1b. Oxygen-Hb Dissociation Curve

Question 1

PaO2:

Answer 1

95-100 mmHg

Question 2

PaCO2:

Answer 2

36-40 mmHg

Question 3

Venous PO2:

Answer 3

40 mmHg

Question 4

Venous PCO2:

Answer 4

42-50 mmHg

Question 5

Alveolar capillaries, with a cool, alkaline environment, tend to ____O2. This is the _____ effect.

Answer 5

Uptake; Haldane

Question 6

Active m. capillaries, with a hot, acidic environment, tend to ____O2. This is the _____ effect.

Answer 6

Release; Bohr

Question 7

A rightward shift in the Oxy-Hb Dissociation curve requires _____ pO2 to produce the same saturation under “normal” conditions.

Answer 7

Higher pO2. Remember that a rightward Oxy-Hb shift is due to increased temp and/or decreased pH. This readily causes release of oxygen from RBCs, so saturation must be increased by increasing the pO2.

Question 8

A leftward shift in the Oxy-Hb Dissociation curve requires _____ pO2 to produce the same saturation under “normal” conditions.

Answer 8

Lower pO2. Remember that a leftward Oxy-Hb shift is due to decreased temp and/or increased pH. This readily slows release of oxygen from RBCs, so saturation can be increased at a lower pO2.

Question 9

What will produce a rightward shift of the Oxy-Hb dissociation curve?

Answer 9

• Higher PCO2
• higher temp
• higher [H+]
• decr pH
• HbSS

Question 10

What will produce a leftward shift of the Oxy-Hb dissociation curve?

Answer 10

• Lower PCO2
• Lower temp
• Lower [H+]
• Incr pH
• Fetal-Hb