Term
What is the importance of radius in airway resistance?
R=8nl/πr4
n=viscosity l=length |
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Definition
If radius is halved
Resistance increases 16x |
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Term
| What is the importance of Reynold's number? |
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Definition
>2000 means turbulent
directly related to density, velocity, radius
(helium is less dense, more likely to be laminar) |
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Term
| Airway resistance formula |
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Definition
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Term
| Most airway resistance occurs in the |
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Definition
4-7th division
(4th being the narrowest generation)
This makes small airways disease difficult to detect. |
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Term
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Definition
| at very low volumes the small airways may close completely |
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Term
Contraction of the smooth muscles narrow airways.
They can be relaxed using _____. |
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Definition
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Term
| Parasympathetic activity in the airways causes _____. |
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Definition
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Term
| Caliber increases as the lung _____. |
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Definition
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Term
| What type of gas is used to improve ventilation in asthmatic? |
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Definition
heliox
it has lower density than regular O2 |
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Term
| In terms of effort, peak expiratory flow is ______ and the slope is ______. |
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Definition
In terms of effort, peak expiratory flow is effort dependent and the slope is effort independent.
This is due to the choke point.
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Term
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Definition
aka equal pressure point
limits flow
worsened by any increase in airway resistance causing a decrease in the endobronchial pressure (or if the driving force is reduced [emphysema]) |
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