Research and respond to the following questions:

1. During exercise the tissue PO2 of 40 mm Hg is the same as it is at rest. Explain how more oxygen is released to meet the demand of the exercising tissue.  Include an explanation of what happens to the hemoglobin saturation curve.
 

2. Explain how people living at high altitude are able to get adequate oxygen to their tissues eventhough their alveolar oxygen pressures are in the 80-90 range.