Ventilation and Compliance Flashcards
There is always residual air left in your lungs at the end of expiration. Why?
So patency of airways is maintained and smaller airways do not collapse, meaning the is less effort to inflate them.
What does TV stand for?
Tidal volume: volume of air breathed in and out of the lungs in each breath
What does ERV stand for?
Expiratory reserve volume: maximum volume of air that is expelled from the lungs at the end of a normal expiration
What does IRV stand for?
Inspiratory reserve volume: maximum volume of air which can be drawn into the lungs at the end of a normal inspiration
What does RV stand for?
residual volume: volume of gas at the end of a maximum expiration
what does VC stand for?
vital capacity: the volume of air a person can expire
tidal volume+inspiratory reserve volume+expiratory reserve volume
what does TLC stand for?
total lung capacity: vital capacity+residual volume
what does IC stand for?
inspiratory capacity: tidal volume+inspiratory reserve volume
what does FRC stand for?
functional residual capacity: expiratory reserve volume + residual volume
what does FEV1/FVC stand for?
fraction of forced vital capacity expired in one second
What does ventilation refer to?
the movement of air in and out of the lungs
what is alveolar ventilation?
fresh air getting to alveoli and available for gas exchange
what is pulmonary ventilation?
total air movement into and out of the lungs
What is partial pressure?
the pressure of a gas in a mixture of gases is equivalent to the percentage of that particular gas in the entire mixture multiplied by the pressure of the whole gaseous mixture
what happens to the PAO2 and PACO2 during hyper-ventilation?
PO2 rises (120mmHg) and PCO2 falls (2ommHg)
Describe changes of PAO2 and PACO2 in hypoventilation
PO2 falls (30mmHg) and PCO2 rises (100mmHg)
describe the role of surfactant
surfactant helps reduce the surface tension of the water in the alveoli which is directed inwardly tending to collapse the alveoli. this means small alveoli useful for their large SA do not collapse increasing lung compliance and reducing the recoil. makes breathing easier.
Describe infant respiratory distress disorder
premature babies have to battle collapsing alveoli with every breath as surfactant production does not start until 25 week of gestation and is only complete by week 36.