Pulmonary Blood Flow, Ventilation and Perfusion -Karius Flashcards

1
Q

normal CO

A

3.5 L/min - 5.0 L/min

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2
Q

Hypoxia response of the pulmonary circulation

A

vasoconstriction

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3
Q

Hypoxia response of the systemic circulation

A

vasodilation

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4
Q

PvO2

PvCO2

A

PvO2 : 40mmHg

PvCO2: 45mmHg

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5
Q

PaO2

PaCO2

A

PaO2 : 100mmHg

PaCO2 : 40mmHg

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6
Q

what causes vasoconstriction in pulmonary circulation during hypoxia

A

SM of pulmonary tissues do it themselves to direct blood to areas of good gas exchange

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7
Q

steps in vasoconstriction of the pulmonary vessels

A
  1. low O2
  2. K + leak channels open
  3. depolarization
  4. opens Ca+2 LCAT channels
  5. more depolarization to SM contractions
  6. vasoconstriction
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8
Q

where do alveoli get blood from and then they go where

A

the RV —-> LA

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9
Q

where do bronchial (extra-alveolar) capillaries get their blood from
and then they go where

A

LV * to supply the lung tissues that are far from the alveolar capillaries
—-> 1. Azygous V (–> RA), 2. LV = venous admixture

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10
Q

how to calculate pulmonary BP

A

CO x PVR(pulmonary vascular Resistance)

= 25/15mmHg (lower then systemic TPR)

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11
Q

BP and capillaries that are open relationship

A

the more capillaries that are open the lower the PVR

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12
Q

PVR during exercise

A

decreases due to more capillaries that are open

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13
Q

PVR relationship with lung volume

A

at very high lung volumes (a lot of air) + at very long lung volumes (Chest wall pushes in)
= Resistance increases because the capillaries get compressed when tissues are stretched or pushed in

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14
Q

main cause of pulmonary HTN

A

vasoconstriction
(in COPD/emphysema) you also see low SA and capillaries and alveoli die = also increases gas volume inside = increases resistance

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15
Q

what brings blood back up to the heart when knees are not locked

A

skeletal muscle pump pumping blood back up to the heart and prevents decrease in venous return

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16
Q
3 zones of the lung
ZONE 1
alveoli size
BF
BP
and Ps
A

Zone 1 : apex (biggest avloli, least amount of BF, smallest BP
PA > Pa > Pv
*Pa is close to 140mmHg

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17
Q
3 zones of the lung
ZONE 2
alveoli size
BF
BP
and Ps
A

Zone 2 : middle
medium sized alveoli, normal BF, normal BP equal to BP at level of the heart
Pa> PA > Pv
*Pa is close to 100mmHg

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18
Q
3 zones of the lung
ZONE 3
alveoli size
BF
BP
and Ps
A
Zone 3: base
smallest alveoli
highest BF
highest BP
Pa > Pv > PA
*Pa is close to 40mmHg
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19
Q

NO function

A

Para—-> vasodilate
SM relaxation
PULMONARY FLOW, decreases PVR

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20
Q

Endothelin 1 funciton

A

made in lung

vasoconstrictor , usually under not normal conditions or disease

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21
Q

Thromboxane A2 function

A

vasoconstrictor not normal conditions

usually during inflammation

22
Q

reason you would want to prone a patient

A

patient has a hard time getting O2 to all parts of the body

prone the Pt and gravity will push chest in = increase PVR = increases BF and BP in pulmonary circulation (more O2 is picked up)

23
Q

pneumonia and pulmonary edema do what to O2 to cross the wall

A

the fluid build up in the capillary and prevents the O2 to cross since it doesn’t dissolve in fluid

24
Q

water leakage from capillaries to alveoli

A

should not happen , stopped by starling forces and lymphatics

25
Q

biggest starling force in the lung

A

Pc (hydrostatic capillary)

26
Q

Ptissue

A

tissue hydrostatic P pushing water from alveoli to the capillary
= -5mmHg (fluid goes into alv), *since Pil is -5

27
Q

which starling forces make fluid go to the alv

A

Pc
Ptissue (-5mmHg)
pi tissue

28
Q

with net filtration of water into alv in lungs , how is O2 able to cross the alveolar wall and do gas exchange

A

LYMPHATICS , get rid of fluid in the interstitium so it doesnt go into the alv

29
Q

ACE has 2 roles

A
  1. converts angiotensin 1 –> angiotensin 2 (increase aldosterone and BP)
  2. inhibit bradykinin production
30
Q

those who are placed on ACE inhibitors can develop what

what would be an ideal drug to take if this happens

A
  1. lowered BP AND
    cough up excess bradykinin made
  2. angiotensin 2 inhibitor (only lowers BP) =ARB
31
Q

how are immune cells and products from inflammation removed from our circulation

A

PGE, leukotriens, Thromboxane A2 are removed by lungs

LUNGS METABOLIZE ARACHIDONIC ACID

32
Q

what is PIo2

A

inpired o2 pressure accounting for water vapor also

PIo2 = (760mmHg - 47mmHg) x %o2

33
Q

normal percent o2

normal water vapor P

A

21%

47mmHg

34
Q

normal R value

A

0.8

= V(dot)aCO2 / V(dot)O2 = (200ml/min) / (250ml/min)

