Ventilation and Compliance Flashcards
What is tidal volume?
The volume of air breathed in or out of the lungs at each breath
What is expiratory reserve volume?
The maximum volume of expired from the lungs at the end of normal inspiration
What is inspiratory reserve volume?
The maximum volume of inspired from the lungs at the end of normal inspiration
What is residual volume?
The volume of gas in the lungs at the end of max expiration
What is vital capacity equal to?
Tidal volume + Inspiratory reserve volume + Expiratory reserve volume
What is total lung capacity equal to?
Vital capacity + Residual volume
What is inspiratory capacity equal to?
Tidal volume + Inspiratory reserve volume
What is the functional residual capacity equal to?
Expiratory reserve volume + Residual volume
What is FEV1?
The forced expired volume in 1 second
What is FEV1:FVC?
The fraction of forced vital capacity expired in 1 second
What are the 2 main types of ventilation?
Pulmonary ventilation
Alveolar ventilation
What is pulmonary ventilation?
The total air movement in or our of the lungs
What is alveolar ventilation?
The amount of “fresh air” reaching alveoli for gas exchange
Does an increased or decreased respiratory rate cause hypoventilation?
An increased RR
Does an increased or decreased respiratory rate cause hyperventilation?
A decreased RR
What is total pulmonary ventilation equal to?
Tidal volume x Respiratory rate
What is partial pressure?
The pressure of a gas in a mixture if it occupied the same volume as the mixture but alone
What happens to PO2 and PCO2 during hyperventilation?
PO2 increases
PCO2 decreases
What happens to PO2 and PCO2 during hypoventilation?
PO2 decreases
PCO2 increases
What effect does surfactant reducing the surface tension on the alveolar surface membrane have on the alveoli?
Reduces the tendency for the alveoli to callapse
What effect does surfactant have on lung compliance and a lung’s tendency to recoil?
Increases compliance
Decreases tendency to recoil
Is surfactant more effective on large or small alveoli and why?
Small alveoli as surfactant molecules are close together and therefore more concentrated
When does surfactant production begin and complete?
Begins - 25 weeks into gestation
Completes - 36 weeks into gestation
What condition is suffered by premature babies who haven’t completed surfactant production?
Infant respiratory distress syndrome (IRDS)
What is compliance and what does it represent in the lungs?
Compliance is the change in volume relative to change in pressure and represents the strechability of the lungs
What does it mean for a lung to have high compliance?
A large increase in lung volume for only a small decrease in pressure
What does it mean for a lung to have low compliance?
A small increase in lung volume for a large decrease in pressure
What is emphysema and is it an example of Low or High Compliance?
Loss of elastic tissue increasing the effort of expiration
High compliance
What is fibrosis and is it an example of Low or High Compliance?
Fibrous tissue becoming inert increasing the effort of inspiration
Low compliance
Is the lung more compliant at the base or apex?
Base
What are obstructive lung diseases?
Those which obstruct airflow (especially on expiration)
What are restrictive lung diseases?
Those which restrict lung expansion
What are 2 examples of obstructive lung diseases?
Asthma
COPD
What are 2 examples of restrictive lung disorders?
Fibrosis
Infant respiratory distress syndrome
What is spirometry used to measure?
Lung function
What are the 2 classifications for lung function measurement by spirometry?
Static - only volume exhaled
Dynamic - time taken to exhale certain volume
What should the FEV1/FVC% be normally?
80%
Will the FEV increase or decrease in obstructive lung disease?
Decrease
Will the FEV increase or decrease in restrictive lung disease?
Increase
What change occurs to the rate of air in obstructive lung disease?
Rate is slower
What change occurs to the volume of air in restrictive lung disease?
Total volume is reduced
