion of oxygen from the lungs and oxygen transport to the tissues. When oxygen delivery to the body tissues is compromised, the result is cellular hypoxia (oxygen deficiency) Few negative physiological effects on performance are seen below 1500m. At an elevation, the air always contains 20. 93% oxygen, 0. 03 carbon dioxide, 79. 04% nitrogen. The pressure that oxygen molecules in the air exert at various altitudes drops proportionally with decreases in the barometric pressure. The very low water vapour pressure at high altitudes promotes evaporation of moisture from the skin surface, because of the high radiant between skin and air, and can lead quickly to dehydration.
