Respiratory Chapter Flashcards
Pressure Gradient
Air moves from a region of higher pressure to a region of lower pressure
Atmospheric Pressure
the pressure exerted by the weight of the air in the atmosphere on objects on the Earth’s surface
Intra-alveolar Pressure (intrapulomonary)
Pressure within the alveoil
Intra pleural Pressure (intrathoracic)
pressure exerted outside the lungs within the thoracic cavity
What keeps the lungs stretched apart?
Intrapleural fluid cohesiveness
Intra-alveolar pressure > intrapleural pressure, which expands the lungs
How does air flow into and out of the lungs?
changes in intra-alveolar pressure by respiratory muscle activity
Define Boyle’s Law
At any constant temperature, the pressure exerted by a gas varies inversely with the volume of the gas
Define Spirometer
Device that measures changes in lung volume
Inspiration =
upward deflection
Expiration =
downward deflection
Tidal Volume (TV)
volume during a single breath (resting)
Inspiratory reserve volume (IRV)
extra volume over tidal volume
Inspiratory capacity (IC)
IRV + TV
Expiratory reserve volume (ERV)
extra volume at the end of TV
Functional residual capacity (FRC)
ERV + RV
Residual Volume (RV)
the minimum volume of air remaining in the lung after maximal expiration (IT CANNOT BE MEASURED DIRECTLY)
Vital capacity (VC)
maximal volume change in lungs= IRV + TV + ERV, maximal inspiration followed by maximal expiration
Total lung capacity (TLC)
VC + RV = total volume possible
