|dc.description.abstract||Summary. Haematological studies have been carried out al various altitudes between 450 m
and 4800 m, on two separate human groups (Quechuas and Aymaras) living in South America.
Changes in the haematological parameters do not develop linearly in relation lo the altitude.
The impact of chronic hypoxia on erythropoiesis is greater above: 3000m. The haemogram
varies quantitatively and not qualitatively (mean corpuscular volume and mean haemoglobin
concentration remain constant). The haematological study also reveals the greater adaptability to high altitude of the Aymaras, an adaptability characterized by an increase in red cell
count and concentration and a decrease in red cell volume. The adaptative phenomena
observed in the Quechuas are reversible, whereas they persist in the Aymaras when they
migrate to the lowlands (450m).||es_ES