Question

People living in the mountains have more red corpuscles in their blood than people living in the plains

Answer 1

Well, as we go from low altitude to high altitude, the air starts getting thinner and thinner…in more accurate terms, the partial pressure of oxygen starts decreasing with increasing altitude.

Now, since partial pressure of oxygen is less in our lungs(alveolar level), the binding of oxygen to haemoglobin in RBCs is decreased…resulting is decreased oxygen supply to the tissues thereby starving them of oxygen(hypoxic stress).

This in turn activates the compensatory mechanisms in our body leading to the release of the hormone erythropoietin from the kidneys, which stimulates the bone marrow to increase the production of RBCs (erythropoiesis)