PULMONARY CAPILLARIES

Question 1

at the arterial end of the pulmonary capillary what is the plasma PO2?

Answer 1

40 mmHg

Question 2

at the arterial end of the pulmonary capillary what is the alveolar PO2?

Answer 2

104 mmHg

Question 3

what is the change in pressure of PCO2 in blood and alveoli during exchange? why?

Answer 3

5 mmHg

because its 45 mmHg in the blood and 40 mmHg in the alveoli

Question 4

why does CO2 have such a lower driving force?

Answer 4

due to 20 fold greater diffusion coefficient of CO2 compared to O2

Question 5

exercise causes a how much fold increase in oxygen demand by the body?

Answer 5

20 fold increase

Question 6

blood in the venous end of alveolar capillary has a PO2 of how much? what about PCO2? why is the PO2 in systemic arteries only 95 mmHg

Answer 6

PO2 of 104 mmHg

PCO2 of 40 mmHg

drop due to 2% of total pulmonary blood flow bypassing alveolar capillaries and supplying oxygen to lung tissue, so mixing of deoxy with oxy blood

Question 7

Partial pressure of O2/CO2 in:

interstitial fluid of PO2/PCO2

intracellularly of PO2/PCO2

mitochondria of PO2/PCO2

Answer 7

40 mmHg/45 mmHg

5 mmHg/46 mmHg

0 mmHg/46 mmHg

Question 8

where is the highest pressure of CO2 in the body?

Answer 8

mitochondrial matrix

Question 9

for hemoglobin and oxygen transport how much do mL/min of O2 do tissues need?

Answer 9

250 mL/min

Question 10

T/F, oxygen bound to Hb does not contribute to the partial pressure?

Answer 10

T

Question 11

what percent of oxygen is transported with hemoglobin?solution?

Answer 11

97%

3%

Question 12

when PO2 falls to 40 mmHg what percent of Hb is still saturated?

Answer 12

75%

Question 13

tissues use how much of the O2 present?

Answer 13

25%