Lecture 24 - Blood Gas Transport

Question 1

What is the partial pressure of O2 at the arterial end and venous end of a pulmonary capillary?

L24 S5

Answer 1

Arterial end: 40mmHg

Venous end: 104 mmHg

Question 2

What is the partial pressure of O2 in the arterial end and venous end of a tissue capillary?

L24 S11

Answer 2

Arterial end: 95 mmHg

Venous end: 40 mmHg

Question 3

What is the partial pressure of carbon dioxide in the arterial end and venous end of a tissue capillary?

L24 S13

Answer 3

Arterial end: 40 mmHg

Venous end: 45 mmHg

Question 4

What is the utilization coefficient of oxygen?

L24 S19

Answer 4

Blood transported to tissues (5 mL) divided by total oxygen bound (19.4 mL)

~25%

Question 5

How does hemoglobin act like a tissue oxygen buffer?

L24 S21

Answer 5

When pulmonary pO2 is high oxygen binds to hemoglobin.

When tissue pO2 is low oxygen is released from hemoglobin

Question 6

What factors decrease hemoglobin saturation of oxygen?

L24 S26

Answer 6

• increase in H+
• increased CO2
• increased temperature

Question 7

In what ways is CO2 transported in the blood?

L24 S30

Answer 7

• dissolved in the blood (~7%)
• carbonic acid (~70%)
• carbamino hemoglobin

Question 8

What is the Haldane effect?

L24 S32

Answer 8

• oxygen binding to hemoglobin displaces CO2
• oxygen bound hemoglobin is a stronger acid
• more acidic hemoglobin has less of a tendency to bind CO2