Lung Volumes and Capacities Flashcards
How do you estimate Anatomical Dead Space?
Weight
How can you measure dead space?
Measuring CO2 in arteries and how much expired
Name 3 functions of FRC
1) Prevents collapse of Lungs
2) Decreases work load
3) Dilutes Toxic Inhaled Gases
Define Total Lung Capacity (TLC)
Max volume lungs can expand with greatest effort
Emphysema is an ___ Disease. Influence on: TLC, RV, VC
1) Obstructive
2) TLC Increases
3) VC Decreases
4) RV Increases
Obesity Influence on TLC, RV, VC; Seated Vs Supine?
1) TLC Decrease
2) VC Decrease
3) RV Same
4) Seated v. Supine become similar
DefineTidal Volume (Vt)
Amount air inspired/expired in a single breath
Define Dead Space
Areas that are well ventilated but poorly perfused and don’t participate in gas exchange
What is normal Resting Vt
500mL
What does Age do to: TLC, VC, RV
TLC: Remains Same
VC: Decreases
RV: Increases
Seated v. Supine: TLC; RV; VC
1) TLC greater while sitting
2) RV = Equal
3) VC Seated >
Equation for VC
VC = IRV + VT + ERV
Can RV be measured by spirometry?
NO
Define Inspiratory Capacity (IC)
Capacity of air that can be max inspired following normal exhale
Define Expiratory Reserve Volume (ERV)
Additional Vol. exhaled > Vt
___ Determines Dead space by using ____ and measuring ___ expired
Nitrogen-Washout Technique
100% O2
N2
Define Inspiratory Reserve Volume (IRV)
Additional Vol. inhaled > Vt
List 7 influencers of VC
1) Posture
2) Diaphragm Movement
3) Strength of Respiratory Muscles
4) Thoracic Wall Elasticity
5) Resistance to air flow
6) Lung Elasticity
7) Disease
If you want to look at the difference in pressure between lungs and a box what technique would you use?
Body Phethysmography
Define Vital Capacity
Amount of air that can be maximally inspired following max expiration
Physiological Dead Space = ___ + ___
Alveolar Dead Space + Anatomic Dead Space
You can use __ to determine FRC
He Dilution
Define Functional Residual Capacity (FRC)
Amount of air that remains in lungs following a normal expiration
Define Residual Volume (RV)
Volume of air that cannot be forced out, no matter how hard one tries