Pulm Mechanics and Pulm Compliance II Flashcards
(20 cards)
treatment for respiratory distress syndrome in neonates
continuous positive airway pressure w/ respirator to keep lungs inflated
transmural pressure = 2T/r
T = surface tension r = alveolar radius
the surface tension of alveoli with surfactant _____ with increasing inflation volumes
- increases
- stabilizes alveolar structure
compliance =
change in volume / change in pressure
how to measure compliance
Inspire, then hold breath with glottis open, and relax chest muscles against weighted spirometer.
-weighted so lung doesn’t collapse to equilibrium pressure
expiration is (active/passive)
passive
when is lung at FRC
end of expiration
Maximum flow corresponds to ____ Palv at mid-inspiration and _____ Palv at mid-expiration
- minimum
- maximum
Ppleural is always ____ during eupneic breathing and reaches a _____ at end-inspiration, corresponding to maximum inflation.
- negative
- minimum
decrease in Ppleural ______ the transmural lung pressure
increases
an abnormally increased airway resistance (small airway disease) –> _____ Cdynamic
decreased dynamic compliance
decrease change in volume, decrease C
laminar flow in trachea and turbulent flow at bifurcations produces
quiet breathing sounds
Re > 3000
turbulent
tissue resistance
- due to the motion and viscosity of the lung and chest wall tissue
- not described by Poiseuille’s law
airway resistance
- due to motion & viscosity of air
- R in Ohm’s and Poiseuille’s laws
where is airway resistance lowest
terminal bronchioles
Epi _____ Airway Resistance in Fight or Flight via _____ receptors in sympathetic
decreases
B2
____ nerve constricts airway (increases R) in parasympathetic via what kind of receptors
vagus
-muscarinic cholinergic receptors
equal pressure point
pressure in mouth = Ppleural
dynamic compression is more pronounced at ____ lung volumes because the lung is ____ compliant
- low
- more
