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Old 11-02-2011
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Default dissociation curve shift

A standard hemoglobin-O2 dissociation curve is shown below. Which of the following conditions will shift this curve to the right?
  • A. Fetal hemoglobin
  • B. Living in higher altitude
  • C. Hypothermia
  • D. Decreased H+
  • E. Decreased 2,3DPG



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  #2  
Old 11-02-2011
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A standard hemoglobin-O2 dissociation curve is shown below. Which of the following conditions will shift this curve to the right?
A. Fetal hemoglobin
B. Living in higher altitude
C. Hypothermia
D. Decreased H+
E. Decreased 2,3DPG
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Old 11-02-2011
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Default High Altitude

I would say B...
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Old 11-03-2011
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B. Living in higher altitude

1st aid page 504
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B. The other choices are plain wrong because they would shift the curve to the left!
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B living in hih altitude
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The correct answer is B.
When p50 > 26.7 mmHg, the curve shifts to the right and has less affinity of hemoglobin for O2. This facilitates unloading of O2 to tissues. Right shift occurs with ↑ temperature, ↑ H+ (↓ pH), ↑ altitude (lower atmospheric O2), and ↑ 2,3 DPG. Left shift results in increased O2 affinity and occurs with ↓ temperature, ↓ H+, ↓ 2, 3 DPG and in fetal hemoglobin.

Recall that Right shifters of the Hgb dissociation curve can be remembered with mnemonic: "CADETs face right"
CO2 ↑
Acidosis, Anemia
2,3-DPG
Elevation
Temperature ↑
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