Oxygen Transport

Question 1

Dissolved O2

Answer 1

Amount of O2 dissolved in arterial blood is linearly proportional to its PaO2

Question 2

Oxygen Hb Dissociation Curve

Answer 2

Sigmoid b/c of positive cooperativity

100%: 20ml/dl
75%: 15
50%: 10
25%: 5

Question 3

P50

Answer 3

Measures affinity

Question 4

Calculation of arterial or venous O2 conc in blood

Answer 4

CO2 = O2 capacity x % saturation
CaO2 is 20 at 98%
CvO2 is 15 at 75%

Question 5

Oxygen delivery

Answer 5

DO2 = CaO2 x Q

Question 6

Oxygen return to lungs

Answer 6

O2 to return to lungs = CaO2 x Q

Question 7

Oxygen uptake by tissues

Answer 7

VO2 = (CaO2 - CvO2)Q

VO2 = DO2 x O2

Question 8

Oxygen extraction rate

Answer 8

O2ER = VO2/DO2

Question 9

P50 altered affinity

Answer 9

Shift right
Dec affinity, inc P50
Inc temp, acidity, PCO2, and BPG

Question 10

Effects of Anemia

Answer 10

Dec oxygen carrying capacity

No change in P50 (compensatory)

Question 11

Sickle cell disease

Answer 11

Increase P50

Decrease oxygen capacity

Question 12

CO

Answer 12

Increase affinity of Hb for oxygen

Decrease P50