Blood Flow and Metabolism in the Pulmonary Circulatio

Question 1

Gas exchange occurs between the

Answer 1

alveolar air and the pulmonary capillaries.

Question 2

• Pulmonary Perfusion

Answer 2

Deoxygenated blood (venous blood) circulates throughout the lung vasculature (pulmonary
capillaries) to be oxygenated

Question 3

PULMONARY PRESSURE CIRCULATION

Answer 3

low-pressure circulation (2;25 mm Hg

Question 4

Perfusion Pressure for Pulmonary Circulation

Answer 4

Pressure difference
between pulmonary artery (mean) and left atrium

Question 5

Perfusion Pressure for Systemic Circulation

Answer 5

Pressure difference
between systemic artery (mean) and right atrium (100-2= 98 mmHg)

Question 6

t/f Pressure around pulmonary vessels is less than alveolar pressure

Answer 6

true

Question 7

t/f pulmonary Vessels increase their caliber as lung expands

Answer 7

true

Question 8

alveolar pressure is closer to

Answer 8

atmospheric pressure

Question 9

when alveolar pressure rises above capillary pressure

Answer 9

capillaries collapse

Question 10

pulmonary vascular resistance is calculated

Answer 10

(input pressure - output pressure) / blood flow

Question 11

t/f in the lungs, there are no muscular arterioles

Answer 11

true

Question 12

pulmonary resistance

Answer 12

1.7 mm Hg/L/min

Question 13

Systemic Resistance

Answer 13

17 mm Hg/L/min

Question 14

mean pressure in the pulmonary artery

Answer 14

15 mmhg

Question 15

Recruitment:

Answer 15

Opening closed capillaries at higher pressures

Question 16

Distension

Answer 16

Widening of capillaries as pressure rises

Question 17

As pressures rise

Answer 17

these vessels begin to
conduct blood, which lowers the
resistance.

Question 18

main mechanism responsible for the decrease in vascular resistance

Answer 18

pulmonary artery pressure increase

Question 19

blood flow is measured to

Answer 19

Assess lung function in respiratory
distress

Question 20

blood flow can be measured from

Answer 20

ratio of oxygen consumed over oxygen
concentration differences in arteries and veins

Question 21

Frick law is used to calculate

Answer 21

blood flow

Question 22

what is the dynamic of blood flow in lungs?

Answer 22

More flow at base, less at apex

Question 23

Pulmonary arterial system: a continuous column of blood

Answer 23

Pressure difference between top and bottom is about 23 mm Hg

Question 24

zone 1 in the lung

Answer 24

No flow (artery < alveolar pressure, rare in health)
alveolar pressure is higher than pulmonary artery pressure
capillaries are flatenned

Question 25

Zone 2 in the lung

Answer 25

Flow = artery-alveolar pressure (waterfall effect) Pulmonary arterial pressure is higher than alveolar pressure venous pressure lower than alveolar Arterial pressure increases down the lung, but alveolar pressure remains the same , pressure difference responsible for blood flow also increses

Question 26

zone 3 in lung

Answer 26

arteriolar - vein pressure (normal). venous pressure higher than alveolar pressure increase in blood flow in this region of the lung is due to distension of capillaries and pressure within them increase recruitment is also involved

Question 27

If there is a severe hemorrhage, what happens to arterial blood pressure in zone 1 ?

Answer 27

it is reduced

Question 28

if alveolar pressure is raised in zone 1, what happens?

Answer 28

hyperventilation

Question 29

If the lung is well ventilated but un-perfused

Answer 29

No gas exchange occurs, is referred to alveolar dead space

Question 30

blood flow is determined by the pressure difference between

Answer 30

arterial and alveolar, and venous pressure has no effect.

Question 31

The random arrangement of blood vessels and capillaries cause

Answer 31

inequality of blood flow at all levels of the lung.

Question 32

t/f Blood flow increases along the acinus

Answer 32

true

Question 33

in active control of circulation, blood flow is directed away from

Answer 33

Poorly ventilated areas of the lung

Question 34

Under normal conditions, passive factors dictate.

Answer 34

pulmonary vascular resistance and distribution of blood flow

Question 35

When O2 in alveolar gas drops

Answer 35

Active response is initiated, and small arterioles in the hypoxic region of the lung will constrict

Question 36

Hypoxic pulmonary vasoconstriction

Answer 36

occurs without input from the CNS determined by alveolar gas, NOT BY PULMONARY ATERIAL BLOOD Pulmonary arterial pressure increases

Question 37

Pulmonary vascular resistance is associated with

Answer 37

Hypoxic conditions vasoconstriciton

Question 38

During the fetal stage, pulmonary vascular resistance is high due to

Answer 38

hypoxic vasoconstriction

Question 39

Hypoxic pulmonary vasoconstriction will direct blood

Answer 39

away from hypoxic areas

Question 40

Starling's law: fluid movement is important

Answer 40

keep lungs dry, slight outward flow of water to lymph drainage

Question 41

When Water Balance Fails

Answer 41

* Interstitial edema: Fluid in perivascular spaces. * Alveolar edema: Fluid in alveoli → poor gas exchange.

Question 42

pulmonary circulation also works for

Answer 42

blood reservoir filtering-removing small thrombi to prevent reaching the brain , trapping white blood cells

Question 43

metabolic functions of lungs

Answer 43

Modifies vasoactive substances (e.g., angiotensin, serotonin). * Many vasoactive and bronchoactive substances are metabolized in the lung and released under certain conditions

Question 44

t/f the lungs receive all cardiac output

Answer 44

true

Question 45

angiotensin 1 is transformed to

Answer 45

II (via ACE, vasoconstrictor).

Question 46

Bradykinin is

Answer 46

inactivated

Question 47

Serotonin is

Answer 47

removed

Question 48

Alveolar edema impairs

Answer 48

gas exchange