Lecture 25: Blood Gas Transport

Question 1

O2 Utilization coefficient

Answer 1

Percentage of blood that gives up its oxygen (normal: 5/19.4 = 25%); would be elevated to 75-85% during exercise

Question 2

What factors determine the tissue PO2?

Answer 2

Rate of oxygen transport to the tissues, rate of oxygen consumption in the tissues

Question 3

What is the effect of increasing or decreasing blood flow on peripheral tissue PCO2?

Answer 3

Increasing blood flow decreases PCO2

Decreasing blood flow increases PCO2

Question 4

What effect does pH have on the O2-Hb dissociation curve?

Answer 4

Decrease in pH: curve shifts right, increased pCO2 causes oxygen to be forced from tissues
Increase in pH: curve shifts left

Question 5

Bohr effect

Answer 5

Increase in blood [CO2] and H+ ions causes shift of O2-Hb curve to the right; enhancing release of O2 from blood in tissues and enhancing oxygenation of blood in lungs
Decrease in blood [CO2] and H+ ions: curve shifts left and more O2 picked up by Hb (occurs in lungs)

Question 6

Haldane effect

Answer 6

Binding of O2 with hemoglobin displaces CO2 from blood, binding of O2 with hemoglobin causes hemoglobin to become a stronger acid
More acidic Hb has less of a tendency to bind with CO2 and causes it to release H+

Question 7

What amount of CO2 transport is completed by dissolving in blood plasma?

Answer 7

7%

Question 8

What amount of CO2 transport is completed as carbonic acid?

Answer 8

70%

Question 9

What amount of CO2 transport is completed as a carbamino hemoglobin?

Answer 9

23%