pulmonary blood supply and gas exchange

Question 1

what supplies lungs with oxygen

Answer 1

bronchial circulation

Question 2

what does pulmomary circulation do broadly

Answer 2

takes C02 to lungs and picks up oxygen

Question 3

what kind of system is pulmonary

Answer 3

high flow low pressure

Question 4

normal arterial PO2

Answer 4

100mmHg

13.3kPa

Question 5

normal arterial PCO2

Answer 5

40mmHg

5.4kPa

Question 6

normal venous PO2

Answer 6

40mmHg

5.3kPa

Question 7

normal venous PCO2

Answer 7

46mmHg

6.2kPa

Question 8

the rate diffusion across the membrane is

Answer 8

• directly proportional to the partial pressure gradient
• directly proportional to gas solubility
• directly proportional to available surface area
• inversely proportional to thickness of membrane
• most rapid over short distances

Question 9

V/Q relationship at base of lung

Answer 9

blood flow is higher than ventilation as arterial pressure exceeds alveolar pressure + alveoli are compressed

Question 10

V/Q relationship at apex of lungs

Answer 10

blood flow is less that ventilation as arterial pressure is less than alveolar pressure + arterioles are compressed

Question 11

autoregulation when blood flow>ventilation

Answer 11

PCO2 increased and PO2 decreases. Blood moving past this area doesnt get oxygenated –> SHUNT

Inc PCO2 causes milf bronchodilation and vessels contrict to divert blood to better ventilated areas

(this only happens pulmonary circulation - in systemic there is dilation in hypoxic areas)

Question 12

autoregulation when ventilation>blood flow

Answer 12

increase alveolar PaO2 –> pulmonary vasodilation

decrease PaCO2 –> mild bronchial constrictoin

Question 13

shunt

Answer 13

passage of blood throigh areas of lung that are poorly ventilated

Question 14

alveolar dead space

Answer 14

alveoli that are ventilated but not perfused

Question 15

physiological dead space

Answer 15

alveolar DS + anatomical DS