Drive - definitions and equations Flashcards
(26 cards)
What is explained by Daltons Law?
The pressure exerted by each gas is a mixture of gases is independent of the pressure excerted by the other gases.
What is explained by Boyle’s Law?
The pressure of a fixed amount of gas in a container is inversely proportional to the containers volume.
What is explained by Henry’s Law?
The amount of gas dissolve in a liquid is proportional to the pressure of gas with which the liquid is in equilibrium
What is the alveolar gas exchange equation?
PAO2 = PIO2 - (PaCO2/R)
What is the equation to calculate pressure?
Pressure = flow x resistance
What is explained by the law of laplace?
The relationship between pressure, surface tension and radius
What is the equation of the law of laplace?
P = 2T/r
What is explained by the term lung compliance?
The change in lung volume caused by a given change is transpulmonary pressure.
What occurs the greater the lung compliance?
the more readily the lungs expand
What 2 factors determine lung compliance?
Stretch-ability of the lung tissues
Surface tension of the air-water interfaces of the alveoli
What is the role of surfactant and what is it produced by?
Produced by type 2 pneumocytes.
Role = reduces the cohesive forces between molecules on the alveolar surface tension (lowers the surface tension)
What is the inspiratory reserve volume?
Amount of air in excess tidal inspiration that can be inhaled with maximum effort
What is the expiratory reserve volume?
Amount of air in excess tidal expiration that can be exhaled with maximum effort
What is the residual volume?
Amount of air remaining in the lungs after the maximum expiration
What is the purpose of the residual volume?
To keep the alveoli inflated between breaths
What is the forced vital capacity?
Amount of air that can be exhaled with maximum effort after maximum inspiration.
What is forced vital capacity used to measure?
The strength of thoracic muscles and pulmonary function
What is the functional residual capacity?
Amount of air remaining in the lungs after a normal tidal expiration
What is inspiration capacity?
The maximum amount of air that can be inhaled after a normal tidal expiration
What is the total lung capacity?
Maximum amount of air the lungs can contain
What is tidal volume?
Amount air inhaled or exhaled in one breath
What is FEV1?
The forced expiratory volume in one second
What is FEV1/FVC ratio?
The proportion of the FVC exhaled in the 1st second
FEV1/FVC = <0.7 what does this mean?
airways obstruction
