Final answer:
Acclimatization is the adjustment of the body to chronic exposure to high elevation, characterized by the production of more erythrocytes to increase oxygen transport despite lower oxygen saturation.
Step-by-step explanation:
The process of acclimatization refers to the biological adjustments that the respiratory system and other organ systems make when an individual is exposed to high elevation for prolonged periods. At high altitudes, the atmospheric pressure is lower compared to sea level, resulting in a lower partial pressure of oxygen. This causes decreased oxygen saturation in the hemoglobin of the blood and reduces tissue levels of oxygen, potentially leading to acute mountain sickness (AMS). Symptoms of AMS include headaches, disorientation, fatigue, nausea, and lightheadedness.
Over time, acclimatization occurs as the body compensates for the lower oxygen availability. The kidneys produce more erythropoietin (EPO), a hormone that stimulates the production of erythrocytes (red blood cells). With more red blood cells in circulation, there is more hemoglobin available to transport oxygen. Although the saturation of each hemoglobin molecule may be low, the increased number of hemoglobin overall helps transport more oxygen through the blood. This adaptation allows individuals to perform physical exertion at high altitudes without experiencing the symptoms of AMS.