Question

Which of the following is correct regarding acclimatization?

A)When blood O₂ levels decline, the kidneys produce more erythropoietin, which stimulates breakdown of red blood cells in the spleen.
B)High-altitude conditions always result in lower-than-normal hemoglobin saturation levels because less O2 is available to be loaded.
C)Decreases in arterial PO₂ cause the peripheral chemoreceptors to become less responsive to increases in PCO₂.
D)At high altitudes, hemoglobin's affinity for O₂ is increased because BPG concentrations increase.

Answer 1

At high altitudes, the kidneys produce more EPO in response to lower oxygen availability, which stimulates the production of erythrocytes, allowing for greater oxygen-carrying capacity in the blood.

Step-by-step explanation:

The correct answer regarding acclimatization is that when blood O₂ levels decline, the kidneys produce more erythropoietin (EPO), which stimulates the production of red blood cells (erythrocytes) not their breakdown. This is a compensatory mechanism that enables the body to cope with lower oxygen availability at high altitudes. High-altitude conditions do often result in lower-than-normal hemoglobin saturation levels, but the body compensates by increasing the production of erythrocytes, thereby increasing the oxygen-carrying capacity of the blood. Increases in the concentration of BPG aid in the release of oxygen from hemoglobin into tissues, rather than increasing hemoglobin's affinity for oxygen. EPO production and erythropoiesis ensure that tissues receive the oxygen they need, especially under the stress of reduced oxygen levels at higher elevations.