F - Lung Volumes and Capacities - Ballam Flashcards
What can be measured with spirometry?
Tidal volume - 500ml
Inspiratory reserve volume - 3000ml
Expiratory reserve volume - 1200ml
What can not be measured with spirometry?
Residual volume
Total lung capacity
Sum of all volumes
Inspiratory capacity
Tidal volume plus inspiratory reserve volume
Vital capacity
Sum of tidal volume, inspiratory reserve, expiratory reserve
Forced vital capacity
FVC
Rapid forced expiration from peak inspiration
Functional residual capacity
What is left in lungs after normal breath out
1200ml
Tidal volume
Breath in and out at rest
500ml
Forced expiratory volume
Rate at which air can be blown out of the lungs in an exertional effort from peak inspiration indicates the resistance to airflow and the compliance of the lungs/thoracic cavity
FEV1/FVC
Amount of functional expiratory volume of the forced vital capacity that can be blown out in 1s
An indication of how much resistance to flow is present and also the compliance of the lungs/thoracic cavity
Obstructive disease
On graph sloped
High resistance to airflow
Also emphysema, asthma
Restrictive disease
FEV1 goes down very quickly
Low compliance, fibrosis and TB
Minute ventilation
The amount of air inhaled into the lungs and exhaled back out per minute
Tidal volume x respiratory rate
Alveolar ventilation
Equals how much air is drawn into and evacuated from normally perfused alveoli
-excludes non gas exchange tubes and alveoli which are under perfused with blood
Alveolar ventilation equation
(tidal volume - physiological dead space) x ventilation rate