35
Q

** How to calculate PAo2 (amount of O2 partial pressure in alveoli)**
= alveolar gas equation
reason this is important

A

PAo2 = PIo2 - (PaCO2 / R)

important to see if alv is damaged (if PAo2-Pao2 is greater then 20 = damage, diffusion impairment)

36
Q

normal A-a O2 gradient

A

difference between the Pa and PA shoudl be less then 20mmHg

37
Q
LUNG ZONES (zone 1)
Pip
PaO2
PaCO2
V/Q ratio
A

Pip = -10mmHg (due to less intrapleural fluid)
PaO2 = 130mmHg
PaCO2 = 28mmHg
V/Q ratio = high (3.0)

38
Q
LUNG ZONES (zone 1)
Pip
PaO2
PaCO2
V/Q ratio
A

Pip = -5mmHg
PaO2 = 100mmHg
PaCO2 = 40mHg
V/Q ratio = 0.8

39
Q
LUNG ZONES (zone 1)
Pip
PaO2
PaCO2
V/Q ratio
A

Pip = -2 to -3mmHg (due to more intrapleural fluid)
PaO2 = 89mmHg
PaCO2 = 42mmHg
V/Q ratio = low (0.6)

40
Q

apex of the lung : how does the Pip change with inhalation

A

the Pip is already very negative and the alv is big

= when inhaling only small amount of air can enter

41
Q

base of the lung : how does the Pip change with inhalation

A

the Pip is more positive and alv are smaller in size

= when inhaling the alveoli can get a lot bigger

42
Q

what is a normal V/Q ratio and how was it calculated

A
V= 4L/min (ventilation)
Q = 5L/min (perfusion = also cardiac output)
normal = 0.8
43
Q

what does it mean if you have a high V/Q

low V/Q

A

high V/Q = more air then blood

low V/Q = more blood then air

44
Q

what are the PaO2 and PaCO2 and PAo2 and PAco2 when V/Q = 0.8

A
PaO2 = 100mmHg (equilibrilize)
PaCO2 = 40mmHg (equilibrilize)
PAo2 = 100mmHg
PAco2 = 40mmHg
45
Q

what are the PaO2 and PaCO2 and PAo2 and PAco2 when V/Q = high due to very little blood coming to the alveoli

A
PaO2 = 150mmHg (only very little blood)
PaCO2 = 1mmHg (only very little blood)
PAo2 = increase 150mmHg
PAco2 = decrease 1mmHg
46
Q

what are the PaO2 and PaCO2 and PAo2 and PAco2 when V/Q = low, due to V=0 blockage in airway
ORIGINALLY

A
*blood keeps coming to deliver CO2 and take O2 from the alv
PaO2 = 80mmHg (equilibrilize)
PaCO2 = 42mmHg (equilibrilize)
PAo2 = decrease to 80mmHg
PAco2 = increase to 42mmHg
47
Q

what are the PaO2 and PaCO2 and PAo2 and PAco2 when V/Q = low, due to V=0 blockage in airway
AFTER A WHILE OF THIS

A
*blood keeps coming to deliver CO2 and take O2 from the alv, however there is not mich more to take and deliver since everything is at equilibrium 
PaO2 = 40mmHg (equilibrilize)
PaCO2 = 45mmHg (equilibrilize)
PAo2 = decrease to 40mmHg
PAco2 = increase to 45mmHg
48
Q

after a while of having blockage in airway what does that represent to the blood

A

like a shunt bypassing lungs since its not able to pick up O2 or drop of any CO2 to the alv

49
Q

when V/Q = high due to very little blood coming to the alveoli
what happens to OVERALL BODY PaO2 and PaCO2 and then the PAo2 and PAco2

A
* done by majority of blood passing lungs and not reaching any alv = LOW V/Q
PaO2 = 80mmHg (equilibrilize)
PaCO2 = 42mmHg (equilibrilize)
PAo2 = decrease 80mmHg
PAco2 = increase 42mmHg
50
Q

how does the V/Q change during COPD/emphysema

A

more air trapping due to many alv walls broken down and capillaries that have died = less blood in these dead areas
V/Q = INCREASED in areas that are dead (no BF)
MOST BLOOD floods areas that are not dead = CAUSING OVERALL LOW V/Q (most of lung is having low V/Q)
=lowered gas exchange

51
Q

how to minimize the difference in V/Q in different areas of the lung in a patient with COPD/emphysema

A

Hypoxic vasoconstriction

redirect blood from areas that are hypoxic in the lung (for improved O2 exchange)