Pulmonary Circulation

Question 1

where does gas exchange occur in the body

Answer 1

lungs and tissues

Question 2

pulmonary gas exchange

Answer 2

mixed venous blood (low O2, high CO2) reaches alveoli, where CO2 gets removed and O2 gets added

Question 3

what does proper pulmonary gas exchange rely on

Answer 3

ventilation (air into alveoli)
and
perfusion (blood supply)

Question 4

tissue gas exchange

Answer 4

arterial blood (high O2, low CO2) reaches tissues, where O2 gets unloaded and CO2 gets added to blood

Question 5

what is mixed venous blood

Answer 5

low PO2 and high PCO2 blood that enters the right side of the heart to go into pulmonary circulation

Question 6

what causes O2 and CO2 to flow across capillaries

Answer 6

PAO2 is higher than PVO2 and oxygen flows from high to low partial pressure

PACO2 is lower than PVCO2 and CO2 flows from high to low partial pressure

Question 7

what does it mean that the lungs have dual circulation

Answer 7

1. pulmonary circulation
2. bronchial circulation

Question 8

pulmonary circulation

Answer 8

pulmonary arteries, capillaries, and veins that circulate blood from the heart –> lungs –> back to the heart to oxygenate it

participates in gas exchange and blood supply to the respiratory bronchioles and alveoli

Question 9

how much of the cardiac output does pulmonary circulation receive

Answer 9

100%

Question 10

how does pulmonary circulation affect blood volume in the lungs

Answer 10

can increase/decrease blood volume based on changes in intrathoracic pressure

Question 11

bronchial circulation

Answer 11

bronchial artery, arterioles, capillaries, venules, and veins that provide oxygenated blood supply to the airways

provides blood supply to lower airways, contributes to the formation of venous admixture

Question 12

path of flow in bronchial circulation

Answer 12

aorta
bronchial artery
bronchial arterioles
capillaries
bronchial venules
bronchial veins
pulmonary veins OR vena cava

Question 13

how much of cardiac output does bronchial circulation receive

Answer 13

1-2%

Question 14

how does venous blood drain from bronchial circulation

Answer 14

drains into either:
1. pulmonary veins (2/3)
2. caudal vena cava (1/3)

creates a venous admixture because bronchial veins contain deoxygenated blood and drains into pulmonary veins (oxygenated blood)

Question 15

what is the drainage of bronchial circulation a physiologic R to L shunt

Answer 15

because it drains deoxygenated blood into L side of heart –> systemic circulation