For those who use kaplan. There seems to be a contradiction. In the review notes in the respiration system chapter. It says that at high altitudes, the affinity of hemoglobin for oxygen decreases to facilitate unloading of oxygen in tissues. Then i would assume that at high altitudes, the oxygen dissociation curve would shift to the right since fetal hemoglobin would shift the curve to the left cuz it has a higher affinity for oxygen. However, in kaplan full length 4-passage 7. It says that high altitudes lead to the exhalation of co2 and an increase in blood pH. an increase in blood ph would shift the curve to the left because acording to Bohr's law, a low ph would shift the curve to the right. Can someone explain? thanks