Zones of the Lung Flashcards Preview

► Med Misc 44 > Zones of the Lung > Flashcards

Flashcards in Zones of the Lung Deck (15)
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1
Q

How many Zones of the lung are there?

A

4

2
Q

what is zone 1 called?

A

collapse

(b/c alveolar pressure collapses arterial)

3
Q

what is zone 2 called?

A

waterfall

4
Q

what is zone 3 called

A

Distension

5
Q

what is zone 4 called

A

Interstitial pressure

6
Q

what is the ideal Zone?

A

zone 3

7
Q

state the pressures in each zone

A
  1. PA > Pa >Pv
  2. Pa > PA > Pv
  3. Pa > Pv > PA
  4. Pa> Pisf > Pv > PA
8
Q

Zone 1:

Explain it

A

Pulm artery pressure negigilble bc Alveolar pressure exceeds it, the distensible cappilieries in the alveolar wall are collapsed. There is NO blood flow in Zone 1

it is normally not present.. its a pathological zone that develops with pulmonary HYPOtension

9
Q

Zone 2:

explain it

A

Pa pressure exceeds PA pressure

after blood passes through the alveoli is “falls” into the venous system

10
Q

Zone 3:

explain it

A

Blood flow is proportional to Pulm Artery pressure minus the pulmonary vein pressure.

11
Q

Zone 4:

explain it

A

it’s a pathological zone that normally is not present. it is present with Pulmonary edema

12
Q

the tip of the swan should be placed in what zone?

A

3

13
Q

Must Know:

West’s zones describe the _____ in the lungs

A

perfusion

14
Q

Must Know:

west’s zones are not “fixed” zones they are varible function zones. what does that mean

A

they are dependent on body position

15
Q

Must Know:

why is zone 3 the best zone?

A

Zone 1 is found in the Non-dependent lung

Zone 3 is found in the dependent lung

hence zone 3 is better perfused and ventilated

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