Pulmonary circulation

Question 1

left side of the circulatory system?

Answer 1

high pressure
oxygenated blood
systemic circulation

Question 2

right side of the circulatory system?

Answer 2

low pressure
deoxygenated
pulmonary (lungs only)

Question 3

where does the lung tissue get its oxygen from?

Answer 3

respiratory zone of the bronchial tree - oxygen directly from gas exchange at air/blood interface

Question 4

conducting zone?

Answer 4

thicker walled airways (trachea, bronchi, bronchioles) too thick for gas diffusion

Question 5

blood supply for the lungs?

Answer 5

supplied by systemic circulation via the bronchial blood supply

Question 6

bronchial vessels branch from?

Answer 6

from aorta

Question 7

what do pulmonary vessels supply lung tissue with?

Answer 7

supply lung tissue with oxygenated blood
functions purely to supply the blood with oxygen from the lungs

Question 8

bronchial circulation receives how much blood from the left ventricle?

Answer 8

receives 2% of the total output from the left ventricle

Question 9

what does bronchial circulation supply?

Answer 9

supplies larger airways and interlobar septa

Question 10

extrapulmonary airways supply goes where?

Answer 10

supply drains into the azygos vein (approx. 50% (1% of cardiac output))

Question 11

extrapulmonary airways are?

Answer 11

large airways outside the lung parenchyma

Question 12

conducting zone pulmonary airways supply drains via?

Answer 12

via bronchopulmonary anastomoses (remaining 50% (1% of cardiac output))

Question 13

what is cardiac output?

Answer 13

the amount of blood that is pumped by the ventricles per minute

Question 14

why does the heart vary its output?

Answer 14

it varies it according to an animal’s needs

Question 15

cardiac output =

Answer 15

HR x SV

Question 16

where does all the blood that is pumped through the right ventricle pass through?

Answer 16

it passes through the lungs

Question 17

because all blood that is pumped through the right ventricle passes through the lungs - what does this mean?

Answer 17

means that cardiac output and lung perfusion are determined by the same factors

Question 18

when cardiac output increases - lung perfusion increases, why does this happen?

Answer 18

since the left and right ventricle cannot beat independently of one another

Question 19

pulmonary vessels respond to changes in?

Answer 19

cardiac output

Question 20

pulmonary pressure of dogs, cats, sheep and goats?

Answer 20

all have low pulmonary pressures (the same as humans)
25/10 mmHg

Question 21

pulmonary pressure of pigs, cows and horses?

Answer 21

all have higher pulmonary pressure
50/15 mmHg

Question 22

what do pulmonary vessels do when blood flow through the lungs increases?

Answer 22

pulmonary vessels reduce their resistance

Question 23

what does ability of blood flow depend on?

Answer 23

depends on the presence of smooth muscle in the walls of small pulmonary arteries

Question 24

how do pulmonary vessels respond to small pressure increase?

Answer 24

the thin, flexible pulmonary vessels expand passively

Question 25

what happens to capillaries that are closed during rest - when the blood flow increase?

Answer 25

they open (capillary recruitment)

Question 26

which has the higher pressure: pulmonary arterial pressures or systemic pressures?

Answer 26

systemic pressure! pulmonary arterial pressures are less than systemic pressures

Question 27

what are alveolar vessels?

Answer 27

these are thin-walled capillaries that perfuse the alveolar septum

Question 28

what are the alveolar vessels exposed to?

Answer 28

exposed directly to alveolar pressure changes (hence compress if this increases)

Question 29

what are extra-alveolar vessels?

Answer 29

pulmonary arteries and veins

Question 30

what do the extra-alveolar vessels accompany?

Answer 30

accompany bronchi in a connective tissue sheath 'bronchovascular bundle'

Question 31

the behaviour of the extra-alveolar vessels is determined by?

Answer 31

by pressure changes within the connective tissue space (parenchyma) of the bronchovascular bundle

Question 32

when low oxygen? - ABERDEEN COWS IN ARGENTINA

Answer 32

closing vessels increase resistance pressure increases pulmonary artery pressure increases backs into right ventricle and then into right atrium pressure backs up into vena cava swelling Bovine high mountain/Brisket disease

Question 33

what is pulmonary vascular resistance?

Answer 33

PVR it is the relationship between the pressure differential across the pulmonary circulation and the cardiac output (CO)

Question 34

PVR = (equation)

Answer 34

difference in pressure / cardiac output

Question 35

how do you find pulmonary pressure differential? difference in pressure?

Answer 35

pulmonary artery pressure - left atrial pressure

Question 36

when is PVR low?

Answer 36

low at rest

Question 37

where do the peribronchial plexus vessels lie?

Answer 37

they lie within the connective tissue along the airways

Question 38

what do the branches of the peribronchial plexus supply?

Answer 38

they supply the subepithelial plexus

Question 39

other than the subepithelial plexus, what does the peribronchial plexus supply?

Answer 39

also supply vaso vasorum (vessels of vessels)

Question 40

what happens to the bronchopulmonary vessels at the alveoli?

Answer 40

extensive bronchopulmonary anastomoses at the level of the alveoli

Question 41

what do pulmonary vessels respond to?

Answer 41

they respond to changes in CO

Question 42

when do pulmonary vessels reduce their resistance?

Answer 42

when blood flow through the lungs increases

Question 43

what does ability of blood flow depend on?

Answer 43

depends on the presence of smooth muscle in the walls of small pulmonary arteries

Question 44

how do the pulmonary vessels respond when there is a small pressure increase?

Answer 44

it causes the thin, flexible pulmonary vessels to expand passively

Question 45

pulmonary arterial pressures are less than what other pressure?

Answer 45

less than systemic pressures

Question 46

what are alveolar vessels?

Answer 46

these are thin-walled capillaries that perfuse the alveolar septum exposed directly to alveolar pressure changes (hence compress if this increases)

Question 47

what are the extra-alveolar vessels?

Answer 47

pulmonary arteries and veins accompany bronchi in a connective tissue sheath

Question 48

what is the bronchovascular bundle?

Answer 48

it is the pulmonary arteries and veins which accompany bronchi in a connective tissue sheath

Question 49

what is the behaviour of the extra-alveolar vessels?

Answer 49

behaviour is determined by pressure changes within the connective tissue space (parenchyma) of the bronchovascular bundle