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Lung Physio
ross University
25
Physiology
Graduate
11/26/2009

Additional Physiology Flashcards

 


 

Cards

Term
tidal volume? normal amount? which two volumes make this?
Definition
volume inspired & expired w normal breath. about 500 ml. Dead space volume + Alveolur volume = Vt.
Term
IRV (inspiratory reserve volume). when used?
Definition
volume that can be inspired above the tidal volume. used in exercise.
Term
expiratory reserve volume
Definition
volume that can be expired after tidal volume.
Term
residual volume
Definition
remaining volume in lung after forced expiration - cannot be expired or measured via spirometry
Term
minute ventilation
Definition
tidal volume X breaths/min
Term
inspiratory capacity
Definition
sum of tidal and IRV
Term
functional residual capacity. what volume is expired to get this? measure?
Definition
sum of ERV & residual volume. volume remaining after tidal volume is expired. includes residual volume thus can't be measured via spirometry.
Term
vital capacity / forced vital capacity. describe this volume.
Definition
sum of tidal volume & IRV & ERV. volume that can be forcefully expired after inspiration.
Term
total lung capacity. Describe this volume. Measure?
Definition
all four lung volumes. the amount in lung after full inspiration. can't be measured cuz it includes the residual volume.
Term
FEV (forced expiratory volume). what percentage of vital capacity? affect of asthma? and fibrosis?
Definition
the amount that can be expired in one second. normally 80% of vital capacity. Asthma = obstructive thus reduces FEV1 only and ratio of FEV1/FVC is reduced. Fibrosis = restrictive lung disease, thus it reduces both the FEV1 & FVC equally, so there's no change in ratio.
Term

relationship of compliance to elastance of the lung

what about to recoil?

Definition

inverse relationship

compliant lungs have low recoil, while stiff lungs have high recoil

Term

compliance on graph? what is compliance? calculation?

what is relationship between compliance & airflow?

Definition

slope of the pressure-volume curve. compliance is the distensibility of the lung.

CL = ΔV/PTP 

V = lung volume

P = transpulmonary pressure

high C means more airflow for a given pressure

Term
For emphysema, what property of the lung is increased, which is decreased? which way does this shift the FRC on the lung-chest wall system?
Definition
compliance is increased. elastacity is decreased. FRC is shifted up.
Term
For fibrosis, what property of the lung is increased, which is decreased? which way does this shift the FRC on the lung-chest wall system?
Definition
compliance is decreased (hard to expand lungs), tendency for the lungs to collapse is increased (increased recoil). FRC is shifted downward.
Term
collapsing pressure of large alveoli, low or high?
Definition
low thus easy to keep open
Term
collapsing pressure for small alveoli? what prevents collapse?
Definition
large thus harder to keep open. Surfactant.
Term
function of surfactant?
Definition
reduces surface tension thus prevents alveolur collapse.
Term
calculation of air flow? where is the highest resistance? how can an asthma pt reduce airway resistance?
Definition
Pressure divided by Resistance. Highest R in the medium sized bronchi, not in smallest bronchioles cuz there are so many of them in parrallel. Asthma pt breathe at a higher lung volume thus with more air in lungs the resistance is lower.
Term
At rest, what is alveolur pressure? what lung volume is present? What's interpleural pressure? What's this pressure caused by?
Definition
Alveolur pressure = 0. Lung volume = FRC. Interpleural P = negative cuz the chest wall is trying to expand and lung is trying to collapse.
Term
during inspiration, what is alveolur pressure? what is lung volume at the end of a normal inspiration? What is interpleural pressure?
Definition
Alveolur P = negative. Lung volume becomes Tidal Volume (1 breath). Interpleural P becomes more negative.
Term
Asthma & COPD. Type of respiratory disease? Which properties of the lung are decreased / increased?
Definition
Obstructive disease (narrowing of airways). FVC (forced vital cap) is decreased, FEV (forced expiratory volume) is decreased. FRC (functional residual capacity) is increased (cuz not all the air is exhaled, but trapped in lungs).
Term
Fibrosis. Type of respiratory disease? what lung properties are decreased / increased?
Definition
Restrictive disease. compliance is decreased (inspiration impaired). Decrease in all lung volumes. Both FEV1(forced expiratory volume per second) & FVC (forced vital capacity) is unchanged. FRC (functional residual capacity) is decreased.
Term
Dead space volume?
Definition
150ml
Term
Calculation for Partial Pressure of a gas.
Definition
Px = Fx (PB - PH20), where Fx = fraction of that gas. PH20 = vapor pressure.
Term
calc Alveolar ventilation
Definition

(VT - VD) X (breathing freq)

VT = alveolar volume

VD = dead space volume

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