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16 Cards in this Set
- Front
- Back
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what is an example of a chemically altered hemoglobin |
dyshemoglobins with sickle cell hemoglobin |
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uptake of O2 by the blood in the lungs is primarily governed by |
PO2 of alveolar air and by the ability of O2 to diffuse freely across the alveolar membrane into the blood |
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what is the PO2 normally present in alveolar air |
102 mm Hg |
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what percent of hemoglobin A will bind O2 at PO2 102 mm Hg |
95% |
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what percent of hemoglobin A will bind O2 at PO2 >110 mm Hg |
98% |
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when all hemoglobin is saturated with O2, further increase in PO2 of alveolar air does what |
increase the concentration of cdO2 in arterial blood |
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what are the 3 properties of arterial blood that are essential to ensure adequate O2 delivery to the tissues |
- sufficiently high arterial PO2 - normal O2 blood binding capacity - hemoglobin must be able to bind O2 in the lungs and release it at the tissues |
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what is a sufficiently high level of arterial PO2 |
90 mm Hg |
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low arterial PO2 (hypoxemia) results in what |
tissue hypoxia (O2 starvation) |
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decreased Hb concentration can cause what |
anemic hypoxia |
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if the affinity of hemoglobin for O2 is too great what can happen |
affinity based tissue hypoxia |
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the degree of association or dissociation of O2 with hemoglobin is determined by what |
PO2 and the affinity of hemoglobin for O2 |
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when SO2 (saturation) of blood is determined over a range of PO2 and plotted against PO2, what is obtained |
sigmoidal curve called oxygen dissociation curve |
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what does the shape of the sigmoidal curve arise from |
increasing efficiency with which HHb (deoxyhemoglobin) molecules bind more O2 once some O2 has been bound |
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the location of the curve relative to the PO2 required to achieve a particular concentration of SO2 in the blood is a function of what |
affinity of the hemoglobin for O2 |
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what 4 things does the affinity of hemoglobin for O2 depend on |
temperature pH PCO2 concentration of 2,3 DPG |
