Pulmonary Circulation Oct13 M1

Question 1

what prof says about pulmonary arteries

Answer 1

carry partially deoxygenated blood

Question 2

what prof says about pulmonary veins

Answer 2

carry oxygenated blood

Question 3

what prof says about bronchial veins

Answer 3

carry partially deoxygenated blood

Question 4

example of physiological shunt

Answer 4

bronchial veins mostly drain into pulmonary veins rather than venous circulation

Question 5

pulmonary arteries characteristics

Answer 5

thin wall, diameter changes easily with pressures

Question 6

pulmonary vascular resistane

Answer 6

resistance in pulmonary circulation

Question 7

what drives movement in pulmonary circulation

Answer 7

Pa (pulm artery) - PLA (left atrium)

Question 8

something particular about the pulmonary vascular resistance

Answer 8

decreases as flow increases

Question 9

why PVR decreases as flow increases

Answer 9

alveolar distension

alveolar recruitment

Question 10

relationship between pressure and flow across the pulmonary circulation

Answer 10

non-linear. at higher flows, the same pressure gradient produces greater increase in flow (bc resistance lower)

Question 11

how lung volume affects the resistance of pulmonary vessels

Answer 11

alveolar vessels (septum) get narrower
extra-alveolar vessels expand

Question 12

why extra-alveolar vessels expand with change in pressure

Answer 12

because are attached to surrounding lung tissue so traction force

Question 13

pulm vessels resistance at volume greater than TLC (intra and extra alveolar)

Answer 13

alveolar vessels: R increases

extra-alveolar: R decreases

Question 14

extra alveolar vessels resistance at volume lower than FRC

Answer 14

increased

Question 15

what influences pulmonary vascular resistance (diameter) the most (2)

Answer 15

transmural pressure and lung volume

Question 16

how pulmonary blood flow varies across the lung + reason

Answer 16

increases as you go from top to bottom and slightly drops at very bottom. Gravity

Question 17

West’s zones of the lung

Answer 17

Zone 1: top
Zone 2: middle
Zone 3: bottom

Question 18

what determines blood flow across a lung zone

Answer 18

Pa, Pv and PA

Question 19

lung zone 1

Answer 19

Palv greater than Pa greater than Pv

Question 20

lung zone 2

Answer 20

pa greater than p alv greater than pv. waterfall condition

Question 21

zone 4 of the lung

Answer 21

pa greater than pv greater than palv

Question 22

what determines flow in lung zones

Answer 22

1: palv-pa
2: pa-palv
3: pa-pv

Question 23

how pulmonary vessels adapt with certain substances

Answer 23

constrict with hypoxia and low pH

dilate with NO bc relaxes SM

Question 24

how systemic vessels adapt to hypoxia

Answer 24

dilate and dilate more if low pH

Question 25

why need to keep alveolar surface dry (and why is this a problem)

Answer 25

for gas exchange | problem bc tendency of fluid in blood to go in alveolar space. (P hydros greater than P oncotic)

Question 26

what mechanism prevents fluid accumulation in lung interstitium

Answer 26

lymphatics

Question 27

interstitial vs alveolar pulmonary edema

Answer 27

interstitial: lymphatics can't handle fluid, excess fluid in pulmonary intersitium alveolar: interstitial P raised so much it broke alveolar epithelial membranes, fluid leak in alveoli

Question 28

cardiogenic pulmonary edema

Answer 28

left heart failure so blood pooling in pulmonary circulation

Question 29

pleural effusion on CXR

Answer 29

one lung's bottom is higher than the other lung.