DSA 1: Lung Volumes and Capacity Flashcards
What is tidal volume?
Amount of air inspired or expired in a single breath
What is normal tidal volume?
500 mL
What is residual volume?
Volume of air that cannot be forced out, no matter how hard one tries
What is inspiratory reserve volume?
Additional volume that can be inhaled greater than tidal volume
What is the gap between inspiration during tidal volume and maximal inspiration?
Inspiratory reserve volume
What is expiratory reserve volume?
Additional volume that can be exhaled greater than tidal volume
- does not include residual volume
- activation of expiratory muscles
What is total lung capacity?
Maximal volume to which lungs can be expanded with greatest effort?
How do you calculate total lung capacity?
TLC = Inspiratory Capacity + Functional Residual Capacity TLC = Vital Capacity + Residual Volume TLC = Inspiratory Residual Volume + Expiratory Residual Volume + Residual Volume + Tidal Volume
What is functional residual capacity?
Amount of air that remains in lungs following a normal expiration
How do you calculate functional residual capacity?
FRC = Expiratory Residual Volume + Residual Volume
What is vital capacity?
Amount of air that can be maximally inspired following a maximal expiration
How do you calculate vital capacity?
VC = Inspiratory Residual Volume + Tidal Volume + Expiratory Residual Volume
What is inspiratory capacity?
Capacity of air that can be maximally inspired following a normal exhale
How do you calculate inspiratory capacity?
IC = Tidal Volume + Inspiratory Residual Volume
When supine, there is a reduced _____.
Functional residual capacity
What are some ways to measure residual volumes?
1) Helium Dilution: Inhale known quantity of helium. The change in concentration allows determination of FRC.
2) Body Plethysmograph: Check changes in pressure between box and lungs
3) Nitrogen-Washout Technique: Breath in 100% oxygen and expired gas is collected until nitrogen measures 0. Using math, FRC is determined.
How does lung volume change with age?
Increases:
- Functional residual capacity (FRC)
- Residual volume (RV)
- Forced Vital Capacity (FVC)
How can obesity affect lung volume?
Except with tidal volume, reduction in all static lung volumes, especially expiratory reserve volume and functional residual capacity (FRC)
What muscles are involved with inspiration?
External Intercostal Muscles
What muscles are involved with expiration?
Internal Intercostal Muscles